Energy overview

Since the founding of the US, energy use here has been dominated by wood, coal, petroleum, and natural gas.
- As the use of wood declined in the latter half of the 1800's, the use of coal increased accordingly.
- Coal peaked around 1910, which was followed by a corresponding increase in the use of petroleum and natural gas.
Over the last century, the average per capita energy consumption in the World has grown by a factor of about 2.5.
- The US and Canada are the world's greatest consumers of energy, both around 11 kW per person, or about 4 times the world's average.
- Though accounting for only 5% of the world's population, Americans consume 26% of the world's energy.
Given that the World's population has roughly quadrupled over the last century, it's no surprise that energy has become a very hot topic.
With the exception of nuclear and geothermal energies, most energy sources can be traced directly to the Sun.
The world consumes about 20 terawatts (tera=10¹⁵) of power from all known sources.
- The US accounts for about 5% of the world's population but consumes about 26% of the total.

A popular energy unit is Btu (British Thermal Unit).
The heat liberated when one cubic foot of naturasl gas is burned is about 1030 Btu.
Because the number of Btu's is typically quite large on various graphs, energy use is often expressed in quads, which represents a quadrillion (10¹⁵) Btu's.
From 1950 to 2010, the total energy consumed in the US increased roughly from 35 to 100 quads.
To get a sense for this magnitude, consider this: 100 quads would be the heat released by burning a sea of natural gas 1500 feet high uniformly covering the surface of the contiguous US.
This energy content is also equivalent to the energy which would be released from about a trillion gallons of gasoline.

The ratio of hydrogen to carbon in the fuels we use has increased over the years along with our increased use of natural gas (as opposed to oil or coal). That's good news for the environment and humankind.
When we burn fossil fuels such as natural gas, the two primary products are carbon dioxide and water. The higher the percentage of hydrogen in a fuel, the less carbon dioxide and more water produced.
As the hydrogen content of our fuels increases, they become cleaner. With supplies of many other fuels diminishing, our reliance on the most abundant element in the universe makes even more sense.
Most scientists and environmentalists agree that hydrogen will be an important energy carrier of tomorrow, along with electricity. Eventually, hydrogen and electricity will be the major energy carriers, used by a greater number of people for a greater number of applications than any fuel in use today.
In the early stages, hydrogen will be produced from natural gas and other fossil fuels. Eventually, it will be produced from a variety of energy sources, including renewable hydro, wind, solar and nuclear power.
Historically, the ratio of hydrogen to carbon in the fuels we use has increased with the development of new fuels. A pure hydrogen fuel is the natural next step.

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