Page 68 - North American Clean Energy March April 2015

biopower

Paving the Road to

a Carbon-negative

Future

Biomass, carbon-capture

& the western U.S.

By Robert Sanders

Biomass power accounts for roughly half of all the renewable energy produced in A carbon dioxide injection well

the United States and, currently, the US uses more of it than any other country in (Photo courtesy of CO2CRC)

the world. Impressive stats, but production can be good and bad—a double-edged

sword of sorts, depending on how it’s sourced and generated.

Biomass can be produced in ways that reduce global warming pollution or in ways that 1. Capture of CO2 from power plants or industrial processes;
increase it. Unfortunately, much of the biomass used commercially comes from resources 2. Transportation of the captured and compressed CO2 (usually in pipelines); and
that aren’t sustainable. he challenge for the renewables’ industry, therefore, is to ensure 3. Underground injection and geologic sequestration of the CO2 into deep underground
that biomass energy is created in ways that protect the environment and that reduce global rock formations. hese formations are often a mile or more beneath the surface and consist

warming and pollution.
of porous rock that holds the CO2 and prevents it from migrating upward.
As the Natural Resources Defense Council’s site on Renewable Energy for America points
out: “Biomass energy should do the job better than the fossil fuels it replaces.” (www.nrdc. By capturing carbon from burning biomass—termed bioenergy with carbon capture and
org)
sequestration (BECCS)—power generators could become carbon-negative even, while

By deinition, biomass is biological material that’s carbon-based, derived from living or retaining gas- or coal-burning plants.
recently living organisms. Generating electricity from urban waste or sustainably sourced According to study leader, Daniel Sanchez, a graduate student in UC Berkeley’s Energy
forest and crop residues, is seen as one strategy for reducing greenhouse gas emissions. and Resources Group, the carbon reduction might even ofset the emissions from fossil fuel
Herein, biomass is considered carbon-neutral: it produces as much carbon as the plants used in transportation.

suck out of the atmosphere.
“here are a lot of commercial uncertainties about carbon capture and sequestration
Furthermore, a recent UC Berkeley study shows that if biomass electricity production technologies,” Sanchez admitted. “Nevertheless, we’re taking this technology and showing
is combined with carbon capture and sequestration in the western United States, power that in the Western United States 35 years from now, BECCS doesn’t merely let you reduce
generators could actually store more carbon than they emit—thereby, making a critical emissions by 80%–the current 2050 goal in California–but gets the power system to

contribution to an overall zero-carbon future by the second half of the 21st century.
negative carbon emissions: you store more carbon than you create.”
In fact, BECCS may be one of the few cost-efective, carbon-negative opportunities
Understanding CCS
available to mitigate the worst efects of anthropogenic climate change, according
Carbon capture and sequestration (also referred to as carbon capture and storage, or to energy expert Daniel Kammen, who directed the research. his strategy will be

CCS) involves a set of technologies, with the aim and process of capturing waste carbon particularly important should climate change be worse than anticipated, or should
dioxide (CO2) from large sources, such as fossil fuel power plants. he intent is to deposit emission reductions in other portions of the economy prove particularly diicult to
and safely store it, thereby preventing the release of large quantities of CO2 into the achieve.
atmosphere.
“Biomass, if managed sustainably can provide the ‘sink’ for carbon that, if utilized

According to the US Environmental Protection Agency (EPA), CCS is a three-step in concert with low-carbon generation technologies, can enable us to reduce carbon in
process* that includes:
the atmosphere,” explained Kammen, a Professor of Energy in UC Berkeley’s Energy

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