This paper describes about a decision model for solar energy utilization and an investigation of optimal configuration of solar energy system considering electricity transportation between interprofessional consumers. Solar energy is effective energy source for CO₂ reduction. Available collectable area for solar energy is limited to consumer's condition. A photovoltaic can supply electricity which is flexible. However its efficiency is low compared to solar heat collector. A solar heat collector has high efficiency. But heat demand varies with consumer type. We investigate optimal ratio of photovoltaic and solar heat collector in several condition. The result shows that solar heat collector is effective energy supply system for consumers which require high hot water demand in daytime. On the other hand, electrical heat pump for hot water supply varies optimal configuration of solar energy system due to the shift of energy source from gas to electricity. To introduce electrical heat pump for hot water supply increases the ratio of photovoltaic due to the increase in electricity demand. However, there is no consumer without solar heat collector. Therefore, solar heat collector does not compare with electrification of consumer.