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Solar Heat for Large Buildings Guidelines and Practical Examples for Apartment Buildings, Hotels and Business
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Page 1: Solar Heat for Large Buildings - Solarge.org: SOLARGEsolarge.org/uploads/media/SOLARGE_Best_Practice... ·  · 2008-03-11Solar Heat for Large Buildings Guidelines and Practical Examples

Solar Heat forLarge Buildings

Guidelines and Practical

Examples for Apartment

Buildings, Hotels and

Business

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This publication was compiled as part of the EU SOLARGE project

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Foreword

Rising oil and gas prices, climate change andgrowing energy import dependency place ourcurrent energy supply arrangements underincreasing threat. A major challenge for thefuture is to cut fossil fuel use to a minimum.About a third of Europe’s final energy con-sumption is accounted for by space and waterheating in buildings. Conserving energy andusing renewables in this sector can reap mas-sive cost savings and are an efficient way tohelp slow climate change.This brochure is intended for building plannersin the residential building, hotel and localgovernment sector who aim to make buildingsready for the solar age. It presents examples oflarge solar thermal systems across Europetogether with experience gathered in operat-ing them.The brochure has been produced as part of theEuropean SOLARGE project, in which elevenorganisations from eight countries aroundEurope use a wide range of measures to pro-mote solar thermal systems in apartment buil-dings, hotels and municipal facilities. Theexamples are intended to encourage similarprojects and invite replication.

The SOLARGE Team

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www.solarge.org

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Contents

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Y

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Y

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Y

Y

Y

Foreword

Large Solar Thermal Systems

Fields of Application

Components

System Approaches

Heating Circuits

Costs of Solar ThermalSystems

Planning Procedure

Solar Air Conditioning in a Nutshell

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50

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Best Practice Catalogue

Hot Water Systems

Hot Water and Space Heating Sytems

Other Applications

Outlook

Publisher's Information

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615

10

5

0

GWth/aGWth

97 98 99 00 01 02 03 04 05 06

1.5

0

p

Heat49 %

Electricity 20 %

Transport31 %

in operation

newly installed

Technical Basics

Large Solar Thermal Systems

The great majority of solar thermal systemsnow in use belongs to detached or semi-detached houses.But solar thermal systems are increasinglybeing used in larger buildings: apartmentblocks, hotels and catering establishments,and public buildings.Many large systems are already installed inEurope. The experience gained with thesesystems is so positive that many operators are planning more systems.One important lesson learnt is that the designof large solar systems cannot be standardised.Each system must be individually designed,taking into account the circumstances anduser needs. A task and a challenge for all architects and engineers involved.

Growth of solarthermal energy in EuropeSolar thermalenergy is booming.Over 19 millionsquare metres (13.5 GWth) of solarcollectors were inoperation acrossEurope by 2006.Source: ESTIF

About half of finalenergy consump-tion is used ingenerating heat,most of it for buil-dings.

Flat plate collectorsPhoto: Conergy

Solar thermal: market developmentThe use of solar thermal heating has spreadrapidly in recent years. Solar systems with atotal collector area of some 19 million squaremetres are now installed across Europe. Thisimpressive figure shows the technology haslong matured and is established in the market.The European Solar Thermal Industry Federation(ESTIF) forecasts that total installed collectorarea will increase by 30 % a year over the longterm. However, market penetration varies greatly between different EU states.

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Public buildingsSports facilities, old people’s homes and swim-ming pools are generally well suited to solarthermal energy because they need hot waterin large quantities. As administrative buildingsmostly only need space heating, solar thermalsystems are not suitable for such buildingsunless air conditioning is required.

Hotels and restaurantsHotels are very well suited to the use of solarthermal energy because they tend to bebusiest in the summer months and in latespring and early autumn.Solar energy is also useful to hotels andrestaurants as a marketing instrument toattract environment-conscious tourists.

Technical Basics

Fields of Application

Solar thermal energy can be used whereverlow-grade heat is needed: For hot water, tosupplement space heating, and to generateprocess heat for thermally driven air conditio-ning systems.Solar thermal systems can supplement thesupply of heat to buildings in summer, latespring and early autumn.

Apartment buildingsLarge solar thermal systems on apartmentbuildings in Europe are mostly used to providehot water. In central and northern regions ofEurope there is also a trend towards ‘combi-systems’ that supplement space heating.

Hotel du Golf de Valescure, FranceApartment building, Salzburg, AustriaPhoto: S.O.L.I.D./Austria Solar

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1 2 3 4 5 6 7 8 9 10 11 12

50

40

30

20

10

0

m Overnight stays in 2003

Bed occupancySolar power

Bed occupancy and solar powerIn many hotels (chart: Germany)hot water consumption tracks solarenergy availability over the year.Source: Federal Statistical Office 2005

Swimming poolsSolar water heating in hotels combines ex-cellently with water heating for swimmingpools. Surplus heat is easily transferred to pool water, improving user comfort at no extraenergy cost.

Solar air conditioning Hotels and restaurants often have large airconditioning needs, as do as hospitals andpublic buildings. Solar thermal energy canbe used here in existing thermally driven airconditioning systems.

Car washesSolar thermal systems provide a simple way ofheating water for car washes. Heating thewater also saves on detergent. It may makesense to connect repair shops and showroomsinto the solar system to smooth heat demandover time.

Solar thermal energy for contractorsSolar thermal energy is also attractive as a product for energy suppliers and contractors.They can install collectors on factory, ware-house and residential roofs or on spare landand sell the generated heat to consumers or a district heating network. This makes for predictable energy prices and stable heatgeneration costs for district heat, in both casesfor the long term.

UPC Arena Graz, Austria:Local heat management contracted to nahwaerme.atPhoto: S.O.L.I.D./ESTIF

Car wash Center in Oberursel, GermanyPhoto: Wagner-Solar.com

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Most modern solar thermal systems use flat plate or vacuumtube collectors. The required systemtemperatures as well as the moun-ting mode determine the type ofcollector.

Collector Type

Air collector

Glazed flat-plate collector

Vacuum tube collector(direct flow)

Vacuum tube collector(heat pipe)

Heat Transfer Medium

Air

Water or water-glycol mixture

Water orwater-glycol mixture

Indirect heating of the heat transfer medium(Water or water-glycol mixture)

Collector types overviewApplications

Preheating for factory shed air-drying systems, ‘open’ air conditioningsystems, and solar drying

Hot tap water, space heating, so-called ‘open’ and ‘closed’ single-stage air conditioning/chiller systems and preheating of industrial processes

Hot tap water, space heating, single-stage and two-stage air conditioning/chiller systems and preheating of industrial processes

Hot tap water, space heating, single-stage and two-stage air conditioning/chiller systems and preheating of industrial processes

ComponentsCollectors and Storage tanks

CollectorsA roof-mounted solar collector captures sunlight and converts it into heat. The unit’sabsorber has what is called a selective surfacecoating, allowing it to convert even diffuse orwinter day solar radiation into heat energywith high efficiency. The collector is protectedby tempered glass which can withstand evenhailstones.Collectors can be mounted on a flat or pitchedroof, integrated into the roof cladding orinstalled as part of the building’s facade.

Technical Basics

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Borehole heat storageSolar heat is transferred tothe ground via boreholes 20–100 metres deep and isdrawn upon as needed. Dueto the lower thermal capacityof soil, the stores are general-ly three to five times largerthan hot water units. How-ever they are less complicatedto build and can be extendedas needed. No direct contactwith groundwater is an ad-vantage .

Gravel/water heat storagePits lined with special sheeting are filled with a gravel/water mixture. Theheat is transported to the store by the water itself or through coiled pipes.Gravel/water storage has a lower heat capacity thanstraight hot water storageunits and needs a bigger volume (about one and a half times).

Aquifer heat storageThis form of storage usesgroundwater to store thermalenergy. Groundwater raisedfrom a borehole is warmed bya heat exchanger and thenreturned to the aquifer via asecond borehole. The heat isrecovered by reversing theflow. The cost per unit heatgenerated is relatively low,but such systems require specific hydrogeological con-ditions which do not existeverywhere.

Heat storageShort-term storageShort-term storage units store captured solarheat for several days to make up for rainyweather. Good temperature stratification is animportant factor in such units. They are there-fore made tall and slender so stable strataspanning a large temperature range can bebuilt up over their height. Collector return flowtemperatures should be as low as possible.This is a precondition for high system efficien-cy. Solar thermal energy can be made to coverup to 30 % of total heat demand.

Seasonal storageSeasonal thermal storage is mostly used indistrict heating networks and can retain heatfor several weeks. There are hot water, gravel/water, borehole and aquifer systems.Hot water tanks used in seasonal heat storageare several thousand cubic metres in volume.Seasonal storage is mostly used in residentialareas with hundreds of individual apartmentbuildings, but latterly as well as in separateapartment buildings. Seasonal storage allowssolar energy to meet up to 100 % of total heatdemand.

Solar thermal storage tanks 100 % solar-heated apartment building (under construct-ion), by Jenni Energietechnik – completed in August 2007Photo: Jenni Energietechnik AG, Switzerland

Seasonal thermal storage technologies

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ControlObtaining the maximum energy yield from asolar thermal system critically depends on theefficient interaction of all system components.The control system is highly important in thisregard.A closed-loop control system controls both theheating and collector circuit. This means thatboth the solar thermal system and the supple-mentary heating system are run at optimumresource levels. Modern closed-loop controlsystems have a heat meter and in some casesremote diagnostics. These allow subsequentadjustment of the solar system and consider-ably simplify troubleshooting and billing for heating costs.Freely programmable controllers are also avail-able. These allow the operation of the solarsystem to be adapted to the individual loadprofile on the fly .

A well coordinated control of solar and auxiliaryheating system is essential for a proper functio-ning.

Technical Basics

Heat exchangerThe solar heat captured by the collector istransferred to the heating circuit by a heatexchanger. On large solar thermal systems this is usually an external unit.The heat exchanger hydraulically separatesthe different circuits so each one can be optimally run.Heat exchangers are also used in what areknown as fresh water stations. These heatmains water separately in each apartment,using the heating circuit as heat source. This is a cost-effective system because there is no need for protection against legionella or for additional pipework to distribute hotwater.

Centralised heat control station for solar and conven-tional heatPhoto: Upmann, Berlin

ComponentsAdditional elements

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Auxiliary heatingThe supplementary heat supply can be ar-ranged within the building centrally or on adecentralised basis. It can be integrated inseries or in parallel.The supplementary heat supply can be inte-grated in various ways depending on the situation in the building and the design of theheating and/or hot water system. Technicalsolutions are available to meet a wide range of needs.

A solar thermal system with decentralised heat storage tanksand auxiliary heating in Spain – El LlimonetPhoto: Qualitat Promocions

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Solar hot water supplyWhen used to supply hot water, solar thermalsystems generally meet up to 60 % of therespective heat demand. Hot water supply iseither centralised via a circulating pipe ordecentralised with a hot water unit in eachapartment.There are also systems (mostly in Spain) withdecentralised storage tanks and supplement-ary heating units. Supplementary heatingtakes the form of the boiler station in eachapartment supplied by a central collector field.In centralised systems, protection againstlegionella is ensured by heating the standbytank once a day to 60 °C. There is no need toprotect decentralised systems in this way dueto the short distance from heat exchanger totapes.”

Space heating/combisystemsSolar supported space heating can be imple-mented in centralised and decentralised heating systems. Approx. 10-30 % (in somecases even more) of the entire heat demandwill be covered by solar combisystems. Howthe solar system is integrated depends onsolar system design and the building's heatingsystem.

Technical Basics

System Approaches

Reflecting differences in culture and climate,solar thermal systems are utilised in widelydiffering ways across Europe. Most systems inSouthern Europe are used for supplying hotwater. Those in Northern Europe often have acentral heat storage unit and additionally pro-vide supplementary heating, but there is also atrend towards district heating networks inwhich conventional heat sources are boostedby solar thermal energy in late spring andearly autumn.The greatest system differences can be foundin heat distribution in apartment buildings.This can be done via the collector circuit, usingheat transfer units in individual apartments, orcentrally via circulating pipes.

Frostproofing and overheating protectionCollectors are generally prevented from freez-ing in winter by adding antifreeze. Where theheat transportation medium is pure water(mandatory in the Netherlands), frost protec-tion is provided by a drain-back system.Control and safety features protect systemsfrom overheating when there is no demand/no flow through the system, as in summer.

Photo: Neuhof-Canonniers, Strasbourg, FrancePhoto: Pracatinat, Fenestrelle, Italy

Overheating protection during the summer and frostproofing in winter is essential for safe and steady operation.Reliable and approved features from experienced planners and system providers ensure a well-protected CSTS forboth extremes.

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Solar systems in new buildingsIn a new building, solar thermal technologycan be planned as an integral part of the heat-ing system to optimise overall energy supply.Planners have a free hand in deciding how col-lectors are integrated into the building (forexample by making them part of the roof clad-ding or the building’s facade) and the spatialarrangement of heat storage and controlunits. Boiler, solar thermal and heat storagecapacity can also be matched to actual needs.Centralised supply systems are usually chosenfor new buildings as the capital cost per unit islower than decentralised systems.However, hot water consumption – a keysystem design parameter – is relatively hard toestimate for a new building. Standardised con-sumption figures usually overestimate actualconsumption. Exact knowledge of future heatloads is essential.

RefurbishmentExact design and dimensioning is also impor-tant for solar thermal systems fitted duringbuilding modernisation. It is helpful to collectdata on hot water consumption beforehand.Installing solar thermal systems during refur-bishment usually means integrating them intoexisting heating and hot water systems. Itoften makes sense to replace any auxiliaryheating at the same time, and to dimensionboth the boiler and the storage to match thesystem as a whole.

Backup for conventional heatingBoilers or heat pumps are available to meetany supply demand when collector output istoo low. Solar thermal systems can be com-bined with generally available conventionalheating systems.Many manufacturers of conventional heatingsystems offer complete control units to runtheir systems in combination with solar ther-mal technology.Storage for solar heat can be centralised ordecentralised according to the heating and hot water system. When retrofitting, existingstorage tanks can be kept and supplementedwith the solar heat storage unit.

Estimate hot water needs as accurately as possibleEconomic operation of a solar thermal systemdepends on accurate dimensioning to supplythe required amount of hot water. If actualconsumption is below estimate, the system is overdimensioned. If the storage unit is fullbut no hot water is used, no more heat can betaken from the solar collector even though thesun continues to shine. Harvested solar energythen goes unused. One solution here is to connect more heat-utilising units to the solarcircuit.

382 dwellings provided with solar heat - see exampleon page 52 for further information.Photo: Schalkwijk, Haarlem, Netherlands

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Fresh water units/semi-decentralised systemsFresh water units are a third option for inte-grating solar thermal energy. Heat transferstations provide heat for hot water in eachapartment. The heat source is usually theheating circuit. However, this requires hightemperatures in the heat circuit. Fresh waterunits are therefore only suitable in buildingsheated by radiators with an appropriate tem-perature range.

Technical Basics

Heating Circuits

Central heating systemsSolar thermal systems can be integrated particularly easily into central heating and hotwater systems. A conventional two or four-pipesystem may be used. Storage, control and supplementary heating are centralised.

Decentralised systemsIn a decentralised system, the hot water is preheated by a common collector field.Supplementary heating and solar heat storageare provided by decentralised boiler units.

Solar heat storage, auxiliary heating unit and controlunit in each flat in an apartment building in Spain.Photo: Vèrtix

Fresh water unit in a building's two-pipe heating net-work. Apartment building in Salzburg.Photo: gswb Salzburg

Boiler room with solar heat storage tanks and controlunitPhoto: Sonnenkraft, Munich, Germany

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*

Load

Heatexchanger

Boiler

Storage tank

Collectors

Schematic diagramIntegration of a solar thermal system

Bivalent hot tapwater heat storage

Backup heated buffer storage

Serial backup heating

Backup heated tap-water storage

* also as fully decentralised system

Hot water units

also as tank-in-tank

system

Serially connected tap water

Parallel-connectedtap water and buffer charging system

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Planning

Planning scenario 3:Compliance with legal requirementsAnother planning objective can be to reduce a building’s primary energy factor and henceits system input/output ratio to comply withlegislation like Germany’s Energy SavingOrdinance (EnEV) or Spanish Building Codes.

Cost-effectivenessThe cost-effectiveness of a solar thermalsystem is mostly determined by three factors:capital cost, energy output and oil price trends.Furthermore, considering synergies raises theeconomics of solar thermal systems. Example:Additional savings can be achieved by makingflat plate part of a facade or roof. Due to theirconstruction, flat plate collectors can serve adual purpose as a heat source and a replace-ment for thermal insulation.

Dynamically rising prices for oil and gas tendto improve the cost-effectiveness of solar heat.

The profitability of a system is enhanced byfurther options, e. g. combining civil works,allocations etc. Experienced planners take allthis into account.

Costs of Solar Thermal Systems

A solar thermal system (including pipework,storage unit, control system and system design)currently costs between EUR 700 - 1,200 perm2 of collector area. The costs vary accordingto the collector type, the situation of the build-ing, and the design philosophy used to opti-mise the system. The following list showssome typical planning scenarios:

Planing scenario 1:Maximum energy savingThis planning objective can be attained with a solar fraction (solar energy as a fraction oftotal energy) equalling 30–100 % of the ener-gy needed for hot water and space heating.Heating costs and greenhouse gas emissionsare reduced for the long term.

Planning scenario 2:Reduced heat generation costsWith a solar fraction of 10–20 % (including hotwater and space heating), the solar system can operate at maximum output. This mini-mises the costs of solar heat generation andthe payback period. The solar fraction may behigher for some apartment buildings and canreach 50 % for some district heating networks.

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1,000 1,200 1,400 1,600 1,800 2,000

Annual global irradiation [kWh/(m2 · a)]

Dimensioning solar thermal systemsHot water onlyMeeting 50 % of the annual energy needs forhot water requires a collector area of 1–1.5 m2

per apartment and about 50–60 l of solar heatstorage per m2 of collector surface.

CombisystemsSystems combining hot water supply withsupplementary heating require roughly 3–4 m2

of flat plate collectors per apartment. The heat-ing will then be about 15–20 % solar-assisted.

Solar district heating networksSolar district heating networks need about10–30 m2 of flat plate collectors per apartment(solar fraction approx. 50 %). That is about 1.5–2.5 m2 of flat plate collectors and 2- 5 m2 ofstorage volume per 1,000 kWh annual heatdemand.

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Preliminary planning checklist1. Does installation of the solar thermal

system fit in with the timing of plannedmodernisation work? The time of the nextroof/facade renewal should match the life-time of the collectors. The same applies forrenewal of the heating system.

2. Location: Can the collectors be orientedbetween SE and SW? Are there any shadingobjects?

3. Collector mounting: Can collectors be fitted to the roof or integrated into theroof/facade? Is it possible to install entirecollector fields?

4. Is there enough space for the solar heatstorage tank and is it accessible for instal-lation? What structural changes are neededfor the storage tank to be installed?

5. Have all structural and energy systemchanges to the building been taken intoaccount? Is the solar thermal system aligned to them? Is there further scope for energy improvements?

6. Choice of planning objective between sub-stituting primary energy, minimising heatgeneration costs and legal compliance(building system input/output ratio or solarordinances).

Planning

Planning Procedure

Solar thermal systems for large buildings arealways tailor-made. This means they needcareful, individual planning.Architects and system designers have to workclosely together from the outset. This ensuresthat the finished system will work optimally.Contractually guaranteed savings makesystems an even safer investment for owners.

Horizontally mounted vacuum tubecollectors on flat roofPhoto: Die Fabrik, Berlin (Germany)

40° installation on flat roof Facade integrationPhoto: Wagner-Solar.com

SW SES

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Installation planning checklist1. Can architect and solar system designer

work together from the outset to developan integrated system?

2. Does the quoted price cover both designingthe solar thermal system and matching itto the heating and/or hot water system?Do the solar system installers have ex-perience with large systems? Are theexpected energy savings subject to guarantee?

3. Does the installation planning take intoaccount that new trades will have to bebrought into the building work and theheating system must first be optimisedfrom an energy standpoint? Is it ensuredthat only suitable components and insu-lation materials for standing temperaturesup to 200 °C will be used for the solar ther-mal system ?

4. Can the system be optimised when opera-ting, i. e. when the building is occupied?When is the timeframe for fine-tuning thesystem?

Acceptance checklistFollowing installation, it is essential to fine-tune the solar thermal system in operation.This optimisation should take place over a pre-set timeframe (e. g. three months). The systemis tested at the same time to see if the guar-anteed energy savings are achieved. The instal-lers may be required to make adjustments.

Initial acceptance1. Are all system components properly fitted

and connected? Have all circuits beentested under pressure?

2. Are all valves and pipes fully labelled?3. Is the system fully insulated, without gaps

in the insulation where pipework passesthrough walls and ceilings?

4. Are all parameter settings documented?

Final acceptance (after stipulated period in operation)5. Are all guaranteed parameters (energy

savings) achieved?6. Are all system components matched (suit-

ably dimensioned heat exchanger, heatmeter, temperature sensor, expansion ves-sel) and properly positioned?

7. Are all parameter settings and modifica-tions to the system documented?

40° installation Photo: Soli fer Solardach GmbH - Altenpfleheim St. Michael, Dresden (Germany)

Integrated collectors Photo: Velux

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Absorption chillers with a liquid absorbentcover the 15 kw to 5 MW range. Input tempera-tures on these systems range from 80–110 °C.COPthermal: 0.6–0.8 for a single-stage chillerand up to 1.2 for a two-stage system.

Absorption chillers need about 3–3.5 m2 of collector surface per kW of cooling capacity.

Another system type, known as a sorption-assisted air conditioning system, uses desic-cant and evaporative cooling (DEC). After cool-ing, the refrigerant (water) is expelled fromthe system. Desiccant and evaporative coolingsystems achieve a cooling capacity in the 20-350 kW range. Such systems can be expandedon a modular basis. The operating temperatureis only around 45–95 °C. This means the heatcan be provided by simple flat plate collectorsand in some cases even by air collectors(COPthermal: 0.5–1.0). Systems using a liquidabsorbent are currently being developed.

As a rule of thumb for open systems, about 8–10 m2 of collector area can be assumed neces-sary per 1,000 m3/hr installed capacity.

Technical Basics

Solar Air Conditioning in a Nutshell

Solar air conditioning systems are offered byseveral firms in Europe for offices and publicbuildings. Solar thermal energy is very well suited for running air conditioning systems, ascooling demand tends to correlate very wellwith the amount of sunshine.

Cooling demand heavily depends on buildinguse, building type, the condition of the buil-ding (thermal insulation) and the interior heatload. In Central Europe, residential buildingsare expected to need air conditioning for 50 to200 hours a year. This increases to 1,000 hoursfor office and industrial buildings. The figure inSouthern Europe is far higher, especially forhotels and office buildings.

The output of solar-powered chillers rangesfrom 10 kW to 5 MW. Such units are used toprovide cold water and for air conditioningsystems.

The 50–400 kW range is generally served byadsorption chillers operating with a solidadsorbent. The input temperature of about60–90 °C is provided by flat plate or vacuumtube collectors (coefficient of performanceCOPthermal: 0.5–0.7).

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Typical performance figures (COPthermal) for thermally driven chillers range from 0.5–1.2 depending on the system. However,the COPthermal performance figure differs from the figure used for electrically driven chillers. The coefficient for a thermally driven chiller is defined as the ratio of the heat given off by the cold water circuitand the heat needed to drive the process(COPthermal = Qcold/Qhot). On electrically driven chillers, COPconv is the ratio of the heatgiven off by the cold water circuit and the electrical energy used (COPconv = Qcold/Eelec).

Factory building with solar cooling, Audi, Ingolstadt,Germany Photo: Solahart/ESTIF

Solar air conditioning – absorption chillerPhoto: Schüco

Solar air conditioning – adsorption chiller in the university hospital, FreiburgPhoto: Universitätsklinikum Freiburg/Fraunhofer ISE

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Best Practice Catalogue

SurveyIn a questionnaire-based survey, data andstatements have been collected from systemoperators, owners and planners. The question-naires covered over 120 items. In addition totechnical and economic variables, surveyrespondents were asked for general remarksand recommendations for future projects. Thefacts and experience collected from surveyrespondents provide a comprehensive insightinto the subject. Planners will find relevanttechnical details together with general re-quirements for planning and implementation.

Best Practice Examples

The systems presented by way of example inthe following pages are selected from a large,nine-country project database which can beviewed in full at www.solarge.org.

The catalogue is divided into seven applications:

Applications for hot water A Hot water for apartment buildingsB Hot water for hotelsC Hot water for public and social buildings

Applications for hot water and space heatingD Hot water and space heating

for apartment buildingsE Hot water and space heating for hotelsF Hot water and space heating

for public and social buildings

G Other applications

Besides hot water and space heating, some ofthe systems also provide heat for swimmingpools and other purposes.

Scheme 1: Direct piping for hot tap water with decentral-ised solar storage and backup heaters (common in Spain)

Scheme 2: Two-pipe installationfor hot tap water with centralisedsolar storage and decentralisedbackup heaters

Scheme 3: Two-pipe installationfor hot tap water with centralisedbackup heater and solar storage(common in D, F, I, DK, NL)

Additional note: All systems depend on the situation of the building and local and national laws. In some cases,for example boilers, solar storage tanks etc. are located directly under the roof. The schemes shown provide only a simplified representation of the options for integrating a solar thermal system into a building.

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How to use the Best Practice CatalogueThe examples presented in the pages that fol-low provide an overview of the different typesof system. This allows comparison with readers’own plans. The examples are also a source ofideas for improvements to such plans.

The examples show where solar thermalsystems can be usefully integrated into heating systems. A wide range of systemapproaches is covered so that a suitablesystem type for every application can be founded.

The number of systems selected bears no relation to the number of systems of each type in operation today. Nor does the selectionimply anything about where solar thermalsystems are best deployed.

As mentioned elsewhere, the size of a plannedsolar thermal system always depends on theindividual situation (consumption profiles,available installation options, integration intoan overall system concept) and cannot bedirectly inferred from apparently similarsystems.

It is therefore always important to obtain ad-vice from professionals with experience inplanning large solar thermal systems.

Scheme 4: Direct pipingfor space heating and hot tapwater with decentralised solar storage and backup heaters (common in Spain)

Scheme 5: Two-pipe installation for space heating and hot tapwater with centralised solar storageand decentralised backup heaters

Scheme 6: Two and four-pipeinstallation for space heating andhot tap water with centralised backup heater and solar buffer(common in D, A, I, DK, NL)

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Contactu Vèrtix

Can Ràbia, 11, LocalE-Barcelona, Spain

kh Rafael López,Antoni Esqué

1 +34 93 2063476

I +34 93 2051586

! [email protected]

Profile

Real estate company New multi-family house,39 dwellings 61 m2 flat-plate collector (gross area), on flat roof 60 % reduction of final energy consumption forhot water generation(calculated)

Best Practice 1

Vèrtix - San Cugat des VallèsMulti-Family House

Facts in briefYear of construction of CSTS 2004/2005Aperture area of collectors 60 m2

Thermal output 42 kWth

Collector yield 796 kWh/(m2 ·a)Total costs of solar hot water system* 89,133 €Subsidies 0 %CO2-emissions avoided 14.13 t CO2 per yearReduction of final energy 59,765 kWh/aReplaced energy source Natural gas

*costs without conventional heating system

MotivationThe main reason to install the CSTS was theSan Cugat des Vallès Solar Ordinance. Thismunicipal ordinance mandates the installationof solar thermal systems for hot water genera-tion in new buildings with a minimum solarproportion of 60 %. This building was the firstVèrtix building where a solar thermal systemwas installed for hot water generation.

Collector area per apartment: 1.5 m2

Investment costs per apartment:* 2,285 €Solar fraction of global heat demand:** 60 %

* without consideration of subsidies** measured

No.

For further information, please refer to www.solarge.org

Barcelona

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hot water k apartment buildingsA

Decentralised heat-ing system. Solarheat storages andbackup heaters are located in eachapartment. The building is compos-ed of 39 apartmentson 5 floors.

Technical DescriptionThe solar storage devices are distributed in a decentralised manner and are connected in series to a modulated combination boiler (for space heating and hot water generation).■ operation mode: low-flow■ type of hot water heating: decentralised■ type of space heating: decentralised■ solar buffer storage: 39 x 150 l

FinancingThe project developer, Vèrtix, financed theCSTS installation themselves without applyingfor a subsidy or special loans.

Comments■ “The CSTS installation on San

Cugat Vallès was the first onecompleted by Vèrtix.However, the implementationof the system was mandatedby the municipality's SolarOrdinance. It was also takenon as a challenge by the pro-ject developer to comply withthis obligation. The favoura-ble results of the installationand the lack of major pro-blems gave Vèrtix the confi-dence to invest in solar ther-mal systems in future buil-dings.”

“The CSTS is running well. Atthe beginning there weresome complaints because ofthe noise from one pump.The pump was changed andno more problems have beenreported. In the beginningthere were also some pro-blems reported with the col-lector fluid. There were somesmall leaks in the circuitwhich caused pressure dropswithin the circuit. The leakswere detected and repairedand the circuit was filledagain.”

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Contactu Tablis Wonen

P.O. Box 1453360 AC SliedrechtThe Netherlands

1 +31 184 444 844

I +31 184 444 866

! [email protected]

Profile

Social Housing Association Multi-Family House (1968), 80 dwellings 90 m2 flat-plate collector(gross area), on flat roof57,000 kWh/a reduction of final energy consump-tion (measured)

Best Practice 2

Tablis Wonen - Sperwerflat IMulti-Family House

Facts in briefYear of construction of CSTS 2003Aperture area of collectors 89 m2

Thermal output 62.3 kWth

Collector yield 448 kWh/(m2 ·a)Total costs of solar hot water system 50,211 €Subsidies 31 %CO2-emissions avoided 10.5 t CO2 per yearReduction of final energy 57,000 kWh/aReplaced energy source Natural gas

MotivationThe project took place as part of an overallrenovation of the hot water installation. Smallindividual gas-fired kitchen tap water heatersthat emitted exhaust gases into the dwellingshave been replaced by a central solar hotwater system. There are several benefits forthe tenants:■ hot water facility has been improved;■ indoor air quality has been improved (no

more exhaust gases, less humidity);■ problems with mould on the kitchen walls

have been solved due to lower humidity inthe flats.

Sliedrecht

No.

For further information, please refer to www.solarge.org

collector area per apartment: 1.1 m2

investment costs per apartment:* 628 €Solar fraction of global heat demand: n/a

* without consideration of subsidies

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Technical DescriptionThe solar hot water system consists of a 90 m2

collector surface and a buffer storage with astorage volume of 3,000 litres. The solar col-lectors and buffer storage tank are connectedby a plate heat exchanger. Solar heat is storedin the tap water. Drain-back protects againstfreezing and overheating.■ operation mode: high flow■ type of hot water heating: central■ type of space heating: central■ solar buffer storage: 3 m3

FinancingThe turn-key system cost amounted to EUR564/m2 (total EUR 50,000) paid for by theowner/investor, Tablis Wonen. Subsidies weregranted from three sources for a total of 31%of the cost.

Comments■ “The complete retrofitting

of the Sperwer building witha central solar hot watersystem resulted in a lot of'wins' for the tenants: Bettercomfort, better indoor airquality, lowered indoor humi-dity, savings in energy billsand a contribution to climatechange mitigation. Since thisproject, 8 other buildingshave been equipped with asimilar central solar hotwater system."

“Installing solar thermalsystems fits in with the socialresponsibility policy goals ofTablis. This is one such exam-ple where the hot watersystem for the flats has beenmodernised to improve livingconditions (no exhaust gasesin the flats, less humidity andmould) and comfort (impro-ved hot water facilities). Inorder to compensate for therelated increase in energyconsumption (due to centralhot water circulation lossesand better facilities) the solarsystems were added.“

hot water k apartment buildingsA

Flatplate collectors

and solar heat

storage of the

Sperwer building

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Contactu ATC Torino

Corso Dante, 14I-10134 Torino, Italy

kh Ing. Paolo Cinus

1 +39 11 3130532

I +39 11 3130461

! [email protected]

Profile

Social housing associationMulti-Family House,42 dwellings

96m2 flat-plate collectors (gross area), solar roof69 % reduction of finalenergy consumption for hot tap water (estimated)

Best Practice 3

ATC Torino – Multi-Family House

MotivationATC Torino, a social housing public agency inthe province of Turin, has dealt with environ-mental and energetic matters since 1996.Whenever possible, new technologies (especi-ally renewable energy sources) have been inte-grated into ATC's buildings in order to reducetheir environmental impact.

Facts in briefYear of construction of CSTS 2005Aperture area of collectors 90 m2

Thermal output 63 kWth

Collector yield 633 kWh/(m2 ·a)Total costs of solar hot water system 76,287 €Subsidies 43 %CO2-emissions avoided 20.7 t CO2 per yearReduction of final energy 76,000 kWh/aReplaced energy source Natural gas

No.

For further information, please refer to www.solarge.org

collector area per apartment: 2.1 m2

investment costs per apartment:* 1,816 €Solar fraction of hotwater demand:** 46 %

* without consideration of subsidies** heat demand for hot tap water

generation (value: estimated)

Moncalieri

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Technical DescriptionThe solar system heats the buffer storage tankvia an external heat exchanger. The buffer storage tank then loads one of three hot tapwater tanks through a second external heatexchanger. The other two hot water storagetanks are heated by both the first buffer stora-ge tank and the boiler. In order to assure thesanitary quality of the hot water, the solar hotwater tank can also be heated up by the boiler.■ operation mode: low flow■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 4.0 m3

FinancingThe province of Turin subsidised a part of thetotal investment costs through a demonstra-tion programme (publications and presenta-tions from various newspapers, newslettersand exhibitions on the Province's web site).

Comments■ “The building located in

Moncalieri near Juglaris,illustrates the appeal of solarthermal technology. Due tothe integration of the collec-tors into a solar roof, which isa cost effective and innovati-ve solution in Italy, our solarthermal system is very attrac-tive from an architecturalpoint of view as well.

hot water k apartment buildingsA

Roof integrated flat-

plate collectors and

solar heat storage in

Moncalieri

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Contactu Wohnungsgenossenschaft

„Karl Marx“ Potsdam e.G.Jagdhausstr. 27D-14480 Potsdam, Germany

kh Klaus Bergemann

1 +49 331 6458 235

! [email protected]

Profile

Co-operative housing societyMulti-Family House,258 dwellings

222 m2 flat-plate collectors(aperture area), on flatroof88,270 kWh/a reduction offinal energy consumption

Best Practice 4

WG Karl Marx e.G.– Multi-Family House

MotivationWithin the scope of the refurbishment of thebuilding, a complete modernisation of theheating system including central hot watergeneration was necessary. For that reason,among others, the possibilities for solar energyintegration were analysed. Although hot waterprovision with a solar thermal system seemedto be a favourable option, the implementationproved to be a great task for the planners andmanufacturers involved as well as for us as thebuilding owner. It should be mentioned thenthat, as of the time of the planning in 1998,

Potsdam

Facts in briefYear of construction of CSTS 2000Aperture area of collectors 222 m2

Thermal output n/a Collector yield approx. 300 kWh/(m2 ·a)Total costs of solar hot water system 200,000 €Subsidies 85 % CO2-emissions avoided n/aReduction of final energy 88,270 kWh/aReplaced energy source District Heating

No.

For further information, please refer to www.solarge.org

collector area per apartment: 0.9 m2

investment costs per apartment:* 775 €Solar fraction of global heat demand: n/a

* without consideration of subsidies

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WG Karl-Marx e.G.- collector field

large solar thermal systems for residentialbuildings were rarely installed so there waslimited background experience for the project.In hindsight, the result was very favourable:The end technical and economic performancelevels met all the predicted benchmarks.

Technical DescriptionThe solar thermal system consists of a 222m2

collector field connected to a separated controlunit and storage devices. The solar thermalenergy is used only for the generation of hotwater.■ operation mode: Low flow■ type of hot water heating: central■ type of space heating: central■ solar buffer storage: 9.75 m3

FinancingThe purchase of the system was predominant-ly financed by soft loans, but 15% was financedby the housing society. The total costs of allimplemented renovations (including CSTS) areshared by the tenants within the legal ranges.

Comments■ “The experience gained

through this project under-line the fact that solar ther-mal systems are suitable forimplementation on large resi-dential buildings. It wasshown that technical andeconomic target values canbe achieved. A key factor inthe implementation was agood working knowledge ofthe consumption profilesbefore the installation of theCSTS. Remote monitoring will ensure the long-termfunctionality of the system.

hot water k apartment buildingsA

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Contactu Municipality of Giurgiu

49-51 Bucharest Street8375 Giurgiu, Romania

kh Lucian Iliescu,Constantin Ionescu

1 +40 246 213588

I +40 246 213747

! [email protected]

Profile

Municipal housing administration2 Multi-Family Houses,2 x 40 dwellings300 m2 flat-plate collec-tors (aperture area), on flat roofs58,000 kWh/a of solar heat

Best Practice 5

Municipality of Giurgiu – Policlinica AreaMulti-Family House

MotivationDuring the summer, the combined heat andpower (CHP) plant in Giurgiu does not produceelectricity and therefore the hot water supplyis turned off completely between April andNovember. The installation of 300 m2 of solarpanels on two housing blocks was necessaryto supply hot water for 80 flats during thesummer months.

Giurgiu

Facts in briefYear of construction of CSTS 2001Aperture area of collectors 300 m2

Thermal output 210 kWth

Collector yield 193 kWh/(m2 ·a)Total costs of solar hot water system 93,666 €Subsidies 0 %CO2-emissions avoided n/aReduction of final energy n/aReplaced energy source District Heating (CHP)

No.

For further information, please refer to www.solarge.org

collector area per apartment: 3.8 m2

investment costs per apartment:* 1,171 €Solar fraction of global heat demand:** 100 %

* without consideration of subsidies** this solar thermal system supplies 100%

of the hot water demand of this bothbuildings during the summer periode

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Collector field andsolar heat tanks inPoliclinica Area

Technical DescriptionIt was decided to use a solar thermal systemfor the provision of domestic hot water duringthe summer months. A joint system with alarge coverage area was built to supply thetwo housing blocks. Heat is stored directly inthe domestic hot water or in existing hotwater tanks; 2 x 5 m3 for each block.■ operation mode: low flow■ type of hot water heating: central■ type of space heating: central■ solar buffer storage: 4 x 5 m3

FinancingThe solar project was part of Romania'sDistrict Heating Rehabilitation Project forGiurgiu which was financed by the DanishEnvironmental Agency (DEPA) through theDanish Cooperation for Environment inEastern Europe programme (DANCEE). TheRomanian counterpart contributed using itsown financing measures.

Comments■ “The installation of 300 m2

solar panels on two housingblocks in Giurgiu enables 80dwellings to be supplied withhot water during the summermonths. These flats are theonly flats in Giurgiu with hotwater supply in the summerand are therefore now veryattractive to buy.

hot water k apartment buildingsA

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Contactu Helsingør Boligselskab

Kongedammen 343000 Helsingøre, Denmark

kh Poul Hansen (chairman)

1 +45 49 2128-61

I +45 49 2128-91

! [email protected]

Profile

Co-operative housing societyMulti-Family Houses,425 dwellings

336 m2 flat-plate collectors(aperture area), on roof 123,000 kWh/a of solar heat

Best Practice 6

Sundparken – Multi-Family House

MotivationThe Chairman of the housing society motiva-ted the tenants to support the installation ofthe system despite the rent increase thatwould be incurred over a limited period oftime. Rent rates would then return to lowerlevels.

Helsingør

Facts in briefYear of construction of CSTS 2000Aperture area of collectors 336 m2

Thermal output 235 kWth

Collector yield approx. 366 kWh/(m2 ·a)Total costs of solar hot water system 240,000 €Subsidies 13 %CO2-emissions avoided n/aReduction of final energy 123,000 kWh/aReplaced energy source District heating

No.

For further information, please refer to www.solarge.org

collector area per apartment: 0.8 m2

investment costs per apartment:* 565 €Solar fraction of global heat demand:** 3.1 %

* without consideration of subsidies** measured

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Flat plate collectorsand the central control system

Technical DescriptionThe solar heating system is a low flow systemwith a 10,000 l hot water tank. Due to theorientation of the buildings the CSTS was desi-gned as two separate systems with a commonstorage tank. Half of the solar collectors (168 m2)face east, the other half of the solar collectors(168 m2) face west.The collector tilt is 15° from the horizontal forall the collectors. Both the east-facing and thewest-facing collectors have their own solar col-lector loop, circulation pump, external heatexchanger and control system.■ operation mode: low flow■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 10 m3

FinancingThe project was financed mainly throughreserves from the housing association's ownrevolving funds as well as a small loan, natio-nal subsidies and a tax break.

Comments■ “There is great potential for

the expansion of the solarcollector area for space hea-ting, but, at the moment, thereturn temperature from theradiator system is consideredto be too high.

hot water k apartment buildingsA

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Contactu Mairie de La Rochelle

Hôtel de Ville - BP 154117086 La Rochelle Cedex 2,France

kh Mr Giret

1 +33 5 46515010

! www.ville-larochelle.fr

Profile

Mairie de La Rochelle12 Multi-Family Houses,941 dwellings1,164 m2 flat-plate collectors (gross area),on flat roof 43 % reduction of final energy consumption (estimated)

Best Practice 7

ZUP Les Salines – 12 Multi-Family Houses

Motivation„We would carry on with the approach follo-wed by the city of La Rochelle since 1970. Withthe district heat development, the restorationof the former solar installation of the Salineswould prove to be a necessary thing to do.“

La Rochelle

Facts in briefYear of construction of CSTS 2005Gross area of collectors 1,164 m2

Thermal output 750 kWth

Collector yield 690 kWh/(m2 ·a)Total costs of solar hot water system 1,446,000 €Subsidies 80 %CO2-emissions avoided 210 t CO2 per yearReduction of final energy 894,000 kWh/aReplaced energy source Diverse

(District heating)

No.

For further information, please refer to www.solarge.org

collector area per apartment: 1.2 m2

investment costs per apartment:* 1,537 €Solar fraction of global heat demand: n/a*

* without consideration of subsidies

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Boiler room withsolar heat tanks,auxiliary heatingand control unit

Technical DescriptionThe CSTS was restored in 2005 and is compo-sed of 1,164 m2 flat plate collectors installed onflat roofs of the twelve buildings. They are pla-ced in a south/south-western orientation of25° and with an inclination of 30°. Total solarstorage is 58 m3 shared between the twelvebuildings.■ operation mode: variable■ type of hot water heating: central■ type of space heating: central■ solar buffer storage: 19 m3

FinancingThe total cost of this project was EUR 1,371,000excluding VAT and EUR 1,446,000 includingVAT (VAT at 5.5%). It was subsidised at 80% byEurope (FEDER funds: EUR 411,494) and by theADEME / Regional Council of Poitou-Charentes(EUR 685,824).

Comments■ “A former solar installation

already existed on this siteand La Rochelle City Hallchose to carry on with thisapproach initiated in theSeventies with a restoration.La Rochelle City Hall arrangedan agreement between thepublic utility company andthe Elvo Ocean Company, theinstallation's operator. Thisoperation was split into threeparts, carried out by three dif-ferent installers. For a projectlike this, it is important towork with an engineeringcompany with lots of goodreferences.

hot water k apartment buildingsA

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For further information, please refer to www.solarge.org

Contactu Hotel Fortuna

Hauptstraße 779199 Kirchzarten, Germany

kh Manfred Meder

1 +49 7661 3980

Profile

Private ownershipHotel, 70 beds 53 m2 flat-plate collectors(gross area), roof inte-grated34,000 kWh/a reduction of final energy consump-tion

Best Practice 8

Fortuna Hotel

MotivationDuring a regular pub meeting in the year2000, hotel owner Manfred Meder and OttoWehrle, collective solar thermal systems instal-ler and producer of solar storage tanks, discus-sed the apparent high consumption of hotwater in the FORTUNA Hotel. A special topicwas the high consumption of oil for the hea-ting of hot water during the warm months.Since the consumption of hot water is a givenin hotels, operating costs were able to be redu-ced through the installation of a well-plannedsolar thermal system.

Kirchzarten

Facts in briefYear of construction of CSTS 2004Aperture area of collectors 46.7 m2

Thermal output 33 kWth

Collector yield 546 kWh/(m2 ·a)Total cost of solar hot water system 55,000 €Subsidies 10.8 %CO2-emissions avoided 7.5 t CO2 per yearReduction of final energy 34,000 kWh/aReplaced energy source Heating Oil

No.

collector area per room: 1.3 m2

investment costs per apartment:* 1,571 €Solar fraction of global heat demand:** 7.7 %

* without consideration of subsidies** estimated

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Technical DescriptionThe solar storage tanks were built within oneinsulation jacket in order to cover the connec-ting pipes. This avoids heat losses between thesolar storage tanks.■ operation mode: high flow■ type of hot water heating: central■ type of space heating: central■ tap water storage: 4.1 m3

FinancingThe owner is also the investor. Nearly 90 % ofthe personal invested resources have a calcula-ted return of investment period of approxima-tely seven years. This is due to the planner'smany years of experience. About 10.8 % of theproject costs were subsidised by the FederalOffice of Economics and Export Control (BAFA).

Comments■ “The structural condition of

the building, a demand ana-lysis, visiting referencesystems, the experiencedcompany that carried outthe installation work and proven systems were all partof the successful integrationof a solar thermal systeminto the existing building services. When awarding thecontract only companiesshould be considered whichcan produce an installationschedule as early as in thepreliminary stages. This wayunnecessary surprises duringassembly can be avoided.“

„Finally the operating costscan be reduced with the helpof a well-planned and well-installed solar thermalsystem because hot waterconsumption is guaranteedin hotels.“

hot water k hotelsB

Roof integrated

flatplate collectors

of Hotel Fortuna

and piping located

in the gable

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Contactu Hotel Novotel Sophia Antipolis

290 rue dostoïevski06410 Valbonne, France

1 +33 4 92387238

I +22 4 93958012

Best Practice 9

ACCOR Group – Hôtel Novotel Sophia Antipolis

MotivationThe solar installation was carried out with thehelp of the ACCOR Group's commitment to beinvolved with sustainable policy and to impro-ve the brand image of the hotel.

Valbonne

Facts in briefYear of construction of CSTS 1999Aperture area of collectors 108 m2

Thermal output 76 kWth

Collector yield 832 kWh/(m2 ·a)Total cost of solarhot water system 84,500 €Subsidies 73 %CO2-emissions avoided 11 t CO2 per yearReduction of final energy 94,650 kWh/aReplaced energy source Electricity

No.

For further information, please refer to www.solarge.org

collector area per room: 1.2 m2

investment costs per apartment:* 871 €Solar fraction of global heat demand: n/a

* without consideration of subsidies

Profile

Hotel chain Hotel, 97 rooms113 m2 flat-plate collectors(gross area), on a flat roof 48% reduction of final energy consumption for hot tap water heating

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Flatplate collectorsof the Hotel inValbonne

Technical DescriptionThe CSTS was designed to cover 49 % of theenergetic needs for hot tap water provision.113 m2 collector surfaces were installed on theflat roof facing south and with an inclinationof 30 %. The collectors are connected to two3,000-litre solar tanks. Back-up storage con-sists of five 3,000-litre electric storage tanks.■ operation mode: variable■ type of hot water heating: central■ type of space heating: central■ solar buffer storage: 6 m3

FinancingThe total cost of this operation was EUR84,505 excluding VAT, subsidised at 73 % by the ADEME and the PACA Regional Councilwith EUR 61,742.

Comments■ “Aware of the importance

of sustainability for the tou-rism industry, the ACCORGroup, of which this hotel is a member, has implemen-ted a coherent environmentalpolicy since 1993. In 1999, acontract to develop renew-able energy sources was signed with the ADEME.Each year the measured solaroutput has exceeded theguaranteed energy outlinedin the solar performance guarantee.“

hot water k hotelsB

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Contactu Woonveste Housing

AssociationAfrikalaan 92P.O. Box 1275150 AC DRUNENThe Netherlands

Profile

Social Housing Associat-ion, WoonvesteMulti-family House for elderly persons,105 dwellings100 m2 flat-plate collectors(gross area), on a flatroof 38,900 kWh/a of solar heat

Best Practice 10

Woonveste – House for elderly persons

MotivationThe installation of this system was in accor-dance with the association's environmentalmission. As part of their environmental poli-cies Woonveste actively aims to reduce energyand water consumption and promotes the useof renewable energy systems in its buildingstock.

s'Hertogenbosch

Facts in briefYear of construction of CSTS 2003Aperture area of collectors 96 m2

Thermal output 67 kWth

Collector yield approx. 405 kWh/(m2 ·a)Total cost of solarhot water system 47,900 €Subsidies 33 %CO2-emissions avoided 11.7 t/aReduction of final energy 55,500 kWh/aReplaced energy source Natural gas

No.

For further information, please refer to www.solarge.org

collector area per apartment: 0.9 m2

investment costs per apartment:* 456 €Solar fraction of global heat demand: n/a

* without consideration of subsidies

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Flat plate collectors

Technical Description■ operation mode: n/a■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 3 m3

FinancingFor the realisation of this project, Woonvestewas supported by the project “Space for Solar”,which provided feasibility studies, an intere-sting turn-key offer based on a call for tenderand an investment subsidy.

Comments■ “When the decision was

made to install a solar waterheater not all tenants werehappy because of the corre-sponding increase in rent. Butnow the solar water heater isin service and the overallenergy costs have been lowe-red by twice the amount ofthe rent increase. Needless tosay, all the tenants are satis-fied. Woonveste will continueits mission to install renew-able energy systems in itsbuilding stock."

hot water k public buildingsC

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Best Practice 11

Contactu Dom starejših obcanov TEZNO

(TEZNO Retirement home)Panonska ulica 412000 Maribor, Slovenia

kh Jasna Cajnko, M. Sc. director

1 +386 2 4602602

! [email protected]

Profile

Social Association Retirement home (2003),200 residents + 80 Employees110 m2 flat-plate collector(gross area), on flat roof29,390 kWh/a reduction of final energy consump-tion

TEZNO – Retirement Home

MotivationThe system, as well as the building, was finan-ced by the Ministry of Labour, Family andSocial Affairs and community of the town ofMaribor. The complete building was taken overby the current users. The supplier of the solarsystem manages and maintains the systemfree of charge.

Maribor

Facts in briefYear of construction of CSTS 2003Aperture area of collectors 100 m2

Thermal output 70 kWth

Collector yield 294 kWh/(m2 ·a)Total costs of solar hot water system 50,000 €Subsidies 50 %CO2-emissions avoided 5.9 t CO2 per yearReduction of final energy 29,390 kWh/aReplaced energy source Natural gas

No.

For further information, please refer to www.solarge.org

collector area per apartment: 1.0 m2

investment costs per apartment:* 505 €Solar fraction of global heat demand:** 2.3 %

* without consideration of subsidies** estimated

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FinancingDue to the present owners having just takenover the building, accurate costs are notknown. The investment cost was approximate-ly EUR 500 per m2 solar collector. Half of theinvestment was paid for by the local commu-nity as part of the programme to help theelderly.

Technical DescriptionThe solar system, which is used to heat hottap water, is composed of two fields of flatselective solar collectors with a total area of100 m2. There are four heat storage tanks, eachwith a volume of 900 litres, which serve asbuffer storage. Two of them are connectedparallel forming the battery. Two batteries areconnected in series. This way, better tempera-ture distribution in the storage tanks is achie-ved. Heat from the buffer solar heat storage istransferred over a plate heat exchanger intotwo additional storage tanks where the tapwater is heated. Each of them has a volume of1,000 litres. Cold tap water flows through thefirst to the second storage tank and is additio-nally heated with a spiral exchanger integra-ted into the last storage tank and gas boiler.■ operation mode: low flow■ type of hot water heating: central■ type of space heating: central■ solar buffer storage: 3.6 m3

Comments■ “During the process of dis-

cussion, planning, construc-tion and operation of thelarge solar system a lot ofexperience was gained. Thefirst two years of operationshowed that the system isaccurately designed and wellconstructed. There were nosignificant costs with systemmaintenance.The experience has been successfully used in new projects.“

hot water k public buildingsC

Flatplate collectorsand hydraulics

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Contactu Consorzio Pracatinat

località Prà CatinatFenestrelle (TO), Italy

kh Claudio Richiardone

1 +39 121 884807

I +39 121 83711

! [email protected]

Profile

Consorzio PracatinatHotel, 200 rooms150 m2 flat-plate collec-tors (gross area), on flatroof 180,000 kWh/a reduction of final energy consump-tion

Best Practice 12

Pracatinat – Educational Centre

Motivation„The educational centre, Consorzio Pracatinat,specialises in environmental education activi-ties, sustainable tourism and accompanyinglocal sustainable development projects.Therefore, it has a natural affinity towardsrenewable technologies. This is clearly testifiedby the decision to install a solar thermal pilotplant, which contributes to create an environ-mentalist image for the centre. Furthermore, adisplay is mounted in the hall of the buildingto show the performance of the solar system.“

Fenestrelle (TO)

Facts in briefYear of construction of CSTS 2004Aperture area of collectors 142 m2

Thermal output 100 kWthCollector yield 697 kWh/(m2 ·a)Total cost of solarhot water system 90,000 €Subsidies 40 %CO2-emissions avoided 41.4 t CO2 per yearReduction of final energy 180,000 kWh/aReplaced energy source Natural Gas

No.

For further information, please refer to www.solarge.org

collector area per apartment: 0.7 m2

investment costs per room:* 450 €Solar fraction of hotwater demand:** 55 %

* without consideration of subsidies** heat demand for hot tap water

generation (value: estimated)

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Flatplate collectorsand panel display inPracatinat

Technical DescriptionThe collectors are connected to a 5 m3 bufferstorage tank, which heats up a hot tap watertank via a heat exchanger. Two further tanksare connected in parallel and are heated up byboth the solar tank and the auxiliary heatingboiler. The recirculation circuit can be divertedeither to the solar tank (in the summer) or tothe other two tanks (in the winter) in order tooptimise the efficiency of the system.■ operation mode: low flow■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 5 m3

FinancingThe plant was partly financed by the provinceof Turin as part of a demonstration program-me.

Comments■ “Due to the intermediate low

efficiency of the system, theinvestment is not yet profita-ble. Small modifications tothe plant, however, should beenough to improve the ener-getic and economic efficiency.Our application was evalua-ted and finally our hotel waschosen for the installation ofa pilot plant. The technicalstaff were supported byexperts in the planning andin the choice of suppliers.Recommendation for the rea-lisation of future projects:before the decision to installa pilot plant is made, itshould be ensured that allthe players involved are infor-med and share the same opi-nion. Otherwise it will be dif-ficult to coordinate all thepeople involved, such as theowner, the planner and thoseresponsible for monitoringthe project.

hot water k public buildingsC

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Contactu DEGEWO gAG

Potsdamer Str. 6010785 Berlin, Germany

1 +49 30 26485-0

I +49 30 26485-120

! [email protected]

Profile

Housing groupMulti-Family Houses,53 dwellings 59 m2 flat-plate collectors(gross area), on a flat roof

29,050 kWh/a of solar heat

Best Practice 13

DEGEWO – Multi-Family House

MotivationThe project was carried out in the contextof the solar reorganisation strategy of theDEGEWO.Due to positive experiences in co-operationwith the project partners and the total energysavings, every renovation or remodelling plantakes the use of solar thermal into considera-tion from the very beginning. The project mustbe profitable for the property company.

Berlin

Facts in briefYear of construction of CSTS 2004Aperture area of collectors 54 m2

Thermal power 37.9 kWth

Collector yield approx. 538 kWh/(m2 ·a)Total cost of solar heating/hot water system 69,944 €Subsidies 16.4 %CO2-emissions avoided 7.38 t/aReduction of final energy n/aReplaced energy source Natural gas

No.

For further information, please refer to www.solarge.org

collector area per apartment: 1.0 m2

investment costs per apartment:* 1,320 €Solar fraction of global heat demand:** 2.9 %

* without consideration of subsidies** measured (this plant concept focuses on

the boiler optimisation whereby fossilenergy savings are considerably higherthan shown by the solar fraction here)

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ging in accordance with the EnEV for waterheating and heater support.■ operation mode: low flow■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 1.3 m3

FinancingThe costs of the installation and renovationwere financed by subsidies (EUR 11,500) fromthe Market Stimulation Programme from theFederal Government, the Retrofit Premiumfrom GASAG and equity capital (EUR 58,500)from the owners' association.

Technical DescriptionThe solar thermal system has a collector areaof 59 m2 and a central regulation and controlunit. The obtained solar energy is used forwater heating, heater support and for thethermal solar Legionella-circuit by the solarcompact station. Water and space heating issupplemented by fossil-generated heat onlywhen necessary.The solar collector system, water heating,space heating and the boilers are operated bya central, automatic controller, so that, apartfrom the energy savings by the solar collectorsystem, this combined system will result infurther energy savings compared to the con-ventional use of the boiler as it taps synergyeffects. As part of maintenance procedures,the water heating system was renovated.The boiler was replaced by a smaller, modern,fuel-efficient boiler that generates approx.60-70% of the annual heating required by thehousing complex. A remaining second boilerreceived a new modulating gas burner. Theheat supply was retrofitted for natural gas and therefore emits fewer pollutants. Thepiping and armatures in the heating plantroom, which were not replaced, received lag-

Comments■ “Large thermal solar systems

can be operated efficientlyand gains and costs can becalculable if the systems areconsidered in planning andimplemented with compe-tent partners from the begin-ning. Personal commitmentand persistence are absolute-ly necessary for the realisa-tion of such projects.

hot water + space heatingk apartment buildingsD

Combined solar ener-gy and boiler controlstation “SEZ” in Berlin

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Contactu Eneco Energie

Diakenhuisweg 39-43Haarlem, Netherlands

! www.eneco.nl

Profile

Energy service company 9 Multi-Family Houses,382 dwellings2,925 m2 flat-plate collec-tors (gross area), on roof 1,433,000 kWh/a of solarheat

Best Practice 14

Schalkwijk – Multi-Family House

MotivationThe housing corporation originally planned toinstall individual combined gas-fired boilersfor space heating and hot water. This would,however, have consumed scarce living space. Asustainable, central heating system thereforeappeared to be a good alternative. Both thehousing corporation and the local governmentsupported this solution and initiated a co-ope-rative venture with the utility company.

Haarlem

Facts in briefYear of construction of CSTS 2002Aperture area of collectors 2,850 m2

Thermal output 1,995 kWth

Collector yield approx. 502 kWh/(m2 ·a)Total cost of solar heating/hot water system 1,825,000 €Subsidies 35 %CO2-emissions avoided n/aReduction of final energy 4,989,000 kWh/aReplaced energy source District Heating

(Natural Gas)

Heat pump

Aquifer

No.

For further information, please refer to www.solarge.org

collector area per apartment: 7.5 m2

investment costs per apartment:* 4,777 €Solar fraction of global heat demand:** 67 %

* without consideration of subsidies** estimated (due to the seasonal aquifer

storage this solar plant supply that highsolar fraction)

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Installation of pre-assembled flatplatecollector structuresfor 382 dwellings inHaarlem

Technical DescriptionNine 40-year old blocks with 382 apartmentswere retrofitted and equipped with solar energy. The system consists of 2,850 m2 glass-covered solar flat collectors, short-term heatstorage, aquifer seasonal heat storage, heatpumps and boilers for peak demand. The energy savings, according to the design,amount to 70 %.■ operation mode: low flow■ type of hot water heating: central ■ type of space heating: central per block■ solar buffer storage: 9 x 9.5 m3

FinancingEneco Energie is the investor and CSTS systemowner. Eneco Energie sells the heat and hotwater to the apartment owners. Grants cover35 % of the overall investment. The net presentvalue of the avoided exploitation of a conven-tional installation, totalling EUR 182,000 waspaid by the housing association to EnecoEnergie.

Comments■ “In the long term, the future

of an energy supplier willdepend on its innovativepower choices: Innovationmeets our goals of socialresponsibility and enables thelong-term continuity of ourbusiness. These are the dri-vers for developing the rene-wable energy market. In thepast 10 years, Eneco Energiehas carried out more than 50 large-scale solar thermalsystems in the housing sec-tor. An efficient organisationthat can initiate, implementand operate large-scale solarthermal systems has beenbuilt. The 2 MW project ispart of the continuous inno-vation process that we aimfor. We intend to remain amarket leader for the imple-mentation of large-scale solar thermal systems in the housing sector.”

hot water + space heatingk apartment buildingsD

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Contactu Die Fabrik

Schlesische Str. 1810997 Berlin, Germany

kh Georg Krug

1 +49 30 6118254

I +49 30 6189974

! [email protected]

Profile

Private ownership Hotel, 120 beds 27 m2 vacuum tube col-lectors (gross area), on a flat roof 16,000 kWh/a of solar heat

Best Practice 15

Die Fabrik – Hotel

MotivationThe hotel, ”Die Fabrik”, is located in a formerindustrial building, where telephones wereonce produced. In 1994, when the building was remodelled as a hotel, rooms, bathrooms,a large lobby and a restaurant were created.The 50-year-old, out-of-date steam heatingsystem was not sufficient to maintain anacceptable level of comfort for the guests.Therefore, in 1999, the whole building wasenergetically modernised, including the boilers(switched to natural gas) and the heatingsystem (pipes, radiators). The installation of a

Berlin

Facts in briefYear of construction of CSTS 1999Aperture area of collectors 23 m2

Thermal output 16 kWth

Collector yield approx. 695 kWh/(m2 ·a)Total cost of solar heating/hot water system 40,000 €Subsidies 33 %CO2-emissions avoided 4.8 t/aReduction of final energy 35,000 kWh/aReplaced energy source Natural gas

No.

For further information, please refer to www.solarge.org

collector area per bed: 0.2 m2

investment costsper bed:* 333 €Solar fraction of global heat demand:** 7.1 %

* without consideration of subsidies** calculated

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FinancingThe solar thermal system was installed as akey element in the energetic modernisation ofthe hotel. The subsidies granted from the UFPProgram amounted to one third of the totalcosts (planning and installation). Thanks to theresulting high level of energy savings, particu-larly through the reduction of system lossesand assistance from solar thermal energy, aswell as the grants, the entire project wasfavourably profitable. As early as 1999 the ove-rall measure was almost profitable.

solar thermal collector for hot-water genera-tion and heating support was planned. Theentire renovation was substantially funded bythe UFP Environmental Funding Program ofBerlin.

Technical Description27 m2 vacuum tube collectors were installedflush to the flat roof of the hotel's rear buil-ding - without a mounting system. This solu-tion was chosen because of static reasons. Thehigh-performance collectors are connectedwith an efficient buffer storage system, mea-suring 2.25 m3, in the heating centre. Integrat-ed into the heating system, with a shared con-trol unit, the system covers 8 % of the energyneeds for heating and 43 % of the energyneeds for hot water generation (simulationresult).■ operation mode: low flow■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 2.25 m3

Comments■ “Within the scope of the

changed utilisation of thebuilding from industrial tohotel use, the solar thermalsystem was, and is, a highlyvalued part of the building'sconcept. The energy createdby the solar thermal systemprovides economic relief fromthe energy costs which isbecoming even more im-portant due to the currentincrease in energy prices.In addition, the image of “DieFabrik” is enhanced by theinnovative energy concept - afactor that is well received bythe guests.“

hot water + space heatingk hotelsE

Vacuum-tube col-lectors and displaypanel of the hotel“Die Fabrik”

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Contactu Dom paraplegikov d.o.o.

Štihova 14Ljubljana, Slovenia

kh Mr Janez Trdina

1 +386 1 4327138

I +386 1 4327252

! [email protected]

Profile

Private ownershipHotel, Sports building Hospital, 120 beds78 m2 flat plate collectors(gross area), on roof

Best Practice 16

DomParaplegikov – Hotel

MotivationThe health resort is designed for the physicallyhandicapped and offers them an option forhealthy and relaxing vacations. Disabled sport-smen can use the resort for preparing for sportscompetitions. This health resort is meant tobecome an incubator of ideas for all areas oflife of a physically disabled person. The solarsystem was completed in 2007. One of the firstresults of the SOLARGE project was the factthat we have installed calorimeters in the solarsystem pipeline and connected to the BMS(Building Management System).

Pacug

Facts in briefYear of construction of CSTS 2006Aperture area of collectors 72 m2

Thermal output 50 kWth

Collector yield n/a Total cost of solar heating/hot water system 34,317 €Subsidies 90 %CO2-emissions avoided n/aReduction of final energy n/aReplaced energy source Liquid gas

No.

For further information, please refer to www.solarge.org

collector area per user: 0.6 m2

investment costsper user:* 286 €Solar fraction of global heat demand: n/a

* i without consideration of subsidies

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Flatplate collectorson roof and Solarheat tanks

Technical DescriptionTwo liquid-gas, high-temperature boilers wereinstalled for space and tap water heating.Rooms are heated by radiators with thermo-static valves. Some parts of the building – the-rapy, congress room, and restaurant – have air-conditioning systems. Hot tap water as well assea water is pumped into the pool and prehea-ted by the solar system. The system consists oftwo sections of solar collectors with a totalarea of 72 m2. Water heated by the solar collec-tors flows through a tube heat exchanger,integrated in the heat storage tank (2 m3) forhot tap water generation and heating supportor through a plate heat exchanger for the pre-heating of sea water for the pool.■ operation mode: high flow■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 4 m3

FinancingThe Health Resort Centre in Pacug was plan-ned in such a way that quality was given firstpriority. The decision for a solar system wasmade a few years ago. This was a very gooddecision in hindsight, because the price ofliquid-gas has increased. The institution, whichfinanced the construction of the health resort,supported the decision. In the end, the priceper square metre of solar collectors was a littlehigher than expected.

Comments■ „We are aware of the gro-

wing importance of energyconservation and thereforethe decision to use as manyrenewable energy sources aspossible was easy. Withregard to the fact that ourbuilding lies in the sunniestarea of Slovenia – 2,292 hoursof sunshine per year – thesolar system was a logicalchoice. One of the first resultsof the SOLARGE project willbe the installation of calori-meters in the solar systemand their connection to thebuilding's managementsystem.“

hot water + space heatingk hotelsE

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Contactu Hôtel du Golf de Valescure

Avenue Paul l'Hermite83700 Saint Raphaël, France

kh M. de Gaudemont

1 +33 494 528500

I +33 494 824188

! [email protected]

Profile

Private ownershipHotel, 40 rooms90 m2 flat-plate collectors (aperture area), roof inte-gration58,000 kWh/a of solar heat

Best Practice 17

Hotel du Golf de Valescure –Hotel

MotivationThe hotel owner made the choice to respondto the environmental concerns of his hotelclientele, especially those from Northern-Europe. Tour operators are becoming more and more sensitive to these concerns as well.This hotel has had a CSTS since its opening in 1981.In a sustainable development approach, theowner decided to totally restore the CSTS fortap water and swimming pool heating. Therestoration enabled the total collector surfacearea to be reduced due to the significant deve-

St. Raphael

Facts in briefYear of construction of CSTS 2003Aperture area of collectors 90 m2

Thermal output 63 kWth

Collector yield approx. 659 kWh/(m2 ·a)Total cost of solar heating/hot water system 101,000 €Subsidies 48 %CO2-emissions avoided 19 t/aReduction of final energy 68,000 kWh/aReplaced energy source Electricity

No.

For further information, please refer to www.solarge.org

collector area per room: 2.3 m2

investment costsper room:* 2,525 €Solar fraction of global heat demand: n/a

* without consideration of subsidies

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lopment in collector efficiency over the past20 years.

Technical DescriptionThe CSTS was installed in 2003 and is compo-sed of 90 m2 flat-plate collectors integratedinto the roof with a south-eastern orientationof 20° and an inclination of 30°. Hot tap wateris stored in two solar tanks measuring 2500 land 2000 l, and a back-up storage tank measu-ring 1500 l. The CSTS was designed to supplyhot water for use in the hotel and the swim-ming pool.■ operation mode: variable■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 4.5 m3

FinancingThe CSTS cost totalled EUR 101,000 includingVAT with EUR 40,000 for the collector system,38,000 EUR for solar installation and EUR8,400 for planning and development. The project was subsidised at 48 % with EUR 48,174provided by the ADEME and the regional coun-cil of PACA.

Comments■ „I have wanted to involve the

hotel in a globally oriented,environmental approach thatintegrates water, energy andwaste management. To fol-low through with such anapproach is to take the leadover other hotels and thus tosecure a competitive advan-tage.“

hot water + space heatingk hotelsE

Roof integrated flateplate collectors ofthe Hotel du Golf deValescure

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Contactu ADAPEI

Quai les Gondonnets84400 Saignon, France

kh Mr Bouillet

1 +33 4 90740-043

I +34 93 2051586

! +33 4 90740-919

Profile

Social AssociationRetirement home, 21 beds56 m2 flat plate collectors(gross area), on the ground33,000 kWh/a of solar heat

Best Practice 18

Saignon Elderly House – Retirement home

MotivationThis specialised retirement centre in Saignon,intended for physically handicapped persons,is an example of a high-quality, environmen-tally oriented design process. This building wasdesigned according to bioclimatic structure,with special regard to solar design, and has aone-floor construction to accommodate theneeds of handicapped persons.

Saignon

Facts in briefYear of construction of CSTS 2002Aperture area of collectors 50 m2

Thermal output 35 kWth

Collector yield approx. 660 kWh/(m2 ·a)Total cost of solar heating/hot water system 57,600 €Subsidies 82 %CO2-emissions avoided 10.5 t/aReduction of final energy 49,700 kWh/aReplaced energy source Heating oil and

electricity

No.

For further information, please refer to www.solarge.org

collector area per room: 5 m2

investment costsper room:* 5,750 €Solar fraction of global heat demand: n/a

* without consideration of subsidies

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Rear side of the

building and flat

plate collectors

located near the

building on an

embankment

Technical DescriptionThe installation has been in service since 2002and is composed of 50 m2 flat-plate collectorslocated on an embankment near the buildingfacing south and with an inclination of 30°.The hot water is stored in a solar tank measu-ring 3,000 litres and has two back-up tanksmeasuring 1,500 and 1,000 litres.■ operation mode: n/a■ type of hot water heating: central ■ type of space heating: central■ buffer storage: 3 m3

FinancingThe 50 m2 solar installation of the retirementcentre in Saignon cost EUR 57,600 includingengineering and VAT and was subsidised withEUR 45,000 from free financing (state regionalcouncil and ADEME).

Comments■ This building was designed

with an environmental andbioclimatic approach and,logically, a CSTS was integra-ted for hot tap water produc-tion.An all-round project was car-ried out using an architectu-ral contest and a commissionwas created to finalise pro-ject details and to draft acontract to choose the con-tracting companies.The CSTS runs perfectly andprovides 60 % of the hot tapwater needs of the building,as determined by the feasi-bility study.

hot water + space heatingk social buildingsF

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Best Practice 19

Contactu Asilo dei Vecchi

via Carlo Alberto Tron, 27 San Germano Chisone, Italy

kh Giorgio Baret

1 +39 0121 58855

! [email protected]

Profile

Waldensian ChurchRetirement home,98 inhabitants78 m2 vacuum tube collectors (gross area),on roof54,000 kWh/a of solar heat

Asilo dei Vecchi – Retirement home

MotivationThe building's managers started the projectand were encouraged by a promotion programfrom the province of Turin which providedexpert technical assistance and economic sub-sidies."Our local promotion programs for renewableenergy sources are based on a complete sup-port structure for the investors. It is essentialto create subsidy schemes and inform the par-ties involved of their existence. Furthermore,technicians must be trained and supported,

San Germano Chisone

Facts in briefYear of construction of CSTS 2004Aperture area of collectors 70 m2

Thermal output 49 kWth

Collector yield 623 kWh/(m2 ·a)Total cost of solar thermal system 72,850 €Subsidies 40 %CO2-emissions avoided 19.5 t CO2 per yearReduction of final energy 94,290 kWh/aReplaced energy source Natural gas

No.

For further information, please refer to www.solarge.org

collector area per apartment: 0.7 m2

investment costsper apartment:* 743 €Solar fraction of global heat demand:** 10.8 %

* without consideration of subsidies** calculated

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especially during system design and the instal-lation. Finally, an adequate monitoring planshould track the operation of each system."

Technical DescriptionThe central heating system provides heat forhot tap water and space heating.Together with the solar system, a new gas condensing boiler was installed. The existingboiler is used to cover the peak loads.■ operation mode: low flow■ type of hot water heating: central ■ type of space heating: central■ solar buffer storage: 3 m3

FinancingThe solar thermal system in San Germano isone of three systems financed by the provinceof Turin as part of a demonstration program.The province of Turin subsidised 40 % of thesystem costs.

Comments■ The collector was designed

for hot water preparation butalso supports the heatingsystem because of the exi-sting hydraulic scheme. Thesystem is running properlyand is monitored monthly.Performance data for thesystem is available on theprovince government's web-site.

hot water + space heatingk social buildingsF

Vacuum-tube col-lectors on the roofof the retirementhome in SanGermano Chisone

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Contactu Marstal District Heating

Jagtvej 25960 Marstal, Denmark

kh Leo Holm Petersen

1 +45 62 53 15 64

I +45 62 53 15 64

! [email protected]

Profile

Private companyvarious, 1,420 users19,000 m2 various types of collectors (gross area),ground mounted8,824,000 kWh/a outputof solar heat

Best Practice 20

MarstalDistrict Heating

MotivationThe plant is part of the national strategy todevelop large-scale solar heating systems fordistrict heating and for seasonal heat storage.

Marstal

Facts in briefYear of construction of CSTS 1996 – 2003Gross area of collectors 19,000 m2

Thermal output 12,850 kWth

Collector yield approx. 464 kWh/(m2 ·a)Total cost of solar heating/hot water system 7,333,000 €Financing 40 % self-financing

23 % loans, 37 % subsidiesCO2-emissions avoided 2,500 t/aReduction of final energy 7,792,000 kWh/aReplaced energy source Natural gas

No.

For further information, please refer to www.solarge.org

collector area per apartment: 26.4 m2

investment costsper apartment:* 10,476 €Solar fraction of global heat demand:** 46.4 %

* without consideration of subsidies** monitored

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Technical Description■ operation mode: variable■ type of hot water heating: decentralised ■ type of space heating: central■ seasonal storage: 14,000 m3

FinancingThe entire system was built in a number ofphases. In general, 30% of the grants camefrom the Danish Energy Agency. The latestaddition was partly subsidised by the EU.

Comments■ „The project in Marstal has,

together with other projectson Aeroe, provided a basis fora new industry on the smallisland of Aeroe. Main activi-ties include the production of large solar collectors andheat exchanger units.”

other applicationsG

Aerial photo ofMarstal and a partof the collectorfield

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Contactu Špan d.o.o.

Tržaška 5371351 Brezovica pri LjubljaniSlovenia

kh Mr Ludvik Špan

1 +386 1 365 8110

I +386 1 365 8122

! [email protected]

Profile

Family company Car Centre 43 m2 vacuum tube col-lectors (gross area),on a flat roof18,890 kWh/a of solar heat

Best Practice 21

Techcentre ŠPAN –Car Centre

Motivation„Špan Company has been constantly growingfor 25 years now, and has always been con-cerned about protecting the environment.Our experiences have been so positive that wesuggest everyone, especially large consumersof hot tap water and service water, to install asolar system. Unfortunately, in 2005, there wereno governmental subsidies available, as hadbeen the case before, so we had to build thesystem exclusively with our own financing.“

Brezovica pri Ljubljani

Facts in briefYear of construction of CSTS 2005Aperture area of collectors 28 m2

Thermal output 20 kWth

Collector output approx. 669 kWh/(m2 ·a)Total cost of solar heating/hot water system 45,800 €Subsidies 0 %CO2-emissions avoided 5.4 t/aReduction of final energy 28,730 kWh/aReplaced energy source Liquid gas

Restaurantund garage

No.

For further information, please refer to www.solarge.org

collector area per 100 m2 heated area: 0.9 m2

investment costs per 100 m2 heated area:* 1,526 €Solar fraction of global heat demand: n/a

* without consideration of subsidies

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Technical DescriptionThe solar system that is used for hot waterpreparation, the heating of a coffeehouse andheating the service water in the carwash, con-sists of ten units of vacuum solar collectorswith heat pipes (30 pipes to one unit). Theunits are connected in series; the flow of heattransfer fluid is variable and depends on thetemperature of the collectors' output.■ operation mode: variable■ type of hot water heating: central ■ type of space heating: central■ buffer storage: 1.5 m3

FinancingThe system was paid for by the owner. Thefinal price of the system was EUR 1,053 per m2

of solar collector area. Only one third of thisprice was the cost of the solar collectors dueto the high quality of installed elements andrather complex configuration of the system.Unfortunately, in the year 2005, subsidies forthe financing of solar systems were not availa-ble, as was the case in the previous year.

Comments■ According to observations of

system performance madesince the system went intooperation in October 2005,the system is very reliabledue to the combination ofantifreeze, drain-back tech-nology and overheating protection. The prioritising of heat storage and variableflow operation contributes to the high solar collectoryield.

other applicationsG

Vacuum-tube col-lectors and solarstorage tank ofthe car centreŠpan

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People will expect higher standards of well-being in both residential buildings and work-place environments, increasing the need for airconditioning and hence cooling, especially inSouthern Europe. Solar thermal energy will beincreasingly important here, too, not leastbecause collectors provide shade for the buil-ding’s envelope and so reduce the need forcooling.

Besides their use in residential buildings,hotels and public facilities, solar thermalsystems will become increasingly widespreadin industrial applications. In the none-too-distant future, solar collectors will be able tosupply process heat at temperatures of morethan 250 °C. Laundries, electroplating opera-tions and drying plants (for example in thecoatings industry) will increasingly be oper-ated with the aid of solar thermal energy.

Outlook

Outlook

The best practice examples from the SOLARGEproject provide a compelling demonstration ofthe advanced state of technology in large solarthermal systems.

Research and development continue, however,as do market trends, and will further accelera-te the adoption of solar thermal energy inEurope.

For example, industry and researchers areworking on the development of storage unitswith greater storage densities and more com-pact dimensions. By 2030, buildings supplied100% by solar energy could be standard inEurope.

Architecturally attractive integration of collec-tors into the building envelope will also be-come increasingly widespread. No longer justheat generators, collectors will become part ofthe roof cladding and a functional design ele-ment in facades.

Driven by the climate change debate andrising oil prices, it will become far more com-mon to design buildings from a total energyconsumption standpoint. Solar thermal energywill play a major role here.

Fresnel collector for a solar cooling system in Bergamo, Italy Photo: PSE

Window integrated collector Photo: Robin Sun

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Facade integrated collectorsPhoto: GREENoneTEC / ESTIF

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Published by

Bundesverband Solarwirtschaft e.V.EnergieforumStralauer Platz 3410243 Berlin/Germany

Compiled and market written by

BSW BundesverbandSolarwirtschaft e.V. (Germany)

in collaboration with the SOLARGE partners

Design

triolog Freiburg (Germany)

SOLARGE project coordinator

target GmbH (Germany)

Project partners

ADEME – Agence de l’Environne-ment et de la Maîtrise de l’Energie(France)

Ambiente Italia srl (Italy)

Berliner Energieagentur GmbH(Germany)

Bundesverband Solarwirtschaft e. V.(Germany)

Ecofys Netherlands BV(Netherlands)

Ecofys S. L. (Spain)

ENERPLAN – AssociationProfessionnelle de l'Energie Solaire(France)

ESTIF – European Solar ThermalIndustry Federation (Belgium)

Rambøll Danmark A/S (Denmark)

University of Ljubljana – Faculty ofMechanical Engineering (Slovenia)

Publisher’s Information

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www.solarge.org

supported byThe sole responsibilityfor the content of thispublication lies with the authors. It does not necessarily reflectthe opinion of theEuropean Communities.The European Commis-sion is not responsiblefor any use that may bemade of the informa-tion contained therein.


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