3.5 - Energy 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)
Pros and cons of fossil fuels:
-high power output, can be stored
-non renewable, GG’s, high fuel cost
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
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 hydroelectric power (HEP):
water that runs downhill turns a turbine (eg dams on reservoirs)
Pros and cons of hydroelectric power:
-no emissions/fuel costs
-reliable
-limited locations + environmental impact
Describe how waves can be used as an energy source:
water motion used to turn turbine on a floating generator
Pros and cons of wave power:
-no emissions/fuel costs, renewable
-only suitable in coastal areas + disrupts other activities on coast
same as tidal
Describe tidal power:
water trapped at high tides to turn turbines
Pros and cons of tidal power:
-no emissions/fuel costs, renewable
-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 maintenance needed
-no emissions/fuel costs, renewable
-PV panels are expensive, low power output + unreliable
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 fuel 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
Describe nuclear power:
-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
Pros and cons of nuclear power:
-high power output with little fuel + no emissions
-high fuel cost, nuclear waste, expensive to (de)commission
Why is it important that we transition to renewables?
-reduce dependency on fossil fuels
-reduce GG emissions, slows global warming
-to provide back-up energy at times of heavy demand
Why do we need to supply more energy?
-^population/urbanisation/development + demand for energy
-^demand for food, more intensive farming (uses lots of machinery)
-^transport being used
-^wealth, more people buying expensive things (appliances, tech, cars)
What is an energy gap?
when a country cannot meet its energy demand using its own resources
How does having an energy gap relate to energy security? How can a country be energy secure?
-having a larger energy gap means needing to import energy, and thus the country is not energy secure
-to be energy secure, a country needs an uninterrupted but affordable supply of energy that is easily accessible
How do LEDCs usually produce energy? Why is this an issue?
-fuelwood
-deforestation/risk of fires
-loss of biodiversity from habitat destruction
-desertification + increased soil erosion
-child labour (used to find wood)
Fuelwood is just wood that is burnt for energy
