For Watson Irrigation of Townsend, Montana, solar was primarily a financial decision.
“It penciled out quick and easy,” explains Konnor Kelsey, Watson Irrigation Operations Manager. “We’re expecting a seven year return on investment, and the warranties are ten years for the inverters and 25 years for the panels. Equipment that’s paid off while it’s still under warranty? It was an easy decision.”
In fact, Konnor explains that the firm would have preferred to install a larger solar array, but was prevented from doing so by state law. Watson Irrigation’s solar array is 50 kilowatts, the maximum allowed by the state’s net metering law. It would have taken a 70-75 kilowatt array to offset their electricity use. A larger array “would have been a no-brainer,” Konnor says. “[The law] is a real limiting factor.”
Watson Irrigation’s solar array was installed by Bozeman Green Build. Bozeman Green Build owner John Palm explains that the most interesting aspect of the job was designing a novel mounting structure for the solar panels. Watson Irrigation didn’t have any ground space to spare, and their shop roof wasn’t angled right for solar. A long, south-facing storage shed on the property would have been just right, expect that it wasn’t sturdy enough to withstand the weight of the solar array. Working with Bozeman engineering firm Nishkian Monks, they designed a support structure involving 6 inch steel pipes that were dropped through the shed roof and into the ground. I-beams were welded to the steel pipes above the shed roof, and the solar panels were installed on this structure. Watson Irrigation did much of the welding and fabrication work in-house.
The installation was completed in September 2015, and Watson Irrigation is pleased with its production so far. “It’s been live for about a month and so far we’ve banked about 2,500 kilowatt-hours,” says Konnor. “I’m expecting it to take away 85 percent of our power bill over the year.”
- Location: 7837 Highway 287, Townsend, MT
- Owner: Watson Irrigration
- Installer: Bozeman Green Build, Nishkian Monks (engineering), Watson Irrigation (welding and fabrication)
- Utility Service Territory: NorthWestern Energy
- Capacity (kW): 49.96
- Incentives: Rural Energy for America (REAP) grant, NorthWestern Energy USB incentive, federal tax credit
- Equipment Used: 156 SolarWorld 320W solar panels, 5 Fronius Symo 10.0W inverters, Unirac U-LA racking