The problem with power generation in the UK is that we have nuclear power stations coming to the end of their working life and they account for up to 20% (check the figure!) of electricity generation. It seems that EU regulations mean that we will have to shut down around half of our coal fired power atations as they are considered to be too polluting.(Another 20% of the total) This means that the UK will lose 40% of its power generation over the next 10 years. It is not possible to design, get planning permission and build a power station in a short time. The problem will be that the UK will have to buy electricity generation from abroad at whatever price they charge. There will be a shortage of power generation so those with spare capacity will be in a sellers market (they will be able to charge what they want). Renewable sources of generation contribute a very small percentage and will not contribute much more in the time scale involved. They are also far less reliable than fossil fuel and nuclear power stations. These are some of the issues that a Prime Minister needs to consider. He needs to avoid a situation where electricity is only available for a few hours each day.

Denis has correctly identified the problem with closing power stations. However, he is incorrect regarding the potential of renewable energy.

It is no longer true that fossil fuel power stations are more reliable than renewables. The National Grid currently has 40% more conventional power stations running than needed at any given moment, because at any time an individual power station can go off line at 20 milliseconds notice, with no warning. By comparison, weather modelling software can now accurately predict the wind patterns locally and nationally for up to an hour ahead. This allows wind farms to switch on and off as needed giving reliable, predicatble output, which can be supplimented by other sources if needed, as there is sufficient warning. This is MORE reliable than fossil fuel plants. Additionally there are more and more projects showing how renewable energy can be stored, such as under sea compressed airbags to store spare energy from turbines, or molten salt heat batteries for storing solar power. In spain there are solar power stations running 24 hours a day. Now that's reliable.

As to the ability to generate volumes of energy, only last week Spain generated 40% of it's national electricity needs on one particularly windy day, and that's using current technology. Renewable energy is way faster to build than fossil fuel power stations - particularly the under sea tidal turbines that are going into service now.

What we need to do to cope with the problem Denis identifies is
1) Take renewable energy seriously and get objectors out of the way
2) Build it, in the UK - wind, tidal, wave - the lot
3) Get the new proposed cross EU electricity grid up and running, so that spare capacity from one EU country can be shared with another.
4) Get serious about energy saving through
efficiency, redesigned transport systems, fixing up the UK's out of date houses so they use less energy.

Do all of these things and we can both keep the lights on and still get rid of polluting fossil fuel power.