The economics of rooftop solar have improved dramatically over the past decade. Installation costs have fallen 70 percent since 2010, and the average residential system now pays for itself in 6 to 8 years. But there is a fundamental access problem that market forces alone have not solved: renters, condo owners, and households with shaded or unsuitable roofs cannot participate.
In Portland, that describes approximately 58 percent of all households. In lower-income neighborhoods, the figure rises to 74 percent. Today, TerraFuture is launching a community solar initiative designed to close that gap.
How Community Solar Works
The concept is straightforward. Rather than installing panels on individual rooftops, community solar projects place larger arrays on suitable host sites, such as commercial rooftops, parking structures, and municipal buildings, and allow nearby households to subscribe to a share of the energy produced.
Subscribers receive credits on their electricity bills proportional to their share of the array's output. There are no upfront costs, no installation requirements, and no long-term contracts. Participants can join or leave as their circumstances change.
Our program launches with eight installations across Portland, totaling 1.2 megawatts of capacity. Each array is sized to serve between 40 and 80 households, depending on average energy consumption in the host neighborhood.
Targeting Energy Burden
We deliberately sited our first eight installations in neighborhoods where energy burden, the percentage of household income spent on energy costs, exceeds the regional average of 3.1 percent. In some of our target neighborhoods, low-income households spend 8 to 12 percent of their income on energy, a figure that is both economically crippling and environmentally unjust.
Our modeling projects that subscribers will see average bill reductions of 15 to 22 percent, translating to annual savings of 180 to 340 dollars per household. For a family spending 10 percent of a 32,000-dollar income on energy, that reduction is significant.
Access to clean energy should not depend on whether you own your roof. Community solar makes the benefits of renewable energy available to everyone, regardless of housing status.
The Numbers Behind the Launch
The total program cost for the initial eight sites is 3.8 million dollars, funded through a combination of federal Investment Tax Credits, Oregon's Community Solar Program incentives, a grant from the Meyer Memorial Trust, and TerraFuture's capital campaign. We anticipate reaching operational break-even by year four.
At full capacity, the eight arrays will generate approximately 1,440 megawatt-hours of clean electricity annually, enough to offset 1,020 metric tons of CO2 emissions per year based on PacifiCorp's current grid emissions factor. Over the 25-year expected lifespan of the installations, that represents over 25,000 metric tons of avoided emissions.
Community Ownership Model
What distinguishes our approach from commercial community solar programs is the governance structure. Each installation is overseen by a neighborhood advisory committee composed of subscribers, with decision-making authority over subscriber selection criteria, waitlist management, and reinvestment of any surplus revenue.
We believe that community energy should be governed by the community. This model ensures that the benefits remain local and that the program adapts to the specific needs of each neighborhood.
Enrollment and Next Steps
Enrollment opens October 15 for residents in our eight launch neighborhoods. We are prioritizing households at or below 80 percent of area median income for the first enrollment period, with remaining capacity opening to all neighborhood residents in January 2024.
Interested residents can attend one of 16 information sessions scheduled throughout October and November, or visit our enrollment portal for details. TerraFuture staff and trained neighborhood ambassadors are available to assist with enrollment in English, Spanish, Vietnamese, and Mandarin.
This is just the beginning. Based on the performance of these initial installations, we plan to expand to 20 sites by 2025, with a long-term goal of making community solar available in every Portland neighborhood.
