Friday, February 20, 2009

U.S. electricity down 0.9%

Though not as dramatically as oil use (12.8% decrease), November 2008 electricity generation in the U.S. was 0.9% lower than in November 2007 (Electric Power Monthly, February 2009, Energy Information Administration).

Coal and nuclear generation were both lower, while natural gas, hydro, oil, and non-hydro renewables (mostly wind) were higher.

Although wind generation was 42.4% higher, that represents only a 0.07% increase as part of overall electricity generation. (Note that the EIA multiplies wind generation by three for accounting purposes to correlate with thermal inefficiency; therefore, at first glance wind's 42.4% increase represents a 0.21% increase in total electricity generation (assuming that wind represents two-thirds of nonhydro renewables), but calculating back from the total leaves wind with 0.07%.)

Meanwhile, the 6.1% increase in hydro generation represents 0.39% of total generation and the 1.0% increase in natural gas generation represents 0.21%. Oil generation increased 4.8%, which represents only 0.05%.

So it would appear that the use of renewables increased, and the use of coal and nuclear correspondingly decreased. But there are other aspects to these figures, namely actual resource consumption.

Although coal generation decreased 2.7%, the consumption of coal for electricity decreased only 1.3%. And despite an increase in natural gas generation of only 1.0%, the consumptiion of natural gas for electricity increased 3.4%.

This suggests greater inefficiency, likely caused by the integration of more wind-generated electricity, which is intermittent, highly variable, and nondispatchable, thus requiring other plants to be ramped up and down or run at a less efficient level of production. The use of more wind may also explain the increase in oil-fired generation, because such plants are typically the quick-response sources more often needed to help balance the fluctuations of wind generation. It may also account for part of the increase in hydro, which is another source able to respond quickly to the variations caused by wind.

In summary, the good news is that demand was down from a year before, and coal and nuclear were both lower, together accounting for a decrease of 1.75% of total electricity production. Despite a 50% increase in wind capacity from November 2007 to November 2008, wind contributed only 0.07% towards the difference between the 0.9% net decrease and the 1.75% decrease in coal and nuclear, or 8% of that 0.85% difference. Twenty-five percent of the difference was provided by increased natural gas, and 36% by increased hydro.

But, again, natural gas consumption increased more than three times more than its increase in generation, and likewise coal consumption decreased only half as much as its decrease in generation.

wind power, wind energy, environment, environmentalism