Average on-peak, day-ahead wholesale electricity prices rose in every region of the Lower 48 states in first-half 2013 compared to first-half 2012. The most important factor was the rise in the price of natural gas (the marginal fuel for generation in much of the nation) in 2013 compared to 10-year lows in April 2012. However, the increase in power prices was not uniform across electric markets as regional natural gas supply issues drove larger increases in the Northeast and Pacific Northwest.
Prices in New England were the highest in the nation mostly because of pipeline constraints that limited the delivery of natural gas. This factor drove electricity prices in New England and New York above $200 per megawatthour (MWh) for several days this winter.