CCGT load following?

DominicJ · Post by **DominicJ** » 04 Jul 2011, 17:20

I had always assumed that the UK's load following plant was mostly CCGT.

But one of the big drawbacks of gas turbine engines in vehicles is that they have appaling partial load efficiencies.

Can anyone correct me?

An Inspector Calls · Post by **An Inspector Calls** » 06 Jul 2011, 14:52

The CCGTs are not used for load following.

Load following (and response) when provided by thermal plant means the generation unit has to operate at part load - this always reduces efficiency. But in the gas turbine section of a CCGT, part loading also has the effect of decreasing the maintenance interval quite severely.

So in the UK load following has traditionally been done by coal, oil (except we now do hardly any oil-fired generation) and PS. The hydro plant we have is not used for load following mainly because the governors are all so ancient they can't respond!

The efficiency of coal plant also drops when part loaded. Very roughly, a coal fired plant running at 60 % load will have an efficiency of 30 %.

goslow · Post by **goslow** » 07 Jul 2011, 11:07

but, aren't they talking about new gas thermal stations to complement renewables?

DominicJ · Post by **DominicJ** » 07 Jul 2011, 11:44

Go Slow
That was what I thought, however, given what AIC said, presumably the new gas is for complete replacement of absent wind, and hydro/pumped storage will supplement present wind or gas?