Due to continuous increase in primary energy consumption worldwide, energy sector requires more and more attention and insights. This growing tendency has only been halted by significant historical events, such as world wars, oil price shocks or world economic crises. In the last 40 years, global energy consumption has practically doubled. In the structure of applied energy carriers, use of fossil has still been in dominance. This phenomenon leads to a more powerful environmental impact. Emission of greenhouse gases and other pollutants has been a constant problem. Besides the enviromnental considerations, fulfilling energy needs of the future requires the expansion of alternative solutions. Exploiting renewable energy sources has always been present in the history of mankind. However, global and conscious use of it has not been in the agenda only since the last couple of decades. Permanent research and development in the topics facilitates their increasing efficiency of utilization. Furthermore, more and more solutions and new technologies have appeared in the field that may reshape future energy supplies.
In 2015, in Hungary, use of renewable energy sources has only been 9% out of the complete primary energy-mix. Fields of application of these energy sources not only consists of high-performance power plants but households and buildings, too. In the case of buildings, several solutions of renewable energy source types are applicable. Besides environmental consciousness, efficacy is a crucial factor, as well, since it requires a high-volume investment. It is important to rationalize technical feasibility and returns of investments in various constructions.