Construction of the world’s largest apartment complex VPP fleet starts next week

Soleil Energy, the EPC arm of the Wasatch Group, is beginning construction on a revolutionary virtual power plant program located on California apartment complex rooftops — with the roofs acting as community-based peaker plants.

September 1, 2020 Jean Haggerty

A mockup of solar panels on a Herron Pointe apartment building

Image: Soleil Energy/sonnen

The Wasatch Group’s new engineering, procurement and construction company, Soleil Energy, is breaking ground on the first of seven virtual power plant (VPP) projects on apartment buildings in California next week. A key point of these VPP projects will be to show what can be done, said sonnen CEO Blake Richetta.

California’s abundant sunshine, high electricity costs, grid woes and wildfire-induced public safety power shutoffs made it a logical place to make a major proof-of-concept case for the type of apartment complex VPP program that the Wasatch Group and sonnen have been developing for the past few years, Richetta and Wasatch Energy Group’s Ryan Peterson, president and managing partner said.

Last September, the Wasatch Group, sonnen and Rocky Mountain Power jointly completed Soleil Lofts VPP, a 600-unit solar and storage-equipped apartment community in Herriman, Utah. Rocky Mountain Power now uses this VPP as part of its grid management system. “We want to offer value to the overall grid to help decongest the system [in California],” Richetta said.

By design, the new VPP projects, which will be able to participate in California’s demand response market, will be able to operate like community-based peaker plants that can be flexed for load shaping purposes. In addition to being able to send power back to the grid, the VPPs will produce clean energy and offer residents of the apartment communities resiliency at a discounted electricity rate, said Richetta.

sonnen’s storage systems will be used at each of the seven Wasatch community properties that will be part of the partners’ new California VPP fleet. The battery system’s role will be to optimize each community’s solar production, grid usage and individual apartment loads; individual sonnen systems within each community will also be able to communicate with each other as a single intelligent battery asset.

According to Richetta, apartment complexes are well-suited to assist the grid as “swarm control” grid assets. “The concentration within apartment communities is a significant benefit to meaningfully reduce grid congestion as it brings a large quantity of rapidly-dispatchable flexibility to support a specific substation on the grid,” he explained.

Also, doing this at the apartment complex level has the added benefit of expanding solar’s reach in middle income and disadvantaged communities. “We want to show that we can do this in places without relying on FICO scores and with existing structures – not just on new construction [residences],” he said. The partners’ first California VPP project will be a retrofit of the 417-unit Heron Pointe apartment complex in Fresno.

At completion in 2021, the seven VPPs that make up the partners’ debut California fleet will produce 60MWh of energy storage capacity and over 24MW of power capacity. The Wasatch Group will pick up the $19.7 million tab for the solar plus storage retrofit at Heron Pointe, but the other projects in the fleet will be supplemented with capital from third party investors.

Ultimately, the Wasatch Group and sonnen plan to replicate these VPP fleet projects elsewhere, including on non-Wasatch properties, Richetta and Peterson said.

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