3.1 Energy Demands Flashcards
What are the main sources of energy used today?
Fossil fuels (coal, oil, gas), nuclear power, biofuels, and renewable sources like solar, wind, and hydroelectricity.
What percentage of the world’s energy demand was met by fossil fuels in 2013?
84% (oil: 31%, coal: 31%, gas: 24%).
What is a biofuel?
A biofuel is any fuel taken from living or recently living organisms, such as methane from decaying waste, ethanol, or biodiesel from vegetable oils.
Why are biofuels considered carbon-neutral?
Because the carbon dioxide absorbed during plant growth balances the carbon dioxide released when the biofuel is
What fuel is used in a nuclear power station, and how does it generate energy?
Uranium or plutonium; energy is released by splitting the nuclei of these atoms, which generates heat.
What is one advantage of nuclear power over fossil fuels?
Nuclear power does not release greenhouse gases like carbon dioxide.
What is one disadvantage of nuclear power compared to fossil fuels?
It produces radioactive waste that needs to be stored for many years.
How much energy does burning 1 kilogram of fossil fuel release?
About 30 million joules (30 MJ).
How much more energy is released from 1 kilogram of uranium compared to fossil fuel?
Uranium releases about 1,000,000 times more energy than fossil fuel
What is the main greenhouse gas released by burning fossil fuels?
Carbon dioxide (CO2)
Name two types of power stations that release carbon dioxide.
Coal-fired and gas-fired power stations.
What is the primary function of the coolant in a nuclear reactor?
To transfer energy from the reactor core to a heat exchanger, where steam is produced to drive turbines.
What is one advantage of a gas-fired power station over a nuclear power station?
Gas-fired stations do not produce radioactive waste.
What is the estimated global energy usage per person per second?
Approximately 2,000 joules.
