Sustainability and Economic Feasibility of Combinations of Renewable Energy Sources (RES) and Fossil Fuels For Production of Heat And Electricity

Known advantages of renewable energies use, such as local availability, low environmental impact, etc. cannot always cover their disadvantages (different for different RES), namely: dependence on concrete locality (geothermal energy), variability over the day and year (solar and wind energy), complicate collection and storing (biomass), and difficulties to proof economic feasibility in comparison with fossil fuels on the market (gas and liquid fuels). Main problem is that the most of comparisons are made with intention to completely replace fossil fuels in all the life sectors and particularly in electricity production. That is for sure not possible when taking into account that RES are energy sources in development and fossil fuels already have the development process behind and have an extremely well organized distribution network, excellent industrial background for different applications and state and international capital support for financing projects for resources development and application. This paper suggests a change of the approach. Except “big moves”, i.e. trials to remove the fossil fuels use, it is proposed to try to find optimal use of proven advantages of RES application in combination with decreased or even minimized use of fossil fuels everywhere where possible. Sustainability and economic feasibility of such solutions are illustrated with examples of combinations of different RES with oil and gas and between themselves. Probably that shall not change the whole situation significantly but shall enable further technological improvements in order to be ready when the next energy crisis comes.