Coal emissions

The hotter you can make steam, the more efficient your power station will run. It's simple thermodynamics - the hotter the steam gets, the more energy it has which can be transferred to your turbines for the same amount of coal burnt.

Unfortunately it's somewhat difficult to find a pipe (to run your steam through) which can accept being put in the flame of the boiler - at around 1400DegC (possibly up to 1700DegC / beyond).

Generally the more nickel you put into your steel (and nickel is expensive) the better things get (although I should say that I'm not a metallurgist).

Comtes 700 is a research project designed to create a power station that can run with a steam cycle at 700DegC - which is plenty hot!
It's operating efficiency would be 50, 55% I believe - approximately equivalent to a combined cycle gas turbine plant.
I believe its gCO2 / KWh emissions will be in the region of 600g / KWh - obviously these can be brought down by adding biomass, but I don't believe that they will be able to be brought below the 500g / KWh mark, although 550g / KWh is possibly feasible.

Adding carbon capture to the plant will obviously decrease it's efficiency, but probably only to around 40%.
Let's remember that adding carbon capture to a combined cycle gas turbine will do something similar to its efficiency.

Price rises

Implementing low carbon electrical systems costs money - as does the need to fix the looming energy gap (as power stations reach the end of their lives and need to be decomissioned with new ones built to replace them).

Eon's biomass Bristol biomass press release was surprisingly candid about the investment program that they are undergoing, which struck me as odd at the time.

I now realise that they were warning the general population about forthcoming price rises - which were announced yesterday.

Two things stike me:

The price of gas is rising by more than the price of electricity. This suggests that we would do better to minimise our dependence upon gas within electrical generation (actually this is probably too simplistic since the price they can charge is set by the market, and is only marginally driven by costs - this can be seen by Scottish & Southern putting up their prices immediately after Eon announced their price rises).

We really now have a choice between cheap fuel and renewable energy - we can't have cheap renewable energy. I would hope that we would keep piling on down the renewable energy path as hard as we can - after all, if a rich nation isn't going to do it, how can we expect a poor nation to?

There really is only one way out of this problem - and a recent Friends of the Earth press release has hit the nail right on the head.