Stockport Low Carbon Policy Implementation Evidence Study · 2018-02-27 · CfSH Code for...

3rd

August 2011

Stockport Low Carbon Policy Implementation Evidence Study

Elisabeth, Houldsworth and Broadstone Mills, Reddish

Prepared by: .............................................. Checked by: ...................................................... Alex Trebowicz Ewan Jones Consultant Engineer Senior Engineer Approved by: .............................................. Emma Gardner Associate Director Stockport Low Carbon Policy Implementation Evidence Study

Rev Comments Checked Approved Date No by by

Draft for client comment EJ EG 07/07/11

1 Issue response to client comments EJ EG 22/07/11 2 Final issue EJ EG 03/08/11

1 New York Street, Manchester, M1 4HD 0161 601 1700 http://www.aecom.com Date Created 3rd August 2011

This document is confidential and the copyright of AECOM Limited. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited.

http:http://www.aecom.com

Table of Contents

Glossary....................................................................................................................................... 1

Executive Summary .................................................................................................................... 2

1 Introduction ....................................................................................................................... 7

2 Costing carbon reductions ............................................................................................ 10

3 District heating feasibility .............................................................................................. 27

4 District heating feasibility implementation guidance .................................................. 64

5 Conclusions .................................................................................................................... 79

Appendix A – Note on zero carbon and Building Regulations targets................................. 80

Appendix B – FIT / RHI summary tables.................................................................................. 85

Appendix C – Site development information .......................................................................... 87

1 AECOM Stockport Low Carbon Policy Implementation Evidence Study

Glossary

AGMA Association of Greater Manchester Authorities

ALMO Arms Length Management Organisation

APEE Advanced practice energy efficiency (improvements to buildings)

BREEAM Building Research Establishment Environmental Assessment Methodology

CESP Community Energy Saving Programme

CfSH Code for Sustainable Homes

CHP Combined heat and power

CIL Community Infrastructure Levy

ECO Eco-innovation funding

ESCo Energy Services Company

FIT Feed-In-Tariff

GPEE Good practice energy efficiency (improvements to buildings)

GSHP Ground source heat pump

HCS Stockport Housing Condition Survey, Michael Howard Associates Ltd, 2008/9

HVAC Heating, Ventilating and Air Conditioning

LDF Local Development Framework

LZC Low or Zero Carbon technology

MBC Metropolitan Borough Council

PFI Private Finance Initiative

PV Photovoltaic cells

RHI Renewable Heat Incentive

SAP Standard Assessment Procedure for dwellings in line with Building Regulations

SHLAA Strategic Housing Land Availability Assessment

SHW Solar hot water (or ‘solar water heating’)

SMBC Stockport Metropolitan Borough Council

SPV Special Purpose Vehicle


Executive Summary

This study has considered how recently adopted Stockport MBC Core Strategy policies regarding energy and carbon (SD-1 to SD-6) will be implemented as development of sites in/around Stockport comes forward, and the role that SMBC may play in facilitating this implementation. These policies deal with the identification and enabling of opportunities relating to energy efficiency improvements, development of decentralised energy networks and generation of energy through low or zero carbon technologies (including renewable energy technologies).

The study has been broken down into the following discreet tasks:

• Task 1 – An assessment of capital and carbon costs for a variety of low carbon and renewable technologies for a range of new build building types (domestic and non-domestic)

• Task 2 – An assessment of a series of domestic retrofit energy efficiency improvement measures for three residential dwelling types

• Task 3 – An overview of the key issues needed to be considered when carrying out a feasibility study for district heating, followed by a high-level feasibility study of five potential development opportunity sites in/around Stockport focusing on an assessment of the technical feasibility and financial viability of each site in relation to either development of, or connection to, a heat network.

• Task 4 – Production of a set of guidance notes that outlines a checklist of considerations for developers when considering the requirements of policy SD-4.

The key output of Task 1 was a series of graphs illustrating the costs associated with achieving a range of carbon reduction targets across a series of renewable technologies/combinations of technologies. This was carried out for a series of domestic (apartment, detached, townhouse, care home) and non-domestic (office, hotel, shopping centre, supermarket) building types. These graphs are show in Sections 2.1.1 to 2.1.4, and Sections 2.1.6 to 2.1.9. A series of high level comments and conclusions are provided as summary conclusions.

A series of financial and carbon costs for domestic retrofit improvements have been developed for a range of improvement measures, including loft insulation, cavity wall/solid wall insulation, upgrading of windows, PV/SHW retrofit.

This cost and carbon data has been quantified in terms of a cost per tonne of carbon saved over a 25 year period – this period is considered roughly equivalent to the lifetime of most of the retrofit measures.


The calculation is useful for comparing the cost-effectiveness of different measures, and allows for each measure to be compared on a relative scale. These approximate costs are shown below.

Loft insulation

Cavity wall

insulation

Solid wall insulation

Window upgrades

PV retrofit

SHW retrofit

Approximate 25 year cost of carbon (£/tonne)

£107 £28 £269 £371 £163 £830

This exercise has been carried out to inform SMBC’s approach to the Community Infrastructure Levy (CIL), which allows local authorities to choose to levy new developments in their areas. The money brought in by the CIL can be used to support further development by funding local improvements, which can include energy efficiency improvements or infrastructure development / upgrades.

The methodology/considerations for district heating feasibility study are presented in Section 3.1 of the report, and include a breakdown of the following approach steps:

• Objectives

• Understanding the proposed development

• Understanding the existing site and surrounding buildings

• Assessing appropriate technologies

• Assessing technical feasibility and financial viability

The conclusions (opportunities and constraints) of the five feasibility studies are outlined below.

Site Opportunities Constraints

1 – Man Diesel

New build housing density can significantly influence feasibility.

Hospital anchor load potential.

Surrounding land-owners/occupiers keen to engage.

Proximity to future Stockport TC network expansion.

Connection issues across train lines (for initial network development and future expansion).

Potential cost increase in developing across train lines.

Surrounding existing residential low density.

2 – Cheadle Royal

Several good anchor loads in close proximity.

Opportunities for developing heating and cooling network capability.

Microgeneration opportunities to supplement heat network development.

Further information required on heating systems in anchor load buildings.


Site Opportunities Constraints

3 – Brinnington

High-rise buildings good as anchor loads.

Heat connections across new development/existing high-rise to drive network development in wider area.

Heat/energy sharing potential across M60 to industrial estate.

Potential waste-to-energy opportunities (local GM waste sites).

Low density of residential areas in Brinnington.

Potential high cost of heat connection across M60.

4 – Goyt Mill

Good potential for energy efficiency improvements and microgeneration technologies.

Financial benefits from on-site electricity generation.

On-site energy sharing potential with adjacent industrial units.

Site could be developed as an anchor load.

Canal cooling potential.

Site is reasonably isolated – low potential of surrounding buildings for heat sharing.

High level of improvements required throughout building.

Refurbishment may require funding support.

5 – Broadstone Mill

Heat sharing with mills to north of site.

On-site energy sharing potential with adjacent industrial units.

Good potential for energy efficiency improvements and microgeneration.

Financial benefits from on-site electricity generation.

Railway line potentially limits heat connections to east.

Surrounding area industrial/low density residential.

The final section of the report provides a series of guidance notes relating to high-level district heating feasibility advice. The notes have been presented as a checklist of opportunities that should be explored when initially assessing the feasibility and viability of a development site.

The guidance notes should be read in the context of demonstrating consideration of the issues outlined in Core Strategy Policy SD-4: District Heating (Network Development Areas).

The guidance has been considered in terms of the different development site types listed in Table 10, so that considerations that relate to specific site types (for example, mill sites, or commercial-led development) are identified after the general guidelines. This methodology is designed to provide simple and concise guidelines of both more general feasibility issues (which can be applied to any site type) and those that are more specialised.

In addition Stockport Council provide a Sustainable Design & Construction Supplementary Planning Document written as a ‘how to’ manual for developers and planners. This document mirrors the topic structure of design standards such as BREEAM and Code for Sustainable


Homes. As such it contains information and hyperlinks to resources on topics such as; Site Layout & Building Design; Materials; and Energy.

The following steps have been described as part of the general guidance, and a reference checklist is provided in Figure 8.

• Consider drivers for district heating development 1

• Define objectives 2

• Collect information relating to development proposals, and development site 3

• Carry out intitial technology feasibility study 4

• Consider role of microgeneration technologies 5

• Carry out full feasibility study

• Propose solutions, OR

• Demonstrate measures for future-proofing

In addition to the above steps, consideration has been given to future-proofing potential relating to sites below the threshold given in Core Policy SD-4. The guidance on this matter suggests a hierarchical approach is taken forward, whereby the level of future-proofing/connectivity measures required is determined based upon both the scale of the heat demand at the proposed development, and the location of the proposed development relative to proposed future network


expansion routes. In these cases, a dialogue should be carried out between the developer and SMBC to determine a clear idea of heat networks planned in/around Stockport, and where these networks are likely to develop (and when). A summary table of this approach is shown below, with a more detailed description of proposed methodology provided in Section 4.

Future

connectivity

potential

SD-4 ‘below threshold’ future-proofing measures required

Capital

cost

increase

1 – No

connectivity

Residential – No measures required

Commercial – No measures required Zero

2 – Low

connectivity

Residential – wet heating system installed, space allowance

made in risers and across floor plates/roof voids to accommodate

hot water system, space allowance in plant for heat exchangers,

trench installed from building to where future district heating

network is likely to occur

Commercial – wet heating system installed, capped off headers

on flow / return pipe-work, plastic sleeves (or removable panel)

through foundations to allow future connection

Low

3 – Medium

connectivity

Residential – Installation of communal heating system, space

allowance for heat exchanger unit in plant room, trench installed

from building to where future district heating network is likely to

occur

Commercial – capped off headers on flow / return pipe-work,

plastic sleeves (or removable panel) through foundations to allow

future connection, design of future energy centre as close to

proposed future network route as possible, use of CHP if

appropriate

Medium

4 – High

connectivity

Installation of district heating pipe-work across site, installation of

single energy centre (where multiple buildings / apartment blocks

occur), energy centre location close to proposed future network

route will occur

High

7

1

AECOM Stockport Low Carbon Policy Implementation Evidence Study

Introduction

Stockport Metropolitan Borough Council (SMBC) has recently commissioned a number of energy and carbon studies relating to development of a Core Strategy document. These studies and reports have informed several of the key policies adopted. Published in March 2011, the Core Strategy DPD inputs into the Local Development Framework (LDF), and guides development in Stockport going forward.

Core Policy CS1 feeds into the overarching aim of making Stockport a more sustainable place and ensuring that new development plays a role in contributing to low carbon infrastructure development and carbon reductions. This sets out a number of Development Management Policies designed to ensure all development addresses carbon emissions reductions.

Key to this is identification and enabling of opportunities relating to energy efficiency improvements, development of decentralised energy networks and generation of energy through low or zero carbon technologies (including renewable energy technologies). Table 1 below provides a summary of the key policies relevant to these issues.

Development Management Policy Policy headline

SD-1 Creating sustainable communities

Encouraging developments to achieve high levels of sustainability through assessment methodologies such as CfSH and BREEAM

SD-2 Making improvements to existing dwellings

Council engagement/support used to drive forward energy efficiency improvements in existing dwellings beyond minimum Building Regulations requirements

SD-3 Delivering the energy opportunities plans - new development

Recognition of applicability of different technologies/ solutions to different areas and development types – setting of carbon reduction targets accordingly

SD-4 District Heating (Network Development Areas)

Guidance on developing or connecting to heat networks to drive forward a vision of delivering a wider strategic Stockport heat network throughout the Borough

SD-5 Community Owned Energy

Guidance on microgeneration opportunities at community level to deliver renewable energy in the Borough alongside commercial development – microgeneration to be considered as first option where feasible

SD-6 Adapting to the impacts of climate change

Guidance on how development design can influence climate change adaptation and mitigation

Table 1 – Summary of key Stockport Core Strategy policies relating to energy and carbon


Although all six policies will affect the nature of development within Stockport, the key policies referred to throughout this study are SD-2, 3, 4 and 5, with particular attention given to SD-4 (see point 4. below).

As a continuation of the work carried out to date, this study has considered how these policies will be implemented, and the role that SMBC may play in facilitating this implementation. The scope for this study is outlined below:

1. Cost assessment of renewable technologies (Chapter 2)

An assessment of capital and carbon costs for a variety of low carbon and renewable technologies for a range of new build building types. The following building types have been considered as those most applicable to expected future development in Stockport:

• Residential (apartment / townhouse / detached)

• Care home

• Office

• Shopping centre

• Supermarket

• Hotel

The output of this task is a series of graphs that relate the capital costs and potential carbon reductions to the Building Regulations carbon reduction targets.

2. Development of costs for domestic retrofit improvement (Chapter 2)

A series of domestic retrofit energy efficiency improvement measures have been considered for the three residential dwelling types considered above. These measures are:

• Loft insulation

• Cavity wall / solid wall insulation

• Upgrading of windows

• PV / SHW retrofit

• District heating network connection retrofit

The measures above have been considered in relation to work carried out in Stockport related to housing, including the 2008/9 House Condition Survey, the draft Greater Manchester Low Carbon Economic Area Retrofit Standards document and high-level data on recent improvements to the housing stock throughout Stockport.

An indicative assessment of the costs of these measures (in terms of capital required and carbon savings) has been provided (see Table 2) to quantify the potential scale of investment required and to inform future development of Community Infrastructure Levy (CIL) charging.


3. Outline district heating feasibility studies (Chapter 3)

This section of the report provides an overview of the key issues needed to be considered when carrying out a feasibility study for district heating. Further to this a high-level feasibility study has been carried out for five potential development opportunity sites. The focus of this task has been an assessment of the technical feasibility and financial viability of each site in relation to either development of, or connection to, a heat network.

The study for each site has focused on design principles and viability issues rather than specific design details. Commentary has also been provided on the sensitivity of a range of potential options where appropriate, relating to factors such as fuel prices, fuel availability etc. In cases where heat networks are deemed to be not feasible initially (or at all), a series of measures for future-proofing sites by considering future connection to heat networks or alternative ways of generating low carbon energy have been suggested.

Consideration has also been given to planning and co-ordination issues, and a series of financing and delivery options (including mechanisms for increasing financial viability).

4. District heating guidance (Chapter 4)

A set of guidance notes has been produced that outlines a checklist of considerations for developers when considering the requirements of policy SD-4. This policy is designed to help realise SMBC’s ambition to develop strategic heat networks throughout the Borough and maximise the opportunities for inter-connecting a series of smaller networks into a larger network through which energy sharing on a larger scale can be achieved.

The guidance notes specifically address the key issues that define the feasibility and viability of heat networks, including (but not limited to):

• building density (including consideration of vacant sites),

• presence of anchor loads,

• connections to existing buildings (and expansion beyond proposed development boundaries),

• mix of building types,

• technology types and fuel types.

Specific guidance is also provided that relates to developments that fall below the threshold described in SD-4. It is intended that these notes will be of use to developers as a means of understanding the ‘why’ and ‘how’ of demonstrating compliance with policy SD-4.

10

2


Costing carbon reductions

2.1 Cost assessment of renewable technologies for new developments

For this task, a range of renewable technology costs have been developed for a series of new-build domestic and non-domestic building types. It has built on the analysis carried out as part of Stockport Climate Change and Energy Evidence Base Study (specifically Figure 37, which illustrates the varying costs of achieving different Code for Sustainable Homes (CfSH) levels using different technologies for a dwelling). The building types considered are:

• Domestic (apartment, townhouse, detached house, plus a care home)

• Non-domestic (office, shopping centre, supermarket, hotel)

The costing exercise carried out has been based on established cost modelling data carried out by AECOM and Cyril Sweet as part of the domestic and non-domestic Zero Carbon Consultation documents for National Government.

The assessment has taken into account regional variations in costs of both technology capital costs and labour costs. Where appropriate, an adjustment has been made where significant changes in capital cost have occurred in recent years (for example, solar photovoltaics (PV) costs are considered to have reduced significantly since the first Zero Carbon Consultation documents were published).

The output of this task is a series of graphs, one for each building type, that illustrate the relationship between carbon savings and capital costs for a series of technologies / technology mixes. The technologies have been considered in terms of meeting carbon reduction targets that follow those outlined for Building Regulations (i.e. 25%, 44% etc.). A technical note on recent important changes to the definition of zero carbon is provided in Appendix A.

Most of the technologies considered are ‘on-site’, and so different technologies have been considered for different building types as appropriate. For example, residential apartments are limited as to roof area available for PV or solar hot water panels (SHW), heat-led commercial buildings such as hotels are likely to achieve more significant reductions in carbon through heat technologies compared to microgeneration technologies.

A brief commentary has been provided for both the domestic and the non-domestic outputs.


2.1.1 Residential apartment – carbon and cost summary for renewable energy generation

options and energy efficiency measures (floor area circa 59m2)

180% £30,000

160%

Carb

on

em

issio

ns r

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ucti

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(%

)

140%

120%

100%

80%

60%

40%

20%

0%

£25,000

£20,000

£15,000

£10,000

£5,000

£0

Ind

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ital

co

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(£)

25% reduction target 44% reduction target 70% reduction target

100% reduction target 100% + reduction target Additional capital cost

Graph glossary

GPEE/APEE Good/Advanced practice energy efficiency improvements

SHW Solar hot water

PV Photovoltaic panels

GCHP/BCHP Gas/biomass combined heat and power

BH Biomass heating


W Wind turbine (on-site)

BTGEN Biomass tri-generation (combined cooling heat and power)

DH District heating


2.1.2 Residential townhouse – carbon and cost summary for renewable energy generation


180% £30,000

Carb

on

em

issio

ns r

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ucti

on

(%

)

160%

140%

120%

100%

80%

60%

40%

20%

0%

£25,000

£20,000

£15,000

£10,000

£5,000

£0

Ind

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(£)



Graph glossary


SHW Solar hot water



BH Biomass heating




DH District heating


2.1.3 Residential detached house – carbon and cost summary for renewable energy

generation options and energy efficiency measures (floor area circa 102m2)

180% £30,000

Carb

on

em

issio

s r

ed

ucti

on

(%

)

160%

140%

120%

100%

80%

60%

40%

20%

0%

£25,000

£20,000

£15,000

£10,000

£5,000

£0

Ind

icati

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dd

itio

nal cap

ital

co

st

(£)



Graph glossary


SHW Solar hot water



BH Biomass heating




DH District heating


2.1.4 Residential care home – carbon and cost summary for renewable energy generation


180% £30,000

160%

£0

£5,000

£10,000

£15,000

£20,000

£25,000

0%

20%

40%

60%

80%

100%

120%

140%

Ad

dit

ion

al

ca

pit

al

co

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(£)

Carb

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s r

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(%

)



Graph glossary


SHW Solar hot water



BH Biomass heating




DH District heating


2.1.5 Domestic summary

Key points:

• At domestic scale a wide range of both heat and electricity generation technologies

are feasible for low carbon energy generation.

• Generally, costs for incorporating heat generation renewable technologies into

apartment-type dwellings are less costly. This is mostly due to cost savings

associated with decentralised energy systems where high dwelling densities occur.

• GSHP and wind technologies (and to a lesser extent, solar water heating) are

generally expensive at domestic scale compared to other technologies.

• Wind turbines at a domestic scale are limited in terms of carbon savings (wind speeds

in urban areas tend to be low) and cost-effectiveness (the cost per tonne of carbon

reduced). Both of these factors can be improved as the technology scale is increased

and off-site wind is considered.

• For townhouse and detached dwellings PV is feasible for achieving high carbon

savings (meeting up to a 70% reduction target) assuming that enough appropriate

roof space is available (taking into account shading, orientation, etc.).

• Biomass heating and biomass-CHP are cost-effective in terms of achieving carbon

savings and is likely to be required when meeting higher carbon reduction targets

(70% and above).

• Biomass heating/CHP and PV cells are likely to be the most cost effective on-site

technologies used to meet zero carbon / carbon neutral targets going forward. In

practice, at a domestic scale this will require some form of energy sharing network (as

opposed to individual dwelling technologies, so where apartment or care-home

dwelling exist in high densities) so that shared benefits are taken advantage of. These

benefits may include increase in energy efficiency at a larger scale, financial

economies of scale, use of a mix of technologies to meet carbon targets, influence

over the carbon associated with a large number of dwellings and potential for

incorporating future low or zero carbon technologies.

• Potential impacts of aspects of biomass fuel use such as fuel delivery frequency on

residential amenity should be considered as early as possible.

• The assessment has not directly considered financial incentive mechanisms for

renewable energy generation (i.e. FiT, RHI) as the tariffs available are heavily

dependent on the specific scale at which technologies are used. The impact of

potential Tariff income on project costs should be factored in as early as possible.

More information on technology sizes and related tariffs is given in Appendix B.


2.1.6 Office – carbon and cost summary for renewable energy generation options and energy

efficiency measures

Carb

on

em

issio

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(%

)

140%

120%

100%

80%

60%

40%

20%

0%

180% £500

£450 160%

£400

£350

£300

£250

£200

£150

£100

£50

£0

Ad

dit

ion

al

cap

ital

co

st

(£/m

2)


100% reduction target 100+% reduction target Additional capital cost (£)

Graph glossary


SHW Solar hot water



BH Biomass heating




DH District heating


2.1.7 Shopping centre – carbon and cost summary for renewable energy generation options

and energy efficiency measures

£0

£50

£100

£150

£200

£250

£300

£350

£400

£450

£500

0%

20%

40%

60%

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180%

Ind

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(£/m

2 )

Carb

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(%

)

25% reduction target 44% reduction target


100+% reduction target Additional capital cost (£)

Graph glossary


SHW Solar hot water



BH Biomass heating




DH District heating


2.1.8 Supermarket – carbon and cost summary for renewable energy generation options and

energy efficiency measures

£0

£50

£100

£150

£200

£250

£300

£350

£400

£450

£500

0%

20%

40%

60%

80%

100%

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Ind

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(£/m

2 )

Carb

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(%

)




Graph glossary


SHW Solar hot water



BH Biomass heating




DH District heating


2.1.9 Hotel – carbon and cost summary for renewable energy generation options and energy

efficiency measures

£0

£50

£100

£150

£200

£250

£300

£350

£400

£450

£500

0%

20%

40%

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(£/m

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Carb

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)




Graph glossary


SHW Solar hot water



BH Biomass heating




DH District heating


2.1.10 Non-domestic summary

Key points:

• The most appropriate technologies to be considered for each building type are largely

dependent on the usage of each building, and its fuel consumption breakdown.

• For all four building types assessed, significant carbon savings can be made through

energy efficiency improvement measures. The cost-effectiveness of these measures

is especially high for heat-led buildings, such as hotels.

• As with domestic buildings, GSHP and wind technology remain relatively expensive

technologies for use at a small/medium scale.

• The most cost effective technologies for achieving carbon savings are likely to be PV

(especially for electricity-led buildings such as supermarkets where large roof areas

are available) and biomass-fired technologies (where sufficient demand for heat

exists).

• It is recognised that meeting 70% (and higher) carbon targets for non-domestic

buildings is extremely difficult to achieve through on-site measures only. For the

building types assessed above, it is shown that these targets can be achieved only

where some form of biomass-fired network solution exists. In the case of the office,

supermarket and shopping centre this may require use of biomass-fired tri-generation

(generation of heat, cooling and power).

• In the case of the hotel, the options available for renewable technologies largely rely

on the use of heat generation such as gas-CHP, biomass heating and biomass-CHP.

These technologies complement the year-round heating demand of this type of

building, leading to improved efficiencies and cost-effectiveness.

• For non-domestic developments, Allowable Solutions are likely to be needed in the

move towards zero carbon. More information on Allowable Solutions is given in

Appendix A.

• The assessment has not directly considered financial incentive mechanisms for

renewable energy generation (i.e. FiT, RHI) as the tariffs available are heavily

dependent on the specific scale at which technologies are used. More information on

technology sizes and related tariffs is given in Appendix B. This consideration should

be taken into account as early as possible in project development.


2.2 Cost assessment of domestic energy efficiency improvement measures

For the second cost assessment task, a series of carbon costs for domestic retrofit improvements have been developed. The following measures have been considered for the three domestic dwelling types (townhouse, apartment, detached) discussed in section 2.1 above:

• Loft insulation

• Cavity wall/solid wall insulation

• Upgrading of windows

• PV retrofit

• SHW retrofit

• District heating connection retrofit

The values determined in this exercise have been developed based on previous project data carried out by AECOM. The capital costs are generally based on quotation and costing information obtained from manufacturers, and energy and carbon data is based on modelling via the Standard Assessment Procedure (SAP) for dwellings in line with Building Regulations. Where appropriate, adjustments have been made to reflect regional variation.

This task has been carried out in relation to the Housing Condition Survey (HCS, Michael Howard Associates Ltd, 2008/9), a statistical analysis of the private sector housing stock in Stockport. Amongst other categories the HCS provides data relating to the energy efficiency of the housing stock, and the Borough-wide requirement of specific measures such as those mentioned above.

Although the data provided in the survey does not allow for an accurate assessment of where specific improvement measures are required, it has been used to suggest the cost required to address issues of energy efficiency in the Borough.

This has direct relevance to the Community Infrastructure Levy (CIL). The CIL allows local authorities to choose to levy new developments in their areas. The money brought in by the CIL can be used to support further development by funding local improvements, which can include energy efficiency improvements or infrastructure development / upgrades. It is intended that the outcome of this section will inform SMBC’s approach to the CIL.

Further to this, consideration has also been given to the draft document ‘Greater Manchester Low Carbon Economic Area Retrofit Standards’. This document takes into account a range of sustainability and energy measures in relation to the SAP performance of different types of dwellings in Greater Manchester.

The following table summarises the developed costs of energy efficiency improvements for the dwelling types considered. Note that certain measures (e.g. SHW) have not been considered for the apartment case as they are deemed practically unfeasible in most cases (for example, where limited roof area on a block of apartments relative to the number of dwellings in the block limits the effectiveness of SHW technology, or where most apartments in a multi-storey block will not have a roof to insulate).


Energy efficiency measure

Estimated cost (£)

Estimated savings

(£/yr)

Estimated payback

(yrs)

Estimated carbon saving (kg.CO2)

Estimated carbon

cost over lifetime

(£/tonne) *

Detached

Loft insulation £400 £39 10 188 85

Solid wall insulation £7,500 £122 61 594 505

Cavity wall insulation

£350 £96 4 467 30

Glazing improvement

£1,900 £58 33 283 269

PV retrofit £14,000 £725 19 3,587 156

SHW retrofit £3,500 £35 100 170 822

Townhouse

Loft insulation £200 £12 16 60 133



£280 £85 3 412 27

Glazing improvement

£950 £17 57 81 470

PV retrofit £10,500 £505 21 2,499 168

SHW retrofit £3,500 £35 101 168 833

Apartment

Loft insulation - - - - -



£200 £60 3 291 27

Glazing improvement

£700 £15 47 73 385

PV retrofit - - - - -

SHW retrofit - - - - -

* Lifetime of measure assumed to be circa 25 years.

Table 2 – Cost and carbon information for retrofit energy efficiency improvement measures

Retrofit district heating connections are subject to significant variation depending on circumstances. Based on AECOM previous project experience and high-level data from industry, the costs assumed for district heating retrofit are as follows:

• Internal plant (heat exchanger) circa £1,500 per dwelling (range £800 - £3,000)

• Consumer connection circa £200 per dwelling (range £100 - £300)

These figures do not include any pipe-work costs, as internal retrofit elements only are considered at this stage. The ranges presented show significant variation – this occurs where existing community heating systems are present (low end of range), where existing ‘wet’ heating systems are present (low-to-mid-range), and where no ‘wet’ system is present (high end of range)1.

1 A ‘wet’ system is one in which heat is distributed via hot water, from the source of heat generation (e.g. a boiler) to

the point of use (e.g. a radiator).


The cost and carbon data shown in Table 2 has been used in relation to high-level energy efficiency improvement requirement data from the HCS.

While it is recognised that the data in this survey is subject to statistical limitations (due to the limited number of dwellings that were surveyed compared to the total number of dwellings in the Borough), the summary below is intended to highlight trends of where energy efficiency improvements are most required, and what the implications of carrying out such improvements are in terms of capital costs required, cost savings and carbon savings.

The following map (adapted from the HCS) describes the postcode districts within which the HCS was carried out, as well as illustrating the three main areas into which data was grouped (AA, BB and CC – specific to HCS requirements and not relevant to this study). The key data extracted from this report considered the number of different dwelling types in each group and the approximate percentage of dwellings in each group requiring different energy efficiency improvement measures. These are described further in the tables below.

Figure 1 – Map of HCS areas and overall data grouping (AA – blue, BB – green, CC – yellow)

• Private dwelling mix in Stockport

Area AA BB CC

Detached 3,607 9,782 15,233

Townhouse 20,324 30,915 22,737

Apartment 3,169 5,200 2,118

Total 27,100 45,897 40,088

Table 3 – Estimate of number of dwelling types across HCS area groups


The energy efficiency improvement measures quantified in Table 2 have been considered in the context of the data extracted from the HCS report. The tables below provide cost and carbon saving data for each measure, which has been determined by applying the capital cost and carbon saving numbers to the HCS data on percentage of dwellings requiring each measures.

• Loft insulation measures

The approximate percentage of homes (detached and townhouse only) requiring loft insulation is circa 12%, equating to approximately 14,000 dwellings.

Loft insulation AA BB CC

Estimated cost (£) £773,379 £1,411,836 £1,393,034

Estimated savings (£/yr) £55,103 £106,758 £114,300

Estimated carbon saving (kg.CO2) 267,248 517,776 554,356

Table 4 – Cost and carbon estimation for implementing loft insulation measures

• Wall insulation measures

The approximate percentage of homes requiring cavity wall and solid wall insulation are circa 49% and 16% respectively, equating to approximately 72,500 dwellings. It should be noted that data for cavity wall installations carried out between April 2009 and March 2011 has been provided by the Stockport Housing Strategy Team, and is incorporated into the estimations below.

Cavity wall AA BB CC

Estimated cost (£) £3,614,225 £6,328,558 £5,831,801

Estimated savings (£/yr) £1,078,846 £1,872,004 £1,696,059

Estimated carbon saving (kg.CO2) 5,232,402 9,079,220 8,225,888

Solid wall

Estimated cost (£) £17,350,869 £32,045,837 £27,917,302



Table 5 – Cost and carbon estimation for implementing wall insulation measures

• Glazing installation measures

The approximate percentage of homes requiring upgrades from single to double glazing is circa 11%, equating to approximately 12,800 dwellings.


Windows AA BB CC

Estimated cost (£) £3,206,872 £5,830,241 £5,092,330



Table 6 – Cost and carbon estimation for implementing glazing upgrade measures

• PV / SHW retrofit

The HCS report does not specifically address issues relating to retrofitting renewable technologies other than to recommend their installation as ‘further measures’ for increasing the SAP performance of dwellings. For this exercise an assumption has been made of costing the carbon saving potential for implementing either PV or SHW retrofit to 8% of the housing stock of Stockport (this approximate percentage is considered an achievable target in terms of practical short-to-medium term application throughout the housing stock).

PV retrofit AA BB CC

Estimated cost (£) £7,488,756 £41,642,407 £38,177,079

Estimated savings (£/yr) £377,215 £2,049,430 £1,903,478


Table 7 – Cost and carbon estimation for implementing PV retrofit

SHW retrofit AA BB CC

Estimated cost (£) £2,115,018 £12,851,160 £11,224,640



Table 8 – Cost and carbon estimation for implementing SHW retrofit

• Cost of carbon

The values in the tables above have been quantified in terms of a cost per tonne of carbon saved over a 25 year period – this period is considered roughly equivalent to the lifetime of most of the retrofit measures.

The calculation divides the capital cost of each implementation measure by the carbon saving over a 25 year period: ‘Cost’ / (‘Carbon saving’ x 25). This is useful for comparing the cost-effectiveness of different measures, and allows for each measure to be compared on a relative scale. These approximate costs are shown in Table 9 below.

Loft insulation

Cavity wall

insulation

Solid wall insulation

Window upgrades

PV retrofit

SHW retrofit

Approximate 25 year cost of carbon (£/tonne)

£107 £28 £269 £371 £163 £830

Table 9 – Estimated cost of carbon for retrofit improvement measures


The tables above highlight that potentially the largest cost benefit in terms of reducing carbon would be a focus on cavity wall improvements. These measures are already being implemented throughout Stockport via various schemes such as Toasty Greater Manchester, where subsidies are offered to residents to install these types of measures in their homes. Such schemes have the potential to significantly reduce the carbon emissions associated with private housing in Stockport.

It is also noted that a significant number of homes in the Borough require solid wall insulation. Although this is more expensive compared to other carbon saving measures, there is also potential for making large carbon savings if either funding can be allocated to this particular problem or a lower cost solution can be implemented (examples of which already exist2).

Measures such as solid insulation and PV retrofit can be considered mid-range in terms of costs of carbon, and should be implemented as part of a longer term approach to carbon reductions throughout Stockport.

2 Solid wall internal insulation example http://www.building4change.com/page.jsp?id=565

http://www.building4change.com/page.jsp?id=565

27

3


District heating feasibility

The adoption of the Core Strategy policies described in Table 1 requires developers, where feasible and viable, to highlight opportunities for the use of district heating as a means of delivering low carbon de-centralised energy to the buildings they propose to build. It is intended that this will lead to district heating networks being prioritised and implemented in areas where opportunities are greatest. In the long term a Borough-wide series of networks may be expanded and integrated into communities and other developments. The Council is working to investigate the opportunities for supply of biomass locally as part of its work to promote district heating.

It is recognised that different development types will have different opportunities and requirements regarding adoption of district heating, which may have a significant impact on either technical feasibility or financial viability (or both). In order to demonstrate that these opportunities have been fully explored (and appropriate conclusions drawn), district heating feasibility studies are required to be provided by developers as evidence that the requirements of policies SD-3 and SD-4 have been taken into account.

This section of the report provides an overview of the key issues needed to be considered when carrying out a feasibility study, followed by five broad case studies of development sites within Stockport. The five feasibility studies will provide consideration of design principles with commentary on technical feasibility, financial viability and delivery/financing options.

The five sites discussed have been provided for assessment by SMBC as those which are representative of similar development planned around the Borough. It is intended therefore that the guidance provided within this report will be relevant for other sites with similar characteristics. These sites will also trigger consideration of low carbon policy targets when planning applications are developed.

3.1 Feasibility study approach

3.1.1 Objectives

A key initial stage in assessing a development or site for district heating potential is determining the objectives that need to be delivered. In general terms these can be defined by considering the following3:

• Carbon reduction targets

• Technical feasibility

• Financial viability

3 Adapted from ‘Community Energy: Planning Development and Delivery’, TCPA, 2010 (http://www.tcpa.org.uk/pages/community-energy-urban-planning-for-a-low-carbon-future-.html)

http://www.tcpa.org.uk/pages/community-energy-urban-planning-for-a-low-carbon-future-.html


• Security of supply

These areas are intended to address issues such as:

• Which energy systems are most appropriate for a development?

• Will they be financially viable at the proposed development scale?

• What are the local and regional carbon emissions target requirements?

• What will be the carbon impact of a proposed development / energy strategy?

• How will proposals help meet local/regional carbon reductions targets?

• Where will the development aim in terms of carbon reduction targets, i.e. minimum requirements or beyond minimum requirements?

• What will be the up-front costs associated with non-traditional energy generation systems, and are they affordable?

• Will the fuel used to generate energy be available throughout the lifetime of the development?

• How will the price of the fuel used to generate energy change over the lifetime of the development, and at what rate?

• How will the marketability of a development change depending on the energy systems (and associated costs) proposed?

• What are the financial incentives available and how might these change in the future?

Asking these types of questions at the outset of conducting a district heating feasibility study will be useful in terms of defining a set of parameters against which proposed solutions can be judged. It will also provide the foundation of a route-map towards decisions regarding energy supply and meeting policy requirements.

3.1.2 Understanding the proposed development and the existing setting

Most opportunities for district heating will occur when some interaction with, or connection to, existing buildings or development can happen. Gaining this understanding will involve an appreciation of both the proposed development and the setting in which is it proposed to be built. Accordingly, the following considerations will help define the criteria by which the applicability of district heating can be established:

• Proposed development

• Building types proposed (e.g. domestic / commercial, what is the mix of uses?)

• Load profiles of proposed building (e.g. heat-led? cooling-led? when will the times of peak demand occur? what is the base-load of the development?)

• Development density (e.g. is the development proposed dense enough to warrant consideration of a decentralised energy supply?)


• New build or refurbishment project

• Renewable energy issues such as visual impact / fuel delivery traffic

• Existing site

• Building mix on/around the site

• Presence of anchor loads (i.e. certain existing building types that are predominantly heat-led and may have a significant heat demand: hospitals, schools, hotels, leisure centres etc.)

• Proximity of anchor loads

• Proximity of other development sites and specific criteria affecting these sites

• Condition and potential refurbishment plans of existing building on/around site

• Availability of different fuel types (i.e. is local gas network over-stretched? how ‘local’ are biomass suppliers?)

• Understanding of system types of surrounding buildings (i.e. gas-fired ‘wet’ systems or electrically heated?)

• Constraints of site (i.e. remotely located? proximity of major roads/train lines?)

Several of these issues can be depicted graphically as an ‘energy map’ to gain a better spatial understanding of the site and the opportunities and constraints that occur. Examples of energy maps are given in Section 3.2.

Understanding these issues is important for determining an appropriate energy supply solution for any proposed site. Often, the interaction between development issues and site issues can be advantageous, for example using connections to appropriate existing buildings as a way of energy sharing can significantly improve the viability of district heating schemes, especially where waste heat is available. Such considerations need to be investigated as early as possible in the process in order to maximise any potential benefits.

3.1.3 Assessing appropriate technologies

An outline feasibility study for a particular site will require an appraisal of which particular technology options may be most suitable for a district heating solution, followed by a review of key design principles. This will require pulling together high-level conclusions from many of the issues highlighted in 3.1.1 and 3.1.2 above.

The more common technology options for district heating (and associated considerations) are listed below.


Technology options

• Gas boilers

• What are the advantages of gas district heating over individual gas boilers?

To consider: financial economies of scale, improved energy generation efficiency at large scale, carbon emissions reduction potential, ease of future plant replacement, maintenance costs, delivery efficiencies/heat losses of district heating.

• Can a gas network be extended, or upgraded at a later date to incorporate low carbon technologies?

To consider: other technologies compatible with district heating systems, location of future development, future-proofing for potential expansion to existing buildings/networks.

• Gas-fired CHP

• What advantages does a CHP offer over a gas-fired boiler?

To consider: base load of development (constant enough to maximise CHP run time?), electricity export potential, technology options to meet peak demands.

• Are there financial benefits to running a CHP engine?

To consider: electricity generation potential, annual running hours of CHP engine, relationship between thermal and electrical efficiency, relationship between gas and electricity prices.

• Biomass heating / biomass-fired CHP

• What are the key issues of biomass as a fuel?

To consider: local availability of biomass, type of biomass available (chips/pellets), space for storage on-site, frequency of delivery, future local availability of fuel, smoke pollution potential.

• What are the advantages of biomass as a fuel over gas?

To consider: carbon factor of fuel, meeting of carbon reduction targets, comparison of generation efficiencies at range of scales, biomass CHP suited to making significant carbon reductions.

• What proportion of the heating demand is met by biomass?

To consider: contribution of other technologies to meeting peak loads, potential displacement of food production, sustainable sourcing.

• Energy from waste

• What type of technology may be appropriate?

To consider: type of technology available (pyrolysis, gasification, incineration, anaerobic digestion), generation of heat or electricity more appropriate?, type of waste (fuel) availability in local area.

• What are the key issues of using waste to generate energy?


To consider: potential for reducing landfill waste, cost of waste as a fuel, sources of waste if not enough available from on-site generation, defining carbon reduction potential of waste as a fuel, emissions management appraisal at design stage.

Other technologies which may be considered depending on site conditions and proximity of existing installations are the use of geothermal energy (connection via a transmission main) and bio-gas.

Financial viability will largely be based on comparing any proposed options to a base-case, that is, one in which ‘traditional’ energy systems are installed (e.g. individual gas-fired boilers in each building/dwelling). This will also provide a good basis for making carbon reduction predictions to define the contributions made towards policy targets.

Opportunities for the use of micro-generation technologies (such as photovoltaics, hydropower, wind power etc.) should also be considered at this stage to maximise the potential for developing a robust decentralised energy mix and for further reducing carbon emissions.

3.1.4 Assessing technical feasibility and financial viability

Design principles

Many factors will have an influence on how a particular technology choice is incorporated into a development site, what its potential for expansion into the surrounding area is, and how easily it may connect to a future larger-scale heat network. The following list describes some of the principles that need to be considered as part of the technical, financial and delivery decisions regarding district heating feasibility.

• Age and condition of existing buildings

To consider: standard of improvements targeted, costs associated with improvements, scale of work needed to be carried out to improve efficiency, effect of improvements on heat demands, effect of improvements on plant sizing and financial viability.

• Design targets of proposed buildings

To consider: contribution of new build to increased carbon emissions, building to current or future Building Regulations targets and the ease of achieving those targets, requirements of local policy and planning targets.

• Phasing of development

To consider: for larger schemes – nature of heat network evolution over time as more development comes on-line, infrastructure phasing to match demand, effect of phasing on costs associated with infrastructure; for smaller schemes – advantages of whole development coming on-line at once, incorporation of future-proofing measures into phasing, changing of design targets over time (e.g. Building Regulations).

• Overall size of development

To consider: for larger schemes – opportunities for taking advantage of larger scale plant/infrastructure, economies of scale; for smaller schemes – threshold for district


heating under Core Strategy policy SD-4, future-proofing of development if below threshold (see below).

• Layout

To consider: effect of site layout on scale of network, effect of density of development and connections to existing buildings/dwelling on technical feasibility, scale of heat losses from pipe-work infrastructure, proximity of plant to heat demand, proximity of plant to future connecting building/developments, space requirement for plant and fuel storage, space requirement for potential thermal storage, rights of access to pipe-work.

• Connecting to a network

To consider: ease with which a connection is made between building and network infrastructure, retrofitting to existing buildings, metering of heat consumption, topographical understanding of site for determining pump sizes and pressures at which systems can operate.

• Cooling

To consider: opportunities for integrating heating and cooling networks, scale of demand for cooling (presence of commercial/industrial buildings), use of waste heat for cooling via absorption chillers.

• Future-proofing

To consider: specification of appropriate plant where heat network not initially feasible for easy future connection, additional plant space for future network expansion plant, specification of plant that allows easy future upgrade or change in technology type/fuel, use of electricity microgeneration technologies to contribute to carbon emissions reductions if heat network not initially feasible.

• Financing and delivery options

To consider: SMBC role in co-ordinating opportunities involving multiple stakeholders, relationships between stakeholders, framework arrangements, ESCo involvement, investment routes for on- and off-site microgeneration technologies, use of Special Purpose Vehicles (SPV’s) for delivering infrastructure.

• Financial incentives

To consider: potential for Renewable Heat Incentive (RHI) payments for generation of low carbon heat, potential for Feed-In-Tariff (FIT) payments for microgeneration where heat network connections are not initially viable.

• Local engagement

To consider: opportunities for engaging with other local buildings / businesses / developers to share energy, demonstration of the wider benefits of district heating to the local community.


3.1.5 Summary

Sections 3.1.1 to 3.1.4 above have summarised some considerations to carrying out district heating feasibility studies including initial objectives, site opportunities and constraints, technology types and design principles. The following section provides five high-level examples of this type of approach. Where appropriate, the feasibility studies are required to address Policy SD-3, including targets, and specifically refer to Policy SD-4, which states that:

1. All development should seek to make use of available heat, biomass and waste heat.

2. Small developments (less than 100 dwellings or non-residential developments less than 10,000m2) should connect to any available district heating networks. Where a district heating network does not yet exist, applicants should install heating and cooling equipment that is capable of connection at a later date and which could serve (or could easily be adapted to serve) that wider network if and when required.

3. Large and mixed-use developments (over 100 dwellings or non-residential developments over 10,000m2) should install a district heating network to serve the site. The council’s ambition is to develop strategic area wide networks and so the design and layout of site-wide networks should be such as to enable future expansion into surrounding communities. Where appropriate, applicants may be required to provide land, buildings and/or equipment for an energy centre to serve existing or new development.

4. New development should be designed to maximise the opportunities to accommodate a district heating solution, considering: density, mix of use, layout and phasing.

5. Where investment or development is being undertaken into or adjacent to a public building, full consideration should be given to the potential role that the public building can have in providing an anchor load within a decentralised energy network.


3.2 Feasibility study examples

This section provides high-level feasibility studies of five development sites in Stockport. These particular sites have been chosen as examples of typical development types within the Borough, and it is intended that the guidance associated with each site may be easily replicated elsewhere. The sites are listed below, and their location in Stockport is shown in Figure 2.

Site name/location Summary Development type

1 – Man Diesel Site, Hazel Grove

Residential-led development on disused industrial site.

Low density residential

2 – Cheadle Royal Business Park, Cheadle

2.8 hectares of land available for development on business park site.

Commercial

3 – Brinnington masterplan, Brinnington

Regeneration development of residential area, including existing community development.

Regeneration residential

4 – Goyt Mill, Marple Mill redevelopment, mixed use (domestic and commercial), SHLAA site.

Mill redevelopment, below SD-4 threshold

5 – Broadstone Mill, Reddish

Mill redevelopment, mixed use (domestic and commercial), SHLAA site.

Mill redevelopment, above SD-4 threshold

Table 10 – Summary of feasibility study example sites

Figure 2 – Location of feasibility sites


3.2.1 Site 1 – Man Diesel site, Hazel Grove

Site detail summary

• Site located in mostly residential / suburban area

• Development site currently owned by MAN Diesel & Turbo UK Ltd

• Current buildings on site are existing MAN Diesel head office building and

redundant industrial buildings

• Development plot circa 28,000m2

• Site bordered by Mirlees Fields (green open space) to west, north and east

• Office development (Rhino Court) immediately to south

• Separated from commercial / warehouse plots (Pepper Road

Estate) by railway line to south

• Further industrial / commercial units to east/south-east

• Stepping Hill Hospital located immediately to north of Mirlees Fields

Development proposals

A planning application has been submitted for a new-build residential and employment development (outline masterplan shown in Appendix C), comprising two hectares of land for employment uses and five hectares for up to 240 dwellings. The main section of land for development currently houses several industrial buildings previously operated by MAN Diesel as a diesel engine manufacturing plant – this operation stopped in 2008, and the site has not been used since. There is potential for this brown-field development site to contribute to SMBC’s housing supply requirements.

An outline energy map of the MAN Diesel site and the surrounding buildings/area is shown in Figure 3 below.


Figure 3 – Energy map of the MAN Diesel site and surroundings

The following points summarise the key development and site opportunities and constraints for this development site.

Technical feasibility

• The current masterplan indicates that up to 240 dwellings may be incorporated on the site. This indicates a maximum dwelling density of around 48 dwellings per hectare. Guidance4 suggests a dwelling density of at least 50 dwellings per hectare as a tipping point for district heating becoming feasible. Higher densities of development can have significant impacts on reducing heat losses within a network, while also potentially reducing infrastructure costs.

4 Community Heating for Planners and Developers, Energy Savings Trust/Carbon Trust, 2004


• The masterplan could be ‘tweaked’ to increase the development density, meaning that the feasibility and viability of a small initial site-wide network would be improved. In this case provision should be made for connecting to a larger heat network as and when such an opportunity occurs in the future. This should be carried out through appropriate specification of plant, and consideration of where plant items and pipe-work routes are located. A more detailed study may be necessary to determine exactly where this ‘tipping-point’ of viability occurs.

• It is understood that several of the local stakeholders at the Pepper Road estate adjacent to the development site are interested in exploring ways of reducing energy demands, largely driven by the desire to reduce energy costs which are significantly high. The Council should continue its engagement with these companies with an aim of achieving an energy sharing solution with benefits for the wider area. It is strongly recommended that these stakeholders continue to be involved in discussions and plans involving energy strategy in and around this development site. This could also include the hospital (see below).

• This site is reasonably close to Stockport Town Centre, so consideration should be made as to how a MAN Diesel on-site network may connect to a wider Town Centre network if it expands in the future. In particular, the Stepping Hill Hospital may be regarded as an excellent point for a town centre network to stretch down to along the A6 corridor.

• In the shorter term, the hospital could provide a potentially significant anchor load with which heat/energy could be exchanged by the proposed development site buildings. It is currently understood that a district heating system exists within the hospital; a ‘wet’ system would be ideal as one that could export or import heat to/from surrounding buildings.

• When considering a connection with the hospital, the biggest constraint is likely to be the existing railway line that separates the hospital and Mirlees Fields. Feeding district heating pipe-work under an existing railway can technically be achieved, although there will be a significant additional cost to such works. Further discussions with both the hospital and Network Rail (regarding their viewpoints, and any planned maintenance both at the hospital and of the rail track) should be conducted to inform feasibility/viability.

• A 240 dwelling development is likely to provide a good heat base-load for district heating, due to a year round demand for heat (heating and hot water in winter, hot water in summer). This potentially works well with systems such as CHP, where the engine should be run for as many hours as possible throughout the year to maximise efficiency.

• The MAN Diesel office building located on the site could provide an additional heat demand that would complement the loads of the proposed development. The office building would provide a building to which electricity from a CHP engine could be exported. Further information would be required relating to the plant type and fuels used within this office building to clarify this option.

• The size and layout of the site lends itself to storage of fuels such as biomass, or for housing buffer tanks (as a way of storing heat until it is required). In the case of biomass, if a robust, local supply chain can be established, then biomass heating could potentially be used as a fuel for a small-scale on-site heating network. Biomass CHP is considered an unsuitable technology for use at this (relatively small) scale, although this feasibility could change if connection to a large anchor (such as the hospital) could be achieved.


• The potential for growing biomass on the Mirlees Fields site should be considered as a way of developing a local supply chain of fuel. This would need to include an area for treating (drying) the wood before use in a boiler.

Financial considerations

• When considering an initially small-scale on-site network, either gas-fired CHP or biomass heating are potentially viable options for this site. Both solutions offer opportunities for taking advantage of financial mechanisms for offsetting initial capital and running costs, although gas-fired CHP may be limited to small-scale generation under the FiT. Further information on this is given below, and at:

http://www.decc.gov.uk/en/content/cms/meeting_energy/renewable_ener/incentive/incenti ve.aspx

• Biomass heating is a technology that generally has lower efficiencies than equivalent gas-fired heating, and is considered to save carbon rather than energy, assuming a local supply is used. A key benefit of this technology however is that it qualifies for a tariff under the recently published Renewable Heat Incentive (RHI, March 2011). This provides a payment for every kWh of heat used that is generated by renewable technologies5, which can help to offset the capital costs required for network development. The level of tariff available is dependent on the size of the heat generation installation, where generally smaller installations receive a higher tariff. The highest tariff available is for plant size of 200kWth or less, which is around the size of system that may be considered for the proposed development (assuming that peak demands are met by back-up gas-fired boilers).

• Gas-fired CHP needs to be considered carefully alongside a ‘standard’ gas boiler system to determine how viable it is as a solution. The key factors that influence this viability are the prices of gas and electricity, the relationship between these two prices, and the achievable heat and electrical efficiencies of a CHP system.

• The benefits of CHP are derived from the production of electricity alongside heat generation. However, the thermal efficiencies of CHP engines are significantly lower than those of equivalent gas-boilers, meaning that they consume more gas than an equivalent gas-fired boiler. CHP is therefore primarily a technology suited to saving carbon rather than energy.

• In general terms, the viability of CHP will increase if electricity prices rise at a higher rate than gas prices, as the cost of electricity being offset (i.e. not imported from the national grid) will be more ‘valuable’ than the price of the gas consumed.

Planning and co-ordination

• Raising the dwelling density will facilitate a network solution with costs reduced by providing some simple urban design guidance. For example, townhouses could be brought closer to the back of pavement in order to reduce pipe lengths and the associated cost of heat network connections.

5 See Appendix B for a list of eligible technologies and tariffs under the RHI.

http://www.decc.gov.uk/en/content/cms/meeting_energy/renewable_ener/incentive/incenti


• The development planning statement suggests that the housing development will be completed prior to the revision to Building Regulations Part L in 2016. A site-wide network solution could therefore be promoted that supports CfSH Level 4/Part L 2013 compliance.

• Stepping Hill Hospital would be the natural anchor public sector load in the wider area as it has an existing network and its own CHP plant. Localised information on public sector anchors should be made readily available to prospective developers in order to promote network responses to the LDF Core Strategy energy policies.

• A network solution would be at the high end of costs for a district heating network, suggesting that achievement of the higher targets outlined under Policy SD-3 might not be possible.

Delivery options

• A network at this site would be likely to be developer-led, however, SMBC should continue to assist developers to discuss their energy management options.

• SMBC could maintain a framework of turnkey ESCo partners who would be selected based on their track record of carrying out detailed feasibility studies and/or developing smaller standalone networks. Developers of suitable sites could then choose competent ESCo partners from this framework.

• There is scope for some sites, depending on their location, to link into wider opportunities. This will depend on investment/management of these opportunities being favourable to potential linkages with new development. It is therefore important that SMBC works closely with partners such as the NHS to understand their motivations/schedules for investment and replacement.

Overview conclusions

• Subject to changes in dwelling density an initial district heating network could be achieved covering the planned MAN Diesel site.

• Engagement required with occupiers on Pepper Lane Industrial Estate to drive forward discussions of decentralised energy options, noting the potential significant constraint

of the train line

• Stepping Hill Hospital offers major anchor load opportunities however the train line could be a significant constraint

• Future development plans to consider progress and reach of Stockport Town Centre network – potential future connection

• Consideration required of existing office building heat demands to inform its connection viability

• Adjacent green space potential for on-site fuel storage / heat storage / biomass growing


3.2.2 Site 2 – Cheadle Royal

Site detail summary

• Office development opportunities within existing Cheadle Royal

Business Park

• Several development plots exist within site, key plot is 2 hectare green strip

in centre

• Site bounded to north-east by A34 • Several large buildings exist on/near

site: Sainsbury’s & John Lewis to

south-east, primary school to north-

west, St Ann’s Hospice to south-west,

Cheadle Royal Hospital immediately

to south of business park

• Surrounding area predominantly low density residential

• Another primary school (Prospect Vale) located close to St Ann’s

hospice

Development proposals

Several development plots exist within the business park for potential office development. The main plot of available land is located centrally within the site, and further smaller plots exist to the south-west of the site.

Several planning applications have been received to date, including a conversion of existing buildings to 23 apartments and a two storey new-build office development. It is also noted that Sainsbury’s are carrying out a series of remodelling works to their store, including installation of air source heat pumps to provide heating and cooling throughout the store.

An outline energy map of the Cheadle Royal site and the surrounding buildings/area is shown in Figure 4 below.


Figure 4 – Energy map of the Cheadle Royal site and surroundings

The following points summarise the key development and site opportunities and constraints for these development sites.

Technical feasibility

• The key opportunity for this site in terms of district heating feasibility is the presence of several anchor load buildings in and around the business park, as shown in Figure 4 above. Each of these offer a potential opportunity for energy/heat sharing, a process that could be driven forward by new development on this site. The central plot (shown in light blue on Figure 4 above) in particular may be ideally located for developing heat sharing associations between these anchor loads. This could offer substantial fuel cost savings and carbon reductions to existing buildings, potentially of interest to those companies registered with the CRC Energy Efficiency scheme.

• The buildings that offer a particularly effective year-round steady heat load are the Cheadle Royal Hospital and the hospice. These buildings would be ideally suited to providing a base load for heat, which can be met with either a gas-fired CHP or a biomass boiler. In either case, back-up (gas-fired) boilers would be required to help meet the peak


demands. Further information would be required as to the type of heating systems used at the hospital/hospice before their suitability as anchor loads can be determined. If electric heating systems are used, it becomes more difficult and costly to retrofit wet system distribution pipe-work within a building.

• The schools in close proximity to the business park should also be considered as important heat anchors, although the yearly profile for heat in these types of buildings is affected by seasonal occupancy, i.e. when empty during school holidays.

• It is likely that a CHP solution is an appropriate technology for this type of building mix, i.e. where several large heat anchor buildings exist alongside a series of commercial buildings whose energy demands may be largely electricity led. If a private wire electricity network can be established alongside a heat network, then potentially most of the electricity generated by a CHP engine could be used on-site.

• The commercial nature of several other buildings in and around the business park means there may be a case for a more detailed investigation into whether the cooling demands of these buildings are significant enough to warrant consideration of a cooling network. This could involve sending heat that is not required in the summer to absorption chillers within commercial buildings to be converted to cooling energy. Although this process is typically less efficient than using conventional electrical chillers, making use of heat that is not needed in the summer months would mean that the overall annual load profile is kept steadier, and the potential for dumping heat that is not used is greatly reduced. A more detailed feasibility study would be required to analyse the extent to which the heat/cooling loads may balance.

• The commercial buildings on the site also offer potential for microgeneration technologies – this type of energy generation should be encouraged alongside heat network solutions, not just for contributing to meeting carbon reduction targets, but also in terms of diversifying the energy mix of development. Technologies that are likely to be appropriate will include PV panels and medium scale wind turbines. A key benefit of such an approach is the ‘building-in’ of resilience and robustness to proposed development, and future-proofing energy supply in relation to reducing reliance on fossil fuels. The potential for income generation from microgeneration technologies will be of interest to the building

6 owners .

• The potential for expansion to the ea

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Stockport Low Carbon Policy Implementation Evidence Study · 2018-02-27 · CfSH Code for...

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