Energy poverty can be defined as the inability to pay the bills required to maintain the comfort conditions (usually in winter) in dwellings. One way forward to face this problem is the use of energy efficient systems, being one alternative the electrically driven air source heat pump water heater. In this paper, the performance of a centralised heat pump (200 kW of heating capacity) is assessed to meet the space heating demand of block dwellings in Madrid (tier four out of five in winter severity in Spain). Two models have been developed: the first one is used to obtain the thermal energy demand on an hourly basis, which can be used to assess other technologies, and the second model is employed to calculate the off-design heat pump performance. The proposed heat pump is driven by a motor with variable rotational speed to modulate the heating capacity in an efficient way. A back-up system is also considered in order to meet the demand. A levelised cost of heating of 92.22 euros/MWh is obtained for a middle-level of energy efficiency building, with energy performance assessment of E, close to D. In addition to that, the following energy-environmental parameters have been achieved: more than 74 % share of renewable energy in primary energy and 131.7 g CO2 avoided per kWh met. If an energy retrofit is carried out, improving the energy performance assessment from E to C, a reduction of 60 % in the heating cost per dwelling is obtained. These results reveal this technology among the most promising ones to be used advantageously in some context where energy poverty arises.
Keywords: energy poverty; centralised heat pump; hourly heating demand; off-design heat pump model
Fecha de Registro: 2020-04-16