Geothermal, Solar

Near-Zero-Homes Help Clear the Air

Geothermal heat-exchange systems and grid-connected solar photovoltaic (PV) are only a few benefits of Near-Zero-Housing that is helping to reduce air pollution in Tennessee. Tennessee ranked third behind California and Texas for smog, according to a September 2003 Environmental Protection Agency (EPA) report. And in June 2003, daily ozone alerts were in place 25 out of 30 days in the Smoky Mountains. Near-zero-emissions-homes are very energy efficient, and the building trend is supplying local contractors with a way to become part of the state’s pollution solution.

Oak Ridge, Tennessee – August 24, 2004 [] “While DOE’s (the Department of Energy’s) long-term goal is to develop technologies that enable net-zero-energy homes at low incremental costs, today’s focus is on leading new home owners and builders toward houses that boast high efficiency and use solar panels to generate some of their own electricity,” Jeff Christian, who is the director of the Building Technology Center at Oak Ridge National Laboratory, said. Workers have completed four near-zero homes for the Habitat for Humanity and DOE Building America program. These houses feature airtight envelope construction, advanced structural insulated panel systems, insulated pre-cast concrete walls, a heat pump water heater, geothermal systems, grid-connected solar photovoltaic, adaptive mechanical ventilation, cool roof and wall coatings with infrared reflective pigments, and solar integrated raised metal seam roofs. Daily average costs for heating and cooling a near-zero house is 45 cents. Adding in the cost of operating the water heater and all of the appliances raises the total daily average to 82 cents. This number takes into account $291 for solar credits that are part of the Tennessee Valley Authority’s Green Power Generation program. In comparison, a conventional house in Lenoir City would use between $4 and $5 of electricity per day. Plans call for a true net-zero-energy house to be built by the end of 2005.