Energy Flashcards
What was the primary source of energy for most of human history?
Wood - which was burned to keep warm and cook food.
What are the main non-renewable energy sources used worldwide in the past 200 years?
- Coal
- oil
- Natural gas (fossil fuels)
- nuclear energy
What is the term for coal, oil, and natural gas?
Fossil fuels
What are some examples of renewable energy resources?
Solar
Wind
Hydroelectric
Geothermal
Biofuels
Tidal
What are fossil fuels?
A hydrocarbon-based material formed from the remains of dead plants and animals over millions of years
Name a non-renewable energy source used for electricity generation in the UK
Natural Gas
How do solar water heaters work?
They use the sun’s energy to heat water, which can be pumped through radiators.
Are biofuels renewable or non-renewable?
Renewable - as they are created from sources like plants
Is electricity renewable or non-renewable?
It depends on how it’s made; it can be either
What are the environmental disadvantages of using fossil fuels?
They produce greenhouse gases leading to global warming, and contribute to air pollution
Why are biofuels considered renewable?
They are made from plants or organic materials, which can be regrown or replenished
Describe how solar energy can be used to heat a house
Solar water heaters use sunlight to heat water, which is then pumped through radiators to warm the home
What is the main energy source for heating homes in the UK?
Natural Gas
What is the difference between renewable and non-renewable resources?
Renewable resources can be replenished naturally over time, whereas non-renewable resources will eventually run out
What percentage of the UK’s electricity is generated using non-renewable resources?
Nearly 80%
Why are fossil fuels used more than renewable resources for electricity generation?
Fossil fuels are
- currently more reliable and provide consistent energy
while renewable resources
- can be intermittent
Why may fossil fuels be burnt?
To provide Heat
How can Heat ,burnt from fossil fuels, be used?
- Burned to provide heat for direct use (e.g. cooking)
- To power engines (e.g. the internal combustion engines in cars)
- To generate electricity
What Are The Pros Of Fossil Fuels?
- Relatively Cheap
- Can be used in any conditions (e.g. don’t require wind or sunshine to work)
- Much of our current infrastructure is designed to run using fossil fuels
What Are The Cons Of Fossil Fuels
- They’re a limited resource so will run out one day
- They produce carbon dioxide when burned, which is a greenhouse gas and contributes to global warming
- They sometimes produce toxic gases when burned - such as sulfur dioxide and carbon monoxide
How Is Nuclear Energy Obtained?
via nuclear reactions, such as nuclear fission reactions
What Can Nuclear Energy be used for?
Used to generate electricity, which can then be transmitted to homes and factories
What are the Pros of Nuclear Energy
- Does not produce any pollutants (e.g sulphur dioxide)
- Can be used in any conditions
- It is very unlikely to run out for a very long time
What are the Cons of Nuclear Energy
- Technically a finite resource
- Nuclear power stations produce radioactive waste, which remains harmful for thousands of years
- It’s quite expensive
What is a non-renewable energy recourse?
- An energy resource that will eventually run out
- Not replaced at the same rate it’s being used
What is a renewable energy resource?
- An energy resource that will not run out
- Can be replaced at the same rate it’s being used
Examples of renewable energy recourses?
Solar
Tidal
Wave
Wind
Geothermal
Biofuel
Hydroelectric
Examples of non-renewable energy resources?
- Coal
- Natural Gas
- Oil
- Nuclear Fuel
How is wind power generated?
By wind turbines which convert the kinetic energy from the wind into electrical energy
Where are wind turbines usually placed? And why?
In exposed areas like moors or coasts
where strong winds are common
How is Solar Power generated?
Solar cells or solar panels which can generate electricity directly from sunlight
Name two places where solar power works well
- Low-energy devices (e.g., calculators, watches)
- Remote regions (e.g., the Australian outback)
Which places are you likely to see Solar Cells?
- On the front of calculators
- Roofs
- Large scale solar farms
What are the Pros of Solar and Wind Power?
- They don’t produce any pollutants while operating
- They have low running costs
What are the Cons of Solar and Wind Power?
- They take up a lot of land space
- Their power production is dependent on the weather, and therefore inconsistent
- They have relatively high upfront costs
Why do wind and solar power take up a lot of space?
Many turbines or solar panels are needed to produce a significant amount of power
What 2 reasons do people not like wind turbines?
- They’re noisy
- Some people think they don’t look nice
Why is peak energy demand an issue for wind and solar power?
There’s no way to increase supply when demand is high
What is Geothermal energy?
The thermal energy generated and stored in the Earth
Where does geothermal energy come from?
- The original formation of the planet
- The radioactive decay of materials (like uranium) deep in the Earth
How is geothermal energy used directly for heating?
Water is pumped into the ground,
heated by Earth’s heat,
and then pumped back up to heat homes.
How is geothermal energy used to generate electricity?
Water is left underground until it turns into steam,
which rises and turns turbines to drive generators
In what areas is geothermal energy most accessible?
- Volcanic regions - Where hot rocks are near the surface
How does geothermal energy affect the environment?
Installing causes slight damage, but running it doesn’t produce pollutants
Is geothermal energy a renewable resource?
Yes
What are the main disadvantages of geothermal energy?
- They can only be built in certain areas of the world
- They can be expensive to build
What are Biofuels?
Fuels made from recently living organisms
What are examples of Biofuels?
- Plants
- Algae
- Animal Waste
How are biofuels different from fossil fuels?
- Fossil Fuel - come from organisms that lived millions of years ago
- Biofuel - come from recently living organisms
Why are plants and algae commonly used for biofuels?
They can photosynthesize,
locking up the sun’s energy,
which is later released when burned
Why are biofuels considered carbon-neutral?
Because the CO₂ they release when burned
was taken in while the plants were growing
Are biofuels renewable?
Yes
What are the advantages of Biofuels?
- They’re renewable
- They can be used in cars
- They’re easy to transport
What are the disadvantages of Biofuels?
- They require a lot of energy to harvest, process and transport
- They require a large area of land to grow
Why don’t biofuels require new cars?
They can be mixed with petrol, so existing cars can use them without modification
What is a major environmental issue with growing Biofuels?
often requires converting natural land,
such as cutting down forests,
which damages the environment
How does biofuel production release CO₂?
Harvesting,
processing,
and transporting biofuels require energy,
which may release CO₂
What is a hydroelectric dam?
Traps water from upstream,
creating a reservoir to generate electricity
What is a Tidal barrage?
Dam in estuaries that traps waters at high tide
and releases it at low to tide
to generate electricity
How do these systems generate electricity?
Water from a higher level flows through turbines,
spinning them to generate electricity using generators
What type of energy is used in hydroelectric dams and tidal barrages?
gravitational potential energy from stored water
What are the advantage(s) of hydroelectric dams?
- They are a source of renewable energy
- Higher electricity demands can be met by increasing water flow
What are the disadvantage(s) of hydroelectric dams and tidal barrages?
- They can flood land upstream
- Upfront building costs are quite high
What are the advantage(s) of Tidal Barrages?
- They generate large amounts of energy
- Produce no pollution
Which energy system provides an immediate response to increased electricity demand?
Hydroelectric
What is a major environmental issue with hydroelectric dams?
They often flood large areas, submerging habitats and sometimes villages
How do hydroelectric dams and tidal barrages affect fish migration?
They can block fish from traveling up or down rivers, disrupting migration
What is the key difference between hydroelectric dams and tidal barrages?
- Hydroelectric dams - trap water from upstream
- Tidal Barrages - Use the rise and fall of sea levels caused by tides
