energy resources - text chapter 3 Flashcards
What is wave energy?
The floating generator moves up and down as the waves pass. The motion turns the generator and electricity is generated and passed along a cable to the shoreline.
What is tidal energy?
Water from each high tide is trapped and let out through turbines.
Negatives of geothermal energy?
- volcanically active areas only
- Expensive to build
What are cons of wind energy?
- takes up alot of room
- expensive
- unreliable
Positives of geothermal energy?
- reliable
- renewable
- no carbon dioxide is released
What is geothermal energy?
geothermal energy is thermal energy generated and stored in the Earth. People can capture geothermal energy through: Geothermal power plants, which use heat from deep inside the Earth to generate steam to make electricity.
What is hydroelectric energy?
Water is stored on high ground then allowed to turn down through turbines, which then turn generators
What are the pros of wave energy?
-free fuel
Positives of solar cells?
-free fuel
Positives of nuclear energy?
- carbon dioxide not released
- very high energy density
- reliable•
- nuclear energy power stations can work all the time
What are solar panels?
Water is heated by the sun which can then be used in bathrooms
What is nuclear energy?
Substances like uranium and plutonium are used in nuclear reactions. The energy from these reactions is used to heat water.The water then turns into steam and rises turning a generator which turns a turbine to generate electricity.
Negatives of hydroelectric?
- Expensive to build
- valley floods → habitat damage
Positive of hydroelectric?
- renewable
- No carbon dioxide released
- reliable
Negative of solar cells?
-Very inefficient so can only be used for small amounts of electricity are needed.
Name the two types of solar energy?
cells and panels
Negatives of nuclear energy?
-radioactive waste
-long start up time
-waste products need to be stored for many years
- nuclear power stations have
high commissioning and
decommissioning costs
What is wind energy?
Wind passes over the turbine blades and turn it which turns a generator. The faster the wind speeds, the more power produced.
Negatives of biofuel?
- low energy density fuel
- lots of land use
- does release carbon dioxide
What are cons of wave energy?
- lots of cabling needed which can spoil the coastline (visual pollution)
- Tidal flow patterns may be affected which could affect marine habitats
What are the cons of tidal energy?
- can spoil the landscape
- damage aquatic landscapes
What is biofuel?
A fuel taken from a living or recently living organisms eg.animal waste, woodchip. It is burnt and used to turn water into steam which then turns a turbine.
What is solar cells?
Sunlight is absorbed by the cell and 10% is turned into electricity.
What are pros of tidal energy?
- free fuel
- reliable
What are solar power towers?
In hot countries the sun is reflected onto a water tank which is then turned into steam which passed through turbine.
Positives of biofuel?
- renewable
- carbon neutral
- reliable
What are pros of wind energy?
-free fuel
What is ment by renewable energy source?
energy source replenished by natural processes
at same rate as it is used
e.g., ethanol, when sugar cane grows
Compare a tidal power station and a hydroelectric power station. Give 2 similarities and 2 differences
similarities:
both rely on water flow
both transfer GPE stored in water to electrical energy.
differences:
tidal in estuaries but hydroelectric in hilly areas
tidal use sea water whereas hydroelectric use rain water
tidal produce more power than hydroelectric.
name the renewable energy resource that transfers the kinetic energy of moving air to energy
wind
name the renewable energy resource that transfers the gravitational potential energy of water running downhill into energy transferred by an electric current
hydroelectricity
name the renewable energy resource that transfers the kinetic energy of water moving up and down to energy transferred by an electric current
waves
Is wood
1 renewable or non renewable
2fossil fuel or non-fossil fuel
non-renewable
non-fossil fuel
why is the demand for electricity lower than in summer than in winter in the UK
warmer weather so less heating used
lighter days so less lighting used
people tend to spend more time outside
Discuss whether wind turbines or solar panels could be used to meet a sudden increase in demand for energy?
when conditions are suitable, wind and solar power can be used when demand is high
but conditions may not be suitable (i.e., it may not be windy or sunny)
when conditions are suitable and demand is low, wind and solar energy resources can be used to store energy in pumped storage schemes (i.e., pump water into uphill reservoirs in hydroelectric power stations)
when demand is high, the pumped storage schemes can then release more energy for use
The lagoon tidal barrage system is claimed to be able to generate electricity for 14 hours a day. Give 2 reasons why its necessary to connect houses to the National Grid rather than to the lagoon tidal barrage system alone.
Apart from cost why would people object to this
- the system cannot generate electricity for 24 hours a day
-the system may need to shut down for maintenance or
breakdown
-damage to the environment,
harm fish, etc.
Evaluate the benefits of growing and using ethanol made from sugar cane grown in Brazil. (environmental and economic gains)
plants, such as sugar cane, for biofuels use up carbon dioxide
using sugar cane ethanol reduces the amount of fossil
fuels burnt
burning fossil fuels causes environmental problems such as global warming and acid rain
Brazil benefits economically from export of sugar cane
ethanol
provides employment for farmers in Brazil
