Human energy needs

Thomas Moore of Arizona State University began by discussing how nature has adapted for 3.4 billion years through fierce evolutionary competition. He said that researchers need to follow nature s example, but accept the fact that in meeting human energy needs there may be ways to improve on nature. He defined the purpose of the workshop as a way to explore how to improve the natural process of photosynthesis and incorporate the kinetically and thermodynamically successful features in human-engineered constructs. 

At the end of World War II, great hopes were expressed for the use of nuclear reactors as a way of providing power for many human energy needs. For example, some optimists envisioned the use of small nuclear reactors as power sources in airplanes, ships, and automobiles. These hopes have been realized to only a limited extent. Nuclear powered submarines, for example, have become a practical reality. But other forms of transportation seldom make use of this source of energy. 

However, if the bicycle is meant to be a substitute for the automobile, the lighter aluminum frame material can dramatically lower the human power output needed to climb hills. The energy saved during the use of the aluminum frame will more than compensate for the greater energy needed to manufacture it. 

The bicycle s energy efficiency superiority extends beyond hninali loconiotion and beyond all other forms of transportation. By com ertmg food into the energy equivalent of gasoline, the kilocalories of food energy needed by a human to pedal a bicycle is only a fraction of that needed to propel planes, trains, and automobiles (see Table 1). 

Nader, L. (1995). Energy Needs for Sustainable Human Development-Anthropological Aspects. In Energy as an Instrument for Social Change, eds. Jose Goldenberg and T. B. Johansson. New York United Nations... 

The process by which yeast breaks down glucose has been carefully studied by biochemists and the way in which this transformation occurs is now known in considerable detail. One of the reasons this process is so interesting is that a nearly identical process takes place in human muscle, in this case to furnish energy needed for muscular activity. 

In evaluating options for obtaining the energy needed to sustain world economic progress in the coming years, it is important to consider the full spectrum of risks to the environment and to human health that each option may create or reduce. This is particularly important in evaluating nuclear power, where often attention has been disproportionately focussed on the presumed dangers. 

A minor part of mined fossil fuels is used as a raw material for the chemical industry (e.g., plastics, synthetic fabrics, carbon black, ammonia, and fertilizers). The major part supplies the energy needs for modem society. Fossil fuels supply about 86% of global primary energy consumption (39% oil, 24% coal, and 23% natural gas), providing energy for transportation, electricity generation, and industrial, commercial, and residential uses (El A 2001). Coal, and to a lesser extent oil, combustion leaves a significant amount of solid waste. The treatment of solid waste from fossil fuel combustion is treated in different chapters of this book. In this chapter we focus on air emissions of fossil fuel combustion, and their impact on human health and the environment. 

Animals can synthesize and store large quantities of triacylglycerols, to be used later as fuel (see Box 17-1). Humans can store only a few hundred grams of glycogen in liver and muscle, barely enough to supply the body s energy needs for 12 hours. In contrast, the total amount of stored triacylglycerol in a 70-kg man of... 

Since the human body is composed of only about 1% carbohydrate by mass, it may seem surprising that the recommended diet contains more than 50% carbohydrate (see figure 1). This discrepancy arises because carbohydrates are the ideal nutrients for satisfying immediate energy needs, and they also furnish the carbon skeletons for the synthesis of other types of biomolecules. 

T. N. Veziroglu. Hydrogen Technology for Energy Needs of Human Settlements, Int. J. Hydrogen Energy 12(2), (1987). 

Fusion promises to provide a nearly inexhaustible supply of hydrogen fuel as well as less radioactive waste, but temperatures of fusion reactions are too high for present materials, and the huge amounts of energy needed to start fusion reactions would explode or melt any known construction materials. The fires of nuclear fusion in our Sun provided energy for early humans long before they discovered the art of combustion, see also Chemical Reactions Chemistry and Energy Explosions Fossil Fuels. 

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