The Athos III solar project is located in Riverside County, California. (Credit: Intersect Power/ PRNewswire)
The project commenced operations in January 2023. (Credit: Intersect Power/ PRNewswire)
Athos III is owned and operated by clean energy company Intersect Power. (Credit: Intersect Power/ PRNewswire)

The Athos III Solar + Storage Project, also known as Blythe Mesa Solar II, is an operational renewable project located in the US state of California.

The project is capable of generating 224MWac / 310MWdc of solar power, enough to power around 94,000 households. Athos III also includes a co-located 448MWh Battery Energy Storage System (BESS).

The project is owned and operated by clean energy company Intersect Power.

Intersect Power acquired the Athos III Solar Project from RRG Renewables in 2020 during its early stage of development and started construction in 2021.

The project commenced operations in January 2023.

Location details

The Athos III project is located in Riverside County of California. The location is approximately 3miles west of the City of Blythe, 5miles west of the Colorado River and 40 miles east of Desert Center.

It is built over around 3,600 acres of private agricultural land.

The project forms a part of Intersect Power’s near-term portfolio of 2.2GW of solar PV and 1.4GWh of co-located storage, slated to become operational by 2023.


In November 2021, Intersect Power secured $2.6bn financing through eight separate transactions for the construction and operations of a six-project portfolio.

The company announced that it will use around $800m of the proceeds to fund the construction of the Athos III Project and the 415MWdc Radian Project.

The portfolio term debt was provided by HPS Investment Partners, while Morgan Stanley Renewables provided the Tax Equity. Construction debt was provided by Coordinating Lead Arrangers MUFG and Santander Corporate & Investment Banking. Cobank, KeyBanc Capital Markets, Helaba, and Nord LB acted as Joint Lead Arrangers.

Athos III Project Details

The Athos III Project will feature solar photovoltaic capacity and a battery storage system along with a 230kV generation interconnection (gen-tie) crossing public lands.

The Bureau of Land Management (BLM) in the US approved the project’s 5.2-mile gen-tie transmission line and access road that crosses BLM-managed public lands in 2015.

The 230kV gen-tie connects the solar facility to the Southern California Edison Colorado River Substation situated approximately 4-miles away.

During construction phase, Athos III created 500 peak union jobs.

Key technologies used

The project uses First Solar’s Series 6 photovoltaic solar modules to produce energy. These modules are based on the company’s CadTel technology.

Additionally, the renewable project uses Nextracker’s NX Horizon smart solar trackers and TrueCapture yield optimisation software.

Nextracker’s NX Horizon smart solar trackers allow advanced monitoring and control to support reliable operations.

Selected for more than 70GW of solar power plants worldwide, the solar tracker offers highly engineered mass-balance rotation instead of relying on rotational torque energy. According to the company, NX Horizon’s integrated hardware and software allow maximum solar energy capture with up to a 120-degree tracker range of motion.

The Nextracker’s TrueCapture advanced tracker optimisation and control software facilitate efficient energy capture during diffuse light conditions.

It utilises advanced sensors, weather forecasting, and machine-learning technologies to maximise energy generation for solar power plants.

The software is equipped with self-adjusting tracker control and yield optimisation system to increase power production by optimising the tracking algorithm of individual solar panel rows.

Contractors Involved

In July 2021, Intersect Power announced Signal Energy as the engineering, procurement and construction (EPC) firm for Athos III project.

Intersect contracted Nextracker for its NX Horizon smart solar trackers and TrueCapture yield optimisation software, while First Solar delivered Series 6 photovoltaic solar modules.

Athos I and Athos II projects

SB Energy, a subsidiary of SoftBank Group Corp, is building the Athos I and Athos II in California.

In May 2021, the company announced the closing of financing for the construction of two projects.

Rosendin was contracted to design and build the Athos I 357MWdc and Athos II 284MWdc projects.

Once complete, the two projects will generate more than 2,200GWh per year of renewable energy, enough to power 179,000 homes.