EUROPEAN PARLIAMENT

Workshop on Assessment of Potential and Promotionof New Generation of Renewable Technologies

22 March 2011

OCEAN ENERGIESSome Basic Ideas and Facts

António F. O. FalcãoInstituto Superior Técnico

Lisbon, Portugal

antonio.falcao@ist.utl.pt

OCEAN RENEWABLES

WAVES

TIDAL BARRAGEOTEC

SALINITY GRADIENTTIDAL STREAMS

WAVE ENERGY

Where inEurope?

DIST

RIBU

TED

TIDAL STREAM ENERGY

Where inEurope? CONCENTRATED AT

SMALL SEA AREAS WITH STRONG CURRENTS

Different ways of classifying WECs:

• Shoreline

• Nearshore

• Offshore

According to workingprinciple

Pointabsorber

Largeabsorber

Terminator

Attenuator

Multibody

Wide Diversity of Wave Energy Converters

In breakwater, Mutriku(Spain), 2008-10

Australia, 2010

USA-Spain, 2008

Denmark, 2009

UK-Portugal, 2008

UK, 2010

Ireland, 2008

Ireland, 2006

Wave Energy Technologies

SeaGen 1.2MW (UK)

TIDAL STREAM TURBINES: SOME PROTOTYPES

OpenHydro, Ireland

Sabella, FranceTISEC, France ENERMAR, Italy

<200m

severalkm

WIND

The wind velocity profile extends over several km.

A wind farm explores a tiny sublayer

20m

WAVES

Most of the wave energy flux is concentrated near the surface

A wave farm can absorb a large part of the wave energy flux.

Like wind energy, the extensive exploitation of waveenergy will require large farms of offshore converters, rated about 0.2 to 5 MW each

Waves are a more concentrated form of energy thanwind.

Tidal stream velocity (up to about 4m/s) islower than wind speed.

But water density is 800 larger than airdensity.

The energy density is muchlarger in tidal streams.

TIDAL STREAM ENERGY VERSUS WIND ENERGY

PROTOTYPE TESTING UNDER REAL SEA CONDITIONS IS ESSENTIAL

Test sites for wave and tidal energy systems in Europe

Source: EQUIMAR – Draft report on the state of ocean energy in Europe: technologies, test sites, and joint projects, 2011

Theoretical Resource - A top level statement of the energycontained in the entire resource

Technical Resource – Part that can be exploited based onexisting technologies

Accessible resource – What can be exploited afterconsideration of external constraints (impractical areas, competing uses, environmentally protected areas, …)

Economic resource – What can becommercially atractive depending on marketconditions

THE ENERGY RESOURE (WAVES, TIDAL STREAMS, …)

ASSESSMENTS WILL DEPEND

STRONGLY ON SCENARIOS

WAVE/OCEAN ENERGY INSTALLED CAPACITY (GW)

Scenarios

Source: WAVEPLAM – State of the Art Analysis

Portugal: how much electrical power fromthe waves?

500km

Estimates : 2.5 – 5 GW installed power fromwaves,mostly offshore

From onshore wind ~ 6-8 GW

(presently ~ 4 GW)

Cost of energy (2006)Capital costs of first prototypesand first production models

Source: Carbon Trust, 2006

The technology is more difficult than wind.

Except for a few shoreline plants (Pico 1999, Islay 2000), there is little or no experience of maintenance, reliability and survival(under extreme conditions) in real open-ocean, for more than a fewmonths.

Scarce reliable information on costs and economics.

Wave Energy: Present Situation(partly applicable to Tidal Streams)

For most technologies, the capacity factor: annual-averaged powerdivided by rated power, is similar to wind (~0.3) (larger for tidal streams).

At the present stage of technology development, the unit cost of electricityfrom waves ranges between wind and large photovoltaics.

10 kW pilot plant, Statkraft, Norway, 2009

SALINITY GRADIENT – OSMOTIC POWER

• A new technology

• R & D in Norway, Netherlands, Germany

Energy produced from mixing fresh (river) water and salt (sea) water across a semi-impermeable membrane.

Environmental impacts of ocean energy

• Dependent on– Site natural characteristics– Technology specificity– Project phase (installation, operation and

decommissioning)– Project scale (prototype, array, farm)

• Magnitude / severity is uncertain due to early stage oftechnology development.

Types of environmental impactsReceptors Stressors Effects and / or ecological issues

•Physical environment

•Pelagic (water column) habitat

•Benthic (sea floor) habitat

•Fish and fisheries

•Marine birds

•Marine mammals

•Humans (users)

•Physical presence of the devices

•Chemical effects

•Lighting

•Acoustics

•Electromagnetic fields

•Cumulative effects

Alteration of currents and waves due to the energy extraction and or physical presence of the devices

Alteration of substrates and sediment transport and deposition which may alter coastline processes and morphology

Benthic habitat disturbance or destruction Water contamination due to e.g. effluent or

waste discharge, oil leaks Collision, strike, entrapment and

entanglement of marine invertebrates, fish, mammals and birds with the equipment (mainly with tidal stream rotor blades)

Interference with animal movements and migration

Displacement of marine species Noise disturbance Effects of electromagnetic on fish (sharks,

rays and skates) orientation and reproduction

Environmental and economic cost impacts duringocean projects life cycle

• Several Life Cycle Assessment procedures have beenapplied for wave and tidal energy projects (e.g.Pelamis, SeaGen, Wave Dragon)

• Life Cycle Assessment: permits assessment of the environmental impacts of each life stage (e.g. raw material extraction, transportation, maintenance process, final disposal, recycling) in terms of CO2 emissions in the device manufacturing

Goaldefinitionand scope

Inventoryanalysis

Impactassessment

LCA Framework

Detailed product life cycle for Pelamis

Some comparative results on LCA regarding energyprojects life cycle

Previous results from the few LCA studies on wave and tidal devices show good environmental performance relative to conventional power plants or renewables such as solar PV or biomass

The technologies that have the lowest life cycle Green House Gas emissions to date are nuclear, large hydro and wind, followed by wave and tidal energy

Tidal energy(SeaGen)

Wave energy(Pelamis)

Some sources of information(most are available at internet)

• Future Marine Energy: Results of the Marine Energy Challenge. Carbon Trust Report, UK, 2006.• Marine Renewable Energy. State of the Industry Report. BWEA, UK, 2009.• The Benefits of Marine Technologies within a Diversified Renewables Mix. BWEA, UK, 2009.• Oceans of energy European Ocean Energy Roadmap 2010-2050. European Ocean Energy Association, 2009.• Marine Energy Roadmap. Forum for Renewable Energy Development in Scotland (FREDS), 2009.• Annual Reports (2008-), IEA-Implementing Agreement on Ocean Energy Systems.• Raventós, A., Simas, T. et al. Life Cycle Assessment for Marine Renewables. Equimar Project, European Commission, 2010. http://www.equimar.org/equimar-project-deliverables.html• Falcão, A.F.O. Wave energy utilization: A review of the technologies. Renewable and Sustainable Energy Reviews, vol. 14, p. 899-918, 2010.• Braein, S., Skramsto, O. et al. Osmotic power. From prototype to industry – what will it take? 3rd International Conference on Ocean Energy, Bilbao, 2010.