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Heat and thermal storage
Cheap power today, heat tomorrow.
Heat is usually cheaper to store than electricity. A large heat pump or an electrode boiler with heat storage can take power in the hours when there is too much of it, and deliver heat when customers need it. For district heating after coal it is one of the main routes.
- Electrode boilers10 to 50 MW
- Heat pumpsA few to tens of MWt
- Storage tanksThousands to tens of thousands of m³
- Our roleStudies, grants, contractor selection, supervision
Four building blocks
Large heat pumps
Heat from ambient air, waste heat or water, far more efficient than direct heating.
Electrode boilers
Cheap and fast. They pay where power is cheap for part of the day, and can provide balancing services.
Heat storage
Large hot-water tanks, or storage in sand and other solid materials for higher temperatures and steam.
Combined with cogeneration
The engine runs when power is expensive, the boiler and heat pump when it is cheap. The tank between them evens out the difference.
What we do for you
- From hourly heat demand and energy prices we design the mix of sources and the size of the storage.
- We find the low-grade and waste heat sources a heat pump can use.
- We check the grid connection capacity, which is often the tightest constraint when heat goes electric.
- We prepare the grant material and a financial model that stands up in front of a bank and the heat price regulator.
- We run the tender and owner's engineering on site, the control and security of the whole system included.
What to watch
- The grid connection is the bottleneck. An electrode boiler of tens of MW needs matching input from the grid. From 2027 reserved input is charged at medium and high voltage, so we design it together with the operating regime.
- Catalogue costs are not enough. The Danish Energy Agency updated its technology data in June 2026; the investment cost of a 20 MW seawater heat pump came out at double the previous edition, while larger pumps came out similar. For a decision we therefore work from quotes, not the catalogue.
- Grid-service revenues fluctuate. Plzeňská teplárenská commissioned a 30 MW electrode boiler for CZK 120 m in September 2025, providing balancing services to ČEPS. But the price of aFRR+ reserve bought long term roughly halved between 2025 and 2026, so we treat these revenues with care.
- Large projects are outside our scope. Prague's strategy foresees 150 MWt of heat pumps at the Central Wastewater Treatment Plant by 2036 for over CZK 8.3 bn. We focus on projects up to CZK 1 bn.
Sources: Danish Energy Agency, June 2026, oEnergetice, 03/09/2025, oEnergetice, 10/06/2026, Ekonomický deník, 30/09/2026. As at 24/10/2026.
Typical projects
| Project | Usual scale | What decides it |
|---|---|---|
| Electrode boiler at a heating plant | 10 to 50 MW | Connection, balancing services, storage |
| Large heat pump | A few to tens of MWt | Heat source, network temperature, power price |
| Hot-water storage tank | Thousands to tens of thousands of m³ | Site, operating regime of the sources |
| Sand or molten-salt storage | Tens to hundreds of MWh | Temperature, steam, technology maturity |
Sources: oEnergetice, 03/09/2025, Danish Energy Agency, 2026, Polar Night Energy, 11/06/2025, Kyoto Group, 09/10/2025. As at 24/10/2026.
FAQ
Heat: your questions.
Electrode boiler or heat pump?
Often both. An electrode boiler is cheap and fast and pays in the hours of cheap electricity. A heat pump is more efficient and runs most of the year, but costs more and needs a heat source. We design the mix from hourly heat demand and price data.
How big a heat store do we need?
That depends on how many hours it should bridge and how large the sources are. Danish tanks installed since 2013 average about 5,000 m³; we calculate the right size for your network.
Can an electrode boiler earn from grid services?
It can, as Plzeňská teplárenská shows. But balancing revenues fluctuate, so the project should stand mainly on cheap heat, not on services.
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