renewable energy focus handbook

[...]... overall energy picture Figure 1.0-11 shows that as late as 1997 only 12% of the energy used to generate electricity in the USA came from renewable sources Of these, 83% came from hydroelectrics Thus, only 2% of the total came from the remaining renewables Disappointingly, so far, the contribution of solar and wind energy has been very small, much less than that of geothermal Most of the renewable energy. .. of energy Thus, natural gas was cheaper than oil or wood 1.0.3 Conservation of energy Energy can be utilized but not consumed.y It is a law of nature that energy is conserved Instead of consuming it, we degrade or randomize energy, just as we randomize mineral resources when we process concentrated ores into metal and then discard the final product as we do, for example, with used aluminum cans All energy. .. into space The consumable is not energy; the consumable is the fact that energy has not yet been randomized The degree of randomization of energy is measured by the entropy of the energy This is discussed in some detail in Chapter 2.1 1.0.4 Planetary energy balance The relative stability of Earth’s temperature suggests a near balance between planetary input and output of energy The y input is almost entirely... inquire what energy resources are available (Section 1.0.8) and next (Section 1.0.9) how we are using the resources at present Figure 1.0-8 shows the planetary energy resources These can be renewable or nonrenewable Geothermal energy has been used for a very long time in Iceland and more recently in Italy, New Zealand, and 10 the United States Great expansion of its contribution to the total energy supply... fixed installations, the opposite is true The relative cost of energy is not determined by utility alone One barrel contains 159 liters or 127 kg of oil With a heat of combustion of 47 MJ/kg, this corresponds to 6 GJ of energy In mid-1990, the price was $12/barrel or $2/GJ, somewhat less than the price of wood at that Renewable Energy Focus Handbook 2009; ISBN: 9780123747051 Copyright Ó 2009 Elsevier... hesitate Introduction Geothermal 3% Wind . Introduction 3 Section 2 ENERGY PERSPECTIVES 29 2.1 Energy perspectives . 31 Section 3 ALTERNATE ENERGY SOURCES 57 3.1 Alternate energy sources. . 59 3.2 Energy reserves and renewable energy sources reference, the Re- newable Energy Focus Handbook e-Mega Reference, 9780123747068  A fully searchable Mega Reference eBook, providing all the essential material needed by Renewable Energy Engineers on. class="bi x0 y0 w1 h1" alt="" Renewable Energy Focus Handbook Note from the Publisher This book has been compiled using extracts from the following books within the range of Renewable Engi- neering