This San Francisco 3-story, 50-unit, 19,260 sq. ft. student housing complex renovation uses three types of solar energy: Solar water heating, solar hydronic heating, and solar PV.
Its engineers, Free Hot Water, won a prestigious 2013 Intersolar Award for designing the solar heating and hot water system to be cost competitive to traditional natural gas systems. As a result, California apartment developers can now go solar at the same cost of a natural gas system. When California and Federal incentives are included, the final cost for solar is even less.
Free Hot Water’s unique solar thermal design reduced the installed costs through several factors, including storage tank solutions, 95% efficient boilers, energy efficient pump station design, quality solar thermal collectors, and a central controller that optimizes the heat and hot water flow of the building’s entire energy system.
Eighteen 4 X 10 made-in-USA solar collectors provide 750 gal/day of solar hot water for tenant showers, laundry, and dishwashing. The hydronic heating system, also tied to the solar thermal collectors, will provide 75% of the heat needed by the building for San Francisco’s chilly climate.
Free Hot Water’s design also included energy efficient lighting and a 4.5 kW solar photovoltaic system, which offset a portion of the building’s lighting costs.
To tie together the various solar heating and energy systems, a control panel enables building managers to monitor the solar PV, solar heating, and the solar hot water system from a single web-based dashboard, allowing managers to view all solar operations on-the-go and quickly address any problems.
Formerly a warehouse, the developer estimates that the renovated building’s three solar systems and energy efficiencies will cut the building's operating energy costs by 66%.