The Edwards Sanborn project is an integrated solar and battery energy storage project under construction in California, US.

With 1,118MW of solar capacity and 2,165 megawatt hours (MWh) of energy storage, Edwards Sanborn is expected to become the largest single-site solar and storage project in the world, upon completion.

Terra-Gen is developing the solar-plus-storage project in phases, with the installation of 346MWac of solar modules and 1,501MWh of battery storage under the first phase.

Construction on the project commenced in the first quarter of 2021 and the solar power plant and battery energy storage system (BESS) is expected to be completed by 2023.

The Edwards & Sanborn solar and energy storage project is estimated to produce sufficient electricity to power approximately 158,000 households and offset about 307,000 tonnes (t) of carbon dioxide (CO2) emissions per year, at full capacity.

Location and site details

The Edwards Sanborn solar and energy storage project is located in the Kern County, California, US.

The project site occupies 6,000 acres of area consisting of a land leased from the Edwards Air Force Base (AFB) and a plot of private land located adjacent to it.

Edwards Sanborn solar and energy storage project details

The Edwards Sanborn solar and energy storage project will feature approximately 2.5 million photovoltaic (PV) modules and more than 110,000 lithium-ion batteries.

The project also involves the construction of service roads, underground and above-ground transmission lines, converter station, electrical substation, gen-tie lines, and facilities for operations and maintenance (O&P).

Power evacuation

The electricity generated from the Edwards Sanborn solar energy and battery energy storage project will be evacuated through a 220kV power transmission line.

It will be connected to the Sunward switchyard interconnecting with the Southern California Edison’s transmission grid.

Project financing

Financing for the first phase of the Edwards Sanborn and solar energy storage project was closed by Terra-Gen in August 2021. Deutsche Bank was the sole bookrunner, joint lead arranger and administrative agent for the financing that comprised five loan facilities and 13 lenders.

The financing for the initial phase of the project consisted of a £596m ($804m) senior secured credit facilities, including a £297m ($400m) construction and term loan, a £243m ($328m) tax equity bridge facility, and a £56m ($76m) construction and revolving letter of credit facility.

Power purchase agreements

The Edwards Sanborn project will supply 24MW of solar energy and 5.5MW of battery energy storage capacity to Starbucks, under a power purchase agreement (PPA) facilitated by LevelTen.

The project has a 15-year contract with Clean Power Alliance (CPA) to deliver 100MW of clean energy storage capacity.

Contractors involved

Mortenson was awarded the engineering, procurement and construction (EPC) contract by Terra-Gen for the Edwards Sanborn solar and energy storage project. The contract covers both the solar and energy storage sections of the project.

Trimark Associates was subcontracted by Terra-Gen and Mortenson to deliver the supervisory control and data acquisition (SCADA) system for the project in February 2021. The subcontract also includes meteorological (Met) stations, networking equipment, and a dynamic loss compensation (DLC) system to meet power purchase agreement requirements.

Electrical Consultants were subcontracted by Trimark to deliver complex revenue meterring, consisting of California Independent System Operator (CAISO-compliant) revenue meters.

Dudek was engaged to provide technical studies, including pre-construction desert tortoise clearance surveys, and an environmental impact report (EIR) for the Edwards Sanborn project.

Solas Energy Consulting was contracted to deliver construction and project management services in September 2021. The company was also the construction bid management service provider during the development phase of the project .

Luminate was selected as the independent engineer for Terra-Gen in connection with the financing of the project in May 2021.

International law firm Milbank represented Deutsche Bank and the commercial bank lenders on the financing of the Edwards & Sanborn project in August 2021.

Latham and Watkins advised Terra-Gen on the financing for the 346MWac solar and 1,501MWh battery storage phase of the project in August 2021.