Abstract
Cost and primary energy consumption are investigated, imaging that a photovoltaic/solar heat/cogeneration system (here, it is called a proposed system) is equipped in a hotel and a hospital. The proposed system is operated using a dynamic programming into which hourly data of electric load, heat load, insolation intensity and air temperature during a year are input. In the dynamic programming, the objective function is the cost or the primary energy, i. e., the former case is the cost minimum operation and the latter case is the primary energy minimum operation. The proposed system is compared with a conventional system, a cogeneration system and a photovoltaic/solar heat system. The results of the cost minimum operation shows that the proposed system in the hotel (the floor area ratio: 1000 %, the heat storage tank : 50 m3) reduces the primary energy to 84% and the cost to 96% of the conventional system. And the proposed system reduces the primary energy to 91% of the photovoltaic/solar heat system and 92% of the cogeneration system. The proposed system with the same size in the hospital reduces the primary energy to 90% while increases the cost to 101% of the conventional system. The primary energy minimum operation reduces the primary energy still lower than the cost minimum operation, while increasing the cost a little.
