I know when I start hearing randomly about something from many different sources that it’s probably an idea worth investigating. Such is the case with the idea of cogeneration, or the notion that combined systems for producing heat and power are more efficient that separate ones.
The latest communique about this subject came to me in late December from Veolia Energy, which recently signed a deal to take over the Medical Area Total Energy Plant (MATEP) assets from six hospitals in the Boston area. Yes, you guessed it, MATEP is a central district energy plant that handles the heating, cooling and generation needs of the facilities on the 200-acre Longwood medical center site. The healthcare industry is big into cogeneration, apparently: Veolia Energy supports more than 5,130 healthcare establishments around the world.
Cogeneration is a much bigger deal in some countries than others, of course. In Denmark, apparently, approximately 50 percent of the energy is produced through cogeneration facilities. The idea is pretty simple: Why not use the heat produced by generating energy to either heat or cool the buildings for which the electricity is being produced. Almost ALL of the buildings in Copenhagen are connected to district energy plants. In the United States, the United Kingdom, Canada, Mexico, France and Spain, cogeneration accounts for less than 10 percent of national generation. (It is slightly more than 10 percent in Germany.) This link provides a primer about district energy and cogeneration from the International Energy Agency.
Of course, cogeneration facilities need to be pretty localized and that’s probably the biggest downside. You need to concentrate on a very specific space, so you can’t necessarily scale it for an entire neighborhood. Still, the Environmental Protection Agency is encouraging organizations to consider cogeneration for industries facilities, residential sites, schools, commercial buildings such as hotels, and so on.
The agency recently recognized four organizations for using combined heat and power systems to help reduce their carbon emissions. They were:
- Calpine Carville Energy Center in St. Gabriel, La. - It is using 410,000 pounds of high pressure steam per hour for production at a nearby plastics manufacturing facility.
- The Commonwealth of Massachusetts Department of Corrections Bridgewater complex in Bridgewater, Mass. - Its natural gas-powered turbine generates about 80 percent of the facility’s annual electricity needs.
- Equity Office Properties in New York - Its system covers about 60 percent of the electricity and thermal needs of its 5th Ave. office.
- Patterson Farms in Auburn, N.Y. - Which generates up to 200 kilowatts of electricity from an engine powered by biogas (ample supply from the dairy cows).
A press release describing the work of these organizations can be found here.
The downside, of course, of the cogeneration technology I’ve mentioned above is that all but one use fossil fuels as their ultimate power source. So, while the idea of stimulating more use of combined heat and power technology is compelling, an even more compelling notion is to study ways to increase the use of cogeneration technology powered by renewable energy.
