Energy Differentiation

Many people fail to properly differentiate between energy forms and related energy systems. One result is that they can be misled regarding solutions to such concerns as "the energy crisis," "energy security," or "dependence on foreign oil." This not only leads to unrealistic thinking but poor public policy. Consider three major energy forms and their differentiation.

First is oil (petroleum), a liquid hydrocarbon fuel used to power automobiles, trucks, buses, trains, farm equipment, airplanes, ships, etc. Oil is processed in refineries into products that are optimized for use in specific kinds of machinery and equipment (devices). Oil products include gasoline, diesel fuel, jet fuel, bunker fuel for ships, and heating oil. Devices that operate on oil products are engineered and tailored to operate on that particular form of energy. In almost all cases, those devices cannot operate on other energy forms such as electric power or natural gas. When it comes to liquid fuels and devices built to operate on liquid fuels, we must think in terms of related specifics, not "energy."

Second is electricity, which is used to power various devices including air conditioners, lights, computers, refrigerators, space heating systems, televisions, VCRs, pumps, fans, communication systems, some trains, motors, various appliances, satellites, etc.  Electric powered devices can rarely operate directly on oil products or natural gas.  When it comes to electricity and devices built to operate on electric power, we must think in terms of related specifics, not "energy."

Third is natural gas. It can be directly combusted to produce heat or processed to create liquid fuels and various chemicals. Devices that operate on natural gas include electric power generators, building heating and cooling systems, water heating, cooking, and industrial processing. When it comes to the direct use of natural gas and devices built to operate on gas, we must think in terms of yet another specific type of system, different from liquid fuel-based systems and electric power-based systems.

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http://www.aspousa.org/index.php/2012/01/energy-differentiation

Most people have trouble wrapping their heads around energy in general, with catch phrases and other vague terms being thrown about in the media. To better understand the limitations of energy sources, we all need to understand energy in general terms first.