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Xcel Energy announces project at Hayden Generating Station to reduce emissions footprint, increase efficiency

DENVER - A new system that is expected to significantly improve a coal-fired power plant’s operational efficiency and reduce its emissions footprint is being tested at Xcel Energy’s Hayden Generating Station in Hayden, Colo.

At coal-fired plants, coal is burned in a boiler to produce the steam that drives the turbines of a generator. As it is burned, coal produces hard mineral waste products called slagging and fouling. These waste products decrease efficiency, requiring more coal to generate the same amount of electricity and resulting in increased emissions. Slagging and fouling can also lead to several million dollars of lost revenue or added cost throughout a company’s fleet of coal plants because of decreased load, periodic plant shutdowns to clear out the waste and use of more coal. 

“This project shows great promise in allowing us to improve our ability to create power more efficiently and in a more environmentally friendly way,” said Lou Matis, vice president of operations. “By minimizing the impact of slag in our coal-fired boilers, Xcel Energy can decrease its number of plant shutdowns for maintenance, increase efficiency and lower overall emissions.”

Xcel Energy worked with GE Energy's Optimization and Control Business to develop the new software platform, which is the first of its kind that can help alleviate the problem. The system uses high tech software and additional boiler sensors to acquire, manage and display historical data, combine it with the plant operator’s personal knowledge of the unit and recommend operational changes to reduce slagging and fouling. Xcel Energy began testing the system in July 2007 at the Hayden Station and plans to continue testing until December.

“This project is another example of our commitment to use innovative technologies to produce electricity in a more efficient way with reduced environmental impacts,” said Mark Freeman, vice president of technical services. “It also represents one step we are taking to add a new layer of intelligence to our plants, bringing our facilities into the digital age. We’re pleased with the preliminary results.”

With the system in place, the company expects to reduce emissions and improve operations with fewer forced outages for slag removal, increased boiler availability and less hours of reduced-load operations.

Preliminary results show that the system works. The Hayden Station now has the least amount of coal slagging and fouling in recent history and the slag that is occurring has visibly changed for the better. It is not as sticky, it sheds easily and blowing soot has been reduced. In addition, combustibles are generally averaging less than 100 parts per million. This is lower than before the system was installed, proving the boiler is working more efficiently.

In the next phase of the project, Xcel Energy will concentrate on reducing nitrogen oxide (NOx), while controlling for slag. Although NOx was already reduced in preliminary testing, the company will work to lower it further. Xcel Energy is also looking into testing the system on other units using different types of coal and exploring how to use the system at other sites. 

“We envision a clean energy future and because of that we’re working to change the way we make and deliver energy to our customers,” Matis said.

Xcel Energy is the nation’s No. 1 wind power provider. At the end of 2007, the company will have 2,880 megawatts of wind on its system and by 2020, will expand its total wind capacity to 6,000 megawatts. The company is a leader in developing new technologies and tools to help bring clean, renewable energy onto its system at an affordable cost for its customers.
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Xcel Energy (NYSE: XEL) is a major U.S. electricity and natural gas company with regulated operations in eight Western and Midwestern states. Xcel Energy provides a comprehensive portfolio of energy-related products and services to 3.3 million electricity customers and 1.8 million natural gas customers through its regulated operating companies. Company headquarters are located in Minneapolis.