Operational Factors affecting the choice of Energy Resource

Energy sources are not always available for generating electricity:

The amount of electricity produced by wind generators depends on the strength of the wind which varies considerably.

The amount of electricity produced by tidal barrages depends on the state of the tide, which varies during each day, and the height of the tide, which varies both on a monthly and yearly cycle.

The amount of electricity produced by solar cells depends on the intensity of light that falls on them.

Each of these energy sources can generate electricity only at certain times; they are all to some extent unreliable.

Hydroelectric schemes are generally very reliable. They can also be started up very quickly to meet sudden increases in the demand for electricity. They can also be operated in reverse using surplus electricity from other power stations to pump water from a lower reservoir to a higher one. This means that most of the energy from the surplus electricity is stored rather than being wasted.

Power stations which use fuels can produce electricity at any time (of the day or of the year); they are reliable energy sources. The time it takes to start them up varies considerably:

nuclear	longest time
coal	/\ || \/
oil
natural gas	shortest time

Currently in this country, the price paid for electricity varies, based on the power station's ability to respond to increases in demand. This means that gets the lowest price per unit of electricity. This led to BNFL (British Nuclear Fuel Ltd) having financial difficulties, with an on going expensive legacy to look after the nuclear waste that has been produced. Profit seeking companies are most likely to build power stations, leaving the country in a poor state of affairs when it runs out.

The cost of electricity