The energy industry comprises the companies and people who locate fuel resources, harness them or remove them from the earth, and then process and distribute them for use. It is one of the largest, most dynamic, and often most controversial industries in the world.

The demand for energy first began when our ancient ancestors discovered they could keep themselves warm and cook food with fire. Since that time, our sources of energy have evolved, and the technologies we use to generate, distribute, and deliver energy have changed dramatically. Today energy is almost as essential to life as the air we breathe and the food we eat. We use energy every day, all day, when we work, play, drive, and eat. Even when we sleep, we need energy to heat or cool our homes and power our alarm clocks to wake us up in the morning.

Virtually no industry in the world today could function without some form of energy. Restaurants need it to power their cooking and refrigeration equipment. Manufacturers rely on it to operate their production lines. Even farmers need power to operate their vehicles. Energy is needed anywhere humans live or work.

For the past 200 years, humans have depended on two primary sources of energy: fossil fuels and hydropower (water), but these traditional sources of energy are finite. Beginning in the last few decades of the 20th century, other sources of energy have gained in popularity and usage. As a result, the energy industry is and will continue to be in a constant state of change as scientists and engineers work to develop energy sources and generation methods that are eco-friendly and sustainable. People want energy sources that have fewer negative impacts on our environment, reduce our dependence on fossil fuels, and are easily renewable, with no more fears of future shortages. It’s a tall order, but one that has led to many exciting opportunities and innovations.

The energy industry is very broad, but it can be divided into th...