Using solar heat for either cooling or electricity production.
At moments with solar energy availability, solar heat at 90 oC is stored in the short-term heat storage tank for supplying the DHW demand at 60 oC (if required) and for either cooling or electricity production as follows:
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Cooling production: The stored heat supplies in priority the cascade chiller for space cooling, which requires heat at over 80 oC to reach a high thermal COP.
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Electricity production: When cooling is not required or the forecasted daily cooling needs are covered by charging the thermal buffer tank, the stored heat supplies the ORC for electricity production. Its operation is preferred over TEGs, having 30% higher efficiency for the same heat input temperature. At all moments, the TEGs operate to dissipate the excess solar heat in case of collector overheating, extending their lifetime.
At moments with no solar energy availability:
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The remaining stored heat is primarily used for DHW and then for cooling production, if required.
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At night time and if all daily or forecasted heating/cooling needs are covered (or buffer tank charged), a fraction of the stored heat at temperature < 75-80 oC supplies the TEGs for electricity production.
Check out Winter mode & Intermediate seasons
