◊ Part of the ‘wind energy’ series of articles ◊
There are many aspects of wind energy production that impact humans, animals and our environment. Some are good, some are quite harmful and require some form of mitigation.
Emissions
A key element in the case supporting wind energy is the avoidance of carbon emissions from fossil fuel power plants.
According to a report prepared by Intrinsik for OPG in 2016, natural gas electricity production produces 525g of Carbon Dioxide for every kWh of energy produced. The Ontario Power Authority (2014) estimated the GHG emission rate of a combined-cycle natural gas-fired power plant is 290 grams/kWh. To throw another estimate into the mix, the Ontario Society of Professional Engineers (OSPE) published an emission rate of 400g/kWh. The range of emission rates are a result of the different types of gas generators – simple or combined cycle.
If you assume the use of wind energy reduces the natural gas generation one for one, it would result in the following carbon emission avoidance:
| Year | 2014 | 2015 | 2016 | 2017 | 2018 |
| Carbon Dioxide Reduction (Million Tonnes) at 400g/kWh | 3.57 | 4.73 | 4.88 | 4.83 | 5.62 |
Note that this is an over simplified case that errs on the high side of carbon avoidance. There will be times that wind energy is being produced and gas generation is not required due to surplus.
Based on the Ontario trend (IESO annual reporting) showing a reduction of natural gas energy and increase of wind energy on the grid it is reasonable to attribute some of the trend to the availability of wind. The gradual overall reduced demand does not account for the magnitude of natural gas generation decline.
If the ECO report on generator unit-cost from 2016 is correct that gas and wind generation is the same, it means the cost of CO2 reduction was $0 (free). You may take that with a grain of salt, however one of the standard measures of CO2 reduction uses the difference in unit-cost between gas and wind to determine GHG emission cost per tonne.
Baking the numbers
According to Ontario Clean Air Alliance Research the 2017 cost of GHG reduction by wind energy was $110 per Tonne using the difference in unit-cost criteria. The cost was generated using questionable unit-costs for wind and gas energy. They used the wind energy price of 8.59 cents/kWh and natural gas price of 5.4 cents/kWh which unfortunately are not representative of the true prices. This is what I mean by ‘baking numbers’.
The bigger picture
According to the 2018 Greenhouse Gas Progress Report by the ECO, the transportation sector is the largest contributor to Ontario’s GHG emissions (35%), followed by industry (30%), buildings (21%), agriculture (8%), waste (4%) and electricity (3%).
Electricity is well positioned to displace GHG emissions in the transportation sector in Ontario. It will require leadership from government to move in that direction since it isn’t changing on its own.
Effect on climate
The presence of wind farms has an impact on the prevailing winds by removing energy and reducing their velocity. This can impact local temperatures and rainfall.
Determining the extent of climate change due to wind farms is difficult due to the limited data collected for locations before development and eliminating other effects.
The wind energy and climate debate is similar to the global warming issue. It won’t be resolved any time soon, however research will continue as wind energy expands globally.
Wildlife and habitat
The presence of wind turbines are known to present risks to migratory birds and bat populations. While turbines present less of a risk to birds than high-rise buildings in urban environments, the harm is incremental to the overall population.
There are many noteworthy studies and reports from around the globe on the topic and it warrants consideration when wind development is being assessed in any jurisdiction.
The Ministry of Natural Resources and Forestry presented a summary of the avoidance and mitigation approach used in Ontario at a conference in 2014. It provides an excellent overview indicating that bat mortality and loss of bird habitat are the greatest concern in Ontario.
Ground water contamination
There are potential impacts to local groundwater that can result from the construction, operation and decommissioning of wind farms.
In the Chatham-Kent area of southwestern Ontario there are complaints from 21 land owners that the pile-foundations of the wind turbines in the area have contaminated the well water. Testing has confirmed that the wells have high levels of shale which is presumed to have resulted from the wind turbines being located above the aquifer of Kettle Point shale that provides water for farms in the area.
An investigation by the Ministry of the Environment and Climate Change has concluded that the vibration from the pile driving and turbine operation are not the cause of the water contamination. Other experts do not agree and the issue remains.
Update 07/27/2019: Charges have now been laid against the Ministry of the Environment and three companies associated with the wind farm related to the ground water contamination. They are scheduled to appear in court in Blenheim on August 14, 2019.
Visual pollution
The appearance of wind turbines on the pristine rural landscape can be offensive to local residents. It should be left to the local authorities to manage any objections, however in Ontario, the Green Energy Act enabled a fast track process that bypassed municipal approval.
The Green Energy Act was repealed in 2018, restoring local authority. Unfortunately there is no new wind energy development for the foreseeable future so any perceived damage has already been done.
In a 2014 study, Health Canada noted an annoyance factor due to shadow flicker and blinking lights at wind farms. It is considered a quality of life concern.
Noise pollution
Wind turbines emit low-frequency sound due to the movement of the blades through the air.
The low-frequency noise, also called ‘Infrasound and Low-Frequency Noise’ (ILFN) has been associated with a number of different health problems.
In Canada, Health Canada conducted a study on wind turbine noise which failed to find any correlation with sleep or stress effects.
Health Canada did find quality of life and annoyance factors.
Windwise Massachusetts claims living too close to turbines causes Wind Turbine Syndrome and Vibroacoustic Disease. The symptoms associated with these conditions include:
- balance problems
- disturbed sleep
- headaches
- tinnitus (ear ringing)
- a sense of quivering or vibration
- nervousness
- rapid heartbeat
- nausea
- difficulty with concentration
- memory loss
- irritability and anger
It is possible to measure noise levels produced by wind turbines however there aren’t sufficient human studies available to definitively correlate cause and effect.
Environmental Regulatory requirements
In Ontario Renewable Energy projects must be approved in accordance with the Environmental Protection Act, Regulation 359/09. Ontario has developed a ‘Technical Guide to Renewable Energy Approvals’ which includes references to:
- human health
- natural heritage (e.g.animals, birds, insects, trees, and vegetation)
- noise
- groundwater
- surface water.
Since the repeal of the Green Energy Act in 2018, developers must also demonstrate a need for the renewable energy being proposed.
Turbine failure and safety
On January 19, 2018 a GE 1.5MW xle turbine suffered a catastrophic failure at the Raleigh wind farm in Chatham Kent, southwest Ontario.
The facility was placed in service in 2011. No injuries were reported.
In May of 2018 a Huron Wind project just north of Tiverton, Ontario experienced a blade failure due to high winds off Lake Huron. The area has over 200 wind turbines.
In June of 2018 the city of Hamilton, Ontario dismantled a series of 10-meter high vertical axis wind turbines due to foundation problems that led to excessive tower movement. There was a concern that the turbines would collapse and cause personal injury.
An unofficial list of international wind turbine failure statistics is maintained by Caithness Windfarm in the United Kingdom.
Fortunately, wind farms are typically installed in rural areas where the risk to humans and animals is low, however fatalities have been reported. According to Caithness Windfarm, the most common problems with wind turbines are blade failures and generator fires. Failures within the turbine would involve the transmission or generator itself. Occasionally blades failure will cause secondary damage to the structure leading to complete collapse. Best not to be around one when it disintegrates!
The expected service life for a wind turbine is over 20 years.
The takeaway
The use of wind energy reduces the amount of greenhouse gases being produced by the electricity sector. The precise amount of the reduction is up for debate, however it is a step in the right direction. It is also beneficial in the effort to reduce climate change. The cost associated with GHG reduction is low, making the use of wind energy a good option for a carbon-reduction strategy.
Wind turbines impact wildlife. The greatest impact is to bats and bird habitat.
Wind Farms can cause groundwater contamination from pylon construction, operation and decommissioning. Sensitive areas with aquifers are particularly vulnerable.
Visual and noise pollution issues impacting health have been reported. A Health Canada study conducted on wind turbine noise failed to find a correlation with ill effects.
International studies have found health effects termed Wind Turbine Syndrome and Vibroacoustic Disease.
It appears that wind energy has both positive and negative effects on the environment. Regulations are required to avoid negative human, animal and other environmental impact. In Ontario, the Environmental Protection Act has provisions under regulation 359/09 to safeguard against harm. Regulations should continue to evolve as industry experience increases.
Derek
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