The Number 22

Nuclear energy generation supplies 20 percent of the electricity in the United States. It’s been that way for years, as reported by the Energy Information Administration, the statistical arm of the Department of Energy.

But a number of factors, according to the EIA, has pushed the relative percentages of several energy sources up because one went down rather dramatically, both statistically and practically.

That would be coal, which dropped from 46 percent in December 2010 to 39 percent in December 2011. The EIA says that the main driver of this decrease is the increased use of natural gas, which increased its share from 22 percent to 26 percent.

Electricity use itself declined 7 percent, so that in itself makes percentage increases and decreases a little chimerical – that is, nuclear generated roughly the same amount of electricity as last December but in a smaller marketplace – as did hydro, which advanced from 6 to 7 percent.

But the decline of coal in favor of natural gas is quite real: coal generation fell 21 percent compared to a 12 percent rise in natural gas generation. The last time coal fell below 40 percent in these surveys was in 1978.

So the news about nuclear energy might seem a numerical blip. But it’s not a trick, and it’s legitimate to note because it speaks to the steadiness of nuclear energy. We’ll have to keep an eye on the monthly report to see what happens when electricity usage returns to its former levels.