GridStor executes tolling agreement for Texas BESS, CPS Energy launches 500MW BESS RFP

December 18, 2025
LinkedIn
Twitter
Reddit
Facebook
Email

Two US companies, GridStor, and CPS Energy are making advancements on Texas energy storage deployment, with GridStor executing a tolling agreement and CPS Energy issuing a new request for proposals.

GridStor executes tolling agreement for 300MWh Texas BESS

GridStor, a US-based developer and operator of grid-scale battery energy storage systems (BESS) has executed a tolling agreement for the 150MW/300MWh Gunnar Reliability Project in Hidalgo County, Texas.

The tolling agreement was signed with an undisclosed ‘Fortune 500 company’.

 Construction on the project has started, and operations are expected to begin by the end of 2026.

This article requires Premium SubscriptionBasic (FREE) Subscription

Try Premium for just $1

  • Full premium access for the first month at only $1
  • Converts to an annual rate after 30 days unless cancelled
  • Cancel anytime during the trial period

Premium Benefits

  • Expert industry analysis and interviews
  • Digital access to PV Tech Power journal
  • Exclusive event discounts

Or get the full Premium subscription right away

Or continue reading this article for free

GridStor acquired the Hidalgo County BESS from developer Balanced Rock Power (BRP) in February 2025. Hidalgo County is also home to the 200MW/400MWh Anemoi standalone BESS developed by developer and operator Plus Power and cleared for operation in June 2024.

GridStor says that during construction, the Gunnar Reliability Project is expected to create over 100 jobs, including skilled tradespersons and apprentices. Once operational, the project will enhance the resilience of the Lower Rio Grande Valley in the Electric Reliability Council of Texas (ERCOT) power system.

Once finished, the Gunnar Reliability Project will be the company’s second operational BESS in Texas. Earlier this year, GridStor’s Hidden Lakes Reliability Project, a 220MW/440MWh BESS in Galveston County, Texas, began operations

Hidden Lakes was also acquired from BRP in March 2024. The project, originally named Evelyn Battery Energy Storage, was noted by GridStor to connect to an existing substation owned by the utility Texas New Mexico Power, which could expedite the grid interconnection process.

Founded in 2022, GridStor received support from Goldman Sachs via Horizon Energy Storage, which focuses on sustainable and infrastructure investments. According to its 2022 sustainability report, the company’s investment aims to address power supply intermittency issues that can hinder renewable energy expansion.

Soon after, GridStor started building its inaugural project- a 60MW/160MWh BESS in Goleta, California, the largest battery storage project in Santa Barbara County.

CPS Energy launches RFP for 500MW of energy storage

Texas utility CPS Energy has issued a request for proposals (RFP) to acquire up to 500MW of additional battery storage in the San Antonio, Texas, area.

This latest RFP supports the utility’s previously approved Vision 2027 Generation Plan.

After finishing the RFP, the utility expects to have over 1,000MW of storage capacity, either operational or contracted, to serve its customers.

CPS Energy has currently deployed 50MW of storage capacity under the Vision 2027 plan. A further 470MW is in development and is anticipated to be operational in 2026.

The RFP aligns with CPS Energy’s dedication to the City of San Antonio’s Climate Action & Adaptation Plan (CAAP), which aims for carbon neutrality by 2050 while maintaining diversification in generation resources.

In October, CPS Energy and IPP Eolian began operating Padua 1, a 50MW/100MWh BESS located in Bexar County, Texas.

Eolian owns and operates Padua, a project developed in response to CPS’s 2020 RFP for 50MW of battery storage. The project also supports Vision 2027.

In the same month, Eolian also closed a US$463 million financing package to support the continued construction of Padua 2 and Padua 3, also in Bexar County.

The Padua Complex is anticipated to be finished in spring 2026, offering 400MW/1.8GWh of capacity. It will be located next to the decommissioning J.K. Spruce coal plant units and the V.H. Braunig natural gas power plant.

Submissions for CPS Energy’s newly issued RFP are due 30 January.

The Energy Storage Summit USA will be held from 24-25 March 2026, in Dallas, TX. It features keynote speeches and panel discussions on topics like FEOC challenges, power demand forecasting, and managing the BESS supply chain. For complete information, visit the Energy Storage Summit USA website.

24 February 2026
InterContinental London - The O2, London, UK
This isn’t just another summit – it’s our biggest and most exhilarating Summit yet! Picture this: immersive workshop spaces where ideas come to life, dedicated industry working groups igniting innovation, live podcasts sparking lively discussions, hard-hitting keynotes that will leave you inspired, and an abundance of networking opportunities that will take your connections to new heights!
24 March 2026
Dallas, Texas
The Energy Storage Summit USA is the only place where you are guaranteed to meet all the most important investors, developers, IPPs, RTOs and ISOs, policymakers, utilities, energy buyers, service providers, consultancies and technology providers in one room, to ensure that your deals get done as efficiently as possible. Book your ticket today to join us in 2026!
9 June 2026
Stuttgart, Germany
Held alongside The Battery Show Europe, Energy Storage Summit provides a focused platform to understand the policies, revenue models and deployment conditions shaping Germany’s utility-scale storage boom. With contributions from TSOs, banks, developers and optimisers, the Summit explores regulation, merchant strategies, financing, grid tariffs and project delivery in a market forecast to integrate 24GW of storage by 2037.

Read Next

Premium
December 18, 2025
California Community Choice Aggregator (CCA) Clean Power Alliance (CPA) last week (8 December 2025) moved one step closer to executing agreements for offtake with two companies developing innovative thermal battery storage projects. 
December 18, 2025
Distributed energy resources (DERs) are emerging as potential solutions for consumers seeking independence and relief from rising energy costs.
December 17, 2025
In an upcoming conversation with Energy-Storage.news Premium and Optimisation platform provider Ascend Analytics, CEO Dr. Gary Dorris PhD, discusses the ‘roller coaster’ revenues of the Electric Reliability Council of Texas (ERCOT) market.
December 17, 2025
According to the Q4 2025 US Energy Storage Monitor from Wood Mackenzie Power & Renewables and the American Clean Power Association (ACP), 2025 energy storage installations surpassed 2024 capacity.
December 16, 2025
In this edition of the Energy-Storage.news US news roundup, EticaAG partners with Shell on battery immersion tech, Pacific Northwest National Laboratory begins utility-scale battery testing, and ON.Energy announces a transformer supply agreement.