Florida’s Public Service Commission recently approved plans for a new biomass plant in Gainesville. At 100 megawatts, it will be one of the largest power stations in the country that produce electricity from discarded plant matter.

Proponents of the plant say biomass represents one of Florida’s only opportunities to wean itself off fossil fuels; others question whether Florida’s forests can sustain a significant increase in biomass energy production. The debate illustrates the significant challenges the state faces as it attempts to increase its investment in renewable technologies.

Josh Levine of American Renewables, the company building the plant, says he expects more Florida utilities to look to biomass as a source of power. Gov. Charlie Crist passed what amounted to a moratorium on new coal plants in 2007 when he signed executive orders requiring the state to slash greenhouse gas emissions and develop mandates for renewable power.

Our state lacks steady winds, waterfalls, or accessible magma, leaving solar and biomass as the two most promising alternatives to fossil fuels. Solar power seems like an obvious choice in the Sunshine State, but afternoon thunderstorms and persistent cloud cover limit our solar potential.

There are also limits inherent in harnessing the power of the sun.

Ed Regan, assistant general manager at Gainesville Regional Utilities, which will buy energy from the biomass plant, says the availability of solar power peaks around noon, when the sun is high in the sky, while electricity demand peaks in the early evening, as people come home from work and turn on appliances.

That leaves biomass as a fuel source readily available in Florida that can provide power at all hours of the day. Power plants in South Florida have been burning leftover sugar cane stalks – known as bagasse – for decades. The new Gainesville plant will use the main source of plant refuse in North Florida: excess wood from forestry operations, sawmills, and urban tree cutting.

Levine says that North Florida is part of the “wood basket” of the United States. Turning wood waste into electricity makes more sense than sending money to West Virginia for coal or Texas for natural gas. It will create local jobs in the forestry industry using products that would otherwise be burned or left to rot on the forest floor. Meanwhile, current drafts of federal climate legislation expand the definition of “renewable biomass” and exempt it from the limits on carbon emissions imposed by proposed cap and trade rules.

The Gainesville Area Chamber of Commerce threw its support behind the plan in April, noting that biomass is the cheapest, most reliable fuel source available after coal and that GRU needed to diversify its fuel supply. Regan points out that the city’s renewable energy programs are partially intended as a form of economic stimulus. Biomass is a boon to local foresters, allowing them to turn to refuse into a profitable commodity. The plant could provide a net of $600 million to the local economy and create hundreds of jobs.

The question is: How much biomass can the state sustainably produce?

One study produced during GRU’s testimony before the PSC shows that woody biomass could sustainably provide for up to 3 percent of the state’s electricity consumption. According to the most recent statistics from the Energy Information Administration (which will be updated this month), it currently supplies 354 megawatts. Florida’s total capacity is more than 55,000 megawatts. In testimony before the PSC, biomass consultant Richard Schroeder said that biomass could technically provide up to 1,800 megawatts statewide, but the practical potential could be much lower.

Critics of the Gainesville plant have questioned whether there’s enough waste wood in North Florida to power a plant as large as 100 megawatts. While many biomass plants are smaller, scientists have pointed out that larger plants can burn wood more efficiently, which means more energy and fewer emissions.

Opponents of the plan also worry about more plants coming online in the region that would compete for the same fuel sources. Plants have been proposed in Tallahassee and Hamilton County, for example, but both proposals failed amid questions about their technical and financial viability.

Studies by University of Florida researchers and independent consultants (including Schroeder) showed that the area around Gainesville offered enough biomass to produce up to 120 megawatts in a cost-effective manner, bolstering the utility’s contention that it could fuel its 100-megawatt plant reliably without impinging on existing uses for woody biomass, such as recycled mulch.

But while there may be enough thrown-away wood available to support GRU’s plan, other questions remain. Will the new federal climate legislation induce states — including our own — to expand biomass production, and perhaps begin growing dedicated crops for energy? To what extent can Florida rely on biomass to power a future free of fossil fuels? If we can’t rely on solar or biomass, what else is there?

[Pic via flickr.com/photos/bogenfreund]