ForeFront Power's First Erthos Ground-Mount Solar System Goes Live in FresnoForeFront Power's First Erthos Ground-Mount Solar System Goes Live in FresnoForeFront Power's First Erthos Ground-Mount Solar System Goes Live in FresnoForeFront Power's First Erthos Ground-Mount Solar System Goes Live in Fresno
August 17, 2026
ForeFront Power has brought its first Erthos "Earth Mount Solar" system online at the City of Fresno's Northeast Surface Water Treatment Plant, a project that has run at 101% of expected energy production since entering commercial operation in late March 2026. The savings behind
ForeFront Power has brought its first Erthos "Earth Mount Solar" system online at the City of Fresno's Northeast Surface Water Treatment Plant, a project that has run at 101% of expected energy production since entering commercial operation in late March 2026. The savings behind this project did not come from cheaper solar panels: they came from what is missing underneath them, since the Erthos system uses no structural steel racking at all. For a California utility customer watching construction costs climb, that omission is the story: it is projected to help save Fresno ratepayers more than $122 million by 2045.
What's New
The Northeast Surface Water Treatment Plant installation is the first of three sites in a combined 27 MW-DC solar and battery portfolio that ForeFront Power is building for the City of Fresno's Department of Public Utilities (DPU). The other two sites, the Southeast Surface Water Treatment Facility and the Fresno-Clovis Regional Wastewater Reclamation Facility, are still to follow. Since the Northeast plant's system reached commercial operation in late March 2026, it has delivered 862 MWh of energy to the city while averaging 101% of its expected output.
Erinne Davis, senior project manager at ForeFront Power, said the site was chosen deliberately. "After conducting our due diligence and vetting Erthos technology, we discovered that the Northeast Surface Water Treatment Plant was an optimal site for an Erthos application," Davis said. ForeFront Power is a San Francisco-headquartered developer and asset manager of commercial and industrial-scale renewable energy, with teams in New York, Mexico City, and across the United States. The DPU portfolio is one part of that broader project base, and the Fresno announcement marks the first commercial milestone in it.
How It Works
Erthos's Earth Mount Solar (a ground-mounted photovoltaic architecture that bolts modules directly to the earth instead of onto elevated steel racks) is the technical basis for the Fresno project. Because the modules sit flat on the ground rather than on structural steel supports, the array is also built with no row spacing between module rows, which Erthos describes as giving it the highest energy density of any solar architecture in the industry on a per-acre basis. The flat-mounted design can still follow natural ground contours of up to a 15% slope, letting it adapt to a site's existing topography without extensive grading.
Davis said that flexibility changed the project's economics directly. "Erthos helped us avoid significant, expensive civil upgrades, as well as the cost of steel for racking and the labor to install that racking," she said. "Realizing these savings on the installation is what enabled the project at this site to move forward." With panels mounted near ground level, cleaning becomes a distinct engineering problem, which Erthos addresses with ErthBot, a dry nylon brush autonomous robot that cleans the array and returns to a charging dock between runs. Each ErthBot unit is designed to cover 3.5 MW-DC of array, and Erthos operates and maintains the robots for ForeFront Power.
The Economics
ForeFront Power first approached Erthos in 2023, after inflation and supply-shock-driven spikes in labor and materials costs made conventional racked solar construction harder to pencil out at some sites. The deal structure that resulted is a 20-year Power Purchase Agreement (PPA, a contract in which one party owns and operates the solar system while the other buys the electricity it produces at a set rate): ForeFront Power owns the Fresno systems and sells the city fixed-rate electricity for two decades, rather than the city owning the hardware outright.
| Metric | Figure |
|---|---|
| Combined DPU portfolio size | 27 MW-DC across three sites |
| Projected ratepayer savings | $122 million+ by 2045 |
| PPA term | 20 years, fixed rate |
| Energy delivered to date (Northeast plant) | 862 MWh |
| Average production vs. expected output | 101% |
| Commercial operation date (Northeast plant) | Late March 2026 |
The combined 27 MW-DC portfolio across all three DPU sites is projected to save Fresno ratepayers more than $122 million by 2045. That figure depends on all three sites eventually running, but it also reflects the underlying cost logic of Earth Mount Solar: strip out steel procurement, racking installation labor, and civil-engineering upgrades, and a fixed-rate 20-year PPA can be priced lower than it otherwise would be, savings that flow to the city's utility customers over the life of the contract.
Competitive Landscape
No rival ground-mount racking vendor is named in current reporting on the Fresno project, which centers on ForeFront Power and Erthos as the two companies executing the deal. Their respective track records frame the partnership:
- ForeFront Power - a developer and asset manager with 15+ years in the industry, more than 1,900 behind-the-meter and community solar projects developed, and 1.6 gigawatt-DC of renewable electricity capacity across its portfolio; headquartered in San Francisco.
- Erthos - maker of the Earth Mount Solar system and the ErthBot cleaning robot, founded in 2019 and headquartered in Tempe, Arizona.
Erthos CEO Jim Tyler framed the Fresno deployment as a proof point for the underlying technology rather than a one-off. "The Fresno project demonstrates how Erthos Earth Mount Solar can unlock projects that might otherwise be constrained by conventional construction costs," Tyler said. "Working with ForeFront Power, we delivered a high-density solar system designed for strong long-term performance, efficient maintenance, and lower-cost energy for the City of Fresno."
Independent analyst commentary specifically on this announcement was not publicly available at publication time.
What's Next
Two sites in the DPU portfolio still have to reach commercial operation: the Southeast Surface Water Treatment Facility and the Fresno-Clovis Regional Wastewater Reclamation Facility. Together with the Northeast plant, they make up the full 27 MW-DC that ForeFront Power and the City of Fresno are counting on to reach the projected $122 million-plus in ratepayer savings by 2045. The Northeast plant's early performance, 862 MWh delivered at 101% of expected output, gives the remaining buildout a working baseline rather than a projection alone.
Each additional site brings the same Earth Mount Solar and ErthBot combination to a new physical footprint, with the 15%-slope tolerance and 3.5 MW-DC-per-robot cleaning coverage setting the practical limits on where and how fast the rest of the portfolio can be built out under the existing 20-year PPA structure.
For a municipal utility procurement officer weighing solar bids, the number that matters is not the 27 MW-DC headline, it is the absence of a racking line item: a system that skips structural steel and civil grading can quote a lower fixed rate over 20 years, which is the mechanism actually producing the $122 million in projected savings for Fresno.
A robot scrubbing panels a few feet off the ground, on an array with no steel beneath it, is a strange image for a technology sold on being simpler. But that is the trade Fresno made: less hardware going up, more automation keeping it clean, and a rate locked in for 20 years either way.
-- Aria Lin, Enterprise Technology Analyst
Sources: CleanTechnica (ForeFront Power / Erthos press release) · ForeFront Power (www.forefrontpower.com) · Erthos (www.erthos.com)