Renewable and Non-renewable Energy Sources

• Humans are very reliant upon electricity.  Think back to the blackout of August 2003 and recall how whole cities were shut down.
• Since we rely on electricity so much, it’s important to produce as much of it as possible and conserve it whenever we can.
• All energy sources are either renewable or nonrenewable.
• A renewable energy source is one that does not get used up when it produces energy, therefore we can keep using it.
• Examples of renewable energy sources are as follows:

Wind

Energy is produced by using large propellers mounted on top of towers (there is one in downtown Toronto near the Exhibition Grounds).  Wind forces the propellers to move.  When the propellers move they spin a generator which is capable of producing electricity.

Solar

This is using energy from the sun to generate electricity.  Solar energy shines upon a device called a solar cell or solar panel which is able to generate electricity.  Currently, solar cells are used to light portable construction signs (warning you of upcoming road conditions) and some shingles (roofing material) contain solar cells so that a house can generate some of its own electricity.

Hydro

• This is when electricity is generated from falling water (example: Niagara Falls).  The falling water spins a turbine which is connected to a generator.  The generator creates the electricity.
• A nonrenewable energy source is one that cannot be used again and cannot be replaced once it’s been used.
• Examples of nonrenewable energy sources include:

Fossil Fuels

These include coal, oil, and gas.  To create electricity from these fuels, they must be burned.  Not only can these fuels not be reused, they create a lot of air pollution.  They are called fossil fuels since they are created over millions of years from dead and buried organisms.  It is estimated that we will eventually use up our storage of fossil fuels within the next 200 years if we keep using them as much as we do.

Nuclear Energy

This is energy that is produced when uranium (U) atoms are split apart (fission) in nuclear reactors.  A lot of energy is released from this process and it doesn’t create air pollution, however, it does produce very radioactive waste products.  Scientists have not yet been able to figure out where to store these waste products. According to Canada’s Ministry of Energy, Science, and Technology, Ontario currently (2004) uses the following sources of energy:

COMPARING ENERGY PRODUCTION TECHNOLOGIES

When comparing different methods of energy production, the following factors need to be considered:

Cost

• Every energy-producing technology has a different price.
• One of the most expensive technologies is solar energy, which is why they are not widely used.

Efficiency

• Remember that efficiency will use less energy and save money.
• Wind power is the most efficient energy production technology, however, it is expensive to operate.
• The efficiencies of hydro, nuclear, oil, and coal are very similar with hydro being the cheapest to operate.

Geography

• Different forms of renewable energy have ideal geographical areas where they can be produced.
• Nuclear power plants use massive amounts of water daily and therefore need to be built next to bodies of water.  One of Ontario’s largest nuclear power plants (Darlington) is located approximately 70km east of Toronto off of Lake Ontario.
• Hydro electricity only operates in areas with large amounts of running water.  Niagara Falls generates energy that is used over the entire Eastern coast of North America.

Storage and Transmission

• It is very difficult to store electricity.
• Devices called “capacitors” can only store small amounts of electricity.
• The problem with electricity is that once it is produced, it must be used.
• If you can’t store electricity, how beneficial are solar cells at night during the winter when furnaces need to operate?  Many renewable energy sources cannot constantly produce energy.
• Energy is constantly traveling through high-voltage wires from power plants that generate electricity.  Since the electricity will encounter resistance as it travels through the wires, heat is lost and less energy can be transferred over long distances.

Impact on the Environment

• All types of electricity have negative impacts on the environment.  Some examples include:
• Wind turbines require large open fields.  Many birds are harmed or killed when they fly into the propellers.
• Burning fossil fuels produces large amounts of air pollution and acid rain.
• Nuclear energy produces highly radioactive wastes which take up to millions of years to break down.
• Hydro requires flooding of neighbouring areas and interferes with fish populations.