Stanford's presidential home goes solar

The official home of Stanford President John Hennessy has gone solar. The electric meter for Hoover House now runs backward at times, with the solar panels creating more electricity than the house requires.

The 40-kilowatt solar panels, the largest photovoltaic system on campus, were energized earlier this month with the flip of a switch that sent photovoltaic electricity flowing to the house and the PG&E grid.

The 252 polycrystalline solar panels, manufactured by Evergreen Solar and installed by REC Solar, are mounted on the flat roof of a partially buried water tank (known as the San Juan Reservoir) near the house. The multiple levels and terraces of the historical house, built by Herbert Hoover and his wife in 1920, before he became president, make it impractical to place the panels there.

The project is an example of smart sustainability that works both environmentally and financially, said Joe Stagner, Stanford's sustainability czar. The clean energy will reduce carbon dioxide emissions by about 14 metric tons per year, and the economic details are favorable.

Because the house is used for official events, it consumes more electricity than the average home. Under PG&E's tiered rate structure, the price of electricity per kilowatt hour goes up with usage, putting the Hoover House at the high end of the rate chart. These higher PG&E rates help make solar power a financially attractive alternative.

Two other monetary incentives sweetened the pot: Excess power from the solar panels will be sold to PG&E, and the project's $362,000 price tag will be chopped by $84,000, thanks to a rebate from the California Solar Initiative.

The other side of the equationusing less electricityis not being ignored. An energy audit of the house is scrutinizing areas such as lighting, swimming pool pumps and kitchen equipment for energy savings, said Scott Gould, the Stanford energy engineer who directed the Hoover House endeavor.

Other photovoltaic projects on campus include the Leslie Shao-ming Sun Field Station at Jasper Ridge Biological Preserve; Synergy House, a student-run cooperative; the Jerry Yang and Akiko Yamazaki Environment and Energy Building (Y2E2); and Reservoir 2, a six-million-gallon water tank in The Dish area.