Wood Mackenzie Cuts Battery Deployment Outlook as Storage Fleet Pressures ERCOT Real-Time Prices
Wood Mackenzie's steep cut to battery deployment forecasts dims the case for sustained bearish pressure on ERCOT real-time pricing through the decade.
Wood Mackenzie on Tuesday (2026-09-22) released its latest forecast showing utility-scale battery deployment flatlining in 2026 and growing just 8% annually through 2031 — a steep retreat from the 30% annual growth projection it made in 2024 that underpinned RMI's analysis of storage's ability to suppress peak power prices.5
The downgrade has direct implications for ERCOT's real-time market. Evidence from California shows that grid-scale batteries are already displacing gas peakers at the moments when real-time settlement prices spike highest.5
During California's record 2024 heat wave, 3.4 GW of grid-connected batteries met 6% of the state's energy needs and materially strengthened reserve margins, RMI said, citing an ICF analysis. Two years earlier, with less than 1 GW of battery capacity online, California suffered rolling blackouts despite a demand peak roughly 10% below the 2024 level.5
RMI's analysis, released earlier in September (2026-09), found those batteries supplied 13% to 19% of total generation at capacity factors on par with gas peakers when supply was tightest, avoiding more than $29 million in peak energy costs on California's grid in 2024.5
For markets like ERCOT, where gas-fired peakers historically clear real-time prices during summer stress events, a battery fleet large enough to match peaker output is a direct drag on those settlement prices. The pace of fleet growth now looks slower than build-out projections implied.5
Wood Mackenzie had already dialed back its five-year battery deployment forecast to 16% earlier in 2026. Tuesday's (2026-09-22) further cut to 8% growth through 2031 traces a consistent line: the original 30% projection was written for a policy world anchored by the Biden-era Inflation Reduction Act. Import tariffs, rising capital costs, and supply chain stress have since compressed the investment case.5
President Trump's August 2026 executive order restricting foreign-produced bulk power components added more headwinds on top. Analysts said it layers fresh regulatory exposure onto an industry already navigating tariff risk.5
RMI's community revenue case for storage remains intact regardless of the deployment pace. A 250 MW/500 MWh installation that came online in February (2026-02) in Medway, Massachusetts, is projected to generate roughly $46 million for the town over 20 years. The 400-MW Purple Sage Energy Center in Nevada will deliver $3.4 million annually to local governments even after partial state property tax abatements, RMI said.5
Australia's National Electricity Market offers a read on what saturation eventually does to battery economics. The Australian Energy Regulator found that installed battery capacity reached 6.1 GW by the end of 2025, up from 2.2 GW at the start of that year, with batteries setting the wholesale price 16.3% of the time across 2025. BNEF's third-quarter 2026 report found average intraday arbitrage returns across the NEM fell 79% year-on-year to $103 (USD 73) per MWh in Q2 2026, as a larger fleet competed margins down.3,4
Texas is running a strong counter-current on the demand side. CenterPoint Energy reported 12.2 GW of firmly committed new industrial load in its Houston service territory, up 63% from one quarter earlier, and expects to energize 8 GW of data center load by 2029, a timeline the company has pulled forward twice already. Lawrence Berkeley National Laboratory researchers estimated data centers could consume between 9.5% and 15.3% of all US electricity by 2030, up from 4.7% in 2024.2,1
How much bearish pressure the storage fleet ultimately exerts on ERCOT real-time prices turns on whether Wood Mackenzie's 8% growth outlook holds or softens further under the weight of Trump's bulk-power executive order and the project timelines it may reshape for builds already in development.5