Will supplies of natural gas last?
posted at 8/24/2011 1:04 PM EDT
Natural gas-fired generators--not solar, wind, biomass or nuclear--have been the real key to reducing the Massachusetts "carbon footprint" while also moderating high costs of electricity in the state. A long string of large combined-cycle, natural gas-fired (CCNG) power-plants recently opening, approved and pending in Massachusetts includes:
Calpine, Dighton, 170 MW, opened 1999
Berkshire, Agawam, 250 MW, opened 2000
Blackstone, Worcester, 570 MW, opened 2001
Millenium, Charlton, 360 MW, opened 2001
Kendall, Cambridge, 170 MW, repowered 2002
Bellingham, Norfolk, 570 MW, opened 2002
Fore River, Weymouth, 820 MW, opened 2003
Mystic, Everett, 1640 MW, opened 2003
Stony Brook, Ludlow, 530 MW, opened 2002-2005
Watson, Braintree, 110 MW, opened 2009
Stony Brook, Ludlow, 280 MW, approved 2008
Clean Energy, Brockton, 350 MW, pending
Pioneer Valley, Westfield, 430 MW, pending
Carolyn Johnson, if she wanted, could have a happy opportunity to combine business, science, environment and "local color" with a review of natural gas-fired power in Massachusetts. The combined capacity of these highly efficient, low-pollution plants--6,250 MW--is more than nine times the capacity of Pilgrim Nuclear Generating Station in Plymouth. The average growth in capacity of CCNG power in Massachusetts, over the past 15 years, would replace the Pilgrim plant's capacity in less than two years if it closed.
When this trend began, a worry was that it would exhaust supplies or import capacity for natural gas and run up the price of electricity. Just recently, the U.S. Geological Survey released a sharply increased estimate of natural gas reserves in Marcellus shale, a giant Appalachian formation running from northeastern Alabama through south-central New York, raising its mid-range estimate for recoverable gas reserves from 2 to 84 trillion cubic feet. [ James L. Coleman, et al., Assessment of undiscovered oil and gas resources of the Devonian Marcellus shale of the Appalachian basin province, August 23, 2011, at http://www.usgs.gov/newsroom/article.asp?ID=2893 ]
A mid-range CCNG plant, Chouteau in Oklahoma, advertises that it typically uses 86 million cubic feet per day to generate 522 MW output. [ at http://www.aeci.org/FacilitiesCH.aspx ] Scaling that to the Massachusetts inventory of large CCNG power-plants, at a 90-percent capacity factor they would be likely to use about 0.34 trillion cubic feet per year. Marcellus shale gas reserves, according to the recent USGS estimate, could supply those plants for about 250 years. Of course, other states are now starting to catch up with Massachusetts in converting to CCNG, and the supply is clearly finite.