Avantus, with Fluence, is progressing on two solar-plus-battery energy storage system (BESS) projects in California, US.
Fluence to provide AC BESS solution for 800MWh California project
System integrator Fluence has agreed to provide its AC-based modular battery storage platform, Smartstack, to independent power producer (IPP) Avantus for the 800MWh Rexford 2 project in California.
Announced 13 July, Fluence will also provide turnkey engineering, procurement, and construction (EPC) services for the 200MW/800MWh Rexford 2 project in Tulare County.
Fluence highlighted that Smartsack utilises the company’s network of partner manufacturing facilities in US states including Utah, South Carolina, and Texas, where key components such as battery cells, modules, enclosures, and thermal management systems are produced.
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The BESS will be paired with a solar PV facility, and construction is expected to begin in 2027 with a targeted commercial operation date in late 2028.
The Rexford 2 project is anticipated to generate over 500 union construction jobs during peak building activity, along with permanent operational positions in the local area. The companies further claimed it is expected to produce hundreds of millions of dollars in tax revenue for Tulare County, funding public services and infrastructure improvements. The facility will be built on previously disturbed land to minimise environmental impact.
Over approximately the past four years, Fluence has expanded its US production capabilities by establishing a network of regional factories, including a module facility in Utah and enclosure and battery management system (BMS) manufacturing in Arizona.
In May, during an earnings call, Fluence CEO Julian Nebreda, highlighted that Fluence was the first to provide “a complete US domestic supply chain,” delivering a “one-stop solution from early project development through delivery and installation and continuing over the full operating life,” supported by in-house EPC capabilities and a dedicated service organisation.
The company uses third-party suppliers for battery cells. Fluence’s primary source of lithium iron phosphate (LFP) cells in the US is the AESC factory in Smyrna, Tennessee, which opened in 2012 and initially produced nickel manganese cobalt (NMC) cells for electric vehicles (EVs).
While AESC is headquartered in Japan, its majority owner is China’s Envision Energy. To comply with rules introduced under the ‘One Big Beautiful Bill Act’ (OBBA) regarding material assistance from prohibited foreign entities (PFEs) and foreign entities of concern (FEOC), the battery maker sold a majority stake in the Smyrna factory to US startup Fixx Energy.
Fixx Energy was founded by venture capitalist Brett Conrad and is led by CEO Jeff Juger, who previously worked with Chinese solar PV manufacturer Jinko Solar.
Avantus signs PPA with Clean Power Alliance for Rexford 2
Avantus announced another update concerning the Rexford 2 project on 13 July. The company has signed a 20-year power purchase agreement (PPA) for the project with California community choice aggregator (CCA) Clean Power Alliance (CPA).
The PPA is for the BESS portion of the project. CPA vice president of power cupply Lindsay Descagnia said of Rexford 2, “This project provides a fixed long-term price, helping protect our customers from energy market volatility while delivering renewable energy and battery storage that can help meet demand when it matters most.”
On 30 June, CPA announced two initiatives, the 2026 Clean Energy Innovation Solicitation for emerging clean energy generation and storage technologies, and a Programme Innovation Request for Information (RFI) focused on new ideas for customer programmes and partnerships.
The Clean Energy Innovation Solicitation aims to identify and support early-stage renewables projects that introduce innovative approaches to generation and/or energy storage—especially those that may fall outside the criteria of CPA’s traditional requests for offers (RFOs)—but demonstrate strong potential to strengthen CPA’s clean energy portfolio or operations.
The Programme Innovation Request for Information seeks ideas for new customer programmes and partnerships that can benefit CPA’s communities and customers. This request targets creative solutions that extend beyond traditional energy procurement, delivering value to both the organisation and its diverse customer base.
Depending on submissions received, CPA may launch a competitive procurement process to evaluate and potentially contract promising concepts that improve CPA’s operations and provide customer benefits.
Financing closed for Aratina 2 project
In related news, Avantus has closed a US$525 million financing package for its Aratina 2 solar-plus-storage project in Southern California.
Currently under construction in eastern Kern County, the project will provide 184MW of solar PV and 452MWh of BESS to the California grid and is expected to be operational by the end of the year.
The financing package includes construction funding, a tax equity bridge loan and letters of credit and has been secured with banks BBVA Canadian Imperial Bank of Commerce and Santander.
Moreover, the company has already secured a 15-year PPA for the Aratina 2 solar-plus-storage project with utility Southern California Edison (SCE).
The project represents the second phase of the Aratina Solar Centre which overall combines a total of 350MW solar PV and 952MWh BESS. Both Aratina 1 and 2 are part of the company’s IPP strategy and will thus retain an ownership stake and operate the two solar-plus-storage projects.
“Aratina 2 is another demonstration of Avantus’ ability to develop and finance large-scale projects in one of the country’s most complex energy markets,” said Omar Karar, executive VP of capital markets and M&A at Avantus.
Backed by global investor KKR, which acquired a majority stake in Avantus in 2024, the California-based IPP is advancing a development portfolio across its core markets of California, Nevada and Arizona, which comprises 13GW solar PV and 44GWh BESS. The company forecasts it will reach its 5GW target of operational assets by 2030, with 788MW reaching commercial operation and 800MW under construction by the end of the year.
Amongst its solar PV portfolio of projects that completed construction this year is the 159MW Norton Solar Project in Texas. Japanese car marker Toyota Motor North America signed a virtual PPA for the entirety of the project’s output.
The Aratina section of this piece is an extract of an article first published on PV Tech, by Jonathan Touriño Jacobo.
Financing of solar and energy storage projects will be at the centre of the Solar & Storage Finance Summit USA event on 15-16 September in Garden Grove, California. The two-day event will cover topics such as FEOC compliance, post-safe-harbour economics and the California market, among others. For more information on the event, which is co-located with the Battery Asset Management USA event, can be found here.
