Project Report: 3.75kW Solar Array LMI Installation at 104 Floresta Street, Gunnison, CO 81230

In 2020, the Equitable Solar Solutions program at Coldharbour Institute in Gunnison, CO approached the Colorado Energy Office to partner on a pilot project to install a reuse solar photovoltaic (PV) system on a low- to moderate-income home. After receiving a list of seven homes in Gunnison County that had participated in the Weatherization Assistance Program, ESS evaluated each home for site suitability with respect to placement of a solar PV array.
Several homes were impacted by terrain and tree shading. One home visited had already installed a solar array. One homeowner is highly interested but needed to address roof repairs that have now been resolved.[1] One elderly homeowner was not interested in participating. Taylor Miller’s home at 104 Floresta St was selected due to the good southern exposure and an electrical load that is compatible with one of the PV systems in our inventory.
The ESS program provided 15 PhonoSolar 250-watt (one is a 260-watt version) modules, a SolarEdge SE3800A grid-inverter, 15 SolarEdge DC optimizers[2], and Snap-N-Rack rails for the project.
Our local solar installer Nunatak Alternative Energy Solutions provided the remaining hardware needed for the Snap-N-Rack mounting system, cabling, connectors, conduit, electrical boxes, meter can and labor for design, installation and commissioning. 
The solar PV array and inverter installation was completed on 4-Jun-2021. Duft Electrical provided equipment, wiring, components and labor to complete the system tie in with the house on 29-Jun-2021. This did require installation of an additional breaker panel on the building exterior between the production meter and the interior main breaker panel.
System commissioning was completed on the afternoon of 29-Jun with the PV array producing up to 2.794 kilowatts of power mid-afternoon under partly cloudy conditions. All 15 DC optimizers and modules successfully paired with the inverter. ESS will follow up with homeowner Taylor Miller on a monthly basis for the first few months to ensure proper system operation.
The total project was completed below budget at a total of $6,907.71 which includes $6,006.71 payment to Nunatak Alternative Energy Services and Duft Electrical, plus 15% administrative/indirect costs of $901 incurred by Coldharbour Institute. This results in an installed cost of $1.84 per watt – well below industry standards for non-LMI system owners.


[1] Funding for a project on 102 Diamond Ln in Gunnison would be greatly welcomed by the homeowner.

[2] Which also meet NEC rapid disconnect requirements.

Figure 1: Crew placing final PV module on rooftop arrays

Figure 2: Nunatak installer completing wiring runs at inverter

Figure 3: Successful energy production during commissioning

Figure 4: All 15 DC optimizers and modules successfully paired

Figure 5: Homeowner Taylor Miller confirming power production

Figure 6: Homeowner with completed solar photovoltaic system