Assessing Solar Energy Using Photovoltaic Power Plants on Building Envelopes

Analysis of the solar energy source using photovoltaic power plants on buildings with respect to the gross potential and its deviation from the optimal options for the spatial orientation of the receiving surfaces for their location makes it possible to assess the admissibility of using building envelope structures for installing photovoltaic modules with a tilt angle in space that differs from the optimal orientation for the area. On the example of the specific inclination angles of the receiving surfaces of the module relative to the horizon when they are placed on the enclosing structures of a building for spatial orientation along the cardinal points, the analysis of the level of utilization of the solar energy potential of the region is carried out on an example of a geographic point located in the south of Russia. The receiving surface with southern orientation, located at tilt angle of 30°, is characterized by the closest incoming solar radiation flux to a similar value with the optimal spatial orientation (–0.2% for a year), while the level of utilization of the solar energy supply increases by 14.3% compared to its value coming on the receiving surface that is horizontal to Earth’s surface. For tilt angles relative to the horizon at a 20°–45° southeast and southwest orientation, the incoming solar radiation flux in spring and summer (the time of active production and processing of agricultural products) is comparable to the flux received on the receiving surface with its optimal spatial orientation for the year (deviation is up to 5%) and slightly below the maximum possible value (up to 7.4%). On surfaces of eastern and western orientation, loss of the utilized power of solar energy is almost 50.0%, while the annual amounts are commensurate with similar values obtained on the receiving surface horizontal to Earth’s surface for tilt angles of 10°–20° (deviation up to 5.0%), for the rest, it is 10.4–36.6%. The use of facades for installing photovoltaic power plant modules provide the least efficient conversion of incoming solar radiation with a decrease in its flux coming to their surface compared to the optimal oriented modules by 27.5–30.7%, and modules placed horizontally to the surface of the Earth (gross insolation flux), by 16.9%.