Cogeneration is not exactly new; we've been reading about it for years. But we haven't heard much about it lately, and we were glad to read in Sunday's paper that our own city-owned power company, Denton Municipal Electric, is looking into building such a plant to serve its customers.
Cogeneration, also called combined heat and power, or CHP, is a process whereby an electric generating plant produces both thermal and electric energy for sale. All generating plants produce thermal energy (heat) as well as electricity, but that heat in such plants is wasted through smokestacks. In addition to wasting that heat, conventional plants foul the air with the noxious waste of whatever boiler fuel is being used to generate the electric power.
Cogeneration plants capture most or even all of the heat produced during electrical generation and heat the ambient air in their own plants with it or offer the heat for sale to nearby customers, usually businesses or industries.
The electric power generated at such plants can be used throughout a power company's system; the heat must generally be sold to nearby customers, as heat is a perishable commodity and dissipates as it moves farther from its source. It also requires expensive insulated pipes to transmit to customers.
Still, cogeneration is an economical and environmentally smart means of producing power if a utility company has the means to do it and the nearby customers to make it financially feasible. The city is apparently investigating both possibilities now, negotiating with potential customers before deciding on a site that could serve them should the negotiations prove successful. It has also approved a contract with an engineering firm to obtain the needed permits that would allow the city to purchase, install and use natural gas turbine engines that would generate both electricity and salable heat.
The 10-megawatt cogeneration plant envisioned by DME would be a small plant by conventional standards - typical coal-fired power plants generate 500 megawatts or more - but it would provide the company with a modicum of homegrown power along with the potential of heat sales that could offset some of the cost of power generation. The plant would also serve as a statement about the city's intent to provide the cleanest power available.
This is a positive step by the city and by Denton Municipal Electric. We're glad to see them take it, and we hope it is just the first of many steps toward the utility's becoming a self-sustaining producer of cheap, clean electrical power.
We wish them well in the endeavor.
