At Shelburne Farms, you expect to see pastures, gardens and orchards in abundance. The rolling 1,400-acre farm along Lake Champlain’s shoreline is on land that has been continuously farmed since the 1760’s and is a National Landmark property. So you might be startled to stumble upon the “solar orchard,” just past the market garden, in what was once a pasture where sheep grazed and is now a large array of solar panels. The solar orchard was installed last September on two acres of an unused, six-acre field that is projected to annually produce 150,000 kilowatt hours of electricity. That is about 25 percent of the approximately 600,000 kilowatt hours a year that the Farm currently uses.
The solar orchard is a partnership project with Green Mountain Power, a major Vermont utility company. GMP installed the equipment, built the inverter house, and owns the power it produces which goes to the grid. The farm purchases the power at GMP’s going rate but, “we know that the farm uses all of it before it can get back to Shelburne,” says Marshall Webb, the Farm’s Woodlands and Special Projects Manager.
The site is ideal for solar, according to Webb: It has good southern exposure, it’s on a road, and it’s near a three-phase power line. It’s very close to The Inn where many of the Farm’s visitors stay and to the Coach Barn where most events take place. “We want to produce energy right here and have people see it,” Webb states, “because Shelburne Farms is committed to renewables, to pushing the envelope, and setting an example. We don’t tout ourselves as a model, but we like to be in the forefront.”
The project had a serendipitous beginning: The utility company happened to be looking for a place to construct a 150,000 kW solar field, and the Farm had both the perfect field and a commitment to renewable energy. Webb calls the project a “win-win” for both GMP and Shelburne Farms. Gradually, Shelburne Farms will expand the field for its own use, using the existing GMP infrastructure.
For GMP, not losing energy in the line has value too. Line loss can be significant and is reduced by distributing energy production throughout its service area. During peak usage in the summer, the solar orchard is cranking and offsets the need for the utility company to purchase expensive power on the spot market. For Shelburne Farms, the ultimate goal is to be 100 percent renewably powered by 2020, if possible.
Toward that goal, another 50 kW field adjacent to the GMP panels is planned for this fall. There’s space for an additional 300 kWs of panels in the field, and the Shelburne Farms portion of the orchard will grow incrementally over time. The Farm’s new installation will use the existing 500 kW capacity transformer, saving on infrastructure costs—and more in mowing costs too: sheep will once again graze in that pasture among solar panels.
How’s the project working out so far? Webb listed the criteria for success: It would “reduce the Farm’s carbon footprint; it would have a sensible economic payback,” and as a bonus, it would have “an educational value” which the Farm can share with everyone. So far, so good.
by: Sally Ballin
GET Aug2011 page 21