Owner: Ben and Margaret Solomon

Designer/Builder: Ben and Margaret Solomon, Steve Matson and Huey

Gelpen

Size of Home: 3,000 square feet

Date of Construction: Originally 1965, remodeled 1980

• 168 SQUARE FEET OF Ametek solar panels, with 480 gallons of domestic hot water storage.
• Two mass wall greenhouse areas for space heating. About 290 cubic feet of vertical concrete was used.
• 100 square feet of PV panels, with 4KW Trace inverter and four Trojan L-16 batteries (installed 1990)

• Two T-2000 Thompson stoves, thermostatically controlled.
• One double-tier radiator running off solar tank for north side heating
• Insulating drapes on north facing windows
• Enclosed north entry
• Clothes line (no dryer)
• No dishwasher
• No television
• A hydronic loop extends from the hot water tank under the driveway and is used for melting snow

• No conventional space heat
• Ninety percent efficient gas boiler installed in 1998 for snow melt. This also provides domestic hot water backup. Prior to 1998 backup was by coil in wood stove flue.

We average two cords of wood per year since 1980 for space heat. Average electricity supplied by the utility is 145 KWh per month at about $12. Batteries last for seven years.

Our original motivation was based on economic as well as environmental considerations. Our house faced due south and there was no tree cover on that side. We built all our own equipment at first, including the solar panels and wood stoves. This activity evolved into an academic major at Sierra Nevada College and we became leaders in the field of small-scale application of renewable resources. We had two federal grants for the Thompson stoves and built electric cars as well as several passive solar buildings.

Aside from having to move wood, our house now functions with very little attention. Once a month I check the battery water. Each two months we need to add some water and do a five-hour equalizing charge. The system functions as a total uninterruptible power supply. The domestic hot water fluid is changed every five hears or so. Our gas bill for snow-melt and domestic hot water backup is expected to average $120 a year. Wood costs $300 a year (in 1998) and electricity $150, for a total of $570 a year.

The heat-collecting greenhouse is an especially nice living space attached as it is to the living room. We integrated our domestic hot water solar collectors on top of the already glazed walls of this area to make a coherent design for the whole project.

A building belonging to Sierra Nevada College is just across the street from our house. This 5,000 square foot structure has been built with recycled materials. South-facing windows and the concrete wall stairwell act as a heat collecting sink and radiator. This is especially effective in the winter and is responsible for a substantial portion of the heating load of that building. The annual cost for natural gas to run the backup radiant floor heating system is about $1,000, which makes this building one of the most efficient passive solar commercial structures ever built. You are encouraged to walk across the street to see how this kind of design can be incorporated into normal architecture.