Frequently asked questions

Surely we need the stable base load that can be provided by nuclear power?

Nuclear power stations do break down and the inflexibility of nuclear power is an embarassment:

  • Like all sources power, nuclear power can fail (the load factor of nuclear power stations is normally about 70%). But when a nuclear power station fails, it is much more disruptive than when the wind dies down in a particular area:

    • If the wind level decreases in a given area it will normally do so gradually.

    • There are normally several hours warning that this will happen.

    • If one or two wind turbines fail within a wind farm this is much less disruptive than if a nuclear power station fails, when 1 GW or more is suddenly lost from the grid.

  • Nuclear power is very inflexible: its output cannot be increased or decreased easily to meet variations in demand. If there were many countries in Europe with as much nuclear power as France, there would be a large excess of power being produced at night. Luckily for France, there is enough residual demand at night in the rest of Europe to mop up their excess capacity.

  • It is true that wind power cannot be varied according to demand but other renewable sources can be. These include hydro power, geothermal power, and concentrating solar power (CSP) with heat storage and backup sources of heat.

  • By connecting up renewable sources across a wide area via an HVDC 'supergrid', peaks and troughs in supply and demand in different locations can be ironed out.

  • In general, variability in wind power is much less of a problem than is sometimes suggested: