Wednesday, February 10, 2010

Could Wind Power Increase Carbon Dioxide Emissions?

The real problem with wind power is its unreliability, as I've stated time and time again. But in places like Canada, can wind power actually increase the reliance on fossil fuels? It seems counter-intuitive but the answer is 'yes'.

In countries like, Denmark, which relied almost exclusively on fossil fuels in order to provide electricity, the introduction of wind power, even as an unreliable source of electricity, can enable the country to reduce its fossil fuel reliance over what it would have been had wind power not been introduced. But this is because it is replacing fossil fuels exclusively.

In a province like Ontario, the situation is far different because we rely on nuclear electricity to produce electricity for what is known as the 'base load'. Nuclear power is extremely useful at providing a constant, consistent amount of electricity over an extended period of time and that is how it is applied in Ontario. In order to handle the vast majority of the fluctuations in electricity demand, Ontario uses coal, gasoline or hydro.

Figure 1: Nuclear power in Ontario over a 3 day period (January 9th -11th, 2010). Blue line represents the rated power, and the red represents the actual production. Data publicly available on the IESO website.

Ontario's demand fluctuates between 15000 MW and 21000 MW these days (see here), but nuclear electricity generally provides a constant 10000 MW of electricity regardless of what time it is during the day. When Bruce A restart is complete in a year or two (hopefully), this will increase to around 11500 MW. That means, at low demand, nuclear power currently are the source for 66% of the electricity. Hydroelectric projects provide an additional 3000-5000 MW of electricity.

So, ideally, at low demand, Ontario's electricity generation is practically emission free. However, because coal and gasoline are easy to 'tune', they are used in small amounts at low demand in order to match supply and demand better.

The problem with wind power really is its unpredictability. One day it might be working at 80% efficiency, the next, it might be producing at 5%. But because of McGuinty's laws, wind power always must be incorporated into the grid when it is available, no matter what.

Figure 2: Wind power in Ontario over a 3-day period (January 9th - 11th, 2010). The blue line represents the rated power, the pink represents the actual output. Data publicly available on the IESO website.

Figure 3: Wind power in Ontario over the month of January. The blue line represents the actual output from wind power sources. Maximum rated output is 1100 MW for all wind powered generators. Data publicly available on the IESO website.

McGuinty is planning on increasing wind power up to at least 3600 MW within the next few years thanks to his recently inked 'deal'. This means, that in a few years, if low demand remains where it is, it is possible that at low demand wind power will replace hydroelectricity and even some nuclear power plants.

Nuclear power in Ontario is not designed to be able to handle such fluctuations in power output. Moreover, once a reactor is off the grid for some hours, it must shut down and remain off for about a day and a half before it can restart at all. So in order to accommodate the potential for high wind power during low demand times, Ontario would have to instruct nuclear power plants turn off completely (derating is possible too but not generally preferable) and remain off during high demand periods.

Then, during high demand periods, Ontario will have to use additional gasoline and coal fired power plants in order to replace the nuclear power plants that are off. To make matters worse, the wind power may drop during high demand periods, requiring even more gasoline and coal fired power plants to operate.

Which then leads to an amusing situation. Producing more wind power may actually result in an increase in carbon dioxide emissions in addition to an increase in your electricity bills.

Still think wind power is an environmentalists best friend?

1 comment:

Michael said...

Sorry Eric, your false claims are completely contradicted by government data for Colorado and Texas showing that emissions and fossil fuel use have drastically decreased in lock-step as wind has been added to the grid there. Similar studies by independent grid operators from other regions show the same result. Besides, to be true, your claim would require a significant re-writing of the laws of physics.

For more, see:

Michael Goggin, American Wind Energy Association

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