Location: San Rafael, California System Size: 89 kW Energy Output: 135,525 kWh per year Savings: $22,849 annually Results: CO2 emissions reduced by 188,761 pounds/year (equivalent to 222,302 car miles/year) Success Story PDF

	"We were able to create a financial package with loan payments slightly less than our monthly savings on electrical bills." - Rick Carlsen, Assistant Director of Public Works

In response to the California energy crisis of 2001, Marin County began looking for opportunities to reduce its energy usage. The first site to be selected was the County's General Services Building next to the historic Frank Lloyd Wright-designed Civic Center. The building houses the garage, roads crew, and radio shop. The County first did an analysis of its power consumption, then reduced its energy use through a series of projects to improve the building's insulation, lighting, and ventilation systems. Next, it wanted to generate its own power using clean solar power.

Like many building managers considering solar energy, Marin County had concerns about the system's potential impact on the facility's roof. Would roof penetrations cause leaks? Would a solar array make roof access more difficult? Would there be wind loading problems or excessive standing loads?

To answer the concerns of the Marin Civic Center, the EI Solutions team recommended the Sunroof FS mounting system, manufactured by RWE Schott Solar. This flat-roof mounting system is self-ballasting and requires no roof penetrations. "Self-ballasting" means that the combined weight of the mounting system and solar modules is sufficient to keep the solar array in place under wind and seismic loads. The system has also passed wind tunnel testing up to 110 mph and weighs less than 3.5 lbs/ sq. foot when installed and is made of stainless steel. Plus the design of the array allows maintenance crews easy access to the roof when necessary.

On an annual basis, the Marin County solar array satisfies 84% of the building's energy demands. Using a combination of net-metering and time-of-use rates, the system is capable of zeroing the building's annual energy bill even though the system does not completely replace its entire energy usage.