Energy Resources Flashcards
Pros of fossil fuels
- relatively cheap
- can be used in all conditions
- much of our current infrastructure is designed to run using them
Cons of fossil fuels
- they’re finite
- they produce CO2 when burned which is a greenhouse gas
- sometimes produce toxic gases when burned due to incomplete combustion, such as sulfur dioxide or carbon monoxide.
Nuclear energy is obtained via. nuclear reactions such as…
nuclear fission
Nuclear reactions are carried out in…
nuclear power stations
Pros of nuclear energy
- does not cause pollution
- can be used in any conditions
- although nuclear fuel is a limited resource, i.e. like uranium, it is very unlikely that it will run out soon
Cons of nuclear energy
- expensive
- technically nuclear fuel is finite
- produces radioactive waste which remains dangerous for a long time so needs to be stored extremely carefully.
How do wind turbines work?
They are placed in exposed placed where there is plenty of strong winds.
Each one has a generator which is turned when the blades turn due to wind - the kinetic energy store is transferred into electrical energy.
The electricity is transferred to the national grid to be distributed.
Solar cells generate electric current from _________ and transfer directly to
sunlight - the appliances.
Pros of wind and solar energy
- cheap relatively
- no pollution
- does not damage the environment
Cons of wind and solar energy
- high costs to set up
- manufacturing the equipment causes pollution
- dependent on the weather, so no way to increases supply during peak demand.
- takes up space and does not look aesthetic.
What is geothermal energy?
thermal energy generated and stored in the Earth’s crust, in the initial formation of the earth but also due to ongoing radioactive decay.
Uses of geothermal energy and how: heat? cheap
Pump water down into the ground where it is heated and then pumped back up to heat homes.
Uses of geothermal energy and how: electricity? $
pump water down into the ground until it becomes so hot that it turns into steam - as the steam rises it turns turbine which have generators and produce electricity.
Pros of geothermal power?
- very little environmental impact
- doesn’t pollute
- renewable
Cons of geothermal power?
- limited to volcanic areas
- power plants are expensive
What are biofuels?
fuel that’s made from recently living organisms - typically plants and algae since they carried out photosynthesis and lock up lots of energy from the sun which is released when burned.
Argument for and against biofuels being carbon neutral:
for: biofuels release CO2 when burned but they took up that CO2 in photosynthesis when growing so no more CO2 is added to the atmosphere than there originally was.
against: to grow the plants, we require space leading to deforestation which gets rid of trees which originally take up CO2 leading to more CO2 remaining in the atmosphere, and the trees are also burned to be disposed which in combustion releases CO2 too. Moreover, energy is required for harvesting and processing and transporting the plants so this requires energy as well which often comes from CO2 and burning more fuels like fossil fuels.
Pros of biofuels?
- cheap
- renewable
How does Hydroelectricity work?
Big dam that prevents water from flowing as it should, so water is trapped and accumulates forming a huge amount of water called a reservoir.
This creates a difference in water levels between one side of the dam and the other - the higher water level, the reservoir has a lot of gravitational potential energy, so when it is released, it has a lot of kinetic energy and flows with great force, turning turbines causing generators to make electricity.
How do tidal barrages work?
Big dam that prevents water from flowing as it should. Twice a day there is a high tide.
Thanks to the barrage, when there is a high tide, the water can be trapped, and once the tide falls, we’re left with a large difference in water levels - This creates a difference in water levels between one side of the dam and the other - the higher water level, the reservoir has a lot of gravitational potential energy, so when it is released, it has a lot of kinetic energy and flows with great force, turning turbines causing generators to make electricity.
Pros of tidal barrages and hydroelectricity?
- large amount of energy produced
- no pollution
- costs are fairly low
- work on small and large scales
Cons of tidal barrages and hydroelectricity?
- often have a big impact on the environment - fish and habitats
- initial set up is expensive
Hydroelectric dams can provide an immediate response to…
increased demand (of electricity)
