P3 - Energy resources Flashcards
What are the 9 main energy resources?
-geothermal
-solar
-tidal
-hydroelectric
-waves
-nuclear
-fossil fuels (coal/oil/gas)
-biofuel
-wind
geosolar tidal hydrowaves nuke the fossils with biowind
What is a renewable energy resource?
one that is being/can be replenished faster than it can be used
What is energy used for in the modern day world?
-transport
-electricity generation
-domestic uses (heating)
Describe a fossil fuel power station:
-fuel is burnt to heat water in a boiler
-water produces steam, turns turbine that turns an electricity generator
Pros and cons of fossil fuels:
-high output, can be stored
-non renewable, GG’s, high fuel cost, mining it is destructive
Describe biofuel and give examples:
any fuel taken from a (recently) living organism (eg animal waste, ethanol from fermented sugar cane, vegetable oils)
Pros and cons of biofuels:
-low cost + can be used to reduce food waste
-renewable + carbon neutral (the CO2 taken in by the organism balances the CO2 released)
-low power output + releases CO2
How does a nuclear power station generate energy?
Don’t describe the process of fission
-fission of U/Pu releases energy that heats a coolant fluid as it leaves the reactor core
-flows to a heat exchanger, heat is used to boil water, and the steam turns a turbine
Pros and cons of nuclear power:
-high power output with small fuel + no emissions
-high fuel cost, nuclear waste, expensive to (de)commission
Describe wind power:
wind turns blades, that turn an electricity generator
Pros and cons of wind power:
-can be built at sea
-no emissions/fuel costs, renewable
-unreliable, low power output + visual pollution
Describe wave power:
water motion used to turn turbine on a floating generator
Pros and cons of wave power:
-no emissions/fuel costs
-only suitable in coastal areas + disrupts other activities on coast
(same as tidal)
Describe hydroelectric power:
-water that runs downhill turns a turbine (eg dams on reservoirs)
-can be used as a pumped storage scheme
Describe a pumped storage scheme:
-can put excess energy to use, pumps water back up dam to reservoir
-can be used to meet higher energy demands
Pros and cons of hydroelectric power:
-no emissions/fuel costs
-reliable
-limited locations + environmental impact
Describe tidal power:
water trapped at high tides to turn turbines
Pros and cons of tidal power:
-no emissions/fuel costs
-only suitable in coastal areas + disrupts other activities on coast
(same as wave)
Describe the 2 types of solar energy:
-solar photovoltaic cells convert sunlight to electrical current
-solar heating panels aims at a solar power tower to heat water, OR heats water in panel by solar radiation, used to supply hot water/heat building
Pros and cons of solar energy:
-no emissions/fuel costs
-PV panels are expensive, inefficient/low power output + unreliable
Describe geothermal energy:
uses heat + radioactive decay (in rocks) from Earth’s crust to heat water that is circulated
Pros and cons of geothermal energy:
-water can be used directly for heating
-no emissions/fuel costs
-expensive to build + needs certain geological conditions
How is energy demand dealt with?
-base load (nuclear, coal/oil), constant + long startup
-variable load (renewables)
-gas fired power stations + pumped storage can meet small fluctuations in demand, near instant startup
Name 4 aspects that should be considered when evaluating a source of energy:
-reliability
-power output
-cost
-pollution/waste products (and their environmental impacts)
Why is it important that we transition to renewables?
-reduce dependency on fossil fuels
-reduce effect of GG emissions on global warming
-to provide back-up energy at times of high demand
Why is using gas-fired power stations better than coal-fired ones?
-burning coal releases particulates (causes global dimming) and more GGs (eg SO₂)
-coal mining is more destructive than gas mining
Why might solar panels not be able to meet all of the UK’s demand of energy?
-large area of land is needed to be covered with solar panels due to its low useful power output
-unreliable so at times it couldn’t supply the whole of the UK
A power station doesn’t always run at maximum capacity, why is this?
-conserves fuel reserves
-spare capacity to compensate for unreliable renewable resources
-to avoid making an unnecessary environmental impact with GG’s
