Comprehensive Study Guide to Renewable and Non-Renewable Energy Resources

Core Definitions of Energy Resources

Energy resources available on Earth are fundamentally categorized into two types based on their longevity and replacement rate: non-renewable and renewable. A non-renewable energy resource is defined as one that will eventually run out because it is not replaced at the same rate at which it is being used. Examples of non-renewable resources include coal, oil, gas, and nuclear energy. Conversely, a renewable energy resource is defined as one that will not run out, as it is being replaced (or can be replaced) at the same rate at which it is used. The primary renewable resources include solar, tidal, wave, wind, geothermal, biofuel, and hydroelectric energy.

Solar and Wind Energy Systems

Solar energy involves uses for both generating electricity and heating. The source of this energy is sunlight, which transfers energy to solar cells for electricity or to solar heating panels for warmth. The advantages of solar energy are its utility in remote locations, very low running costs once the initial installation is complete, and the fact that it produces no pollution or greenhouse gases. However, solar energy has significant disadvantages: the supply is entirely dependent on the weather, the initial purchase and installation are expensive, and it currently cannot supply large-scale demand. Wind energy is used exclusively for generating electricity through turbines turned by the wind. Like solar, it has low running costs, no fuel costs, and produces no pollution or greenhouse gases. Its drawbacks include being weather-dependent, requiring large amounts of land to meet large-scale demand, and the potential for noise pollution for residents living near the turbines.

Water-Based Renewable Resources: Hydroelectric, Tidal, and Wave Energy

Hydroelectric energy generates electricity by using water flowing downhill to turn generators. It is highly reliable because the supply can be controlled to meet demand, has no fuel costs, and low running costs. However, it is expensive to build hydroelectric dams and results in flooding large areas behind the dam. This destruction of habitats leads to greenhouse gas production from rotting vegetation. Tidal energy uses turbines on tidal barrages turned by water as the tide moves in and out. It is a predictable supply with no fuel costs and can produce large amounts of electricity without pollution. The downsides include the high cost of building and maintaining barrages, the potential to harm animals and change marine habitats, and the restriction of access for boats. Additionally, while predictable, the supply varies depending on the time of the month. Wave energy utilizes floating generators powered by waves moving up and down. While it has low running costs and no pollution, it is expensive to build, install, and maintain. Like tidal energy, floating generators can harm animals, change marine habitats, and create dangers for boats. Its supply is also dependent on the weather and cannot currently meet large-scale demand.

Geothermal Energy and Biofuels

Geothermal energy generates electricity and provides heating by tapping into radioactive substances deep within the Earth which transfer heat energy to the surface. It is advantageous because it has low running costs, no fuel costs, and produces no pollution or greenhouse gases. The primary disadvantages are the expensive initial setup and the fact that it is only possible in a few suitable locations worldwide. Biofuels are fuels produced from living or recently living organisms, such as plants and animal waste, and are used for generating electricity and transport. Biofuels can be carbon-neutral, meaning the amount of carbon dioxide released when the fuel is burnt is equal to the amount of carbon dioxide absorbed while the fuel was growing. They are reliable and the supply can be controlled to meet demand. However, biofuels are expensive to produce and require significant land and water that could otherwise be used for food production. Furthermore, the demand for biofuel crops can lead to deforestation as forests are cleared to grow them.

Questions and Discussion

What is a non-renewable energy resource? A non-renewable energy resource will eventually run out and is not replaced at the rate it is being used.

What is a renewable energy resource? A renewable energy resource will not run out because it is being (or can be) replaced at the same rate as which it is used.

What are the main renewable and non-renewable resources available on Earth? The renewable resources are solar, tidal, wave, wind, geothermal, biofuel, and hydroelectric. The non-renewable resources are coal, oil, gas, and nuclear.