FULL TOPIC 1: ENERGY

How do you reduce the amount of energy leaving to useless energy stores?

Lubrication and thermal insulation

What does lubrication do?

Reduce frictional forces

What does insulation do?

Reduce the rate of energy transfer by heating

What are some examples of thermal insulation?

Cavity walls

What is conduction?

The process where vibrating particles transfer energy to neighbouring particles

Where does conduction take place?

Solids

What is convection?

Where energetic particles move away from hotter to cooler regions

Where does convection take place?

Liquids and gases

What do radiators create?

Convection currents

What is a convection current?

The flow that transfers heat within a fluid

How do radiators create a convection current?

• energy is transferred from the radiator to the nearby air particles by conduction
• the air near the radiator becomes warmer and less dense.
• the warm air rises and is replaced by cooler air
• the warm air cools and sinks
• the cycle repeats

What is the conservation of energy principle?

Energy can be transferred usefully

What happens to energy when transferred between stores?

Not all energy is transferred usefully into the store that you want it to go to

What is dissipated energy?

Wasted energy

What is power?

Power is the rate of energy transferred

What is power measured in?

Watts (W)

What is specific heat capacity? SIMPLE

How hard it is to heat something up

What is internal energy?

The total energy stored by the particles making up a substance or system

What is specific heat capacity? EXACT DEFINITION

SHC is the amount of energy needed to raise the temperature of 1KG of a substance by 1°C

What is specific heat capacity? EXACT DEFINITION

SHC is the amount of energy needed to raise the temperature of 1KG of a substance by 1°C

What happens when energy is transferred?

The energy is stored in one object's energy stores

What different types of energy stores are there?

Thermal

How is energy transferred?

1) Mechanically - force doing work
2) Electrically - work done by moving charges
3) Heating/Radiation - light

What is a system?

A single object or group of objects that you're interested in.

What happens when a system changes?

Energy is transferred - it can be transferred into/away from the system

What is a closed system?

A system where neither matter nor energy can enter or leave

What is the net change in the total energy of a closed system?

Always zero

What is work done?

Energy transferred

When can work done be done?

When a current flows or by a force moving an object

What fuel do we depend on in modern day?

Currently we depend on fossil fuels

Why has the electricity use of the UK been decreasing in the 21st century?

We get better at making appliances more efficient and become more carfeul in energy use in out homes

What is the rate of electricity usage and population in the UK?

As the population grows people begin to use more and more electrical appliances

What do we burn fossil fuels for?

Electricity

Why do people want to use more renewable energy sources?

• Non-renewable energy sources damage the environments
• More increasingly aware that non-renewables will run out
• Pressure from other countries and the public

Why are energy providers reluctant to build new power plants?

Building new power plants costs money especially when fossil fuels are so cost effective

How are fossil fuels and nuclear energy reliable?

There's enough fossil and nuclear fuel to meet the current demand

How can power plants respond quickly to changes in demand?

They are extracted from the Earth at a fast enough rate that the power plants always have fuel in stock

Why are fossil fuels running out?

If no new resources are found

How expensive is nuclear energy?

The set up costs are quite high compared to other energy resources

Why are fossil fuels so popular?

They are incredibly cost effective

What do coal

gas

Why is a surplus of CO2 bad for the environment?

CO2 adds to the greenhouse effect

What does burning coal and oil release?

Sulphur dioxide

What does sulphur dioxide cause to the environment?

Acid rain - harmful to trees and soils and can have far-reaching effects in the ecosystem

How do we reduce acid rain?

Taking the sulphur out before the fuel is burned

Why do people not like coal-mining?

They make a mess of the landscape = the view can be spoilt by fossil fuel power plants

How do oil spillages cause environmental problems?

Affecting mammals and birds that live in and around the sea

How expensive is nuclear fuel?

Relatively cheap but the overall cost of nuclear power is high due to the cost of the power plant and final decommissioning

What is the risk of nuclear power?

Major catastrophe like the Fukushima disaster in Japan

What are bio-fuels made from?

Plants and waste

How do bio-fuels generate electricity?

Bio-fuels can be solid

What makes bio-fuel carbon neutral?

If you keep growing plants at the same rate that you're burning things

How reliable are bio-fuels?

Fairly reliable

How do we combat the immediate demands in bio-fuel?

Bio-fuels are continuously produced and stored for when they are needed

How expensive is bio-fuel?

Very expensive

What are some worries about bio-fuel?

Growing crops specifically for bio-fuels will mean there isn't enough space or water to meet the demands for crops that are grown for food

How does bio-fuel affect the environment?

Large areas of forest have been cleared to make room to grow bio-fuels = lots of species losing their natural habitats

What are tidal barrages?

Big dams built across river estuaries

How do tidal barrages work?

As the tide comes in it fills up the estuary. The water is then allowed out through turbines at a controlled speed

How are tides produced?

Tides are produced by the gravitational pulls of the moon and the sun

How are tides used to generate electricity?

A tidal barrage

What kind of pollution does tidal barrages produce?

No pollution

What are the problems with tidal barrages?

Preventing free access by boats

How reliable is wave power?

Tides are pretty reliable = they happen twice a day without fail and always near to the predicted height

What are the disadvantages of wave power?

The height of the tide is variable so lower tides will provide significantly less energy than the bigger 'spring' tides

How expensive is wave power?

Initial costs are moderately high

What is wave power?

Lots of little wave powered turbines

What kind of pollution does wave power produce?

No pollution

What are the main problems of wave power?

Disturbing the sea bed and the habitats of marine animals

How reliable is wave power?

Fairly unreliable

How expensive is wave power?

Initial costs are high

What does hydro-electric power require?

flooding of a valley by building a big dam

What kind of pollution is caused by hydro-electric power?

No pollution

What impact does hydro-electric power have on the environment?

Big impact due to the flooding of the valley

How does flooding of the valley impact the environment?

Rotting vegetation releases methane and CO2 and possible loss of habitat for some species

What is an advantage of hydro-electric power?

Provides immediate response to an increased demand for electricity

How reliable is hydro-electric power?

Reliable except in times of drought

How expensive is hydro-electric power?

Initial costs are high

What is geothermal power?

Energy in underground thermal energy stores

Where can geothermal power be found?

Volcanic areas or where hot rocks lie near the surface.

Why is geothermal power so great?

Free reliable energy that does very little damage to the environment

What is geothermal power used for?

Generate electricity or heat buildings directly

What are the disadvantages of geothermal power?

Aren't many suitable locations for power plants

How do solar cells generate electricity?

Generate electric currents directly from sunlight

What kinds of things are best powered by solar cells?

Batteries in calculators

Where are solar power often used in?

Remote places where there's not much choice and to power electric road signs and satellites

What kind of pollution do solar cells cause?

No pollution

How reliable is solar power?

In sunny countries

What is a disadvantage of solar cells?

You can't increase the power output when there is extra demand

Where are wind turbines located?

In exposed places like on moors or round coasts

What in the wind turbines produces the electricity?

Each turbine has a generator inside - the rotating blades turn the generator and produce electricity

Do wind turbines create pollution?

No pollution in practice but a little when they're manufactured

Why do people not like wind turbines?

Destroys the scenery

How many wind turbines are needed to replace one coal power station?

You need 1500 wind turbines to replace one coal-fired power station and 1500 of them cover lots of ground

What is a fault in the wind turbines situation?

The turbines stop when the wind stops or if the wind is too strong

How often do wind turbines produce electricity?

70-85% of the time

What are the costs of wind turbines?

Initial cost = quiet high
but there are no fuel costs and minimal running costs

Can you remove wind turbines?

Yes

What are energy resources used for?

Used to generate electricity