The utter dependence of man on this form of energy is not very encouraging, for the simple reason that this source of energy, as its name suggests, is not a permanent supply of energy and will eventually run out. On the other hand, the renewable energy sources provide hope as they are in plentiful supply, and need just to be harnessed to solve the energy crisis faced today.
Ever since the fossil fuel energy availability explosion in the 19th century, the demand rate for energy has been on an exponential increase. The increased demand is depleting the energy reserves at a much faster rate than what had been previously anticipated, and this has led us today to a very crucial point in time where we have to find and tap other sources of energy if we desire to keep our lives tuned in to the same style as we're used to.
The one most relevant factor and the biggest contributor to this energy problem is the phenomenal increase in the world population, which is expected to rise even more and at an increased rate, if not at the present rate, in the future. Another reason is that we have accustomed our lifestyles according to the notion that we would always have unlimited access to freely available energy, and our current practices and economies run on the immediate and unstoppable supply of huge quantities of energy. Educational, economical, social and technological sectors all rely on this supply of energy and are designed accordingly. However, we are about to face a very serious challenge, one that will have to be fought on an international scale and would need our combined effort to overcome.
The energy demands in the world are expected to rise by 1-2% every year for many decades (Physics Today 2004), and the fact that many of our energy supplies will, at this rate, deplete within an average lifespan of a human being is not helping at all. The energy supplies that we have either depend upon the amount stored as fossil fuels and other stores like nuclear fuel in the earth, or the amount of energy supplied by the sun that we can harness economically through different methods (Physics Today 2004). Both the factors have their own sets of problems, but the problems and constraints on the development of renewable energy provided by the sun directly are to be considered in this paper.
Case in point is the development of renewable forms of energy in the US. Energy demands can be measured in quads (Q), where 1Q = 1015 BTU, which can be approximated to 1.06 x 1018 joules (Physics Today 2004). The energy consumption of the US forms about a quarter of the total energy consumption of the world, roughly a 100Q per year, and this consumption is expected to ri