Stored energy
kWh · MWh
How much heat the accumulator holds
This is the storage capacity. It determines how long the accumulator can supply a given demand.
Think of it as the size of the tank.
Technology
Heat goes in storage. Heat comes out.
A thermal accumulator takes in energy, holds it as heat in a solid material, then delivers it as heat. It does not return electricity.
How it works
Three steps. Always in this order.
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Charge
Energy comes in as electricity and is converted to heat inside the accumulator. Depending on the configuration, recovered heat can also contribute to charging.
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Store
Heat is held in aluminosilicate-based solid materials, inside an insulated enclosure, until it is needed.
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Deliver
Heat is extracted and supplied through heat exchange equipment: hot air, steam, thermal oil, glycol or hot water, depending on the application.
How it fits together
From source to process. Four links.
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Input
Energy sources
- Electricity
- Recovered heat, depending on configuration
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Accumulator
Thermal storage
- Aluminosilicate-based solid materials
- Stored energy, in MWh
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Output
Heat exchange and distribution
- Hot air
- Steam
- Thermal oil
- Glycol
- Hot water
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Use
Process
- Drying
- Process heating
- Hot water and steam
Charging the accumulatorHeat delivered
Simplified diagram. The output is heat: the accumulator does not return electricity. Heat exchange equipment is selected for each application.
Energy and power
Two quantities. Not to be confused.
Power
kW · MW
How fast it charges or delivers
Charging power and delivery power are sized separately, based on the site’s electrical service and the process demand.
Think of it as the flow from the tap.
Example
The Valleyfield installation has a storage capacity of 15 MWh. That is an energy, not a power.
Heat or electricity
A thermal accumulator is not a battery.
| Heat storage | Electricity storage | |
|---|---|---|
| What goes in | Electricity; recovered heat depending on configuration | Electricity |
| What is held | Heat, in a solid material | Electrochemical energy |
| What comes out | Heat: hot air, steam, thermal oil, glycol or hot water | Electricity |
| Intended use | Process heat and space heating | Electrical uses |
The two approaches serve different needs. Tessart focuses on heat storage.
Frequently asked questions
Integration, uses, data. The short answers.
Does the accumulator return electricity?
No. The intended output is heat. Energy comes in as electricity or, depending on the configuration, as recovered heat. It comes out as heat.
How does it integrate with an existing process?
Through heat exchange equipment suited to the process fluid: hot air, steam, thermal oil, glycol or hot water. Equipment already in place can remain in service. Integration is designed with your engineering team.
What uses are possible?
Drying, process heating, hot water, and steam through suitable integration. These are applications to assess for each site. Not all of them have been deployed to date.
What data is needed to assess a project?
The heat consumption profile, ideally hour by hour. The required temperatures. The current heat source. The available electrical power. The electricity rate in effect.
What is the difference between MWh and MW?
MWh measures energy: the amount of heat stored. MW measures power: how fast the accumulator charges or delivers its heat. A project is sized on both.
Can recovered heat be used?
Depending on the configuration, yes. Each source is first qualified on temperature, flow and continuity.
What is the efficiency? What is the service life?
These values depend on the configuration and the use. We share them as part of a project analysis, along with the assumptions behind them.
Is thermal storage right for every site?
No. Its relevance depends on the consumption profile, temperatures, available power and rates. A preliminary analysis answers the question before engineering costs are committed.
Does StoQ work on the same principle?
Yes: store heat, then return it. StoQ applies that principle to home heating.
A more specific question? Ask our team.
Numbers are best discussed on a real case, with your data.