Here's a quote from UK energy minister in the press release:

Malcolm Wicks, Energy Minister, said: "This is a welcome move by Centrica which is investing to secure the future energy needs of UK consumers. Langage will contribute towards the UK's security of supply as new and more efficient power stations are needed in the coming years to replace existing plant."

Elsewhere in the press release is the commissioning date for new power station, 2008/09.  Here are a few of my assumptions: Norwegian gas from Ormen Lange will come online during 2007, will deliver 20 bcm pa i.e. some 20% of current gas demand and N Sea gas is declining at 8%pa from current output of 90 bcm pa.  On this basis Ormen Lange will only 'fill the gap' between 2007 and 2010 by which time UK supply position will be back to what is was immediately before Ormen Lange startup, hence current big LNG program.

In effect only LNG can supply the incremental gas required by this new power station....and LNG is anything but cheap.  Furthermore I can't share the minister's confidence regarding 'security of supply' as continual supply of LNG depends on reliability of supplies from such places as Qatar (where they have a current moratorium on new LNG contracts due to questions regarding the North field). If / when new LNG contracts are let by Qatar UK will be only one of a sizeable (and growing) number of nations who will be competing for LNG supplies and the tankers to transport same.

In summary the new plant is quick and relatively cheap to construct and is cleaner than coal plants, for example. Whether the gas supply to fuel it will be dependable and cheap is another matter entirely.

The map is very interesting and makes you realise what a heroic expansion in renewable energy will be needed to replace even a small shortfall in fossil fuel generation
Coal fired Drax, our biggest station is rated at 4GW. At 68% load factor it produces 24TWhr of electricity consuming 10M tonnes of coal and producing about 30M tonnes of CO2.

To replace this one power station with photovoltaic generation at 10% load factor would require about 140M of Sanyo's best 200W  panels, about 7 panels for every house in the county.

250kW inland wind turbines at 30% load factor would require over 45,000 such turbines.

Large offshore wind turbines at 3MW and operating at 40% load factor would require 2,280 such turbines.

One curiosity on the chart. It colour codes the fuel for each power station and lists coal, gas, oil, hydro, nuclear and wind and also lists steam as a fuel. It shows one of the latter in Brighton but I don't think there is a power station in Brighton. The nearest I know of is at Shoreham
where there is a new combined cycle gas fired system  which replaced the old coal fired unit.

Anyone any idea what a steam powered generator could mean in this context?

[blockquote]Large offshore wind turbines at 3MW and operating at 40% load factor would require 2,280 such turbines.[/blockquote]

Now you're talking. I imagine the overall size of offshore turbines will continue to increase, at least for afew more years , so 6MW per unit in 10 years time? is that feasible?

so then we're talking 1000+ units to replace Drax. PLenty of space off the UK for those sorts of numbers. Add in small domestic roof mounted windmills and we're quite quickly into serious gigawattage.