In what would be the largest solar project in the valley, Gunnison County leaders are embarking on an initiative to utilize the rooftops of five government buildings to harness the power of the sun, offsetting the energy consumed within those structures on a daily basis.
As envisioned, photovoltaic (PV) cells — or electricity-producing solar panels — would be installed on top of the following county buildings: the courthouse, Blackstock Government Center, O’Leary Building where Health and Human Services is housed, Public Safety Center and Public Works building. Combined, the magnitude of the solar arrays would total about 270 kilowatts (kW). When completed, the Gunnison County Courthouse alone is expected to generate 40 percent of its daily energy use, while other buildings are estimated to generate 20-30 percent.
“This has been contemplated since the beginning of the courthouse project,” said County Manager Matthew Birnie. “The assumption was that PV would be added in the future.”
Sustainable Operations Director John Cattles estimated the cost for the solar arrays for all five buildings at about $1 million with hopes that a Department of Local Affairs (DOLA) grant — applied for recently — will fund about half of project costs.
Improving ‘energy use intensity’
The project is one of two identified in an energy performance contract being pursued with Johnson Controls, a Milwaukee, Wisc.-based consultant. Under the contract, Johnson Controls will perform an “investment-grade audit” of county facilities — an examination of buildings for energy efficiency improvements.
The company then will attempt to identify ways to address those improvements, saving money and enhancing environmental conditions within the buildings.
Cattles told Gunnison County Commissioners Tuesday that the Gunnison County Courthouse is highly rated when it comes to its “energy use intensity” (EUI). That’s the amount of a building’s energy consumption relative to its gross square footage. Ratings fall between one and 100, and the lower the EUI rating, the better the building’s energy performance.
The Gunnison County Courthouse site has an EUI of 30.
However, the source of energy for the courthouse is reflected in a separate EUI rating. According to energystar.gov, “source energy represents the total amount of raw fuel that is required to operate the building. It incorporates all transmission, delivery, and production losses. By taking all energy use into account, the score provides a complete assessment of energy efficiency in a building.”
The courthouse’s source EUI is 80, due in large part to electricity used for heating. By generating a large portion of its own renewable energy, the building not only improves its EUI rating, but it saves money as well.
What to do with excess energy
Cattles said the purpose of the solar project is to simply produce what the county will use during daylight hours, with little to no excess energy.
“The goal is to meet our daytime load — that we’re not exporting to the utility — and that we’re maximizing our roofs,” Cattles explained.
However, during certain periods of time when energy use is lower, there is a potential for the project to produce more than the county needs. Potentially, batteries could be used to store the excess energy.
“Rather than put back on the grid, you would put it into a battery,” Cattles said. “But batteries are very expensive.”
That means any excess energy produced most likely would be returned to the city’s system.
Since county buildings are served by the City of Gunnison, a three-way agreement must be reached between the city, the county and the city’s energy provider, Municipal Energy Agency of Nebraska (MEAN). This is a requirement by MEAN for any solar project over 25 kW. The agreement would specify the price at which MEAN will buy back any excess energy produced by the county.
Currently, MEAN will pay about 4 cents for every kilowatt-hour (kWh) put back on the city’s grid for projects under 25kW. However, the county’s rate must be negotiated with MEAN because of the large size of the project to ensure adequate infrastructure is in place, said Gunnison City Manager Russ Forrest.
“It’s a great project for the county and it creates a renewable resource in our backyard,” Forrest said. “We actually have a framework that can accommodate this. A project like this is a win-win.”
Forrest said the city, the county and MEAN currently are looking to a contract established with Waverly, Kan. on a similarly sized project for guidance.
Construction could begin this fall
Cattles said Johnson Controls will help develop a design for the solar array and determine financial aspects, such as calculations on energy and operations savings, during the months of May and June which will result in the release of a request for proposals for financing.
The audit will be finalized in July, which will describe background objectives, energy saving measures and costs. A “workshop” will be held to demonstrate how improvements will be implemented.
The project will form a basis for the performance contract in August which will provide a guarantee for energy savings to be realized by the county.
The county will identify a preferred lender in September and must lock in a financing rate within 30 days, with construction to begin in October.
Cattles estimated that the cost of the project will be recouped during the lifespan of the solar equipment — about 25-30 years. If awarded, the grant from DOLA could provide the county a faster return on its investment.
“It’s a significant investment,” said Cattles. “Hopefully we’ll be successful with the grant, and this will be a successful project for the county.”