7.2 Energy sources — uses and managementIB Environmental Systems and Societies SL: Flashcards
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What is a renewable energy source?
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- What is a renewable energy source?
- One replaced naturally at least as fast as it is used, e.g. wind, solar, tidal, hydro, geothermal.
- What is a non-renewable energy source?
- A finite stock used far faster than it forms, e.g. coal, oil and natural gas.
- Give two reasons global energy consumption is rising.
- Population growth and rising demand per person.
- About what share of global energy still comes from fossil fuels?
- About four-fifths.
- Name four criteria for judging the sustainability of an energy source.
- Renewable or finite; emissions and pollutants; land use and habitat impact; reliability.
- Give four factors that affect a country's energy choices.
- Resource availability, cost and wealth, government policy, technology, public attitudes, existing infrastructure.
- Why did Morocco choose solar energy at Ouarzazate?
- It has few fossil fuels but high sunshine and desert land; solar reduces its dependence on imports.
- What does intermittent mean for energy production?
- Output varies with time and weather, so supply may not match demand.
- Why do intermittent renewables create a need for storage?
- Surplus energy must be saved for periods of low output so supply meets demand.
- Name three energy storage systems.
- Pumped hydroelectric storage, batteries, molten salt (heat) storage; also hydrogen.
- How does pumped hydroelectric storage work?
- Surplus electricity pumps water uphill; the water is released through turbines when electricity is needed.
- Distinguish energy conservation from energy efficiency.
- Conservation is using less; efficiency is getting the same service from less energy.
- How can conservation and efficiency reduce import dependence?
- Lower demand means less fuel or electricity has to be imported, reducing exposure to price and supply.
- Why is biomass only near carbon neutral?
- Carbon released on burning is reabsorbed only if the fuel is replanted or is a waste product.
Written by the Exaim team, led by Shaun Daswani (Head of Upper Secondary, Improve ME Institute; MSc Financial Mathematics, Imperial College London; BSc, UCL) and Jason Daswani (operational lead, Improve ME Institute; LSE).