Solar Proptech Firm Allume Announces Shared Power for Multifamily

Allume Energy, which makes a hardware product called SolShare for sharing rooftop solar power on multifamily units with renters, announced its initial installation in the U.S.

“By allowing multi-family buildings, including renters, to access the benefits of solar energy,” the company could enable “widespread rooftop solar and provide a solution to energy equity,” a press release said. The technology could be particularly helpful to low- and middle-income renters, providing some relief from high electric prices.

Sharing rooftop solar has been difficult because of the requirement that power from the rooftop grid flow into an inverter and then into an electrical meter, which then directs the power to a specific part of a building.

“The building owner can deliver that energy to a common area (lobby, gym, etc.) and thereby offset the building’s energy consumption,” the company says. “This benefits the landlord but does not directly benefit tenants.”

If power is directed to tenants, then there is the question of how residents should share the electricity and resulting savings. “What if a tenant goes on prolonged vacation or moves out, leaving the space vacant?” the company says. “The results are inefficient at best. Inefficiency (and cost) compounds if the building has multiple solar arrays servicing multiple inverters, each tied to its own meter.”

A landlord could install the array and allow the tenants the benefits, but then there is a split incentive because the property owner likely will want some financial benefit to at least break even on installation, operation, and maintenance.

SolShare sits between the inverter and meters and distributes power to a series of meters in turn per second, similar to the way that a computer allows multitasking between different applications by slicing up resource access many times a second and then portioning them out.

“SolShare’s flexible software lets tenants monitor their clean energy use while landlords can set rules for how solar energy should be used in the building,” the company says. “For example, a landlord could allocate 50% of the solar power for common areas (thus reducing the building’s energy bill), then share the remaining 50% among tenants (reducing their energy bills). If a tenant moves out, their allocation could be divided among the remaining tenants.”

The technology allows a split of energy benefits between tenants and landlords. The system can also provide data useful for ESG reporting.

“Allume was founded in 2015 in Melbourne, Australia, and is now expanding into the U.S. and U.K.,” said the firm. “The company’s first deployments in the U.S. were last year in Orlando, Florida, and, most recently, in Jackson, Mississippi. In its Orlando deployment, SolShare eliminated the equivalent of 1800 pounds of CO2 emissions and saved each building tenant $242 in electricity per year. SolShare now runs on over 1500 apartments.”