Context: Dave and Margot Ringenburg relocated to the Triangle in 2007, and like thousands of
other transplants, were in the market for a new home. But unlike most home shoppers, this super eco-conscious couple was not interested in the traditional offerings of most new neighborhoods. Instead, they were committed to building a high performance new home that would not only use less energy, but also create its own power from clean, renewable sources.
Project: To help the Ringenburgs create their green dream home, Southern Energy Management (SEM) met with the Ringenburgs and their architect, Chapel-Hill based green builder, John Hartley, to develop a plan within the couple’s budget for achieving high energy performance using both conservation and renewable power. Using the national Energy Star program as a framework, SEM’s building science team provided consultation and third-party verification for the home’s energy-saving features. Simultaneously, SEM’s solar team worked with the Ringenburgs to design and install a combined solar thermal and solar photovoltaic system. After conducting an initial solar siting of the wooded Ringenburg property, SEM concluded the site was not suitable for a solar pv system due to heavy shading. In response, the Ringenburgs constructed a special shed behind their home where their 36-panel solar system could be installed for optimal sun exposure and efficiency.
Outcome: SEM’s consulting and third-party verification of the energy-saving features of the Ringenburg home earned it a home energy rating of 8 – the best rating we’ve ever seen. A home energy rating is a standard measurement of a home’s energy efficiency, and is based on the national HERS Index. An index of 100 represents a home that complies with current energy codes, while an index of 0 represents a zero energy home. The lower the rating the better. (To earn Energy Star certification, a home must have a HERS Index of 85 or lower.)
In addition to its superior energy efficiency rating, the Ringenburg residence receives almost all of its hot water and some of its electricity from the sun.
Electricity produced by the Ringenburg’s 7.2 kW solar PV system supplies energy to a GridPoint battery system that provides secure backup power and keeps essential loads turned on in the event of a utility outage. Electricity from their PV array also flows into the nearby utility grid, where it adds to the local supply of green power through the NC GreenPower program. It is estimated that heating and cooling the 2,075 square-foot home will cost only $298 per year, or $25 per month. In addition, the Ringenburgs will receive an average of more than $100 per month from NC GreenPower for the electricity their PV system adds to the utility grid.
SEM’s holistic approach and our experience integrating building design with renewable energy proved to be a perfect match with the Ringenburg’s goals for their new home. Their vision and commitment combined with our team’s expertise led to a comprehensive solution that sets a new standard in North Carolina. The home will eliminate over 27,000 lbs/year of air pollutants (CO2, SO2, NOx) from being emitted into the environment by conventional power plants.