Effect of energy conservation by adopted PV/SC system in subtropical regions

At present, large amounts of CO
2
are emitted from residential households which are increasing rapidly. Thus, it is expected that renewable energy system, e.g., photovoltaic (PV) system, and solar collector (SC) system will be adopted in those houses. However, the initial cost of PV system is very high and it is difficult for house owners to recover the initial cost within the life time of PV and SC system. Therefore, Japanese government proposed Renewable Portfolio Standard (RPS), Feed-in tariff and etc, to support the house owners. This paper evaluates the reduction of energy, CO
2
and cost by comparison of performances with the proposed PV, SC and hybrid (PV/SC) systems included economic effect of Feed-in tariff. The performances were evaluated from the adoption effect of the proposed system by testing electric houses with electrical water heater system or heat pump system (HP). As a result, energy reduction rate of all-electric house with adopted PV/SC electrical water heater system is 94.1%. Furthermore, cost reduction rate and applied Feed-in tariff of all-electric house with adopted PV/SC electrical water heater system is 176.5%. Cost reduction rate and applied Feed-in tariff of all-electric house with HP adopted PV/SC system is 195.9%. Empirical results indicate that this adoption of PV/SC system can reduce energy consumption, CO
2
and cost efficiently.