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Unit 1•Lesson 3 3 min read

Renewable vs. Non-Renewable Energy Sources

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Learning Objectives

Differentiate between renewable and non-renewable energy sources.
Provide examples of major renewable energy sources (solar, wind, hydro, geothermal, biomass).
Provide examples of major non-renewable energy sources (fossil fuels, nuclear).
Discuss the basic advantages and disadvantages of each type of source.

Where Does Our Energy Come From?

Humans use enormous amounts of energy to power homes, run cars, and operate factories. The sources we use to get this energy can be divided into two main categories: renewable and non-renewable.

Non-Renewable Energy Sources

A non-renewable resource is one that is used up much faster than it can be replaced. Once it's gone, it's essentially gone for good on a human timescale.

1. Fossil Fuels:

These are the most common non-renewable sources. They were formed from the remains of ancient living organisms (plants and animals) that were buried and subjected to intense heat and pressure over millions of years.

Coal: A solid fossil fuel.
Petroleum (Oil): A liquid fossil fuel, refined into gasoline, diesel, etc.
Natural Gas: A gaseous fossil fuel.
Advantages: They are relatively cheap (for now) and easy to transport. Our current infrastructure is built around them.
Disadvantages: Burning them releases greenhouse gases (like CO₂), which contribute to climate change and air pollution. They are a finite resource.

2. Nuclear Energy (Uranium):

Nuclear power plants use the element uranium as fuel. They split uranium atoms (fission) to release a huge amount of heat, which is used to generate electricity.

Advantages: It produces a massive amount of energy from a small amount of fuel and does not produce greenhouse gases.
Disadvantages: The uranium fuel is non-renewable. The process creates radioactive waste that is very difficult and dangerous to store for long periods. There is also a risk of accidents.

Renewable Energy Sources

A renewable resource is one that can be replenished naturally in a short amount of time or is essentially inexhaustible.

1. Solar Energy: Energy from the sun. Photovoltaic (PV) cells (solar panels) convert sunlight directly into electricity.

Advantages: It is clean (no emissions) and abundant.
Disadvantages: It is intermittent (doesn't work at night or on cloudy days). Requires large areas for solar farms.

2. Wind Energy: Energy from the movement of air. Wind turbines convert the kinetic energy of the wind into electricity.

Advantages: It is a clean source of energy.
Disadvantages: It is also intermittent (doesn't work when the wind isn't blowing). Turbines can be noisy and can be a hazard to birds.

3. Hydropower (Hydroelectric Energy): Energy from moving water. Dams are built on rivers to create a reservoir. When water is released, it flows through turbines to generate electricity.

Advantages: It is a reliable, low-cost source of electricity once the dam is built.
Disadvantages: Building large dams can damage river ecosystems and displace communities. It's limited to areas with suitable rivers.

4. Geothermal Energy: Energy from the heat inside the Earth. Water is pumped deep underground, where it is heated by magma. The resulting steam is used to turn turbines.

Advantages: It is a reliable and clean energy source.
Disadvantages: It is only available in specific tectonically active locations.

5. Biomass Energy: Energy from organic matter, such as wood, crops, or garbage. This material is burned to produce heat, which can generate electricity.

Advantages: It uses waste materials. It is considered 'carbon neutral' because the carbon released when burned is offset by the carbon absorbed when the plants grew.
Disadvantages: Burning biomass can still produce air pollution. It can require large amounts of land and water to grow crops for fuel.

Key Terms

**Renewable Resource
An energy source that is not depleted when used, such as wind or solar power.~|~Non-Renewable Resource: A natural resource that cannot be readily replaced by natural means at a pace quick enough to keep up with consumption. Examples include fossil fuels.~|~Fossil Fuels: A natural fuel such as coal, oil, or gas, formed in the geological past from the remains of living organisms.~|~Solar Energy: Radiant energy emitted by the sun.~|~Hydropower: Power derived from the energy of falling or fast-running water, which may be harnessed for useful purposes.~|~Geothermal Energy: Thermal energy generated and stored in the Earth.

Check Your Understanding

1

Which of the following is a non-renewable energy source? A) Wind B) Coal C) Solar D) Geothermal

2

What is a major environmental disadvantage of burning fossil fuels?

3

Solar panels work by converting radiant energy from the sun directly into what other form of energy?

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Heat Transfer: Conduction, Convection, and Radiation