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How can excess energy generated by solar panels be stored using a thermal battery?

Solar panels are becoming increasingly popular, but one of the biggest challenges is energy storage, as most electricity companies do not buy back the excess electricity generated. Typically, this excess is not utilized, but with proper storage, we can make use of this additional electricity. A common storage technology is the electrical battery, which typically contains toxic, environmentally harmful materials and rare earth metals, making it unsustainable in the long term. The Intelligent Thermal Battery can be an excellent addition to solar panels, storing and utilizing energy in the form of heat.

When examining a solar panel system, we differentiate between two main scenarios.

In the first scenario, the peak output of the installed solar panel system is less than the total electrical power demand of the building. In this case, there is no excess production from the solar panels, so additional electricity cannot be utilized through storage. On weekends, the energy demand of the building might be reduced, thus necessitating energy storage.

The image below illustrates a day when solar energy production is lower than the building’s demand.

In the second scenario, solar energy production often exceeds the demand during the year. In such cases, the system will be on standby, meaning that part of the potentially generated electricity is not produced due to a lack of consumption. Our control system can detect these events, and by initiating the charging of the HeatTank, we can increase the electrical consumption of the building’s HVAC system (chiller or heat pump). This way, we can use the otherwise non-produced electricity to cover part of the cooling or heating needs during periods when the sun is not shining and the solar system is not generating enough electricity.

The following diagram shows the operation of such a system over a one-day period. During the day, the excess production can be used to charge the HeatTank, which then helps meet the cooling needs in the evening. There are also instances, illustrated in the diagram, where the HeatTank can be charged again in the early morning at high cooling efficiency, discharged during the late morning, and then a second charge-discharge cycle can be implemented during the day through solar optimization.

Combining systems in this way not only improves the return on investment for the HeatTank but also positively impacts the return on investment for the solar system, as the amount of electricity that can be generated increases.


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