San Francisco Department of the Environment

Residential – Castro Duplex

Solar Domestic Hot Water in the Castro

San Francisco resident Elizabeth Balaqui owns a beautiful 2-unit Victorian home in the heart of the Castro District. In May 2009 Elizabeth decided to install both solar electricity and solar water heating to offset some of the building’s carbon emissions. “I have always been interested in energy conservation,” she told us. “And now it’s just a really good time to do it, with the federal, state and local incentives. That’s what prompted me to go solar.”

Elizabeth’s solar water heating system, which was installed by San Francisco-based SunWater Solar includes two Schuco flat plate collectors and an 80-gallon solar hot water storage tank. After the water is heated by the solar collectors, it gets routed to the 80-gallon storage tank, which then supplies the pre-heated water to two 40-gallon conventional water heaters, one for each of the building’s two separate units. The system cost around $12,000 before tax credits. Elizabeth will receive a tax credit covering 30% of the total installation cost. It’s too early to report any energy savings, but Elizabeth is confident that there will be a noticeable reduction in her next gas bill.

Even on overcast days, Elizabeth’s solar water heating system generates a significant portion of her water heating needs. On a recent cloudy morning, a brief break in the clouds caused the temperature gauge on the panel to rise from 80º to 107º F in a matter of moments, as sun light reached the collectors.

Elizabeth installed a solar photovoltaic (PV) system at the same time, noting that having SunWater Solar and her PV installer, Berkeley-based Sungevity, working closely together to design their installations in a way that would accommodate both sets of equipment was key.

The solar water heating system took three days to install. Chris Chappell of SunWater Solar noted that the City permitting process went smoothly and that “modern solar hot water systems are designed to be installed in a way that is much faster than systems of 20 or 30 years ago."

Elizabeth is very pleased with her new system and says that it has been working well. She highly recommends solar water heating for every homeowner, saying, “Solar water is the way to go!”

city seal png