By Brian E. Clark
MADISON – Xcel Energy has filed an application with the state Public Service Commission to install biomass gasification technology in a boiler at its Bay Front Power Plant in Ashland.
“This addresses a lot of the things raised in the Governor’s Global Warming Task Force and will displace 100,000 tons of coal and 4,000 tons of petroleum coke,” David Donovan, the utility’s manager for regulatory policy, said Monday.
The $58 million project would fully convert the Ashland plant from coal to biomass and remove 80,000 tons of carbon dioxide emissions. It already has two boilers fueled by waste wood products, Donovan said. When completed, it would be the largest biomass plant in the Midwest.
The move was hailed by environmental groups.
“This is a great sign of progress,” said Andy Olsen, a representative of Environmental Law and Policy Center. “We hope Xcel can carry this through to completion.
“We also hope they can work with the state and conservation groups to make sure this is a model project for sustainable use of wood,” he said.
Mark Redsten, executive director of Clean Wisconsin, also praised Xcel and said the project “will both lessen Wisconsin’s reliance on imported fossil fuels and propel us closer to the renewable energy goals of Gov. Doyle’s Task Force on Global Warming.”
Speaking during a break at an energy conference Monday organized by WisPolitics.com and WisBusiness.com, Donovan said if all goes well, design work on the boiler and other equipment is expected to begin next year and the unit could be operating by late 2012. He said his utility began planning the switch more than a year ago.
When completed, the project will reduce emissions of nitrogen oxides by more than 60 percent, sulfur dioxides by more than 80 percent and particulate matter by more than 80 percent, officials said.
The plant currently uses just over 200,000 tons of waste wood each year. When the project is running, the plant will use an additional 185,000 to 250,000 tons per year and be able to generate enough renewable electricity to serve 40,000 homes, officials said.
Dick Kelly, president and CEO of Xcel, said the Bay Front project “demonstrates our continuing commitment to the environment and a clean energy future.”
“We’re helping our customers and communities practice sustainability while increasing local economic development. By combining energy efficiency, advanced energy technologies, and improvements to existing generating resources, we’re on track to reduce carbon dioxide in our Midwest service territories 22 percent from 2005 levels by 2020.”
The Bay Front Power Plant began operation in 1916. In 1960, it operated five boilers and six turbines. Since then, two of the boilers, and three of the turbines, have been retired.
The three remaining boilers feed into a combined steam header system that can support three turbine-generator sets. During a major plant improvement project completed in 1991, the plant was equipped with an upgraded air quality control system, which includes two gravel bed filters designed to remove more than 98 percent of particulate matter.
Last year, Xcel installed nitrogen oxide (NOx) emission control equipment on the two boilers that primarily burn wood, allowing both to continue to operate into the foreseeable future.
When evaluating various alternatives for the remaining boiler, which primarily burns coal, Xcel officials decided that expanding Bay Front as a biomass resource was preferred over incurring significant environmental compliance costs relating to the Clean Air Interstate Rule and regulations on mercury emissions.
Donovan said the primary source of biomass at Bay Front is expected to be the lower quality, unused pieces of tress that are currently left in area forests following traditional harvests, such as logging slash, underutilized species and damaged trees, cull, treetops and mortality classed trees.
Initial investigations conducted by Xcel show more than ample supplies of this lower quality biomass within the area, officials said.
To ensure future biomass supplies are available on a reliable basis, Xcel is working with the Wisconsin Office of Energy Independence, University of Wisconsin–Madison and local agricultural experts to explore the feasibility of developing biomass plantations and grower cooperatives.
Donovan said those could include fast-growing hybrid poplar and black willows for potential tree plantations.