The convenient truth is that the world does not have an energy shortage; it simply lacks an energy infrastructure capable of using the abundant source of solar energy that we receive from the sun every day. The current worldwide demand of about 363 terawatt-hours per day could be met by covering just 0.5% of the world's land area with silicon solar panels. Doing so, and building out other necessary infrastructure requirements, could meet our energy needs and eliminate dependency on nonrenewable petroleum.
As we examine our energy future, we should keep in mind three fundamental requirements:
1. Abundance. Because of the value that energy gives us in improving the quality of life, the long-term abundance of an energy source and of the materials required to produce it is very important.
2. Cleanness and greenness. Clean, green energy is important because we only have one Planet Earth. When we pollute and damage it, we are destroying our home.
3. Widely distributed availability. Moving energy from point to point is an energy-consuming and wasteful practice, so ease of transport and accessibility are important considerations in building the energy future.
We typically refer to fossil fuels as sources of energy. In reality, fossil fuels are stored forms of potential energy created from solar energy ages ago, so the real source was the sun. These fossil fuels are nonrenewable sources of energy; formed over eons, they are now being spent in a matter of decades.
Gasoline, diesel, biodiesel, ethanol, methanol, hydrogen, and electricity are not true sources of energy because they need to be converted from other sources into these more convenient forms. Whenever one type of energy is converted into another type of energy, some of the source energy is lost as waste heat or friction (entropy). This entropy waste is one of many reasons why the conservation of all natural materials--including petroleum--is for the betterment of society.
Solar energy, however, is different; it is constantly being generated and radiated into the universe. Any solar energy that we do not use becomes wasted light and heat energy, dispersed into the empty void of space as a sort of dark, weak energy that is unavailable for our use.
A basic source of energy is fusion energy, which is in fact the primary source of all energy in the universe. Our sun is a fusion energy source, as are all of the billions of suns in the universe. Our sun has been producing reliable fusion energy for several billion years and is estimated to have a remaining life of more than 4.5 billion years. All we need is an infrastructure to collect and utilize the already ample solar energy it sends our planet's surface daily--more than 2 million terawatt-hours.
How much solar energy do we receive from the sun? Let us look briefly at the sources.
Amount of Solar Energy Available
There are four major types of energy sources that we get from the sun: heat, wind power, photosynthesis (biomass cultivation), and photovoltaic power. Heat is what warms the earth and makes it livable as a planet. Wind power is available, useful, and relatively inexpensive, but it is too limited to fulfill worldwide demands. Biomass is also an available option, but as a product of photosynthesis, it is less efficient than photovoltaic generation of electricity. Also, the competition for resources among agriculture, forestry, and energy must be carefully and cautiously evaluated before considering the use of biomass for energy on a large scale.
Now let us look at how much photovoltaic solar energy is available from the sun. Starting with National Oceanic and Atmospheric Administration Solar Constant data measured at the stratosphere, we can estimate the average amount of sun continuously reaching the Earth's surface at 174 watts per square meter, which obviously varies by latitude, season, cloud cover, and other variables. …