Global warming and limited amounts of fossil fuels (oil, coal and gas) have made many people nervous about the future of life on Earth. In order to discuss energy and the energy industry, we need to know what the main sources of energy are, as well as what kinds of energy will be used in the future.
Oil, coal, and natural gas are easily transportable and can be saved for long periods to create electricity when needed. They completely changed the world. Without fuels like this, it would have been impossible to build the kind of global economy we have today. However, there are several big problems with these fuels. First, they are non-renewable, which means that people use them faster than they can be produced. Second, they create greenhouse gases.
The Earth has a limited supply of the fuel needed to create nuclear energy, however we still have enough for tens of thousands of years of energy. Some people are afraid that nuclear energy is unsafe because of nuclear power plant accidents over the years. However, Thorium is a nuclear fuel that we will discuss later in the course.
Renewable energies come from the sun’s light, the Earth’s heat, moving water, or burning materials like wood or farm waste. The Earth’s temperature is heating up, big money is being invested into renewables, and there are only 47 years of oil left in the Earth (if we keep using the same amount of fossil fuels we use today).
Solar energy (energy from the sun) was in use before humans even knew how to light a fire. About 70% of sunlight goes back into space, and we can’t cover the whole Earth in solar panels, so at this time just a very small percentage of solar energy gets used. Solar panels collect sunlight and turn it into electricity. These panels can be used for a long time and require little or no maintenance and last over 20 years. Solar energy is not as effective in colder places with less sunlight.
Windmills are mostly used to create energy for industrial uses. Wind farms have been in use for many years all around the world, but they can only be used in areas which experience high winds. Windmills sometimes create noise and cannot be used near residential areas. These problems mean that wind energy can only be used in certain places around the world.
Geo means ‘Earth’, and thermal means ‘heat’. Heat is continuously produced from the center of the Earth. Geothermal temperatures increase about 25-30 degrees Celsius per kilometer that you go into the Earth. Eventually, it gets hot enough to boil water. Once the water boils and turns into steam, it can be used to make electricity.
Biological materials (also called biomass) like trees, plants, grass and waste can be used as energy sources for heating, power generation and transportation. Wood, agricultural waste, and trash are used to produce biomass energy. Biomass fuels are renewable, but produce greenhouse gas.
Hydrogen is the most common element on Earth but it is usually connected to another element. Hydrogen does not create pollution when it is burned, just water and air. This fuel can be used to power homes, vehicles and even space rockets. However, it takes a lot of energy to separate hydrogen from other elements. So as of 2020, it is still very expensive to create hydrogen power and difficult to store.
Storage is a Big Problem
Nonrenewable energies (fossil fuels and nuclear power) are stored as fuel until they are ready to be converted into electricity. Think about solar energy; at night time, the solar panels are useless. So batteries are needed to save this electricity generated in the day. Batteries, especially lithium batteries, will probably be an important part of the future for green energy.
The next lessons will look at several energy companies that may be part of the greener, cleaner future of energy. But first, look at this graph below and think again about the information we just learned: