For most of the last 30 years, coal and nuclear power--the big two--dominated Pennsylvania's electricity generation fleet. But, in 2012, major change arrived. During the first 6 months of 2012, natural gas electricity rose another 39% to provide 25% of the Commonwealth's electricity. The big two is now the big three.
As more electricity in the Commonwealth was generated with gas, less was produced from coal. From January to June 2012, coal generation fell 19% but provides about 38% of the state's electricity, more than any other fuel, and similar to the 35% that coal generated nationally during the period. (All data from or based on EIA's latest monthly report: www.eia.gov/electricity/monthly/pdf/epm.pdf).
Nuclear power provides the second most electricity in the Commonwealth, and Pennsylvania ranks second, behind only Illinois, in nuclear electricity generation. Nuclear plants here increased their output 5.7% in the first six months, generating roughly 35% of Pennsylvania's power, considerably more than the 20% nuclear produces nationally.
Pennsylvania's hydro generation fell 19% in the first 6 months, but the on-going, substantial Holtwood hydro project on the Susquehanna River will boost hydro production once completed. Though hydro was down, wind increased 12%. Pennsylvania is also benefiting from a surge in new wind farms that are being constructed in 2012 and that will boost future wind generation totals.
Unlike wind and hydro that were up or down, biomass production in Pennsylvania was essentially stable. Landfill gas projects provide most of Pennsylvania's biomass power, and Pennsylvania is a national leader in capturing landfill methane and converting it to electricity.
As for solar, the EIA data also does not capture most of the 150 megawatts of solar generation in Pennsylvania, because it is behind the meter or distributed generation. Recognizing the EIA solar data hole, renewables together provided about 3% of the electricity generated in Pennsylvania during the period, considerably less than the 13% all renewables generate nationally.
In summary, coal ranks first in Pennsylvania, nuclear second, gas third, and renewables fourth.