Alternative energy options in the mix for county buildings

Geothermal and solar offering good return

Alternative energy could be going mainstream in more Gunnison County buildings as old systems wear out and new technologies become more affordable.

At a work session in Novemberj, county facilities manager John Cattles told the Board of County Commissioners there was at least one viable option for introducing additional alternative energy systems into the mix in relatively short order, with more coming online as costs continue to fall.
In researching where the county should focus its resources, Cattles found that the valley’s winds weren’t ideal for power generation and the once-popular solar thermal technology that uses light from the sun to generate heat and turn a turbine has been outmoded by photovoltaic panels, which converts sunlight directly into electricity
“There’s been a sea change in the industry over the last few years and solar thermal has just been overtaken by photovoltaics,” Cattles said. “The reason is Chinese manufacturing that has driven the cost of photovoltaics down very low, really to the point where it’s economically not viable to build solar thermal that matches the capacity of photovoltaics.”
But the relatively low cost of power within the city of Gunnison, where most of the county buildings are located, and even in the surrounding county, Cattles said, makes photovoltaics less economical, at least for now.
“Photovoltaic is really not economically viable at this time, Cattles said. “The reason is that the city of Gunnison electricity rates are extremely low. They’re about half the state average and Colorado actually has a low average among the states. That makes it very hard for photovoltaics to compete.”
With the county paying about 7 cents per kilowatt hour for power at its buildings within the city limits and about 13 cents per kilowatt hour outside of city limits, Cattles said photovoltaics fall right in the middle, at around 10 cents per kilowatt hour expected over the life of the system.
The facilities the county owns outside the city limits are the public works shops and one of the county’s pumping stations. “Those are good candidates for a photovoltaic system,” Cattles said. “When I look for good candidates, I want them to use the energy right now, [as it’s being produced]. Pumping stations are great because they’re running all the time and can use the energy as it’s produced.”
In their strategic planning process, the commissioners identified environmental protection as one of their objectives and set goals to identify county properties that are well suited to alternative energy production and to increase the energy efficiency of one building each year for five years by 10 percent over a 2012 baseline.
Central to the ongoing reconstruction of the county courthouse is a system of 30 wells drilled hundreds of feet into the earth, designed to collect ground-source heat that will be used to both heat and cool the building for decades.
Using photovoltaics to power the mechanical systems that keep that ground-source heat in circulation could offset the amount of power the courthouses pulls from the grid almost entirely, county manager Matthew Birnie said. But that could still be some time away.
More immediately, Cattles told the commissioners, a system similar to the one being used at the courthouse could be installed at the Blackstock Government Building, where some equipment has been cobbled together and other equipment is almost ready for replacement.
“If we’re looking at alternative energy sources, using geothermal at this facility in the near future is the one that is the next best move for the county,” Cattles said, explaining that the size of the property Blackstock is built on could accommodate a large geothermal well field. “Horizontal systems are much less expensive and it’s possible we would have enough ground here to do that type of a system.”
“And we have aging mechanical systems at this facility. The chiller in this building is nearing its end of life and the boilers will be at the end of their expected lifespan within the next five years,” Cattles continued. “Those systems are going to need major rebuilding in the near future and at the time I would recommend converting over to a ground source heat pump system.”
While the focus of Cattles’ analysis was cost, Birnie pointed out “There are non-fiscal considerations to make.”
Commissioner Jonathan Houck wanted to know how the county could start moving ahead with some of the available opportunities to pursue alternative energy sources, like those with fleet vehicles that run on compressed natural gas and the changes recommended by Cattles.
Birnie said a good start would be prioritizing the projects in the county’s capital improvement plan and then finding funding for each as opportunities came along.
“These really are investments rather than expenditures,” Birnie said, adding that the payback period on the ground-source heat systems was short relative to the expected life of the wells, which are protected by warranty for 50 years. “So you end up with almost free energy going forward after that payback period. So even if we can’t pursue grants, that is something we would look at prioritizing.”