Sensible heat storage: What to track
Negative-price hours and whether giant units keep their promises
What this tab covers The attributes worth tracking regularly, with the latest value, the direction of travel and why each matters.Watch whether cheap-hour electricity spreads and whether the first large industrial units hold their efficiency and uptime claims.
| Category | Attribute | Latest | Trend | Why it matters |
|---|---|---|---|---|
| Techno-economic | LCOS trajectory (storage capex) | Molten salt USD 26.1-40 per kWh heat (2020); 21.8-25.8 expected by 20301 | ↗ improving | Sets the cost premium over a plain gas boiler. |
| Techno-economic | Levelised cost of heat versus gas | USD 35-62 per MWh modelled in the US (gas about USD 22 in Texas); Australia USD 59 with storage vs gas USD 29.1 (2021)1423 | ↗ improving | Shows how close stored electric heat is to fuel parity. |
| Technical | Capacity fade and state of health (heat loss and cycling) | Pit store losses 6-24% a year; Kraftblock 4,700 test cycles, no degradation observed810 | → stable | Leakage, not chemistry, decides how long heat can be held. |
| Supply chain | Critical mineral cost and geopolitical concentration | None needed; water USD 0.005/kg, rock USD 0.02-0.3/kg13 | → stable | Low exposure to mineral price shocks. |
| Market | Cheap-hour availability (the analogue of ancillary market saturation) | At least six European countries had over 500 hours of negative prices in 202522 | ↗ improving | More cheap or negative-price hours mean cheaper charging. |
| Regulatory | Safety and environmental compliance | No thermal runaway; boiler and pressure codes apply rather than battery codes; molten salt is corrosive13 | → stable | Low permitting burden supports siting at factories. |
| Impact | Lifecycle carbon payback period | No payback period found; life-cycle footprint of molten salt storage about 0.031 kg CO2e per kWh (PV charging)24 | → stable | Low embodied carbon means payback should be short, but it is not yet quantified. |
| Market | Global thermal storage deployed | 234 GWh (2019); over 800 GWh projected by 20301 | ↗ improving | Scale drives cost and bankability. |
| Market | Largest operating industrial thermal battery | Antora 5 GWh, Big Stone, South Dakota, supplying POET (company data, 2026); Rondo 100 MWh, California (2025)528 | ↗ improving | Shows whether units scale from pilots to plant size and hold uptime claims. |
Sources
- Innovation Outlook: Thermal Energy Storage IRENA, 2020
- Rondo Energy's 100 MWh solar-powered heat battery now operational (news report of company claims) ESS News, 2025
- KRAFTBLOCK: scalable, modular, high temperature thermal energy and power storage (EIC Accelerator, periodic report) European Commission CORDIS, 2025
- Seasonal pit heat storage: cost benchmark of 30 EUR/m3 solarthermalworld.org, 2019
- Study on the hybrid energy storage for industrial park energy systems, Table 2: thermal storage materials (National Science Open 3(3)) National Science Open, 2024
- Bottom-Up Estimates of the Cost of Supplying High-Temperature Industrial Process Heat from Intermittent Renewable Electricity and Thermal Energy Storage in Australia (Profaiser et al., Processes 10, 1070) MDPI, 2022
- Year of the water battery: global pumped storage capacity surpasses 200 GW (2026 World Hydropower Outlook) International Hydropower Association, 2026
- Industrial Thermal Batteries: Decarbonizing U.S. Industry While Supporting a High-Renewables Grid (Rissman) Energy Innovation, 2023
- Life cycle assessment of compressed air, vanadium redox flow battery, and molten salt systems for renewable energy storage (AlShafi and Bicer, Energy Reports 7, 7090-7105) DOAJ / Elsevier, 2021
- Antora Energy closes US$550 million Series C to scale US thermal battery deployment (news report of company data) Energy-Storage.news, 2026