Renewable energy resources
3 marks · EasyHydroelectric power stations use falling water to generate electricity.
State the energy store for the water at the top of the reservoir.
Name the energy transfer that occurs as the water falls.
Explain why hydroelectric power is classed as renewable.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) gravitational potential energy
(b) gravitational potential energy is transferred to kinetic energy
(c) The water cycle replenishes water so the energy can be used again.
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · States gravitational potential energy (not just 'potential energy').
B2 (b) · 1 mark · States energy transfer from gravitational potential to kinetic energy.
B3 (c) · 1 mark · Explains hydroelectric power is renewable as water is naturally replenished by the water cycle.
Worked solution
a) The energy store is gravitational potential energy. b) As the water falls, gravitational potential energy is transferred to kinetic energy. c) Hydroelectric power is renewable because the Sun drives the water cycle, so water is naturally replaced.