Gas shale competes with thermal coal as a fuel to produce electricity and the shale-drilling boom has led to very cheap gas. Gas use by power companies jumped 32 percent in the first half of 2012, while coal demand dropped 18 percent. US coal output stripped demand by 152 million tons in the twelve months ended in June. Thus, shale gas is potentially coal's worst enemy. In 2008, US natural gas prices topped $12 per million BTUs; it's now around $3.