Evaluation of Passive and Active Solar Systems in High-Rise Buildings

Solar energy can be harnessed in many ways for the purposes of heating, cooling and lighting. The sun delivers many times more energy per year than is consumed worldwide. The term passive solar refers to systems that absorb, store and distribute the sun s energy without relying on mechanical devices like pumps and fans, which require additional energy. Passive solar design reduces the energy requirements of a building by meeting part or all of its daily heating, cooling, and lighting needs with solar energy. The three most common passive solar design systems are direct gain, indirect gain, and isolated gain. Carefully designed elements such as overhangs, awnings, and eaves shade windows from the high-angle summer sun, while allowing the light from the low-angle winter sun to enter the building. In active solar systems, solar collectors are used to convert the sun s energy into useful heat for hot water, space heating or industrial processes. This issue is followed by photovoltaic panels which convert direct solar radiation to the electricity within availability for integration on building envelopes. Following the previous design considerations, the designer can then next coordinate the passive-mode systems, the mixed-mode (or background) systems with the full-mode (or active operational) systems to be provided. Only after all the passive-mode and mixed-mode systems have been maximised can design solutions be sought in operational and active systems (e.g., full lighting, heating and air-conditioning systems), depending on the level of internal environment servicing to be provided. Also, the productive mode (like photovoltaics) should be considered and adopted where costs permit.