But analysis of individual electrical generating plants across the globe finds carbon emissions are still lowered, and specific types of plants could be targeted in future policy making

Increasing the efficiency of power plants is often assumed to be an effective means of reducing carbon emissions. However, an empirical analysis of plants’ efficiency and emission led by a University of Colorado Boulder sociology professor casts some doubt on that conventional wisdom.

The study, “How organizational and global factors condition the effects of energy efficiency on CO2 emission rebounds among the world's power plants,” by Professor Don Grant examines almost every fossil-fuel plant in the world in operation between 2004 and 2009. It seeks to establish whether efficiency improvements decrease emissions or, as some skeptics say, motivate the consumption of more electricity causing emissions to actually rise — an unwanted consequence called the rebound effect.

There is a growing debate among experts about this issue, but Grant’s research is one of the few to test competing predictions with plant-level data. And what he and colleagues find is that it largely depends on the characteristics of the power plants and the country in which they are embedded.

The rebound effect was observed in most “core” countries — such as the United States, China and India — but was smaller than what skeptics suggest and certainly not on the same scale as gains created by increased plant efficiency.

However, by examining data on individual power plants, rather lumping them together by country, Grant and Professors Andrew Jorgenson of Boston College and Wesley Longhofer of Emery University were able to refine these findings and specify which types of plants showed tendencies toward this rebounding effect.

“Large and older plants were found to be most susceptible to these effects, as were plants located in the core or more developed regions of the world economy,” Grant said.

“Surprisingly, rebound effects also tended to occur in countries with more environmental non-governmental organizations (ENGOs), suggesting these groups may be co-opted by local fossil-fuel industries.”

Grant said the study should help public policymakers forge more targeted legislation to reduce carbon emissions from particular types of power plants.

“There’s definitely been a move over the last 20 years to come up with more targeted policy,” he said.

“In the past officials would target an entire economy, and then they began to target individual sectors (such as electricity,)” Grant said.

“What we are suggesting is perhaps officials need to take that one step further and target plants with particular profiles.”