News•January 13, 2016

States' Electricity Goals Have Limited Reach: Study

Renewable electricity goals put in place by 29 states are cutting pollution that causes climate change, but they are only making a minuscule difference in overall U.S. and global greenhouse gas emissions, according to a report released Tuesday by the Lawrence Berkeley National Laboratory.

Electricity generation is the globe’s biggest single source of greenhouse gas emissions driving climate change, mainly from coal-fired power plants. State renewables goals, called renewable portfolio standards (RPS), aim to cut the percentage of a state’s electricity that comes from burning fossil fuels. In the U.S., electricity generation represents about 31 percent of the country’s annual greenhouse gas emissions.

Berkeley Lab's analysis of the benefits of 29 states' renewable portfolio standards in 2013.
Credit: Berkeley Labs

“In general terms, we certainly find that RPS programs in 2013 reduced greenhouse gas emissions providing important climate change reduction benefits,” Ryan Wiser, a senior scientist focusing on energy markets and policy at Berkeley Lab, said. “The scale of the climate change ‘problem’ is enormous, if we are to believe the IPCC, and existing state RPS programs have just scratched the surface.”

The Berkeley report focuses on the most recent year for which data is available — 2013. That year, 2.3 percent of U.S. electricity came from low-carbon sources such as wind and solar that were built to meet renewable portfolio standards. Those sources resulted in a 3.6 percent reduction in total electricity produced from fossil fuels nationally, the report says.

The standards led to a 59 million metric ton reduction in greenhouse gas emissions across the states with the renewables standards, supporting 200,000 renewable energy jobs there. Total U.S. greenhouse gas emissions in 2013 were nearly 6.7 billion metric tons.

Coal-fired power plants use a lot of water for cooling, so less water is consumed for electric power generation when states switch to renewables. Water consumption in states with RPS standards fell by 27 billion gallons because of renewables use, or roughly 2 percent of total U.S. power sector water consumption.

“Water use is largely a regional issue,” Wiser said. “We do see significant water use reductions in a number of drought-prone regions. The largest withdrawal savings are thought to exist in California, and the largest consumption savings are in the state of Texas.”

Both states have suffered withering drought recently, with California continuing to endure its most severe drought in recent history.

Renewables standards vary widely from state to state. When Hawaii Gov. David Ige signed the state’s renewable energy bill into law last June, the Aloha State became the first in the U.S. to mandate all of its electricity come from renewables, a goal that must be met by 2045.

Vermont followed Hawaii in June with what may be an even more ambitious goal — to generate 75 percent of the state’s electricity from renewables by 2032, with 55 percent coming from renewables by 2017, less than two years from now.

California, Maine and New York each have a mandate for at least 30 percent of their power to come from renewables.

Other states have taken a step back. Kansas rescinded its renewables mandate earlier this year, turning it into a voluntary goal. States such as Florida, Idaho, Wyoming and Georgia have no renewables mandate at all.

“This analysis today was of course retrospective in nature, looking at the year 2013,” Galen Barbose, a scientist in Berkeley Lab’s electricity markets and policy group, said. “State RPS targets will ramp up considerably from those levels over time.”