# Sensible heat storage: What to track

Negative-price hours and whether giant units keep their promises

Source page: https://www.materialinsights.org/energy/e_sensible_heat/tracking/

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 2030^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Nov/IRENA_Innovation_Outlook_TES_2020.pdf) | ↗ 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)^[14](https://mdpi-res.com/d_attachment/processes/processes-10-01070/article_deploy/processes-10-01070.pdf)^[23](https://energyinnovation.org/wp-content/uploads/2023/07/Industrial-Thermal-Batteries-Report-1.pdf) | ↗ 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 observed^[8](https://cordis.europa.eu/project/id/190167786/reporting)^[10](https://www.solarthermalworld.org/news/seasonal-pit-heat-storage-cost-benchmark-30-eurm3) | → 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/kg^[13](https://nso-journal.org/articles/nso/full_html/2024/03/NSO20230051/T2.html) | → 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 2025^[22](https://www.hydropower.org/news/year-of-the-water-battery-global-pumped-storage-capacity-surpasses-200-gw) | ↗ 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 corrosive^[13](https://nso-journal.org/articles/nso/full_html/2024/03/NSO20230051/T2.html) | → 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](https://doaj.org/article/d37d47b8031142639be97889b0f5e897) | → 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 2030^[1](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Nov/IRENA_Innovation_Outlook_TES_2020.pdf) | ↗ 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)^[5](https://www.ess-news.com/2025/10/20/rondo-energys-100-mwh-solar-powered-heat-battery-now-operational/)^[28](https://www.energy-storage.news/antora-energy-closes-us550-million-series-c-to-scale-us-thermal-battery-deployment/) | ↗ improving | Shows whether units scale from pilots to plant size and hold uptime claims. |

#### Sources

1. [Innovation Outlook: Thermal Energy Storage](https://www.irena.org/-/media/Files/IRENA/Agency/Publication/2020/Nov/IRENA_Innovation_Outlook_TES_2020.pdf) IRENA, 2020
2. [Rondo Energy's 100 MWh solar-powered heat battery now operational (news report of company claims)](https://www.ess-news.com/2025/10/20/rondo-energys-100-mwh-solar-powered-heat-battery-now-operational/) ESS News, 2025
3. [KRAFTBLOCK: scalable, modular, high temperature thermal energy and power storage (EIC Accelerator, periodic report)](https://cordis.europa.eu/project/id/190167786/reporting) European Commission CORDIS, 2025
4. [Seasonal pit heat storage: cost benchmark of 30 EUR/m3](https://www.solarthermalworld.org/news/seasonal-pit-heat-storage-cost-benchmark-30-eurm3) solarthermalworld.org, 2019
5. [Study on the hybrid energy storage for industrial park energy systems, Table 2: thermal storage materials (National Science Open 3(3))](https://nso-journal.org/articles/nso/full_html/2024/03/NSO20230051/T2.html) National Science Open, 2024
6. [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)](https://mdpi-res.com/d_attachment/processes/processes-10-01070/article_deploy/processes-10-01070.pdf) MDPI, 2022
7. [Year of the water battery: global pumped storage capacity surpasses 200 GW (2026 World Hydropower Outlook)](https://www.hydropower.org/news/year-of-the-water-battery-global-pumped-storage-capacity-surpasses-200-gw) International Hydropower Association, 2026
8. [Industrial Thermal Batteries: Decarbonizing U.S. Industry While Supporting a High-Renewables Grid (Rissman)](https://energyinnovation.org/wp-content/uploads/2023/07/Industrial-Thermal-Batteries-Report-1.pdf) Energy Innovation, 2023
9. [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)](https://doaj.org/article/d37d47b8031142639be97889b0f5e897) DOAJ / Elsevier, 2021
10. [Antora Energy closes US$550 million Series C to scale US thermal battery deployment (news report of company data)](https://www.energy-storage.news/antora-energy-closes-us550-million-series-c-to-scale-us-thermal-battery-deployment/) Energy-Storage.news, 2026

## Other sections

- [Summary](https://www.materialinsights.org/energy/e_sensible_heat/index.md)
- [Overview](https://www.materialinsights.org/energy/e_sensible_heat/overview/index.md)
- [Correlation](https://www.materialinsights.org/energy/e_sensible_heat/correlation/index.md)
- [Science and technology](https://www.materialinsights.org/energy/e_sensible_heat/sg-sci/index.md)
- [Engineering and performance](https://www.materialinsights.org/energy/e_sensible_heat/sg-eng/index.md)
- [Economics](https://www.materialinsights.org/energy/e_sensible_heat/sg-econ/index.md)
- [Impact and additionality](https://www.materialinsights.org/energy/e_sensible_heat/sg-impact/index.md)
- [Relationships](https://www.materialinsights.org/energy/e_sensible_heat/links/index.md)