Tag Archives: wind power

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Nuclear: Better GHG Performance than Wind for Power Generation

By Romeo St-Martin
Communications Officer
Canadian Nuclear Association

Is renewable energy necessarily green? Only if it can generate electricity without adding more carbon to the atmosphere.

Power utilities across Canada and around the world are ramping up their renewable energy sources, and adding wind to their supply mixes because it seems so clean, so green.

But a recent independent study of life-cycle carbon emissions questions whether wind power really reduces greenhouse gases in real-world uses.

Hatch report coverThe study, by the Toronto-based engineering firm Hatch Ltd., compared greenhouse gas (GHG) emissions from nuclear power plants and from wind farms backed by natural gas plants.

It’s an apples-to-apples comparison: Nuclear plants generate around the clock, but wind plants operate only when the wind blows. To match a nuclear plant’s output, a wind farm needs backup.

The replacement power usually comes from hydro dams, which can open additional gates to raise electrical output, or from natural gas plants that fire up additional burners. Gas plants are faster and easier to build than hydro dams, so they often supplement wind farms.

Looking at actual generation data, the Hatch team estimated that wind farms produce only 20 percent of their potential, and assumed that natural gas plants would make up the difference.

The analysis estimated nuclear power emitted 18.5 grams of greenhouse gases per kilowatt-hour (kWh) through the entire life cycle, compared to 385 grams per kWh for wind backed by natural gas. In other words, a decision to invest in wind plants is actually a decision to produce climate-changing greenhouse gases.

“When considering wind backed by natural gas power (20%/80%) to compensate for intermittency, emissions from the modified grid mix closely resemble that of natural gas production, diluted by a low-emissions power source,” the study noted.

To the average person, the term “renewable energy” suggests an energy source that does not contribute to climate change. But “renewable” doesn’t always mean “low-carbon.” A closer examination, such as the Hatch study, shows that nuclear energy is the better choice for the climate.

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The Thousand Islands Energy Research Forum

By John Stewart
Director, Policy and Research
Canadian Nuclear Association

The Thousand Islands Energy Research Forum took place at the University of Ottawa this past weekend. CNA took advantage of this great opportunity to present the recent Hatch life cycle emission study, which had been launched on October 8 at our Toronto fall seminar.

John Stewart presentation

TIERF, an annual academic event that mixes energy policy and technology, drew about 40 university, government and industry participants this year. They brought presentations and technical posters on energy technology research, ranging from shale gas to geothermal to nuclear.

CNA director of research and policy John Stewart delivered a summary of the Hatch study along with CNA’s key messages from it. While nuclear is roughly as clean-emitting as wind for power generation, wind cannot stand alone due to its intermittency, and any assessment of wind’s environmental effects must include the impact of managing that intermittency.

In Ontario today, new wind farms are only generating about 20% of their capacity, and when the wind fails to blow, the difference is generally made up by burning natural gas, a fossil fuel. This means that building new wind capacity means building in more, not less, GHG emissions to Ontario’s supply mix – undoing some of the benefits of the province’s successful exit from coal.

CNA’s presentation on October 25 was preceded by an excellent analysis by u of O’s Olayinka Willliams on “The Integration of Wind Power Generation with Hydroelectricity in an Electric Grid,” which expounded the many problems of bringing randomly intermittent wind power into a grid, even when hydro is available to back it up.

GHG emissions by energy type

According to the Electric Power Research Institute, “the existing electric power grid, especially its distribution systems, was not designed to accommodate a high penetration of distributed energy resources while sustaining high levels of electric quality and reliability.” (“The Integrated Grid,” February 2014). Bollen and Hassan’s 2011 engineering text Integration of Distributed Generation in the Power System says the problems include increased risk of overload and increased losses; increased risk of overvoltages; increased levels of power-quality disturbances; and impacts on power-system stability and operation.