Summary
With a goal of reaching carbon neutrality by 2025, the City of Missoula, MT sought to implement a solar system at the city’s wastewater treatment plant. With an innovative proposal that beat out four competitors, Ameresco’s plan addressed several challenges including the unique site conditions that had waste concrete and rebar buried just inches below the soil. The solar project is just one of two known projects operated under a solar energy agreement in Montana and is also the largest behind the meter, non-export solar PV array in the state.
“Our city has a long track record of implementing forward-thinking conservation and climate change measures and the completion of the solar PV array at our wastewater treatment facility is another demonstration of our commitment to sustainability. We are thankful to our partners at Ameresco for helping us maximize our investment in clean energy and for producing work that will enable the city to lower our electricity consumption and emissions, and in turn move us towards our goal of carbon neutrality.”
– Ross Mollenhauer
Engineering Manager, City of Missoula
$0
Upfront Cost
25 Years
Project Term
545 KW DC
Solar PV Size
703,511 kWh
Year 1 Energy Production
Customer Benefits
The solar project is just one of two known projects operated under a solar energy agreement in Montana and also the largest behind the meter, non-export solar PV array in the state. Other benefits include:
- Estimated to produce over 700,000 kWh each year
- Designed to offset over 20% of the wastewater treatment facility’s annual electricity consumption
- Delivers significant cost savings given solar energy’s lower cost compared to utility provided electricity
- Advances the City of Missoula’s goal of carbon neutrality by 2025
Solution
Presented with several challenges to overcome including the city’s interest in third-party ownership arrangements, Ameresco first had to study legislation to ensure third-party ownership via a solar energy agreement was feasible in Montana. To maximize the solar production potential for the site as required by the city and far exceeding the utility’s 50kW AC net metering cap, Ameresco also studied the facility’s interval demand data to maximize the size of the solar array while not exporting power to the grid. Next, we worked with the subcontractor partner to design geo-ballasted, non-penetrating ground mount racking to accommodate the unique site conditions. Ameresco designed, built, owns, operates and maintains the solar system which includes:
- 545 kW DC behind the meter non export solar array
- 25-year solar energy agreement
