The Energy Information Administration reports:
Total natural gas use for power generation in the United States was down 14% during the first seven months of 2013 compared to the same period in 2012 (see chart), mostly because of higher natural gas prices relative to coal prices. High natural gas-fired generation in 2012 occurred as a result of the lowest spot natural gas prices in a decade—in fact, the two fuels contributed approximately equal shares of total generation in April 2012. Despite lower gas use for generation thus far in 2013, natural gas generation remains consistently higher than levels before 2012, as shown in the graphs below.
Energy prices have been notoriously volatile for my entire life. That’s the nature of markets; left to the players involved, energy markets will tend to shift natural gas to where it works best and to use coal where it’s most effective. Our own house has natural gas heat and our electricty is from a coal plant.