Powerspan to Pilot Test Mercury Removal Technology at AmerenUE's Rush Island Power Plant

Portsmouth, N.H., May 1st, 2006 - Powerspan Corp., a clean energy technology company, and Ameren Corporation subsidiary AmerenUE today announced plans to pilot test a promising mercury removal process at AmerenUE's Rush Island Power Plant in Jefferson County, Missouri. The technology, called Photochemical Oxidation, or PCO, uses ultra-violet light to oxidize and remove mercury from coal-fired power plants. Pilot testing at the Rush Island plant is scheduled for late 2006. The primary objective of the PCO pilot test program is to demonstrate the oxidation of elemental mercury in a coal flue gas stream using ultra-violet light and the subsequent capture of the mercury in various particle collection devices, including wet and dry electrostatic precipitators and fabric filters. In addition to the field testing, preliminary cost estimates for full-scale commercial applications will be developed. "If successfully demonstrated, PCO represents a straight-forward, cost- effective approach to controlling mercury emissions from power plants, particularly those that burn lower rank coals," said Powerspan chairman and CEO Frank Alix. He added, "We look forward to working with AmerenUE, which has distinguished itself as a leader in using innovative technologies for reducing other power plant emissions." "Ameren prides itself on being an industry leader in seeking innovative ways to reduce emissions from coal-fired power plants," said Ameren Chief Operating Officer Tom Voss. "This project allows us to continue that tradition while helping to develop technologies that will play a part in meeting the new requirements for mercury emissions." Grant funding for the project is provided by the U.S. Environmental Protection Agency, Region VII, through the Missouri Department of Natural Resources' Air Pollution Control Program. Additional funding is provided by AmerenUE and Powerspan. Developed by the U.S. Department of Energy's National Energy Technology Laboratory and licensed by Powerspan, the PCO process uses ultraviolet light to produce an "excited state" mercury species in coal combustion flue gas, leading to the oxidation of elemental mercury. Mercury exists in both elemental and oxidized forms in power plant flue gas streams, with the elemental form being the more difficult to capture. Once in the oxidized form, however, mercury can be collected in existing particle collection devices such as electrostatic precipitators and fabric filters. Given its ability to work with conventional particulate control systems, PCO has the potential to serve as a cost-effective technology for reducing mercury emissions from power plants. Testing of the PCO process conducted in Powerspan's laboratories has shown 90 percent oxidation and removal of elemental mercury from simulated flue gas streams. Powerspan Corp., a clean-energy technology company based in Portsmouth, New Hampshire, is engaged in the development and commercialization of proprietary multi-pollutant control technology for the electric power industry.Visit http://www.powerspan.com/ for more information. Ameren Corporation (NYSE:AEE) is among the nation's largest investor-owned electric and gas utilities, with more than $18 billion in assets.The largest electric utility in Missouri and the second largest in Illinois, Ameren companies provide energy services to 2.4 million electric and one million natural gas customers throughout its 64,000-square-mile territory.

For More Information Contact

Stephanie Procopis, Director of Marketing +1-603-570-3000 www.powerspancorp.com sprocopis@powerspan.com ----------------------------------------

Tim Fox +1-314-554-3120 www.ameren.com tfox@ameren.com To subscribe or visit go to:  http://www.electricenergyonline.com