Larimer County cuts energy bills with panels, pledges

By JoAn Bjarko
North Forty News

Two arrays of solar photovoltaic panels perched on the roof of the Larimer County Courthouse Offices building will cut the facility's energy bill by 1.36 percent annually.

While that may seem to be just a blip in energy consumption, the county's energy conservation specialist, Stacey Baumgarn, said, "The example is that every little bit matters."

In addition, county employees recently received Earth Day Challenge pledge forms from the county's volunteer Green Practices Committee. The forms list ways anyone can save energy at work and at home. Everyone was asked to commit to doing at least one new practice.

"It all adds up" is one of the county themes.

Baumgarn said estimated payback time for the solar arrays is 17.5 years if calculated using today's energy costs. The panels, put in place on April 15, will go into action soon.

The majority of the $158,529 cost for the solar arrays came from two federal grants for renewable energy and conservation, with Larimer County contributing $35,000 of local funds.

The 26.82-kilowatt system has an array braced against existing infrastructure that shields the rooftop heating and air conditioning system. Another set of existing braces supports window washers.

One solar array is 71 feet long by 20 feet wide installed at a 31-degree tilt; the second is 140 feet long by 5 feet wide installed at a 40-degree tilt.

Drew Kundtz, the project manager for contractor Standard Renewable Energy of Boulder, said a 40-degree tilt is the optimal angle for photovoltaic panels at this latitude, but contractors also installed panels at a 31-degree tilt to make use of an existing structure. The difference in tilt, he said, was not enough to justify the cost of additional support braces.

According to Kundtz, the basic technology for these photovoltaic panels is 30 years old. The intervening years have been used to make them more efficient and less expensive, he said. The panels were manufactured in Mexico. Kundtz said they should last up to 40 years, but their efficiency goes down after 25 years.

Larimer County anticipates the 138 solar panels will produce 39,024 kilowatt-hours annually, offsetting an equivalent amount of electricity the county now purchases from the utility grid. All of the electricity produced by the system will be used for the office building. On average, the building uses 238,555 kwh of electricity per month – equivalent to the energy used by 329 homes per month.

The system will also prevent 60,000 pounds of carbon dioxide from being emitted into the atmosphere on an annual basis, similar to the emissions of 377 vehicle trips to Denver and back.