City to narrow power plant choices
Published: Sunday, January 27, 2008 at 6:01 a.m.
Last Modified: Sunday, January 27, 2008 at 12:18 a.m.
Future energy demands in Gainesville will partially be satisfied by burning biomass fuel from trees - a decision that was made before a request was issued last October for power plant proposals.
The questions that remain include: whether trash will also be burned, whether the plant will be owned by the city or a private company, and what environmental protections will be employed.
City commissioners are expected to discuss all of these issues Monday afternoon as they select three finalists from the 11 proposals submitted by companies hoping to build the city's next power plant.
The commission could vote to extend an invitation to the three finalists, asking the companies to submit binding proposals with more concrete information and cost estimates.
The power plants vary greatly in technology, efficiency and size.
Staff at GRU has evaluated the proposals in three broad areas: cost effectiveness, environmental consistency with the community and the risk associated with the project and its reliability.
Each category was given close to equal weight with risk and reliability accounting for 35 percent of the score, environmental issues 34 percent and economics 31 percent.
Given that weighting, GRU recommended to the commission that the three top scoring proposals came from Sterling Planet, Nacogdoches Power LLC, and Covanta Energy Corp.OwnershipAll but one of the companies proposed maintaining ownership of the plant and selling the energy to GRU.
Ed Regan, chief strategic planner for GRU, said when the decision was made not to build a coal power plant in 2006, it became necessary to consider non-ownership proposals.
He said that GRU doesn't have the ability to tie up resources in expensive technologies that are inherently riskier.
"We still wanted a shot at some of the more exotic power resources," Regan said. "When you have someone with a really deep pocket, backing up the project so you can take risks, it makes that feasible."
However, former Mayor Mark Goldstein said a privately owned power plant would be a huge mistake.
"Having a publicly owned utility is one of the greatest things a city can do," Goldstein said. "Why would we give away the goose that lays the golden egg?"
Last year, GRU generated roughly $30 million in profits for the city.
Goldstein said that money enables the city to maintain a high quality of life. A publicly owned utility can also protect consumers from price gouging, he said, and is more responsible to the community for emissions.
Only one project, a biomass-only proposal from Railex Polygen, offers GRU the option to own and operate the facility. Some proposals offer an option for the city to buy the plant at market price after a fixed time period.Fuel sourceAll the proposals being considered are fueled primarily by biomass, which is defined as plant and plant-derived material. More specifically, the power plants will use wood biomass, from a variety of sources including residue from logging and land clearing, urban wood waste, forest thinning and pulpwood.
However, most of the companies responding would also use municipal solid waste - trash that is ordinarily taken to a landfill - as fuel.
The director of the Florida Institute for Sustainable Energy, Eric Wachsman, said the best fuel source option for the city depends on where priorities lie.
"If you're judging purely on an environmental basis, on the impact of greenhouse gasses, then biomass alone is the best," Wachsman said. "But if you look at the lager picture, at throwing things away and putting them in the ground, then waste is a major resource we should be tapping into."
Three of the proposed power plants would use only biomass fuel: Railex Merchant Energy Infrastructure Group, Timberland Harvesters Inc., and Sterling Planet Inc.
Sterling Planet's proposal expresses an interest in also using municipal solid waste as a fuel. And the others propose using a mix of wood and trash fuel.EmissionsMany areas, including Hillsborough, Lake, Lee and St. Lucie counties, are using some of the technologies proposed here to help deal with excessive trash problems, and energy production is a bonus byproduct.
However, local activists have pointed out that converting trash to energy can release toxins like mercury and dioxins into the air.
"Frankly nobody knows what is in garbage because anybody can throw just about anything in the garbage stream," said Rob Brinkman, chairman of the local Sierra Club chapter. If batteries, computers and tires are burned, more toxins are released.
The Sierra Club on a national level is opposed to burning municipal solid waste.
Wachsman said emissions vary greatly based on how closely the trash is sorted before it is processed to keep out items that are toxic when burned.
"If the plan is using everything than you may have some problems," he said.
Aside from that, Wachsman said, there are also technologies that can help clean the emissions after the trash is burned.
All of the plants vary significantly in post-combustion technology.
"Realistically speaking, things have improved over the decades, but that doesn't mean that we really know they are safe," Brinkman said.
Brinkman also argues that if municipal solid waste is burned, the remaining product - called ash - will be polluted. Whereas the ash from burning biomass is clean and can be used as a fertilizer sometimes in the forests that the wood was gathered in. Ash from trash must be put in a landfill.
Wachsman said that ash is no more harmful than the trash that would be put in the ground anyway.
"You're better off burning the trash and burying the ash than just burying the trash," Wachsman said.
He adds that using trash as a fuel could make rates much more stable and reduce production costs.
"The more flexible the plan is in the fuel utilized, the more cost effective," Wachsman said.Forest sustainabilityWhen GRU staff scored the proposals, equal consideration was given to what the companies proposed in terms of emissions, as to the companies dedication to ensuring the forest resources used in biomass were renewable.
Regan said ensuring that the forests in the area don't become stripped and barren from over-harvesting was a top concern.
Covanta Energy Corp. scored the highest in terms of commitment to sustainable forest resource management. The three proposals that had the best overall scores in terms of environmental impact were: Envortus Inc., Taylor Biomass Energy LLC and Green Power Systems.
All three of those propose using municipal solid waste, but the difference is they wouldn't burn the trash, they would gasify it, which Wachsman said is a much more emission-friendly technology than burning.
Envortus scored poorly in terms of cost effectiveness and risk. Taylor Biomass, however, scored second in terms of economics but last in terms of risk and reliability.
"We're OK with being on the cutting edge of technology, but we don't want to be on the bleeding edge," Regan said, explaining why the risk category and exposure to financial loss was given so much weight.
Megan Rolland can be reached at 338-3104 or megan.rolland@ gvillesun.com.
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