The best and cheapest near-term strategy for reducing coal plant CO2 emissions without forcing utilities to simply walk away from their entire capital investment is to replace that coal with biomass (see “If Obama stops dirty coal, as he must, what will replace it? Part 2: An intro to biomass cofiring”).
Today, Energy Daily (subs. req’d) reports on the huge — but little covered — news from one of the nation’s biggest carbon polluters:
The Georgia Public Service Commission gave the green light Tuesday to a Georgia Power request to convert the utility’s 155 megawatt coal-fired Plant Mitchell near Albany, Ga., to burn woody biomass, a move that will result in the first biomass plant in the vast generation fleet of Georgia Power parent Southern Co.
This will become “the largest biomass facility in the United States,” according to Southern Company COO Tom Fanning. And this is not the only biomass effort Southern Company is pursuing:
Alabama Power, another Southern affiliate, is studying co-firing woody biomass and switchgrass at its coal-fired Gadsden plant near Birmingham and co-firing woody biomass at its coal-fired Barry plant near Bucks, Ala. Southern affiliate Gulf Power is evaluating co-firing biomass at its coal-fired Plant Scholz near Marianna, Fla.
The huge advantage of biomass conversion or co-firing is that you don’t have to build an entire planet from scratch, thus lowering the capital costs. Plus you already have the powerplant sited and you have transmission sited and you have train lines and water supply. Plus this is new baseload renewable power — arguably the most valuable commodity in the entire power sector these days.
And since biomass captures carbon dioxide already in the atmosphere during the process of growing, it is the only form of carbon capture that is likely to lead to deliver significant kilowatt-hours for the next one to two decades (see “Is coal with CCS a core climate solution?”).
So, again, this is, in the near term, the most practical and affordable strategy for utilities with coal plants that want to reduce CO2 emissions without simply writing off the entire value of their plant. Hence, this is a crucial strategy for coal-intensive utilities in the Southeast and Midwest that have long opposed renewable energy standards and climate action:
Southern for years has spearheaded utility industry opposition to a national renewable electricity standard (RES) that would require power companies to obtain a percentage of their electricity from wind, solar power or other green resources, saying the mandate would discriminate against utilities in the Southeast, which lacks the abundant wind and solar resources found in the Midwest and Southwest, respectively.
If this is to be a scalable medium-term solution, then the country will need to make an all out effort to develop cellulosic biomass for use in power plants. Even today, the resource is significant in the key regions:
However, the Southeast has enormous quantities of woody biomass, a renewable fuel that utilities can use to meet the RES. Southern’s Web site states that 8 million acres of forest and timberlands lie within a 100-mile radius of Plant Mitchell, providing 12 million tons of surplus supply wood fuel annually. The converted Mitchell plant, which will have a capacity of 96 MW, is expected to consume about 1 million tons per year.
The conversion of the Mitchell plant to biomass may signal recognition by Southern Co. that — with stronger Democratic majorities in the House and Senate and President Obama a strong backer of a federal RES — developing its extensive biomass resource may be both politically and economically prudent. The converted Mitchell plant is expected to begin operation in June 2012.
Interestingly, the new biomass power plant will generate more electricity than the current coal-fired unit. Here are some interesting details from a 2008 story in Biomass magazine:
According to Lynn Wallace, a company spokeswoman for Georgia Power, the nameplate capacity for the converted wood biomass-powered unit would be 59 megawatts lower due to the different physical characteristics of wood in comparison to coal. Wood contains more moisture and produces only 4,000 British thermal units (Btu) to 5,000 Btu per pound compared to coal at 12,000 Btu per pound, she said.
As a wood biomass-powered unit, the facility would actually produce more electricity than it does as a coal-fired unit, Wallace said. The unit currently operates at low capacity and is not considered one of the company’s base-load power units; however, the biomass-powered unit would operate continuously and be part of the company’s base load.
Surplus wood fuel for Plant Mitchell would come from suppliers operating within an approximately 100-mile radius of the plant. Wallace said the wood primarily would be waste wood, such as tree limbs, tree tops, needles, and leaves, which is normally left behind by timber harvesting companies. “We wouldn’t be competing with their wood supply,” she said.
Wallace said consumers are asking to have more energy produced from feedstocks and from processes that produce lower emissions. She said the wood biomass-powered unit will produce less sulfur dioxide and nitrogen oxide emissions and will engender a net reduction in carbon emissions.
Wood biomass is also less expensive than coal, Wallace added. The new feedstock requirement for the unit is expected to create between 50 and 75 new jobs related to waste wood recovery. She said waste wood that is left on the forest floor also emits methane gas and can easily fuel forest fires if it’s not cleared away.
The key, of course, to make sure this is all done in the sustainable fashion. That will be the job of regulators and the Obama administration.
When I was at the Department of Energy, we were pursuing research into developing better fast-growing hybrid poplars, which are “the fastest growing hardwood trees available to homeowners and landowners in America and they are growing successfully from the Northern Gulf Coast to New England, throughout the Midwest and into the Northwest.” They are a high-energy crop that “grow well on marginal land, so they don’t take up valuable food-producing soil.”
The fundamental reason biomass conversion and co-firing are a core climate solution is that anyone who can deliver considerable amounts of low carbon power for under $0.15 a kilowatt hour — and especially if that is baseload power — will be a major player in the transition to a low carbon economy. And if you can do that in regions of the country that don’t have a vast solar resource suitable for concentrated solar thermal or wind — and especially if it is closer to $0.10 a kilowatt hour — then you will be doubly valuable.
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