Projections for electricity emissions underestimated the pace of power transition

A new study explores how the U.S. power sector evolved on a much lower carbon path than analysts were projecting about 15 years ago.

Why it matters: The Lawrence Berkeley National Laboratory report is a reminder about the limits of our ability to look into the energy future. But it also shows that while energy transitions are generally slow, that's not some ironclad law of nature.

Where it stands: The report comes as the White House seeks to breathe life into its aggressive target of 100% zero-carbon power generation by 2035.

The big picture: "This historical record demonstrates the ability of technological and policy changes to set the power sector on a dramatically different emissions trajectory," the study notes.

How it works: The study compares the business-as-usual projections from Energy Information Administration's (EIA) 2005 Annual Energy Outlook to what actually happened.

• A suite of forces created a different path, such as much lower power demand than projected; the shale gas boom helping to shove coal aside; steep renewables costs declines; and more.

Yes, but: The report notes that the past "does not trivialize the challenges that remain" for further decarbonization. "Nor does it offer a specific roadmap for how best to achieve additional power-sector emissions reductions."

The intrigue: The authors are not picking on EIA. For one thing, they note its "reference" cases do not assume policy changes.

• The report also compares them to a separate Energy Department study in 2008 and five separate private-sector projections from 2004.
• All of them were way off on power sector CO2. "The general findings presented in this report are ... robust across a number of past projections."