Impact of Different Short-term Thermal Energy Storage Strategies on the Performance of an Inverter Controlled Air-to-Water Heat Pump(IATWHP) in Residential Buildings in Belgium.

A solar energy assisted heating system is used in combination with electrical and thermal energy storage to cope with the time shift between renewable energy generation and energy demand. This study analyses the autonomy that can be reached for several combinations of photovoltaic solar panels (PV), solar thermal panels (ST), electrical storage (ES), thermal energy storage (TES) and heat pump (HP) capacity for a low energy building. The influence of the different systems sizing on the energy supply autonomy is investigated. The solar fractions of the heating and domestic hot water demand are calculated for a reference building in Belgium for different sizing combinations. The simulations are executed in TRNSYS and Matlab. A 15kWh/m2a building can achieve a solar fraction (SF) of 22% with only solar thermal. A SF of 45% can be attained with only TES and 90% with a combined system of TES and ES or only ES. The autonomy is limited by the available roof surface. A TES increases the solar fraction with 5 to 15%. Doubling the battery capacity in the reference case results in 5 to 7% of solar fraction increment.