The Garfield County Fairgrounds riding arena is showing how a combination of feedback on energy use, energy efficient technology, and rooftop solar energy can turn a large public building into an electricity producer.
The 39,000-square-foot facility produces more electricity than it uses, and the combined upgrades have been saving taxpayers about $700 a month this winter.
In 2011, the county installed a 440-panel rooftop solar electric system on the riding arena roof. The system was originally predicted to generate 57 percent of the electricity the building used.
Funding for the solar project came in part from a Colorado Department of Local Affairs (DOLA) New Energy Communities Initiative grant to Garfield Clean Energy, and through a power purchase agreement.
As part of the solar installation, the building was connected to the Garfield Energy Navigator, an online energy tracking system that provides daily readings on the solar power generated and the building's energy use.
The Navigator showed energy use was high at night and on the weekends. Staffers started shutting down the building during those times, and quickly saw the results.
In November, also through the DOLA grant, Garfield Clean Energy worked with county staff to replace the riding arena lights with more fixtures and bulbs. The upgrade cut the arena's December usage by 72 percent, from 22,000 kilowatt-hours down to 6,000 kilowatt-hours. For reference, a typical U.S. home uses about 600 kilowatt-hours a month.
The combination of smart action by building managers, quick access to data, more efficient technology, and a solar system financed by a power purchase agreement add up to make the building a mini power station.
According to utility data, cost savings in December 2011 were $778 (or 54 percent less than prior years) thanks to the energy efficient lighting and the lower-cost electricity locked in through the power purchase agreement.
"Because the building is equipped with the solar array, these savings in energy use mean the solar panels covered 106 percent of the building's electricity needs in November, 117 percent in December and 108 percent in January 2012," said Michael Ogburn, Energy Engineer for CLEER, the nonprofit that manages the programs and services of Garfield Clean Energy. The excess energy goes onto the regional electric grid and is credited to Garfield County's electricity bills.
"In monetary terms, the combination of a lighting retrofit and the solar power purchase agreement brought the electricity bills down to approximately $700 per month this winter, compared to approximately $1,400 per month in prior winters." These combined numbers mean that the building should be producing more electricity than it consumes throughout the year, possibly making it the country's first "net zero electricity" riding arena.