The Sun is the primary source of all energy on Earth. The Sun radiates more energy in one second that people have ever used. Only a small part of the radiant energy produced by the Sun strikes Earth. Yet, every day enough solar energy strikes the United States alone to supply the industrial and residential energy needs of the United States for about one and a half years. Some of this energy is reflected back into space. Some of the energy is used by plants for photosynthesis. Some of the energy warms land and water surfaces; driving winds, weather, ocean currents.

But humans predominantly use solar energy that was stored in fossil fuels millions of years ago. Fossil fuels, coal, natural gas and oil, provided nearly 80% of the United States energy needs in 2006. Because these fuels require millions of years to develop, and because we are using them so quickly, they are considered non-renewable. In fact we are using these fuels so quickly that many experts predict that we will totally exhaust reasonably retrievable supplies within a few decades. Already the scarcity of supplies is causing costs to increase. In addition, the enormous social, political and economic costs of conflicts in the Middle East can be attributed to the dependence on oil. The costs of fossil fuels are environmental as well as social, political and economic.

Another non-renewable energy source, nuclear power, provided nearly 12% of U.S. energy needs in 2006. But concerns about nuclear accidents and the lack of approved long term storage sites for nuclear wastes has held up the production of new nuclear power plants in the past several decades. Renewable sources such as solar panels, wind turbines, wave turbines, biofuels, and hydroelectric plants provided about 10% of U.S. energy needs in 2006. As fossil fuels become more expensive and more scarce, these resources will become more attractive. Already, as people factor environmental and social expenses into the cost of fossil fuels, renewable sources are becoming the energy sources of choice in many places.

Emerging technology will bring down the costs of many renewable sources and generate new sources. In addition, one aspect of emerging technologies has been a reduction of required energy for the same task – something people call conservation. While we can reduce energy requirements by driving less, turning off lights when we leave the room, and wearing sweaters instead of turning up the heat, we are also building cars, electrical appliances, factories, and homes that are more energy efficient.

How we face the challenges of providing energy over the next few decades will shape our culture in ways we can’t even imagine.

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