SCG Clean Energy Heat Battery

Executive Overview

The SCG Clean Energy Heat Battery is a 33 MWh Rondo Heat Battery (RHB) operating at SCG's cement plant in Saraburi Province, Thailand — Southeast Asia's first industrial heat battery and the world's first commercial heat battery at a cement manufacturing facility. Built in eight months by Rondo Energy in partnership with SCG Cleanergy, the system delivers 2.3 MWth of continuous high-pressure steam to the plant's heat recovery turbine, generating 24-hour clean electricity for cement production. The unit is charged from the Thai grid and a nearby floating solar farm, was built entirely in Thailand using local suppliers, and supports SCG's Net Zero 2050 goal.

How It Works & Differentiation

The 33 MWh RHB stores electricity as heat in refractory bricks at temperatures up to 1,500°C — above the 1,400°C threshold required for cement clinker formation — and discharges as superheated steam via a heat recovery turbine. It is the only heat battery worldwide configured to drive a steam turbine for electric power generation rather than delivering heat directly to a process. The modular Rondo platform scales from 33 MWh to greater than 1 GWh per installation, and can deliver over 100 MWth for large industrial customers. Round-trip efficiency exceeds 97%. The unit's fully local Thai manufacture demonstrates that the supply chain for the platform can be reproduced outside the United States, which is strategically significant for regional rollout.

Commercialization & Traction

SCG Cleanergy is developing additional clean industrial heat projects across Southeast Asia following the Saraburi commissioning. Rondo's global pipeline includes the 100 MWh Holmes Western deployment in California, a 100 MWh Heineken deployment in Portugal under EDP's heat-as-a-service model, and the Diageo IDP project in the United States. Manufacturing cost for the RHB platform is approximately $85–210 per kWh in 2025, with a target of $20–55 per kWh by 2035 as production scales toward Rondo's stated 90 GWh annual gigafactory capacity. The ASEAN energy storage market was approximately $3.55 billion in 2025 and is projected to reach $4.92 billion by 2030.

Scalability & Strategic Context

The Saraburi plant is the first demonstration that Rondo's heat battery can deliver value specifically in cement manufacturing — one of the hardest-to-decarbonise industrial sectors, with temperatures exceeding 1,400°C required for clinker production. Cement accounts for approximately 8% of global CO₂ emissions, and the sector's process heat requirements mean electrification via heat pump is not technically feasible at kiln temperatures. The combination of a locally manufactured unit, proven steam turbine integration, and a major regional industrial conglomerate as the operating partner provides a template directly replicable at other SCG facilities across the ASEAN region and at cement plants operated by other global producers who are also listed as Rondo strategic investors.