City to expand use of solar power at wastewater plant
Grand Junction city officials have a bright view of the future of solar power generation, at least as it applies to helping power the Persigo Wastewater Treatment Plant along River Road.
Ten proposals are being reviewed, and a bid is expected to be awarded shortly, for a major expansion of the solar power generation system at Persigo. An initial 98-kilowatt system has been turning the sun’s rays into photovoltaic energy at Persigo since the beginning of the year, but the new plans call for adding another 400 kilowatts to the system by the end of next year.
According to Terry Franklin, city utility manager, the system has been “working really well,” and that after the system expansion, he expects about 12.5 percent of the total power used at Persigo to be generated via solar power.
Persigo used more than 6 million kilowatt hours in energy in both 2010 and 2011, according to the city.
The proposal calls for engineering, design, construction and connection services for a 400-kilowatt solar array, hooked into the Xcel Energy electrical distribution system and operational before Dec. 1, 2013.
Franklin said there was “quite a bit of interest” in the proposal, with bids coming in from Boulder, Denver, Salt Lake City and even Florida.
Carbondale-based Sunsense Solar completed the first installation at Persigo, and the company has found a niche in partnering with municipalities on solar generation at utility facilities. It also performed a 100-kilowatt installation at Grand Junction’s water plant and is exploring a similar project in Palisade.
Key to Sunsense’s success in these deals is the fact that the company can offer a 10-cent renewable energy credit from utility partner Xcel, while Sunsense’s bid competitors compute their savings based on a lower-tier, 9-cent renewable energy credit from Xcel.
That said, the project is out for public bid and received a lot of interest.
In reviewing the bids, Franklin said city officials want to “see who is going to give the city the best return, in the 20 years of the renewable credits and the amount of energy savings.”
“Who is the best in the long run will end up getting the project,” he said.
There are some obvious advantages to using a similar architecture and product in any solar expansion.
Franklin said the expansion system doesn’t have to be the same, but “we want an apple and an apple, not an apple and an orange.”
Franklin told city officials in September that the city could expect to save more than $350,000 over 20 years with the expansion project.
His experience so far with installed photovoltaic systems has Franklin eager to expand.
Using a measurement via the National Renewable Energy Laboratory that says Grand Junction can reasonably expect 1,550 kilowatts of production per kilowatt installed, he says the system at the city’s water plant is reaping 1,750 to 1,800 kilowatts.
When fully expanded next year, the water plant will be running on 100 percent solar power, and the system has allowed the city to lower the actual rate it’s charged by Xcel, saving the city about $10,000 every year, Franklin said.
In another city solar project, the recycling center, Curbside Recycling Indefinitely, is set to be operating on 100 percent solar power in mid-January via an installation by High Noon Solar.