Article from Solar Today Magazine, 1997

By Mary Jim Evans

An Atlanta research and educational organization houses its offices in a residential building that is a showcase of innovative renewable energy and energy-efficient technologies.

Since 1978, he Southface Energy Institute in Atlanta, Georgia, has offered education, research and technical assistance programs on sustainable energy and environmental technologies. As an independent nonprofit membership organization, Southface has gained national recognition for its consumer programs, professional training and work in affordable housing.

In cooperation with the U.S. Department of Energy, Lawrence Berkeley Laboratory, the National Renewable Energy Laboratory, Oak Ridge National Laboratory and corporate and individual sponsors, Southface developed a state-of-the-art demonstration building, the Southface Energy and Environmental Resource Center, to provide a permanent showcase for innovative technology and a resource for builders and homeowners throughout the south. The Center opened in the summer of 1996 - a time when literally millions of people were visiting Atlanta for the Olympics.

A Showcase of Innovation

Although no one lives in the building, it is designed like a house, and the products, appliances and technologies provide valuable information for homeowners and home builders. The home and office areas display innovative ideas for saving energy, water and other natural resources; for reducing waste and using recycled materials; for maintaining a healthy indoor environment; and for ensuring accessible design. Some of these ideas are detailed in the sidebar on this page.

Visitors often ask, “How much would it cost to build my house using these ideas?” This is a smart question, but it’s tough to answer. Although some of the products in our building may cost more to buy, they will save money by lowering energy and water bills, lasting longer and requiring less maintenance. Many of these technologies also improve comfort and protect your family’s health and the health of our planet.

A better question might be, “How much will it cost NOT to build my home using these ideas?” Standard homes waste hundreds of dollars each year in needless energy and water use. When energy efficiency technologies are included in a home’s mortgage, they usually save much more than they cost. Many products offer rates of return over 20 percent, and they immediately improve the comfort and durability of the building.

Doing It Right

The Center demonstrates the best practices and latest products and equipment for energy-smart, resource-efficient residential design and construction. The purpose is two-fold. First, the building stimulates “bottom up” interest and demand on the part of homeowners and buyers for energy efficient, environmentally responsible housing and household products. Second, it encourages “top down” leadership on the part of the housing industry and market competition among suppliers that will accelerate the introduction of energy-saving and environmentally friendly products, materials, design strategies and construction practices.

To share this information, Southface offers a number of services. The Southface Journal is a quarterly publication for Southface members that provides information on upcoming activities as well as practical advice on sustainable energy and environmental issues. The Homebuilding School offers a comprehensive program of instruction for individuals who want to be involved in building their own homes, whether they want to pound every nail or just negotiate intelligently with their architect, contractor and tradespeople. Seminars and workshops on topics ranging from energy efficient construction and remodeling to alternative-fueled vehicles are held on an ongoing basis. Visitors can use the Energy Design Lab, a comprehensive collection of energy and construction design software, to refine the design of their building project. Southface’s services also include building energy audits, a home design review, a library and website and a speaker’s bureau.

If visitors to the Center use the technologies displayed in the building, they can save themselves money and make their homes more comfortable. But the benefits of renewable energy and energy efficiency technologies go beyond the immediate value to the consumer. They also include such things as decreasing air pollution and greenhouse gas emissions, reducing our dependence on oil imports and improving the health of regional economies by keeping local money circulating in communities. It’s a scenario in which everybody wins.

Hands-On Learning This is a partial list of the renewable energy and energy efficiency technologies used in the Southface Energy and Environmental Resource Center. PASSIVE SOLAR DESIGN The major glass area faces south for maximum solar gain in winter. The south-facing windows equal approximately 7 percent of the floor area of the main level. A two-foot (.6 m) overhang keeps the direct overhead summer sun out, but allows the lower winter sun to enter the building. The half-inch (1.3 cm) thick floor tile set in a 2.25-inch (5.7 cm) thick mortar bed provides about 170 cubic feet (4.8 m3) or 20,000 pounds (9027 kg) of thermal mass to store the solar heat that comes through the windows. East and west glazing is minimized to reduce solar gain in the summer. HIGH PERFORMANCE WINDOWS The Pella Designer Series Classic windows feature argon-filled, double low-emissivity coated, insulated glass. A wood thermal break between the two panes of glass reduces heat flow through the frame. The total window R-value is 2.96 (U-value .34). These windows reduce energy loss and fading of materials in the building. SOLAR ELECTRIC SHINGLES The integrated photovoltaic (PV) shingles resemble conventional fiberglass roofing shingles and produce 4 watts AC/ft2 peak power in full sun, or about 16 watt-hours/ft2 daily (8 kW/day for the array). United Solar Systems and Energy Conversion Devices manufactured the 1 foot by 10 foot (.3 m by 3 m) PV modules of amorphous silicon cells deposited on a thin, flexible, lightweight stainless steel substrate, which is laminated in advanced polymers. The overlapping modules replace conventional shingles. There is one sealed roof penetration for each module and wiring connections are made below the roof decking. The electricity produced by the shingles is used in the building or fed back to the utility. One of the ways supporters can contribute to Southface is to sponsor one or more solar shingles. SOLAR WATER HEATER The American Energy Technologies solar water heater is designed to provide at least 50 gallons (189 liters) per day of 122°F (50°C) hot water for a family of three people. A 2 foot by 10 foot (.6 m by 3 m) solar collector on the roof of the breezeway to the garage provides approximately 20,000 Btu per day of solar water heating. The solar-heated water transfers heat via a side arm heat exchanger into a 40-gallon (151 liter) backup electric water heater. A desuperheater on the geothermal heat pump provides additional hot water. OFFICE DAYLIGHTING The south-facing windows and overhead cupola provide natural daylighting, which reduces the use of artificial lighting. The solid roof of the cupola prevents direct solar gain in summer. PHOTOVOLTAIC OUTDOOR LIGHTING The outdoor lights for the parking lot rely on sunlight to generate electricity. The crystalline silicon photovoltaic (PV) panel produces electricity during the day, which is stored in a ground-mounted battery. The direct current fluorescent lamp is controlled by an automatic light cycle of 8 hours per night. There is battery energy storage for six days of operation without direct sun. The landscape lights also use a PV cell that generates electricity from sunlight and stores it in a battery for use at night. Another PV cell powers a motion detector. A small battery inside the light fixture stores the electricity. The PV cell can be mounted separately to ensure access to sunlight, and the fixture does not require conventional electrical service.

Mary Jim Evans is a former project manager at the Southface Energy and Environmental Resource Center, and is regarded, along with Elizabeth Robertson of GEFA, as co-founder of the Greenprints conference series.