In thermochemical storage, charging heat splits a compound (dehydrates a salt, desorbs water from zeolite, reduces a metal oxide). As long as the products are kept apart, the energy stays stored with very little loss — attractive for long-duration and seasonal use.
Energy densities can be several times those of sensible storage, but reactors, heat and mass transfer and cycling stability make these systems more complex; most are at demonstration or research stage.
Key facts
- Mechanism
- Reaction enthalpy ΔH
- Losses while stored
- Very low
- Use
- Long-duration, seasonal
- Maturity
- Demonstration / research
System families6
- Adsorption systems
- Absorption systems
- Hydration and dehydration
- Metal oxide redox systems
- Reversible chemical reaction systems
- Thermochemical composite materials
Applications5
- Seasonal solar heat storage
- Industrial heat upgrading
- Transportable heat
- High-temperature solar fuels and storage
- Compact building heat storage
Development focus5
- Reactor design and heat transfer
- Material cycling stability
- Mass transport of vapour
- System cost per kWh
- Integration controls
Related calculators
Calculators are available to staff / admin only.
Related topics
- Thermochemical MaterialsThe materials behind thermochemical storage: zeolites and silica gel, salt hydrates, hydroxides, carbonates and metal oxides.
- Underground / SeasonalBoreholes, aquifers and large pits hold heat for weeks or seasons — the backbone of solar district heating.
- Thermal Energy StorageThe foundation of the sector: technologies that hold energy as heat or cold in a medium and release it when it is needed.
Project & partnership desk
Planning Thermochemical?
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