Wednesday, February 18, 2015

Hoovering Up CO2 with CCS-equipped Biomass Power Plants

Biomass-fired power plant (Credit: Getty Images) Click to Enlarge.
Last year's update from the Intergovernmental Panel on Climate Change identified biomass-fired power plants that capture their carbon—and thus sequester atmospheric CO2—as one of the most critical tools available for stabilizing climate change by the end of this century.  Last week, researchers at the University of California at Berkeley reported that carbon-capturing bio-power plants could go two steps further, rendering the entire Western North American power grid carbon-negative by 2050.

The idea behind bioenergy with carbon capture and storage, or BECCS, is to capture carbon emissions from a combustion power plant's effluent using the same equipment and methods employed by a few CCS-equipped coal-fired power plants.  Once such plant, which started up in September in Saskatchewan, is the world's first commercial-scale coal power plant to capture over 90 percent of its carbon. 

But whereas power plants that capture and sequester fossilized carbon can, at best, achieve carbon-neutral performance, BECCS can be carbon-negative.  That's because the carbon in the wood and other biofuels they burn was sucked from the atmosphere as the plants grew.  Storing that atmospheric carbon underground is tantamount to generating electricity while actually doing Earth's climate a favor. 

Last week's report, in the journal Nature Climate Change, purports to be the first detailed simulation of how BECCS would play out in a particular region.  The research team, led by Daniel Kammen, director of the Renewable and Appropriate Energy Laboratory at UC Berkeley, simulated BECCS deployment on the Western power system (which interconnects most of the U.S. and Canada west of the Rockies, plus Mexico's Baja California).  Their SWITCH-WECC model is a standard power grid model augmented with information about the location and cost of biomass fuel sources. 

After screening the sustainability of biomass resources available in the region from forestry, agriculture, and municipal wastes, the researchers identified enough biomass to meet between 7 and 9 percent of projected electricity demand for 2050.
No doubt critics will question the validity and relevance of Berkeley's findings, starting with the alleged carbon benefits.  Many critics argue that bioenergy production leads to changes in land use—such as clearing of forests—that can generate large carbon releases and thus undercut the notion of negative emissions.

Read more at Hoovering Up CO2 with CCS-equipped Biomass Power Plants

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