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Wind in the Big Picture

Wind energy produces electricity without emitting any pollutants or greenhouse gases at all, requires no mining or drilling, helps preserve habitat and open space, and poses no national security threats. Wind energy could easily and cost-effectively contribute 20% of California's electricity supply by 2030.


Wind is Part of the Solution to the Earth's Biggest Environmental Problems

When you turn your house lights on, chances are that the electricity was generated by a power plant that burns fossil fuels - coal, oil, or natural gas. These sources of energy account for more than 70% of current U.S. electricity generation and 58% of California's electricity generation. According to the Union of Concerned Scientists, fossil-fuel-fired power plants are the leading U.S. source of carbon dioxide emissions - a primary contributor to global warming, our most serious environmental problem and one that threatens every species on Earth.

The burning of fossil fuels for electricity generation is the single greatest source of air pollution in the U.S., causing cancer and other chronic health problems. The extraction of fossil fuels also degrades our land and water resources -- consider the coal industry's practice of "mountain top removal" which takes a heavy toll on human lives as well as the environment.

And yet fossil fuels are projected to account for the vast majority of power plant capacity additions over the next 20 years at a time when dramatic reductions in fossil fuel use are urgently needed to protect the planet.


Wind is Already Playing a Significant Role in Reducing Pollution and Carbon Emissions

Wind is the most widespread, commercially available renewable source of power in the U.S. In California, as of 2012, over 5,800 megawatts (MW) of wind energy capacity already generates enough energy to serve the electricity needs of more than 1.5 million households. Each year, as compared (conservatively) to pollutants from a relatively low-emission new natural gas plant, this clean electricity prevents the production of:

  • 2,250 tons of carbon dioxide (CO2) - a primary greenhouse gas

  • 450 tons of nitrogen oxides (NOx) - which creates smog

  • 310 tons of particulate matter (PM10) - which causes respiratory health problems
California's current wind energy generation also reduces the demand for natural gas by 200 million cubic feet per day, which in turn reduces the marginal price of natural gas for all gas consumers. This gas-price-reducing effect saves consumers an estimated $50 million annually.

Wind Energy can have side benefits as well. In some cases, wind projects help preserve habitat or open space, by making land profitable without dense housing and commercial developments. This is because the "footprint" of wind projects amounts to only about 5% of the total project area, preserving that space for agricultural or ranching use, or for no "use" at all.


Wind Energy is Reliable

In addition to providing clean energy, wind also makes our electricity system more reliable. While not intended as a "capacity" resource to meet system peak load, California's existing wind projects do provide "capacity value" to the system in an amount equivalent to about 25% of their nameplate electrical rating. Values for new projects will be higher. Wind's variable output (very similar to changing consumer demand for power) can be readily managed by grid operators (See Energy Commission report and a CalWEA editorial on these topics).

According to the Utility Wind Interest Group, there are no fundamental technical barriers to wind penetrations of up to 20% of system peak demand, which is far beyond where we are today. An article in IEEE's Power and Energy Magazine addresses a number of popular misconceptions about wind power and power systems and provides excellent information on wind integration issues.

Nationally, sustained growth could allow wind to provide 20% of total U.S. electrical generation within the next couple of decades, approximately 340,000 MW.


The Environmental Impact of Wind Energy

Most human activities have some negative impact on the environment, and wind projects are no exception. If wind energy is to help combat global warming, wind projects will have visual impacts and will affect birds, bats, and other wildlife. The wind industry has joined with the nation’s leading conservation organizations to create and support the American Wind Wildlife Institute (AWWI) in an effort to minimize those impacts. AWWI also puts those impacts in perspective, stating that "The predicted and devastating impacts of climate change on biodiversity need to be incorporated into the risk calculus of renewable energy development in ways that they are not today. Even as the conservation community partners with the wind industry to minimize impacts of siting renewable energy, it will be necessary to accept some, and perhaps substantial uncertainty about the [local, direct] risk to wildlife populations if we are to limit the greater risks of global extinctions from unlimited climate change." Climate activist Bill McKibben has likewise effectively argued that global warming is the greater imperative.

Fortunately, for the vast majority of the hundreds of wind projects across the country, the U.S. General Accounting Office (GAO) reports that "In the context of other sources of avian [mortality], it does not appear that wind power is responsible for a significant number of bird deaths." The one wind project area that has proven to be uniquely hazardous for birds is the Altamont Pass, near Livermore, California.

The Altamont- one of the first wind resource areas to be developed in the U.S., in the mid-1980's - is acknowledged to have a relatively high number of avian fatalities compared with all other wind project sites in the country. This is due in part to the abundant raptor prey (rodents) in the area. The level of avian mortality in the Altamont may not be as high as has been widely reported, however. Independent reviews commissioned by both CalWEA and the California Energy Commission show that the conclusions of a widely-cited 2004 report, which contained mortality estimates significantly higher than found in past studies, are not credible. See summary of these reviews.


Human Health Impacts of Wind Energy

On wind energy and human health, Health Canada (Canada's federal health agency) released the results of a major study on wind energy and human health in November 2014. The study's key findings include a lack of any link between exposure to wind turbine noise and self-reported illnesses (such as dizziness, tinnitus, or migraines) and chronic conditions (such as heart disease, high blood pressure, or diabetes), and no association between low-frequency noise and infrasound and any of the self-reported illnesses or chronic health conditions assessed (e.g., migraines, tinnitus, high blood pressure, etc.)


The Wind Industry Takes Environmental Stewardship Seriously

Although wind power is one of the most environmentally friendly energy sources available today, CalWEA and the wind industry are committed to reducing avian impacts. In the Altamont, the industry is working with Alameda County to develop measures that will reduce avian fatalities in the area. Measures already in place are estimated to cost the industry approximately $9 million annually in lost revenues and direct costs.

CalWEA has worked to facilitate what appears to be the most promising way to reduce avian impacts: repowering - i.e., replacing the many older turbines with far fewer, larger modern ones. Studies indicate that various measures taken in the Altamont, including repowering, taken since 2005 to reduce golden eagle mortality and that of other focal species had, by 2010, already achieved a 50% reduction in fatalities, with substantial additional capacity to be repowered by 2016.

CalWEA is also working to promote the state of the science related to pre-construction site evaluation and monitoring techniques. In 2008, CalWEA commissioned a scientific review of California's Guidelines for Reducing Impacts to Birds and Bats from Wind Energy Development to better understand the scientific basis for these Guidelines. Having documented many deficiencies, CalWEA is now exploring ways to improve guidelines for study techniques to promote their efficacy and efficiency in predicting and avoiding avian and bat impacts. In 2009, the California Energy Commission awarded CalWEA a grant to conduct research to improve the accuracy of methods for estimating the number of bird and bat fatalities at wind energy facilities.


How New Wind Technologies Help Reduce Wildlife Impacts

As a green industry, the wind industry takes the issue of avian mortality seriously and is committed to reducing harm to wildlife caused by wind projects. The following are some of the measures the industry has taken which result in avoiding and reducing avian impacts as compared to early experience in the Altamont Pass:

  • Repowering, or replacing old wind turbines with new ones, is essential. Modern turbines are much larger, so fewer than one-tenth as many turbines are needed to generate the same amount of energy

  • Blades on modern turbines rotate more slowly, are more visible, and are situated much higher, so they are not only easier for birds to avoid, but are high enough to avoid sensitive flight zones for many raptors

  • Perching opportunities on turbines and their towers have been minimized

  • Power lines are buried when feasible and otherwise constructed to minimize the risk to raptors

  • Guy wires are not used on new turbine towers

  • As a result, for example, following the repowering of the Buena Vista project in the Altamont Pass in 2006, avian fatalities have been reduced by 65% from the rate previously experienced, according to a report prepared on behalf of Contra Costa County.

  • Project developers routinely avoid sites with high environmental sensitivity. At other sites, developers work with county and other local officials to carefully evaluate potential environmental impacts well before the start of construction.

  • Where there is possible risk of significant avian mortality at a site, pre-construction avian monitoring is conducted to better understand impacts and to develop a mitigation plan. (For more information on siting projects in California, see CalWEA's comments before the California Energy Commission on this topic.)

Birds are Affected Far More Profoundly By Other Human Activities

It is important to keep wind's impacts on wildlife in perspective. In addition to the global warming and air quality impacts associated with fossil fuels that profoundly affect wildlife habitats, many other human activities are far more hazardous for birds than wind turbines.

The U.S. Fish and Wildlife Service estimates, for example, that communications towers conservatively kill 4 to 5 million birds annually in this country, and possibly as many as 50 million. Up to two million birds are killed annually in oil and wastewater pits, mainly in the western states. And a study published in 2013 shows that household and feral cats are likely the single greatest source of anthropogenic mortality for US birds and mammals, killing a median of 2.4 billion birds and 12.3 billion mammals a year.

By comparison, the agency estimates that existing wind turbines kill an estimated 33,000 birds annually. Even if this number were to increase linearly with the number of new turbines -- which is unlikely due to the industry's improved technology and siting techniques, wind-related avian fatalities would still account for a very small fraction of birds killed by other human causes.

Even when wind energy grows to supply 20% -- one fifth - of the nation's electricity, the American Bird Conservancy anticipates one million associated bird kills annually, about one one-thousandth of the one billion birds now killed every year by human causes.


Using Wind Energy Conserves Water

Wind energy projects consume virtually no water, using just one one-thousandth of a gallon per kWh (mostly for blade cleaning). In contrast, California's conventional power plants use 300 gallons for each kWh, an amount equivalent to 1% of the state's urban water use. According to the California Energy Commission, 17 billion gallons of water per day are used to cool California coastal power plants, harming small and large marine animals through the physical impact of pulling massive amounts of water through the intake systems and by raising water temperature.

Water scarcity and water politics have shaped California's history and produced some of its largest public works projects, which have dramatically affected, and continue to affect, the state's ecosystems. Using wind turbines for power generation reduces the demand for scarce water resources.


How Does Wind Energy Work?

The American Wind Energy Association has created an excellent guide to the physics and technology of wind energy. This article and others can be found at these links:

AWEA Wind Energy Fact Sheets
NREL Wind Energy Basics
California Energy Commission Reports on Wind Energy
More Educational Links


Fast Facts about California Wind Energy

+ Wind energy projects totaling approximately 6,022 megawatts (MW) of capacity are operating in California today,1 providing enough electricity to power more than 2 million California households.2 This represents more than a tripling of wind energy capacity since California's Renewables Portfolio Standard (RPS) law was adopted in 2002.

+ In 2014, California wind projects generated 12,977 gigawatt-hours (GWh) of electricity – 6.5% of all power generated within California.3 In the same year, out-of-state wind projects generated 10,917 GWh of electricity for California, representing 11.2% of total power imports.3 Combined, wind projects supplied 8.1% of California’s total system power,3 enough to power all homes in Sacramento, Santa Clara, and San Diego Counties combined.2

Major Wind Development Areas 5

# MW
# Wind Turbines
Altamont Pass (Alameda, Contra Costa, San Joaquin Counties) 510 4,029
San Gorgonio Pass (Riverside County) 683 2,159
Tehachapi Pass (Kern County) 3,236 4,731
Solano County 1,032 601
Imperial County 265 112
Shasta County 101 44
San Diego County 52 26
Other 35 181
Total 5,914 11,883

+ Generating wind power creates no emissions and uses virtually no water:
  • The water consumption savings from wind projects in California total more than 3.4 billion gallons of water per year1
  • The wind power installed in California will avoid over 7.8 million metric tons of carbon dioxide emissions annually, the equivalent of taking 1.7 million cars off the road1

+ Wind energy accounted for 29% of California’s in-state renewable energy production in 2014.4

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1. American Wind Energy Association. (Data as of January 2016)

2. Calculated by CalWEA based on California Energy Commission data.

3. California Energy Commission, Total System Power Report (for 2014).

4. CEC, Tracking Progress - Renewable Energy, Rev. 12/22/15

5. American Wind Energy Association. (Data as of December 2014) Updated January 2016.