Energy recycling
Energy recycling is the
Forms of energy recycling
Waste heat recovery
Waste heat recovery is a process that captures excess heat that would normally be discharged at manufacturing facilities and converts it into electricity and steam, or returns energy to the manufacturing process in the form of heated air, water, glycol, or oil. A "waste heat recovery boiler" contains a series of water-filled tubes placed throughout the area where heat is released. When high-temperature heat meets the boiler, steam is produced, which in turn powers a turbine that creates electricity. This process is similar to that of other fired boilers, but in this case, waste heat replaces a traditional flame. No fossil fuels are used in this process. Metals, glass, pulp and paper, silicon and other production plants are typical locations where waste heat recovery can be effective.[1]
Combined heat and power (CHP)
Waste heat recovery from air conditioning
Waste heat recovery from air conditioning is also used as an alternative to wasting heat to the atmosphere from chiller plants. Heat recovered in summer from chiller plants is stored in Thermalbanks[5] in the ground and recycled back to the same building in winter via a heat pump to provide heating without burning fossil fuels. This elegant approach saves energy - and carbon - in both seasons by recycling summer heat for winter use.
Some companies offer products to install on the HVAC Condenser Unit, to collect waste heat that the condenser is supposed to evacuate in the air, to heat up heat-producing devices like water heaters. Those devices are called heat recovery units (HRU). For residential applications, some units available are : HotSpot Energy Heat Recovery Unit [6] or LG Heat Recovery Units [7]
For industrial applications, these units are usually called waste heat recovery unit (WHRU).
Heat pumps
Thermal storage
Thermal storage technologies allow heat or cold to be stored for periods of time ranging from hours or overnight to
Current system
Both waste heat recovery and CHP constitute "decentralized" energy production, which is in contrast to traditional "centralized" power generated at large power plants run by regional utilities.[4] The “centralized” system has an average efficiency of 34 percent, requiring about three units of fuel to produce one unit of power.[11] By capturing both heat and power, CHP and waste heat recovery projects have higher efficiencies.
A 2007 Department of Energy study found the potential for 135,000 megawatts of CHP in the U.S.,[12] and a Lawrence Berkley National Laboratory study identified about 64,000 megawatts that could be obtained from industrial waste energy, not counting CHP.[13] These studies suggest about 200,000 megawatts—or 20% -- of total power capacity that could come from energy recycling in the U.S. Widespread use of energy recycling could therefore reduce global warming emissions by an estimated 20 percent.[14] Indeed, as of 2005, about 42 percent of U.S. greenhouse gas pollution came from the production of electricity and 27 percent from the production of heat.[15][16]
Advocates contend that recycled energy costs less and has lower emissions than most other energy options in current use.[17]
Currently RecyclingEnergy Int. Corp. takes advantage of recycling energy in heat recovery ventilation and latent heat pump and CHCP.[18]
History
Perhaps the first modern use of energy recycling was done by Thomas Edison. His 1882 Pearl Street Station, the world's first commercial power plant, was a CHP plant, producing both electricity and thermal energy while using waste heat to warm neighboring buildings.[19] Recycling allowed Edison's plant to achieve approximately 50 percent efficiency.
By the early 1900s, regulations emerged to promote rural electrification through the construction of centralized plants managed by regional utilities. These regulations not only promoted electrification throughout the countryside, but they also discouraged decentralized power generation, such as CHP. They even went so far as to make it illegal for non-utilities to sell power.[20]
By 1978, Congress recognized that efficiency at central power plants had stagnated and sought to encourage improved efficiency with the Public Utility Regulatory Policies Act (PURPA), which encouraged utilities to buy power from other energy producers. CHP plants proliferated, soon producing about 8 percent of all energy in the U.S.[21] However, the bill left implementation and enforcement up to individual states, resulting in little or nothing being done in many parts of the country.
In 2008 Tom Casten, chairman of Recycled Energy Development, said that "We think we could make about 19 to 20 percent of U.S. electricity with heat that is currently thrown away by industry."[22]
Outside the U.S., energy recycling is more common. Denmark is probably the most active energy recycler, obtaining about 55% of its energy from CHP and waste heat recovery. Other large countries, including Germany, Russia, and India, also obtain a much higher share of their energy from decentralized sources.[21][22]
References
- ^ a b "The Unsung Solution: What rhymes with waste heat recovery?". Orion Magazine, November/December 2007. Archived from the original on 2014-03-23. Retrieved 2008-02-02.
- ^ "Solar Panel Recycling Solution".
- U.S. Environmental Protection Agency. 11 June 2015.
- ^ a b "Clean Heat and Power Association". Archived from the original on 2007-07-01.
- ^ 'Thermalbanks'
- ^ "Residential Heat Recovery Water Heaters | Free Hot Water | HotSpot Energy LLC".
- ^ "Heat Recovery Units (HRU)".
- ^ "High Temperature Industry Heat Pumps examples".
- ^ Wong, Bill (June 28, 2011), "Drake Landing Solar Community" Archived 2016-03-04 at the Wayback Machine, IDEA/CDEA District Energy/CHP 2011 Conference, Toronto, pp. 1–30, retrieved 21 April 2013
- ^ Wong B., Thornton J. (2013). Integrating Solar & Heat Pumps. Archived 2013-10-15 at the Wayback Machine Renewable Heat Workshop.
- U.S. Department of Energy.
- ^ Bruce Hedman, Energy and Environmental Analysis/USCHPA, "Combined Heat and Power and Heat Recovery as Energy Efficiency Options", Briefing to Senate Renewable Energy Caucus, September 10, 2007, Washington DC.
- )
- ^ "The Energy Information Administration, Existing Capacity by Energy Source, 2006".
- U.S. Environmental Protection Agency. Archived from the originalon 2011-12-18.
- U.S. Energy Information Administration.
- ^ "Recycled Energy Development, "What RED Does"". Archived from the original on 2009-09-13. Retrieved 2009-09-21.
- ^ RecyclingEnergy
- ^ "World's First Commercial Power Plant Was a Cogeneration Plant". Cogeneration Technologies. Archived from the original on 2008-04-25. Retrieved 2008-02-02.
- ^ "Testimony of Sean Casten before Senate subcommittee on Energy, Natural Resources, and Infrastructure, 5/27/07" (PDF).
- ^ a b "World Survey of Decentralized Energy, 5/06".
- ^ a b
'Recycling' Energy Seen Saving Companies Money. By David Schaper. May 22, 2008. National Public Radio.