By Roy L Hales

By 2016, twenty percent of the energy Xcel Energy is feeding into Colorado’s grid will have to come from renewables. The state’s Public Utilities Commission ruled that up to 20 MW per year of this can come from industrial facilities that convert waste heat to power. The new renewable is recycled energy technologies.

Heat From Industrial Facilities To Power

“The Southwest Energy Efficiency Project (SWEEP) is working with Xcel Energy to spur and design some incentives for a rather exciting and innovative technology that converts heat from industrial facilities to power,” said Christine Brinker, director of combined heat and power at SWEEP.

Waste heat, which would otherwise be vented into the atmosphere, can be converted into electricity, with no additional emissions and no additional fuel consumption. Anything with a large furnace or kiln qualifies. Plants that manufacture cement, steel, glass, paper, chemicals, or bricks would all qualify. So do bakeries. Since no additional emissions are created and since these technologies would offset electricity otherwise purchased from the grid, these technologies reduce the total emissions of existing plants.

As Pristine As Wind And Solar

“Recycled energy technologies are just as pristine as wind and solar,” Brinker added. 

More than a dozen states include these technologies in their renewable standards. Steam turbines have been used for close to a century. Some of the newer technologies are just recent. They are collectively known by many names, including “waste heat to power.” Plants range from 20 kilowatts to about 100 megawatts in size.

This is not a form of net metering, according to Colorado statutes. In Colorado, net metered systems can send some of their excess electricity to the grid at retail rates, whereas recycled energy technologies would most likely be paid a lower rate.

There are already a handful of projects in Colorado. One in the northeast corner of the state keeps 27,600 tons of CO2 from the atmosphere every year. This project is on the 4,346-mile Trailblazer natural gas pipeline, which snakes through Wyoming, Colorado and Nebraska. A rural electric co-op has used the heat escaping from one of the compressor stations to make electricity for their town. This project produces $600,000 a year in revenues. 

An Opportunity To Participate

“This gives industrial plants an opportunity to participate in Colorado’s renewable energy standards, both to support it and benefit from it,” said Brinker. “There are a number of industrial plants that would not find other renewable energy technologies applicable for their particular site or application, but they may have a source of waste heat that is not otherwise being used. Now they have an opportunity to convert that waste heat into electricity and get a profit from it.”

Xcel Energy will publish its new rate by the end of February after which projects of up to 10 MW can apply for these incentives. The utility has been authorized to pay about $500 per kilowatt of recycled energy. This is to be paid over 10 years, which reduces the payback period on a company’s initial investment. 

“I have heard of a couple of projects that are under consideration, but it is too early to speak to any details about those,” said Brinker.

Businesses that want to explore their potential for waste heat to energy may also be interested in the Department of Energy’s Combined Heat and Power (CHP) Technical Assistance Partnerships. The DOE offers screenings to help companies evaluate whether they should use recycled energy technologies. You can access the DOE website @ http://www.energy.gov/eere/amo/chp-technical-assistance-partnerships-chp-taps

(Top Image Credit: Photo Credit: Rio Tinto Kennecott has converted its waste heat into power for the copper smelter since 1995 (Image Courtesy of Rio Tinto Kennecott)