A new report by the National Renewable Energy Laboratory (NREL) estimates the rooftops of the nation’s low-to-moderate income (LMI) households could potentially accommodate 320 GW of photovoltaic (PV) solar technology.

“A key policy goal is to expand solar access more equitably to ensure the benefits of solar, including reduced energy burden, increased resilience, and hedge against electricity rate changes are available to all ratepayers,” said the NREL report. “To achieve this goal, a deeper understanding of the potential LMI market is needed. Although LMI households represent about 43 percent of the U.S. population, it is unknown what proportion live in buildings suitable for PV, how this potential is distributed among the buildings they live in, or what fraction of their electricity needs could be met with rooftop solar.”

The report determined that single-family, owner-occupied rooftops collectively held the greatest opportunities for PV installations, particularly in the LMI communities within Southeastern states including Alabama, Mississippi, Arkansas and Louisiana. However, for most LMI households, solar potential would require installation on renter-occupied and multifamily properties. And while the report acknowledged the challenge with solar installations on multifamily and rental property buildings, it noted several regional success stories in overcoming that challenge.

“Such models must ensure that rental-property owners are incentivized to install solar on their buildings—for example, by bundling utility expenses with rent payments as a means of passing solar costs and savings through to the renter,” the report continued. “These models also would need to address the diverging requirements and energy burdens of owners and tenants. For example, California recently developed an incentive program dedicated to affordable multi-family housing, with requirements that at least half of energy generated onsite be used to serve tenants loads. In Colorado, the Denver Housing Authority’s 2 MW low-income community solar garden has demonstrated a scalable model for offsite generation through utility partnerships. Virtual net metering also can be effective in enabling building owners to provide surplus generation directly to their occupants.”