Renewable Energy - Wind Lecture

8/12/2019 Renewable Energy - Wind Lecture

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Wind

Biol 4861

April 15th, 2014

Bryce Pippy

Renewable energy:


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Harnessing wind

Wind power in use since early times

Windmill = wind-driven mill

Also commonly used to pump water

Generation of electricity from wind camemuch later

First wind turbine to generate electricityinstalled in 1887


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Wind energy production of electrical energy from wind usingturbines

Turbines can be inland, coastal, or offshore

Very straightforward form of energy

Wind turns turbine directly to spin generator

Not reliant on steam more efficient energy production

Many conventional power sources still rely on boiling water

Wind turbines commonly horizontal-axis or vertical-axis design

Introduction to wind energy


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Mechanics of a turbine

http://www.offshorewind.biz/2012/07/31/usa-sandia-re-evaluates-vertical-axis-wind-turbines/
https://www.youtube.com/watch?v=SQpbTTGe_gk


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Turbines typically produce 1.5-2.0 MW per turbine

Variable sizes

Largest current wind turbine (Enercon E-126) produces 7 MW of powerand has a total height of 650ft (including blades)

Smaller turbines may only produce 100-200 kW

Turbine technology


7/26http://visualinfo.ru/proizvodstvo/samyj-vysokij-vetryanoj-generator.html

A bit of perspective

Worlds argestPassenger irline


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Canada is 9thin the world for windenergy, producing 4,500 MW

New Brunswick has 113 wind turbinesin three locations

Wind produces 294 MW in-province

USA 2ndlargest producer of windenergy

Considerable untapped potential fordevelopment worldwide

http://www.nbpower.com/html/en/save_energy/wind_energy/wind_energy.html

Wind energy statistics


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Offshore vs. inland turbines

Inland:

Energy transport may beeasier already in place

Synergy with agricultural andother land use less dedicatedarea

NIMB aesthetic concerns

Wind may be more erratic

Offshore:

Transport of energy difficult underwater cabling

Poses obstacle to fishing andshipping

Residential & aestheticconcerns not an issue

Coastal and offshore areas

have high winds


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Renewable source fuel is free and plentiful

Low GHG production

Developmental scale is flexible

Large-scale wind farm operations

Personal or house-mounted turbine for offset

Minimal land usage

Wind farms can still be used for agriculture with little conflict

High Energy payback ratio

Advantages of wind energy


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GHGs from energy production

http://www.publications.parliament.uk/pa/cm200506/cmselect/cmenvaud/584/5111706.htm


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Costs energy to make energy concept of net energy from lecture 17

Manufacture, installation, operation, and dismantling of power plants allrequire energy input

Energy cost varies for different energy sources

Consider the efficiency of a power source by comparing energyproduced to energy consumed this is an Energy Payback Ratio (EPR)

Similarly; consider time needed to make up for all the energy used this is an Energy Payback Period (EPP)

Energy Payback Ratios


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Energy Payback Ratios by source

From Energy Center of Wisconsin Net energy balance and greenhouse gas emissions from renewable energy storage systems, 2003.


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Disadvantagesof Wind Energy

http://

xkcd.com/556/


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Variablewind is unpredictable Wind can be too weak ortoo strong want wind between 5 and 15 m/s

Negative reputation in some eyes (opinions vary)

too much noise, ugly

Not In My Backyard

Mortality in bird and bat populations

Must be placed in ideal locations issues of transport

Disadvantages of Wind Energy


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Energy produced during off-peak times is not necessarily useful

Insufficient demand

Wind energy is sporadic in timing, and so may not match demandfor energy

To capitalize on this excess production the energy must be storeduntil it is needed

Energy Storage


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Battery storage

Expensive

Impractical at this scale (technology lacking)

Water storage (Pumped-Storage Hydroelectric or PSH) Use turbine to pump water up a gradient during off-peak, converting

kinetic energy to potential

Run water downhill (through turbine) to extract energy

Infrastructure (and water) required

Compressed Air Energy Storage (CAES)

Storage Strategies


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Store excess energy by pumping air into a storage container atincreasing pressure

Can be man-made container or natural (salt cavern or abandoned mine)

Air is released and heated (using natural gas or oil) to retrieve storedenergy

Compression of air generates heat, expansion requires heat

Search underway in NB for suitable salt caverns

Compressed Air Energy Storage

htt ://www. o ularmechanics.com/technolo / ad ets/news/4292830-3


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Mortality most obvious effect

Can be from collision with turbine or barotrauma

Collision mortality greater in birds

Barotrauma potential threat, particularly in bats

Other sublethal effects to consider as well

Interference with migratory routes

Disturbance

Loss of habitat

Avian and Chiropteran impacts


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Location is important in placement of wind farms

Areas of steady, strong wind ideal

Poor area choice, poor power generation inefficient

Migratory birds have similar wind requirements to turbines

Soaring behaviour up slopes

Wind that is ideal for wind energy also used in migration

Migrating eagles use wind farm areas when thermals arent available

Birds use wind, too!


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Measuring wind farm fatalities

Collision mortality and death rates commonly estimated usingcarcass counts

Collection of carcasses within a certain distance of each turbine

Examination for cause of death

Collision fatalities fairly obvious decapitation, evisceration, severe trauma

Because sampling done periodically (1/month for example) correctionfor removal of birds by scavengers applied

Extrapolate from birds found to mortality for the turbine / site

Commonly described in deaths/turbine/year or deaths/MW/year


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Bird fatalities commonly cited as a major environmental concern of wind energy

Particularly with reference to large birds and endangered or protected species

Species of highest risk have low numbers, slow growth

Raptors, large waters, seabirds may be at risk

Particular concern for endangered species

Turbines pose a threat to both migratory and local birds

Impact of mortality on populations debatable

Fatality rates extremely variable each turbine different

Bird mortality at wind farms


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Relative to other anthropogenic sources, windenergy mortality is minor

Building collision, electrocution, and poison-related deaths substantially higher

Still concern over turbine collisions?

Social cost negative reputation

Additive mortality increased strain on species

Rapid development of wind energy could pushendangered species to extinction

Bird mortality at wind farms


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Sublethal effects may be severe

Loss of habitat / nest sites

Forced alteration of migratory route (avoidance) couldmean greater energy expenditure

Mitigation is possible

Selective stopping

Smart placement of turbines (population modeling)

Repowering of old turbines

Discouraging birds from using area

More research is needed to develop and test strategies

Impacts of wind energy on birds


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Bats are adept at detecting moving objects via echolocation

Collision with turbine and blades is less likely to be a threat

So why are bat fatalities so high?

Decompression hypothesis - Pressure difference created by turbineblades can cause internal hemorrhaging

Barotrauma tissue damage from pressure changes

Also experienced by divers

No universally accepted explanation available for bat mortality

Bat deaths from wind energy

Renewable Energy - Wind Lecture

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