ENERGIANALYSE.DK

Increasing penetration levels of wind and solar power in the energy system call for the development of Smart Grid enabling technologies. As an alternative to expensive electro-chemical and mechanical storage options, the thermal energy demand in buildings offers a cost-effective option for intermittency-friendly electricity consumption patterns.

Combining hot and cold thermal storages with new high-pressure compressor technology that allows for flexible and simultaneous production of useful heat and cooling, the paper introduces and investigates the high-efficiency Thermal Battery (TB) concept. In a proof-of-concept case study, the TB replaces an existing electric resistance heater used for hot water production and an electric compressor used for air refrigeration in a central air conditioning system. A mathematical model for least-cost unit dispatch is developed. Heat pump cycle components and thermal storages are designed and optimized. A general methodology is applied that allows for comparing the obtained results with other Smart Grid enabling options.

It is found that the TB concept leads to improvements in the intermittency-friendliness of operation Rc (improves from -0.11 to 0.46), lower CO2 emissions (reduced to zero), and lower operational costs (reduced by 72%). 

The results indicate that TB may be the most cost-effective Smart Grid enabling option for supporting higher penetration levels of intermittent renewables in the energy system.