BOSTON (AP) — New England’s grid operator says wholesale electricity prices dropped by nearly 23 percent last year thanks to falling natural gas prices and lower demand.

ISO New England announced Wednesday that prices are now at their lowest levels since 2003.

The ISO says prices dropped from $46.23 per megawatt hour in 2011 to $36.09 last year. That means consumers paid $1.5 billion less for electricity in 2012 — from $6.7 billion in 2011 to about $5.2 billion in 2012.

The ISO says the drop is partly driven by a 20 percent price decrease for natural gas, New England’s dominant fuel for energy production.

The ISO says lower demand — due in part to the economic downturn, milder weather and better energy efficiency — has also pushed prices down.

Copyright 2013 The Associated Press.