Electrical energy is usually measured in watt-hours, but the BTU can also be used: one watt-hour is equivalent to 3.413 BTU’s.

WHERE DOES COAL COME FROM?

You may have heard coal described as a mineral. This isn’t true. Coal is really an organic material composed of the remains of trees and other plants that lived hundreds of millions of years ago, during a time when the earth had a warm and moist climate.

When the plants died, they fell into boggy water. There they turned into a spongy substance called peat, Eventually, these peat deposits were covered by sediment, and subjected to huge pressures. In time, the peat dried and hardened to become coal.

Coal is our most abundant fossil fuel (so-called because coal is fossilized plant matter).

WHERE DOES OIL AND NATURAL
GAS COME FROM?

Many millions of years ago, the seas covered portions of the Earth that are now dry land. These prehistoric oceans were inhabited by countless tiny animals and plants. As these living things died, they sank to the sea floor. There they mixed with sand and mud to create marine sediment.

In time, the layers of sediment were covered with more sand and mud, and eventually, by rock. Ages of heat and pressure — along with the decomposition of the dead plants and animals — changed the organic material into crude oil.