ERCOT Tomorrow vs. NEM Today: Will Texas Look Like East Australia in a Few Years?

Across the globe, few electricity markets are transforming as rapidly as ERCOT in Texas and NEM in Eastern Australia. Both are dealing with similar challenges, such as soaring renewable energy adoption, aging thermal plants, and the urgent need for system flexibility. But when it comes to battery energy storage systems, one market is clearly in the lead. While ERCOT currently dominates headlines for the sheer pace of BESS deployment, Australia’s NEM has developed a more mature and diverse storage environment. Many U.S.-based asset owners and investors are wondering if ERCOT’s market trajectory will begin to mirror the NEM. In this article, we will explore BESS adoption in both markets, the similarities and differences, and what lessons can be drawn from the east coast of Australia.

ERCOT is the leading U.S. market for BESS capacity growth, primarily driven by merchant developers and energy price volatility. Batteries are able to participate in real-time energy markets, Fast Frequency Response (FFR), and Regulation Up/Down services to revenue stack and drive profits for investors. The table below from Mondo Energy shows ERCOT BESS growth since 2020:

Even with these growing figures, ERCOT’s market design is energy-only, with no centralized capacity market. Participation is limited to a narrow band of energy and ancillary services, and the regulatory framework is still catching up to the speed of storage deployment. Despite this, the revenue opportunity remains strong for fast-acting, well-optimized BESS assets.

Australia’s National Electricity Market (NEM), operated by AEMO, spans five regions and is rapidly integrating large-scale battery storage. The NEM offers a highly evolved landscape for battery storage, as BESS assets not only participate in energy arbitrage but also play critical roles in Frequency Control Ancillary Services (FCAS), voltage support, synthetic inertia, and grid-forming services. Hybrid solar+battery projects are common, and grid-forming standards are actively being enforced. The NEM employs a centralized dispatch framework. Under AEMO’s Integrating Energy Storage Systems (IESS) reforms, batteries can now act as both scheduled loads and scheduled generators, unlocking operational flexibility and regulatory clarity.

Despite some structural differences, which we will cover in more detail below, ERCOT and the NEM share striking parallels when it comes to battery storage adoption. Both markets are navigating a rapid influx of variable renewable energy, prompting developers and system operators to lean heavily on BESS for flexibility, reliability, and real-time market responsiveness. These shared pressures have led to overlapping trends in asset cycling, investment pipelines, and merchant-led innovation. Here are some of the key similarities between these markets:

• High penetration of variable renewable energy
• No centralized capacity markets
• BESS assets cycling multiple times per day for energy arbitrage
• Accelerated development pipelines
• Market-driven incentives for fast-response flexibility

While ERCOT and the NEM face similar system challenges, their approaches to market design, regulatory oversight, and battery integration diverge significantly. These structural differences shape how storage assets participate, earn revenue, and support grid stability. Understanding these contrasts is essential for developers and operators navigating each market.

ERCOT and NEM are both high-renewables, energy-only markets, and Texas is beginning to experience the same grid dynamics that have driven BESS deployment in eastern Australia. As renewable penetration in ERCOT climbs, so does system volatility, negative pricing frequency, and pressure on thermal generation to remain flexible. These conditions mirror the early NEM landscape, where storage became essential to manage renewable ramp rates and stabilize system frequency.

Extreme weather events, such as Winter Storm Uri in February 2021 and heat-driven demand peaks in the summer months, have forced ERCOT to rethink its reliability structure. As a result, ERCOT has already implemented expansion of its ancillary services markets, including Fast Frequency Response (FFR) and ECRS (ERCOT Contingency Reserve Service). These mirror similar services in Australia, like FCAS (Frequency Control Ancillary Services), and are creating opportunities for more frequent and valuable BESS dispatch.

There is also growing discussion in ERCOT around future products like synthetic inertia, voltage support, and flexible ramping reserves. These products are already in motion or under pilot in the NEM. These changes point to a future ERCOT market structure that more closely resembles Australia’s hybrid services model, where storage is not only a price arbitrage mechanism but a cornerstone of market reliability.

For ERCOT to fully mirror the NEM’s battery-first posture, several critical changes would be needed.

Standardization of Communications Control: Australia’s NEM has led the way in requiring grid-forming BESS to meet rigorous telemetry, dispatch compliance, and inverter performance standards. ERCOT would need to move toward similar standardization, requiring advanced communications, high-speed telemetry, and automated controls. This would improve system operator confidence in BESS performance during extreme events.

Enhanced Co-Optimization: To unlock full flexibility, ERCOT may need to enable real-time co-optimization of energy and reserves markets, an approach under discussion in the NEM. This would allow BESS to dynamically switch between energy arbitrage and regulation support based on system needs and price signals. See our latest article on RTC+B.

Long Duration Incentives: ERCOT’s current market signals primarily reward fast, short-duration response. As with the NEM, which is now seeing longer-duration batteries enter the pipeline, ERCOT would need to broaden its reserve product structures to reward sustained output contributions.

SYSO delivers comprehensive support for BESS operators navigating the evolving ERCOT landscape. Through real-time operational oversight, SYSO manages dispatch and forecasting to ensure assets capture value from market price spikes, Fast Frequency Response (FFR) windows, and intraday volatility. Beyond operations, SYSO provides deep expertise in regulatory readiness, helping clients stay compliant with ERCOT’s dynamic participation models. As ERCOT explores enhanced co-optimization and expands its ancillary services, SYSO ensures asset owners are strategically positioned to capitalize on emerging revenue streams. With SYSO, BESS owners gain a partner that understands both current challenges and future market direction. For those looking to lead in ERCOT’s next era, contact our team today.