Following up on Editorial about Climate Change
There are other sources of carbon dioxide in addition to electric power generation. Heating buildings and heating domestic hot water are also significant sources of CO2. Nationwide, 46 percent of the energy used by buildings is used for heat. Here in New England, heating and domestic hot water takes 64 percent of the energy used by buildings, and electric power takes but 36 percent. CO2 production by New England buildings is a greater proportion than 64 percent due to our large percentage of oil burned for heating. Switching all power generation to renewables would mitigate well under half the CO2 due to buildings.
There is a new heating technology that was invented in the South End, and prototyped in Western Massachusetts that can save up to 50 million tons of CO2 per year. This technology is a completely different way to heat buildings from a central plant, which enables the reject heat from all power plants, as well as solar energy, to be used for heating. The essence of the technology is to distribute water at 120°F, which is a much lower temperature than is normal for central heating systems. This temperature is compatible with the heat rejection system of virtually all power plants, making it possible to use all their reject heat. Low temperature water can readily be distributed in inexpensive uninsulated pipes similar to water main pipes. Use of low temperature heat solves the intermittency problem of solar energy, as storage of solar heat is easily done in large tanks of water, or even in the ground. Buildings are retrofitted as necessary to use the low temperature heat.
Informal studies have shown good economics. Mystic station in Everett is threatened with shutdown, and may require subsidies to keep it running. Preliminary estimates show that the thermal output of this plant could heat Everett and neighboring towns at a cost compatible with gas heating, pay a subsidy to the plant, and pay off the capital investment in about six years.
Using all the heat from the power plants in New England would save about 14 percent of the peak day winter gas demand for New England, reducing the need for new gas pipelines; and would save 7.6 million tons per year of carbon dioxide. Applied nationally, this technology could save 50 million tons of CO2 per year, making a dent in climate change
Robert W. Timmerman PE, CEM, LEED AP