A New Frontier
Biomass developers are experts at using heat to make power. A very different method of doing so—one that elicits no combustion— hails from a free fuel source and may be the next frontier for the veterans of the biomass industry.
Waste-heat-to-power (WHP) is the generation of emissions-free electricity from heat that is the byproduct of industrial processing. Some typical applications include steel or paper mills, chemical manufacturing facilities and glass manufacturers. In addition to traditional industrial manufacturing, oil and gas processing facilities are also home to sources of waste heat. Such energy-intensive industries require high-temperature heat to process and refine their products. For example, a facility might use 3,000-degree-Fahrenheit heat to refine their product. Once the refining has been done, energy is still left in the heat, which is perhaps reduced to 400 F or lower. Such low-temperature heat is often cast aside and regarded as worthless. This is waste heat, and is in fact an extremely valuable commodity, a source for baseload, emissions-free electricity.
In addition to energy-intensive manufacturing facilities, gas compression stations and landfill gas facilities serve as ideal hosts for capturing waste heat. Both of these types of facilities employ the use of turbines or engines, and during the process emit capturable heat from their exhaust streams. Gas compression stations are often in remote locations and are responsible for compressing gas to keep it flowing along pipelines across the country. All power generated from WHP on compression stations and landfill gas facilities must interconnect into the grid, which is different than power generated from waste heat on industrial sites, as it may be used to reduce the site’s overall power needs. In states that value waste heat as a renewable equivalent, this can be a lucrative investment.
Advanced WHP technologies are being used today in the WHP, biomass, geothermal, and solar thermal markets. These technologies include Organic Rankine Cycle, Kalina cycle, Sterling engine, and the newest variation, thermoelectrics. Such technologies are capable of capturing heat as low as 195 F, and some may be able to reach lower temperatures. Innovation of such technologies is making what has always been considered waste a very valuable prospect.
WHP potential is gaining momentum. In May, the governor of Ohio added WHP to the state’s renewable resource and energy efficiency standards, and 13 states currently recognize WHP as a renewable equivalent (defined as heat that is the byproduct of a process whose primary purpose is not the generation of electricity from a fossil fuel). Bipartisan bill H.R. 2812— The Heat is Power Act—has been introduced in Congress to offer WHP equal tax treatment with other sources of renewable energy, and a recent paper published by the U.S. EPA in August estimates a potential market size of about 10 GW.
The possibility for 10 million American homes to be powered by emissions-free electricity from something currently disappearing into thin air is too good to waste. The WHP industry looks forward to welcoming more developers to the frontier and recognizes that the veterans of the biomass industry may very well be our next pioneers. Heat is power―let’s capture it!
Author: Kelsey Southerland
Executive director, Heat is Power Association