Spread the wealth: Equitably send rooftop solar energy to every renter (without virtual NEM)

PV systems designed to self-consume solar energy are coming back into vogue. Reasons include rising utility rates, the addition of electric vehicles, and — the biggie — public utility commissions rolling back net metering payback rates for exported solar energy, for both home and building owners. In this article from the Q1 2024 issue of Solar Builder, we’ll stay out of the politics of net metering and instead highlight a compelling piece of hardware that efficiently interconnects and distribute solar power on site.

This is just part of a longer feature from the Q1 2024 issue of Solar Builder. Access the full article via the digital version of the magazine, right here:


SolShare installation

Deploying solar on apartment complexes could aid substantially in resolving energy equity. More than 15 million people in the U.S. live in low and medium rise apartment buildings, with roof space for solar but no way of accessing it. Multifamily units also historically house individuals and families in lower income brackets, which have an energy burden three times higher than other households, according to the U.S. Department of Energy.

Unfortunately, multitenant building solar installations often still fall prey to the split-incentive problem: A building owner pays to install a solar energy system, but most of the economic benefit goes to the tenants.

“The owner of the building (the landlord or property company) is often not the entity that benefits the most from an onsite solar installation,” notes Michelle Davis, with Wood Mackenzie. “And just like for any commercial solar project, the question of financing depends on the creditworthiness of the offtaker (owner or property company). Then there are always questions of how the monetary benefits are shared.”

Most behind-the-meter PV systems in the multifamily segment cater to virtual net metering agreements. These PV systems only connect to the common meter of the complex, which counts total PV system output and then virtually divides the credits among the tenants. A good deal if you can get it, but virtual net metering agreements are unreliable these days. Look no further than California.

In markets that lack enticing virtual net metering programs for shared systems, SolShare provides solar energy at the point of generation.

Allume launched its SolShare product in Australia in 2015 to more equitably divide solar PV production in the multifamily segment. Allume is now running on over 2,300 apartments and targeted the U.S. for expansion in 2020.

Mel Bergsneider, executive account manager with Allume, is bullish on the U.S. multifamily market because of the prominence of real estate companies that own thousands of assets across the country. If they can gain traction, deployment could scale quickly.

“A lot of real estate people have never looked at the numbers post-IRA,” Bergsneider notes. “‘ Wait, I can get up to a 50% tax credit on this system, offset operating costs and maybe have a revenue stream?’ It is very attractive.”

The SolShare system physically mounts next to the PV inverter to send solar energy directly to tenants without having to rig individual conduit runs and inverters for every apartment. SolShare outputs wire at the central meter panel, making it a non-invasive and cost-effective install process. It takes 1 ac input supply and physically wires to each meter via a load side tap.

“We want it to be equitable to the tenants,” Bergsneider says. Existing SolShare installations have demonstrated electricity bill savings of up to 40%.

The solar capacity of one SolShare unit is 20 kWdc / 16.4 kWac max, and it can handle 10 apartments at 120 V or five apartments at 240 V. It is solar inverter and PV module agnostic.

“We also have capacity to read apartment energy demand as well as energy delivered to apartments via current transformers,” Bergsneider says.

SolShare installation

How it works: SolShare rotates the supply of solar like a sprinkler system — splashing PV in 5-second intervals in each utility meter bucket to ensure everybody gets an even distribution of solar regardless of their usage or load at a given moment. Any “overflow” from these buckets could be sold back to the grid.

Allume has its own “virtual” functionality, of course. Via its performance portal, the Allume team can adjust the allocation of solar for any tenant / common area combo required. The sprinkling can also be configured in other ways, like by square footage of rental unit.

SolShare’s software lets asset owners tailor the solar allocation. 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.

SolShare’s recommendation: Set up each meter to have its own NEM arrangement. The utility will then read this one PV array as 5 to 10 individual systems. Each utility meter will track its own usage and grid exports, and each single tenant will get their own credit (and can monitor their own clean energy use).

For the building owner…

The SolShare solution is fundamentally about the equitable distribution of solar energy at project sites that often lack this possibility. Cool, for sure. But this is America, and owners will want their cut too. SolShare accomplishes this by connecting to common loads to reduce operating expenses (and possibly rent).

“We include project savings and/or added revenue streams into the proposal,” Bergsneider says, which helps to not only show the value of the PV project for the building and its tenants, but also in contrast to another system design. “Here’s what that benefit would be in terms of project savings on equipment. Here’s your portion of savings for common area loads, and here’s a total for the whole install. We model tenant savings and asset owner financials.”

Allume is seeing some landlords include SolShare connection as a fixed fee. You might bristle at the idea of a fee for solar access, but depending on the market, that fee can functionally become a fixed rate to guard against rising electricity prices.

“We can model for that fee,” Bergsneider says. “The bottom line is that the tenant will see a net benefit. That’s what we care about.”

The exact metrics in the performance portal can be beneficial for asset owners with multiple properties.

“Many asset owners, when reporting on sustainability metrics, don’t know what’s going on with the apartments because each is individually metered and has their own utility account,” Bergsneider says. “We have heard from those owners that it is difficult to determine the ‘energy use intensity’ metric beyond common loads. This is a way to help reporting for the whole asset.”

This reporting may be particularly helpful in markets like Los Angeles and New York, which are seeking lower carbon footprints in the city. Additionally, Bergsneider says “buildings with lower utility bills have 3% to 7% higher occupancy rates,” thereby helping increase the building’s asset value.

SolShare is a compelling solution for keeping everything behind the meter and focusing on self-consumption versus relying on virtual net metering programs. These are more likely to be new and nascent distributed solar markets, which is why Allume started its U.S. expansion in the South, with plans to move into the Midwest, then the Northwest, and then the Northeast.

“We’re looking into states and different environments where solar is not the first option to be considered. We’re exploring more of the Southeast not only because of the approvals that we’ve gotten so far but also local partnerships we have.”

The company’s first deployments in the U.S. were in Orlando in 2022, and in Jackson, Miss., in early 2023. In its Orlando deployment, SolShare saved each building tenant $242 in electricity per year.

At the Belhaven Residential complex in Jackson, a multifamily building owned and operated by Belhaven Residential, all of the tenants qualify for Mississippi’s LMI benefits under the state’s distributed generation program. Entergy Mississippi is also providing a $6,500 grant in exchange for access to clean energy data gathered by the project. Solar Alternatives, a Louisiana-based solar contractor, installed the 22 kW array.

Massive solar companies such as SunPower or Sunrun are working much closer to national builders and public utility companies. For smaller installers, the SolShare model is possibly a viable path to multifamily projects. The Allume team is also working with Climate First Bank to help offer more competitive rates.


Chris Crowell is the Editor-in-Chief of Solar Builder.

Listen to more in-depth conversations on Solar Builder's YouTube channel

Our most popular series include:

Power Forward! | A collaboration with BayWa r.e. to discuss higher level industry topics.
The Buzz | Where we give our 2 cents per kWh on the residential solar market.
The Pitch | Discussions with solar manufacturers about their new technology and ideas.

Tags: , ,