Electricity - Section 4

What are fossil fuels?

Coal, oil, and natural gas formed from prehistoric plants and animals

What percent of global electricity is generated by fossil fuels?

About 65%

How is electricity generated from coal?

Coal is burned to heat water, steam spins a turbine, which turns a generator

What does the turbine do?

Turns from steam to rotate the generator

How much energy does 1 kg of Alberta coal release?

About 27 megajoules (MJ)

What is nuclear fission?

Nuclear fissions is when atoms are split apart, which releases energy

What is the energy from nuclear fission used for?

To create steam that drives turbines

What is geothermal energy?

Heat from Earth’s interior used to produce steam

How is geothermal energy used to generate electricity?

Steam is piped from the ground to turn a turbine

What is biomass energy?

Energy from burning decomposing waste like crops and food

What gases from landfills can be used as fuel?

Combustible gases from biodegradable waste

What is cogeneration?

Using waste heat from industrial processes to generate electricity

What percent of global electricity comes from hydroelectric power?

About 20%

How does a hydroelectric plant work?

Water flows through penstocks to spin turbines connected to generators

What is a penstock?

A channel that directs water to the turbine

What is tidal power?

Energy from moving ocean tides trapped and released through turbines

Why is tidal power rare?

Few places have strong, predictable tides

What is wave power?

Energy from up-and-down movement of water driving pistons connected to generators

How does wind power generate electricity?

Wind turns blades connected to a shaft that spins a generator

What is a wind farm?

A group of wind turbines working together to produce electricity

Where is a wind farm located in Alberta?

Cowley, Alberta

What is the photovoltaic effect?

The process where sunlight produces electricity in solar cells

Who discovered the photovoltaic effect?

Alexandre Edmond Becquerel

What material improved solar cell efficiency in the 1950s?

Silicon

What are solar modules and arrays?

Groups of solar cells connected together to increase power output

What does the International Space Station use for power?

About 2500 m² of solar panels

Why aren't batteries used to power entire cities?

They are too bulky, expensive, and short-lasting

What are rechargeable batteries used for?

Backup power for emergency lights and computers

Why are rechargeable batteries inefficient?

They use more electricity to charge than they produce

What is a fuel cell?

A device that generates electricity directly from a chemical fuel like hydrogen

How does a fuel cell work?

It uses a fuel source like hydrogen to generate continuous electricity

Where are fuel cells used?

In electric vehicles and portable electronics