Renewable Energy Sources (10) Flashcards
Wind power involves putting lots of wind turbines up in _____________ places
Exposed
Wind turbines convert the ___________ energy of moving air into ______________ energy
Kinetic
Electrical
3 advantages of wind turbines
Cheap to run
Renewable
No pollution
3 disadvantages of wind turbines
Expensive to set up
Ugly
Noisy
No wind = No output
3 advantages of geothermal energy
Free
Renewable
No environmental problems
2 disadvantages of geothermal energy
Only possible in certain places where hot rocks lie quite close to the surface
Drilling down several km is expensive
How does geothermal energy work
Water is pumped in pipes down to hot rocks and forced back up due to pressure. This turns a turbine which drives a generator
Energy transfers in geothermal energy
Heat to kinetic to electrical
How does solar energy work
Solar cells (photocells) transform light energy from the Sun directly into electrical energy.
3 advantages of solar energy
Renewable
Running costs are minute
No pollution
2 disadvantages of solar energy
Not practical on a national gird
Too expensive to set up
Can be a problem if there isn’t a lot sun
One way of harvesting wave power is with lots of small wave converters located around the ________
Coast
Energy transfers in wave power
Kinetic to electrical
3 advantages of wave power
Renewable
No pollution
Minimal running costs
No fuel costs
3 disadvantages of wave power
Fairly unreliable (waves tend to die out when the wind drops)
Initial costs are high
Unlikely to provide energy on a large scale - only really useful on small islands
Tidal barrages are big _______ built across river estuaries, with ___________ in them. As the tide comes in it fills up the estuary to a height of several _________. This water can be allowed out through ____________ at a controlled speed. It also drives the ____________ on the way
Dams Turbines Meters Turbines Turbines
Energy transfers in tidal barrages
Kinetic energy to electrical energy
3 advantages of tidal barrages
Renewable
No pollution
No fuel costs
Minimal running costs
3 disadvantages of tidal barrages
Prevents boats from crossing Spoils the view Alters the habitat of wildlife Height of the tide is variable so lower tides provide less energy than the higher ones Initial costs are moderately high
Hydroelectric power often requires the flooding of a ____________ by building a big _______. Rainwater is caught and allowed out through ___________, converting the GPE of the water to KE as it _________, which is then converted to electrical energy by the ______________
Valley Dam Turbines Falls Generator
Energy transfers by hydroelectric power
GPE to KE to electrical
3 advantages of hydroelectric power
Renewable No pollution Reliable unless there's a drought Immediate response to increased demand No fuel and low running costs
2 disadvantages of hydroelectric power
Big impact on the environment due to flooding the valley
Loss of habitat for some species
Initial costs are high
Resevoirs can be ugly when dried up
Most large power stations have huge ___________ which have to be kept running all night even though demand is very low. This means that there is a surplus of ______________ at night - and it’s surprisingly difficult to find a way of storing this spare energy for later use. One of the best solutions is __________ ___________
Boilers
Electricity
Pumped storage
In pumped storage, ‘spare’ night-time electricity is used to pump water up to a __________ reservoir. This can be released quickly during periods of peak __________.
Higher
Demand
Pumped storage uses the same idea as _______________ power however it isn’t a way of generating power - but simply a way of __________ energy which has already been generated
Hydroelectric
Storing
