Co-housing group goes solar [Davis - Muir Commons]

source: Sumita Mukherji Davis Enterprise 2002.6.30

The Muir Commons Homeowners' Association on Monday will complete an installation of the
largest residential photovoltaic system in Davis.

The 10,000-watt system will produce up to 70 percent of the MCHA common house's
electricity from the sun and will offset 21,500 pounds of carbon dioxide emissions each year,
say those involved with the project.

The common house is a 3,668-square-foot facility that includes a large kitchen and dining area
to accommodate group meals and is the heart of the Muir Commons co-housing community.

A photovoltaic system converts sunlight to electricity. The system consists of cells that are
made of a semiconductor material, usually silicon, to eventually produce a direct current
similar to a car's battery, notes literature from the California Solar Center.

Muir Commons is the first newly constructed co-housing community in the United States;
residents moved into the co-housing group in 1991.

According to the Muir Commons Web site, www.muircommons.org, co-housing communities
are resident-developed neighborhoods that are planned and managed by residents. The living
arrangement allows residents to share household tasks and tools, and reduce consumption and
living expenses.

Charles "Chas" Ehrlich, a resident of Muir Commons, thought of the idea of the photovoltaic
system when he was considering ways to conserve energy for the co-housing community.

Ehrlich calculated that the system would cost Muir Commons Housing Association
approximately $80,000; after state Energy Commission rebates, the costs would be lowered
to about half of that. The association will also maintain reserve funding of about $40,000.

Each of Muir Commons' 26 households will pay $8 per month for 20 years, Ehrlich
continued. Furthermore, the solar installation was part of a solar workshop that was hosted by
solar installation contractor Sine Electric.

In the weeklong workshop, for which students paid tuition, attendees developed in-depth
knowledge and practical skills about solar power theory, system design and installation
practice, notes the Muir Commons Web site.

The co-housing association approved the solar energy project last November. The
photovoltaic system should pay for itself with approximately 10 years, Ehrlich said.

In an additional 10 years, the reserve funding will have paid for itself, too, he added.

The photovoltaic system should last more than 30 years, he added, and is warrantied for 25.
In 20 years, the system should produce 360 megawatt-hours of energy, Ehrlich added.

Additionally, the photovoltaic system would save the Muir Commons Housing Association
approximately $350 per month in energy costs.

(4 SMA SunnyBoy 2500 inverters provide the brains to the PV system)

At 10,000 watts, the photovoltaic system is unusual in both its size and installation method,
said Scott Ragsdale, chief financial officer for Cooperative Community Energy, which bought
the solar equipment for the Muir Commons Housing Association.

That's because Cooperative Community Energy, which has a branch office in Davis, is the first
solar photovoltaic equipment buyers cooperative in California, he added.

Ragsdale, an Oakland resident who grew up in Davis and worked in architectural offices
where part of the Davis Village Homes development was designed, said he was drawn back
to the city because its residents show a lot of enthusiasm for clean energy sources.

"It takes a lot of coordination to put one of these solar systems on your roof - you need to
satisfy city, utility and state requirements," he said.

Single-family households interested in using photovoltaic systems generally use two-kilowatt
systems, which costs $19,000 before rebates, and about $8,850 after rebates, from the state
Energy Commission, notes CCE's Web site, www.ccenergy.com.

However, the Web site also encourages would-be solar energy system consumers to
conserve energy and research solar and other renewable forms of energy before making a
purchase.

Ragsdale said he is optimistic about the future of solar energy.

"The wildly destructive events of this past year have made it pretty obvious that we need to be
aggressive about using alternatives to fossil fuels," he added.

For more information about the project, e-mail Ehrlich at ckehrlich@yahoo.com. For more
information about photovoltaic systems, visit www.ccenergy.com.