P3 Energy demands Flashcards Preview

1st science) Physics > P3 Energy demands > Flashcards

Flashcards in P3 Energy demands Deck (10):
1

What is a biofuel?

Any fuel taken from living or recently living organisms. Renewable as biological source either regrows or continually produced (sewage + rubbish) used at same rate as produced.

2

What is nuclear power?

Energy taken from atoms.

3

What is hydroelectric power generated by?

When rainwater collected in reservoir (or water in pumped storage scheme) flows downhill. Flowing water drives turbines turn electricity generators at bottom of hill.

4

What is wind power generated by?

Force of wind drives turbine's blades around.
Turns generator. Power generated increased as wind speed increases.

5

What is geothermal energy generated by?

Energy transferred from radioactive substances heat Earth's surrounding rock.
Energy transferred by heating towards Earth's surface.

6

What is solar energy generated by?

Solar panels which absorb sunlight.

7

What are the advantages of nuclear power?

No greenhouse gases (unlike fossil fuel).
much more energy transferred each kilogram of uranium (or plutonium) than from fossil fuels.

8

What are the disadvantages of nuclear power?

Used fuel rods contain radioactive waste, has to be stored safely for centuries.
Nuclear reactors safe in normal operation. Explosion in reactor could release radioactive material over wide area. Would affect the area + people living there for many years.

9

How is supply and demand a major energy issue?

Higher in winter than in summer.
Power stations can't start-up instantly. Start-up time depends on type of power station.
Renewable resources unreliable. Amount of electricity generated depends on conditions.
Use nuclear + coal-fired power stations to provide constant amount of electricity (base load demand).
Use gas-fired power stations + pumped-storage schemes meet daily variations in demands + extra demand in winter.
Use renewable energy when demand high + when condition for renewable energy resources when demand low to store energy in pumped-storage schemes.

10

What are the cost comparisons?

Overall cost of new energy facility involves capital costs to build it.
Running costs for fuel + maintenance + more capital costs to take it out of use at end of working lifetime.
Costs of new energy facilities usually passed on to consumers through increased fuel bills.

Energy-saving schemes such as low-energy light bulbs in home reduce need for more power stations.
Schemes like improved home insulation reduce demand for non-renewable energy resources.