Using energy and materials

Using energy and materials responsibly is an important aspect of designing

Renewable energy

In 2018 around a third of the UK's electricity was generated by renewable energy sources. They are a non-finite resource as they harness the Earth’s natural resources. Examples include:

  • wind
  • solar
  • tidal
  • hydroelectric
  • biomass

Wind

Wind energy is harnessed through the use of wind turbines - normally tall towers with three propeller blades (vanes) that appear frequently around the UK.

A countryside landscape showing the different components of a wind turbine.

The blades turn with the wind, driving a generator, which produces the electricity. While there are many dotted around the countryside as single towers or in a small group, they are now more commonly grouped together off-shore in large quantities to form a wind farm.

Advantages of windDisadvantages of wind
Wind energy is constantly available and sustainableWhen there are periods of low wind, little or no energy is produced
There is no cost for wind and the running cost of a wind turbine is relatively lowThey cost a lot to build and put in place
Some people do not like the look of wind turbines or feel that they spoil the natural landscape

Solar

Solar panels are made from photovoltaic cells, which harness the Sun’s light energy and convert it into electricity. Solar power provides clean energy from a plentiful supply, but there is still considerable development work to be done to try to make solar panels more efficient. The placement of the solar panels is also very important to ensure they track the path of the Sun and harness the optimum amount of solar energy.

Advantages of solarDisadvantages of solar
Clean, renewable energy sourceSome people do not like the look of solar panels or feel that they spoil the appearance of a building
Reduces household energy billsCosts a lot to install
Does not produce much electricity when there is considerable cloud cover, during the winter months or at night

Tidal

The UK currently only generates a small amount of energy from tidal power, but it is estimated that the UK could potentially harness around a fifth of its electricity demand in this way. Tidal energy relies on the gravitational pull of the Moon, which causes the change in water levels known as tides.

The mechanical process of a tidal barrage and the flow of the water through a turbine from the incoming and subsequent outgoing tide.

A tidal barrage is built across the mouth of a river where it meets the ocean. The barrage is constructed so that the incoming tide passes through turbines to generate electricity. It also harnesses the reverse flow of the water when the tide goes out.

Advantages of tidalDisadvantages of tidal
Clean, renewable energy sourceConstruction of tidal barrages is expensive
Tidal power plants will last for a long timeEnvironmental impact of tidal barrages is unknown
Could produce a fifth of the UK’s needs as it is an island surrounded by the sea

Hydroelectricity

Hydroelectric schemes use a dam to block a valley or a major river, often creating a reservoir behind the dam.

The hydroelectric process of how a flow of water changes into electricity. Water flows from a reservoir through a turbine. Electricity flows from the generator through cables.

Once the water has built up behind the dam, it is directed and released by valves through turbines. The turbines turn generators to produce electricity.

Advantages of hydroelectricDisadvantages of hydroelectric
Clean, renewable energy sourceConstruction of dams is expensive
Valves can be opened very quickly to produce energy at peak times Objections from people in the surrounding environment
No pollution when running itAffects the wildlife by flooding the valley

Biomass

Biomass energy involves growing plants or using animal materials, not for consumption but so that they can be burned to produce heat. Plants such as rapeseed or willow are specifically grown as biomass crops so that they can be burned in a furnace.

Advantages of biomassDisadvantages of biomass
Clean, renewable energy sourceCreates atmospheric pollution when burned
Carbon dioxide is released in the process and can be reused by plantsLand used for energy crops may be needed for other purposes such as agriculture
Replacement plants can be grown very quickly to ensure a good supply