A few press articles in recent weeks have discussed the fact that carbon emissions in Germany and the European Union have increased slightly over the last year or two because the country has shut down many of its nuclear power plants. It is important not to miss the forest for the trees, and to understand that this short-term increase is entirely caused by the shutdown of Germany’s nuclear plants and is only a temporary blip in the long-term, steady decline in emissions achieved by Germany’s transition to renewable energy.
Over the last decade, wind energy has allowed Germany to greatly reduce fossil fuel use and pollution, reductions that would have been even larger had the country not also greatly scaled down its use of nuclear power over that same time period.
As Germany ramped up its use of wind energy, coal use by Germany’s electric sector fell by more than 12% between 2004 and 2010, a reduction of 20 million tons per year. Wind energy was able to drive that reduction in coal use despite nuclear power output declining by 16% over that time period (falling from nearly 34% of the country’s electricity mix in 2004 to less than 25% in 2010).
Other European countries that have adopted even greater amounts of wind energy than Germany have seen even larger declines in pollution and fossil fuel use. Because Spain and Portugal now obtain 15% and 20%, respectively, of their electricity from wind, up from around 1% a decade ago, they have cut in half the amount of carbon dioxide their electric sectors emit per unit of electricity produced.
Electric sector coal use in Europe’s top five wind-using countries fell by 21% between 2004 and 2010. These savings totaled more than 100 million tons of coal per year.
The easiest way to assess the impact wind energy has had on pollution is to compare the emissions trend in the five countries that lead the world in wind energy use (Germany, Spain, Portugal, Denmark, and Ireland) versus the trend for similar countries that have not deployed as much wind energy. Between 1999 and 2010, each of these five countries greatly increased its use of wind energy (Table 1). For the comparison case, the aggregation of all European OECD countries increased their use of wind by a much lower amount.
Table 1: Wind Energy Growth in the Five Highest Wind Energy Use Countries
Country, Wind Energy’s Share 2010, Wind Energy’s Share 1999, Increase 1999-2010
Denmark | 22.6% | 6.8% | 13.8%
Portugal | 20.2% | 0.3% | 19.9%
Spain | 17.0% | 1.6% | 15.4%
Ireland | 11.0% | 0.1% | 10.9%
Germany | 6.9% | 0.03% | 6.9%
All OECD Europe | 4.3% | 0.5% | 3.8%
The best measurement of a country’s emissions profile is to look at changes in the amount of CO2 emitted by the electric sector for every unit of electricity produced, i.e., the emissions intensity of a country’s electric sector. One would expect that adding a zero-emission resource like wind energy to the power system would reduce the emissions-intensity of the country’s electric sector, and International Energy Agency data indicates that this is the case (Table 2). The countries that added the most wind energy saw the greatest declines in their emissions intensity, while countries that added less wind energy (like Germany and the aggregation of all OECD Europe) saw smaller declines in their emissions intensities.
Table 2: Percent Change in Electric Sector CO2 Emissions/kWh from 1999-2010
Country, % Change in CO2 emissions/kWh 1999-2010, Increase in wind’s share 1999-2010
Portugal | -53.07% | 19.9%
Spain | -46.45% | 15.4%
Denmark | -24.96% | 13.8%
Ireland | -34.24% | 10.1%
Germany | -12.58% | 6.9%
All OECD Europe | -12.6% | 3.8%
Interestingly, Germany would likely have seen a much larger decline in emissions intensity had the country not significantly decreased its use of zero-emission nuclear energy over the 1999-2010 period. Germany’s nuclear output dropped by 16.7% between 1999 and 2010, declining from 34.6% of the country’s electric output in 1999 to 24.5% in 2010.
Does this mean the current surge in coal demand is a blip? When asked by The Economist magazine, Tom Brookes of the European Climate Foundation, a non-governmental organization based in The Hague, said yes.
It is important to keep in mind that the temporary and small uptick in coal use in Germany over the last two years is purely the result of the country shutting down many of its nuclear power plants following the events at Japan’s Fukushima nuclear power plant in early 2011. As Germany continues to ramp up its use of wind and solar energy, the decline in fossil fuel use and carbon dioxide emissions will resume.
Fact check: Reason Foundation FAIL on wind and emissions, October 11, 2012
Fourteen wind energy myths debunked, June 20, 2012
Fact check: Roanoke Times op-ed misses a few key facts, March 13, 2012
Fact check: Silverstein errs on wind’s variability, emissions cuts, February 27, 2012
Fact check: Pavlak errs on wind integration, February 14, 2012
Fact check: New Dutch report misinformed on wind power and emissions, January 13, 2012
Fact check: Martikainen misguided on capabilities of renewable energy, December 1, 2011