Climate mitigationU.S. Power Sector is Halfway to Zero Carbon Emissions

Concerns about climate change are driving a growing number of states, utilities, and corporations to set the goal of zeroing out power-sector carbon emissions. To date 17 states plus Washington, D.C. and Puerto Rico have adopted laws or executive orders to achieve 100% carbon-free electricity in the next couple of decades. Additionally, 46 U.S. utilities have pledged to go carbon free no later than 2050. Altogether, these goals cover about half of the U.S. population and economy.

These are ambitious targets, but a new look at the past 15 years in the electricity sector shows that large reductions in emissions are possible.

New research from the Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab) analyzes historical trends to examine how much progress the power sector has already made in reducing emissions. The study, “Halfway to Zero: Progress towards a Carbon-Free Power Sector,” looks back at the 2005 Annual Energy Outlook from the Energy Information Administration (EIA), the U.S. government’s official agency for data collection and analysis.

“Business-as-usual projections saw annual carbon dioxide emissions rising from 2,400 to 3,000 million metric tons (MMT) from 2005 to 2020,” said Berkeley Lab scientist Ryan Wiser, lead author of the study. “But actual 2020 emissions fell to only 1,450 MMT. The U.S. cut power sector emissions by 52% below projected levels – we are now ‘halfway to zero.’”

According to the study, relative to projected values, total consumer electricity costs were 18% lower; costs to human health and the climate were 92% and 52% lower, respectively; and the number of jobs in electricity generation was 29% higher.

Drivers of Change
From technological advances to policy, the study identified the main drivers from the last 15 years that contributed to lower carbon emissions in the U.S. power sector. Total demand for electricity was almost exactly the same in 2020 as it was in 2005, and was 24% lower than projected fifteen years earlier. “This drop in demand was due in part to sectoral and economic changes, but also to greater energy efficiency driven by policies and technology advancement,” said Wiser.

The researchers found that wind and solar power dramatically outperformed expectations, delivering 13 times more generation in 2020 than projected. This is also a result of technology development and state and federal policies, as prices plummeted for new wind and solar technologies. In addition, nuclear generation has largely held steady, tracking the past projections and helping to ensure no backsliding in carbon emission.

The study found that switching from coal to natural gas for power generation played a big role in lowering carbon emissions. Natural gas generation grew rapidly, driven by the shale gas revolution and low fuel prices.