Some Basic Reasons for Developing Renewable Energies

Abstract

Human beings, like any other thermodynamic system that tries to have a continuous evolution, need to interchange energy and matter with their environment. Consequently, they are open systems which fully interact with the biosphere. Until now, effects of human beings on their environment have been absorbed by its autoregulation capacity mainly due to the relatively low values of demography, per capita consumption, and ecological negative impact of waste disposals. Nevertheless, increasing world population with higher requirements of both, raw materials and energy, exhausts the earth’s resources and overcomes its recycling capacity. The very serious problems arising from these facts are, or should be, sufficiently well known and will not be commented here again. Instead, such problems will be considered as a hint suggesting a new way of understanding the unavoidable new management of matter and energy that humans require for their welfare, together with an environmental regeneration. - Let us consider the biosphere as a system, rather than human beings as individuals, groups, or as a whole. The biosphere is in fact a thermodynamical closed and non-isolated system. It is closed because matter interchanged with its limits, outer space on one hand and inner parts of the earth on the other, can be clearly neglected, at least under a human time scale; so, its ability to accommodate disposals is limited. It is not isolated because there is an energetic interchange through its limits; most of this interchange is radiative, and solar radiation income is by far the most significant. - The main consequence of the biosphere being a closed, non-isolatedsystem, whose energy input is solar radiation, becomes evident: to maintain the progress of mankind we must recycle the constant amount of matter available, some nowadays as pollutants, with the inexhaustible, plentiful, clean, and highly available energy of solar radiation, avoiding pollution. All of us know that the time period in which to do that is short; a couple of human generations, about 50 years, appears to be the limit. Fortunately, this amount of time is what we foresee is needed to implement new processes that, using the finite amount of matter available, including the pollutants, and driven directly or indirectly by renewable energies, will be able to fulfil reasonable requirements of an increased population, a significant part of which is under acceptable consumption of matter and energy.