Environmental issues and impacts for wind power

Transcription

1 Environmental issues and impacts for wind power Prof John Twidell AMSET Centre UK EU/Thailand Seminar, Bangkok; Oct 4 &

2 Now on the Board of Westmill Windfarm, near Oxford, UK University science & engineering My background Speak at windfarm Planning Appeals R&D on large and small wind turbines

3 The ethos of wind power is environmental harmony and sustainability

4 In so many locations, wind power is invaluable

5 Consider a modern wind turbine any colour: usually white can be seen, dynamic, & heard can kill birds & bats can be heard can be shaped attractively can be heard; masks noise open view quiet unseen underground can be seen, static Power grid local noise Foundation small, can be attractive substation

6 Stages of implementation Manufacture Government policy and support mechanisms Site selection Planning permission Local interaction Operation Decommissioning Every stage must consider environmental issues

7 Environmental issues Environmental issues are complex and many Factors are scientific, social, political and legal They present a huge subject, not to be taken lightly Do not trivialise impacts Ultimately, a balance of good (benefits) and bad (harm) is needed But. we need clean electricity!

8 The Planning system varies by country, e.g. UK; there are no international regulations 1. Look for sites, liaise with land owner (hopes to earn ~$US 4,000 per turbine), prepare fully 2. Discuss with local officials & local community 3. Apply to local district council (which needs full documentation and Environmental Impact Assessment, EIA) 4. Attend Planning Hearing by elected Councillors; local people can write and speak briefly; verdict approve or reject 5. If approve, then go ahead 6. If reject, may Appeal to National Planning Inspector (cf judge) 7. Appeal Hearing, lawyers and experts for and against ; local presentations for and against ; lasts ~ 3 to 4 days 8. Inspector decides approve or reject 9. If approve, then go ahead 10. If reject, then most developers stop; only recourse is points of law in High Court: very expensive, many lawyers!

9 Planning permission takes time and money (lawyers!), e.g. UK onshore

10 Wind turbine impacts visual (no hiding place!) larger diameter, slower rotation noise from machinery, blade tips, tower passing (=40 bba at 250 m; sleepable) birds very seldom (< house windows) bats; avoid hedge lines, researching TV and microwave avoid line-of-sight with local transmitters Radar- difficult, special erasing software Shadows may give flicker through windows grid limitations for exportable power

11 Example: sunshine flicker Concern is moving shadows across walls that upset people (e.g. epileptics, school children in class). Only when clear sky, low sun, certain days in year, certain angles, smallish windows and complaints. Solution: automatic and brief turbine shutdown.

12 Bird strike Statistical study for effect on bird population Endangered species carefully protected; refuse permission Each species has distinctive flight pattern Expert ornithological research needed, as paid by wind industry Compensate with new, separate breeding areas

13 Visual impact Some people like to look at rotating wind turbines (especially the owner!) Many official reports and regulations give guidance e.g. Visual Assessment of Windfarms: Best Practice: Scottish National Heritage 2002 Most are not bothered Some hate the sight of them (especially neighbours of the owner!) Decision is by distance and fraction visible, with personal opinion Aided by photographs and computer imagery using digitised maps A cluttered view; but with a telescopic lens?

14 Photomontage techniques for predicted views

15 Serious study is needed Environmental factors are of major importance Impacts are both positive and negative Aim to reduce the -ve, increase the +ve Both the public and the site staff appreciate good environmental practice Much environmental knowledge is gained from Windfarm Environmental Impact Assessment, EIA, e.g. bird behaviour, public perception, noise reduction, sympathetic design Reports from many experts (expensive)

16 Classes of impact in general Chemical e.g. air and water pollution, climate-change emissions Physical Ecological e.g. noise, collision, radar, TV e.g. bird & bat strike, flora, fauna, agriculture, ecocompensation Psychological/emotional e.g. visual impact on humans, infra-sound?

17 Impacts are Positive (+) i.e. benefits, and so welcome by all e.g. generate electricity, abate emissions from substituted fossil fuels, provide jobs, give energy security Negative (-) and so unwanted e.g. associated acoustic noise, flicker Neutral (o) and so unnoticed e.g. foundations, maintenance

18 Area of impact GLOBAL, international e.g. climate change abatement, energy security REGIONAL, governmental e.g. employment, investment, bird population, radar LOCAL, community, site specific e.g. noise, visual impact, sunshine flicker

19 Global Regional Local chemical physical ecological Psychological/ emotional (human only)

20 Chemical impacts: CO 2 abatement from reduced electricity generation from fossil fuels Abatement of fossil CO 2 is the most significant global impact (+ve, benefit) because of Climate Change and national reduction targets World wind capacity now (2011) ~215 GW, abating ~240 Mt CO 2 /y (~ 70Mt coal/y) Carbon trading is internalising this externality

21 Other chemical impacts +ve : abated SO 2, NO x, wastes, ash and other chemicals, especially if coal plant is marginalised +ve: abated cooling water if thermal plant marginalised +ve: abated extraction, transportation, logistics, fuel of fossil fuels +ve: abated ill-health from pollution

22 Avoided emissions from wind power in the EU in 2007: Wind Energy The Facts, part 5 ch 5

23 Physical impacts: acoustic sound outside the turbine -ve, noise is annoying sound to everyone (so < 40 dba outside nearest house) Mechanical noise, e.g. from gearboxes, is now largely eliminated Blade-generated noise is intrinsic, but decreased by accurate angle of attack and efficient blade profiles Pulsation of blade noise by tower-passing and wind shear is intrinsic

24 Sound noise is a sign of less efficient operation Therefore the more efficient the machine, the quieter it is likely to be

25 Credit GE wind power, from mattgoesgreen.com/wp-content/uploads/2010/11/939ddf77ind-turbine.jpg 27/10/2011

26 Physical impact: visibility Turbine rotors need to be high and in open country, so always potentially visible Reduce near-zone visibility by careful siting Choose colours, finishes etc to reduce visibility (but standard blades are white as uniform products of specialised factories) Few large turbines better than many small (cheaper, more spaced ~5 diameters, slower rotation)

27 Middelgrunden windfarm, off Copenhagen: artistic design inspiration

28 Physical impacts: electromagnetic radiation, predominantly line-of-sight interaction TV (easily solved with local boost transmitter not in line-of-sight) Microwave communication (avoid line-of-site turbines) Radar (may be a real difficulty for air traffic controllers; special software removes signals)

29 Ecological impact -ve Bird and bat strike (but does it effect species population?) -ve Disruption at installation -ve No trees +ve Windfarm space is secured +ve Ecocompensation (e.g. ponds, low vegetation for fauna & flora, marine fish breeding) Decommissioning & removal are easy

30 Psychological and emotional impact Emotional factors are real and require sympathy Each person is different Understanding the technology, personal association, ownership, community benefit and the passing of time make these impacts more positive Only humans consider aesthetic visual impact, which may be positive, but is often negative Landscape, countryside, setting, industrial are complex terms

31 Analysis of impacts by evaluating avoided external costs: Wind Energy The Facts, Part 5, chapter 5

32 Social attitudes about EU energy sources: vital importance of public acceptance of policy (but anti anything in my back yard ) Special EB 262 (EC, 2007) from Wind Energy The Facts, EWEA 2009

33 Global Regional Local chemical + no CO 2 + no SO 2, no NO x + No smoke etc + No cooling water + No fuel transport physical + energy security + no radioactivity + no wastes + open access + grid reinforcing - radar - microwave comm +limited lifetime (25 y) - power variability - acoustic noise - TV - marine collision ecological + climate change abatement emotional (human only) -rare species? + sustainability -bird population? + fish breeding + eco-compensation + agriculture OK - bird & bat strike + eco-compensation visual impact (- for lobbyists, + for enthusiasts) - sunshine flicker

34 In conclusion Local people must accept responsibility for global benefit Governments and developers must give local compensation, e.g. community funds, ecocompensation v