Ørsted Activates 500MWh Old 300 Texas BESS, Fully Integrated into ERCOT Grid

August 9, 2026

Energy-Storage.News USA

Overview

Ørsted has commissioned its 500 MWh Old 300 Battery Energy Storage System (BESS) in Texas, fully integrating it into the ERCOT grid. Co-located with a 430 MW Old 300 solar PV project, the system uses Tesla Megapacks manufactured at the Lathrop megafactory. This BESS will supply power on demand, enhancing grid stability and is projected to generate approximately $110 million in property tax revenue for local services.

In Depth

Key Findings

Ørsted, the Danish renewable energy giant, has officially commenced commercial operations of its 500 MWh Old 300 Battery Energy Storage System (BESS) in Texas, achieving full integration into the ERCOT (Electric Reliability Council of Texas) grid. This substantial energy storage deployment is set to significantly contribute to the stabilization and reliability of the regional power supply.

Technical & Clinical Details

The Old 300 BESS is strategically co-located with the 430 MW Old 300 solar PV project, enabling it to effectively mitigate the intermittency inherent in solar power generation. The system incorporates cutting-edge Tesla Megapack batteries, produced at Tesla’s Lathrop megafactory in California. Tesla Megapacks are high-efficiency, high-reliability large-scale lithium-ion battery systems specifically engineered for grid-scale energy storage. With a 500 MWh capacity, the BESS can power tens of thousands of homes for several hours, providing crucial support to the grid during periods of low renewable energy output or peak demand. Furthermore, Ørsted anticipates that this hybrid project will contribute approximately $110 million in property tax revenue to local services, underscoring its significant economic benefits.

Background & Context

The ERCOT grid in Texas has faced challenges with power supply stability, particularly under extreme weather conditions, despite rapid growth in renewable energy adoption. Major power outages, such as during the 2021 winter storm and recent heatwaves, have highlighted vulnerabilities when demand surpasses supply capacity. Consequently, battery energy storage systems are recognized as essential infrastructure for absorbing fluctuations from renewable sources and enhancing grid resilience. Investments by major energy companies like Ørsted in BESS demonstrate the growing confidence in combined renewable energy and storage technologies as economically and technically viable sustainable energy solutions.

Strategic Significance & Outlook

The operational launch of the Old 300 BESS is a testament to Ørsted’s expanding renewable energy portfolio in the U.S. and marks a significant milestone in Texas’s and the nation’s energy transition. The success of this project is expected to serve as a model for future large-scale BESS deployments across other regions. Grid operators can leverage BESS to manage power networks more efficiently and accelerate the achievement of renewable energy integration targets. The substantial contribution to the local economy, coupled with its environmental benefits, positions this project as a key driver for sustainable development. Moving forward, Ørsted plans to implement more hybrid renewable energy and storage projects, aiming to lead the global energy transition.

Source: https://www.energy-storage.news/orsted-puts-500mwh-old-300-texas-bess-into-operation/

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