UK gas plant remains largest source of power

OREANDA-NEWS. November 06, 2015. Combined-cycle gas turbines (CCGTs) comfortably remained the UK's largest source of power generation in October, but coal-fired output hit a six-month high and climbed above nuclear in the generation mix following the return of units from summer maintenance.

CCGT plant made up 34pc of generation in October, producing around 15.7TWh, data from transmission system operator National Grid show. This was down slightly from the 16.1TWh generated in September, but well above the 13.9TWh monthly average for CCGTs this year.

Plentiful gas, a hike in the UK-only carbon price floor earlier this year and another mild start to the winter have kept spark spreads for most of the UK's gas plant above dark spreads for coal plants, and this is set to continue into the first quarter of next year. Last year, generation economics had swung back in favour of coal plant by October, after CCGTs had been more profitable in the summer months.

At yesterday's closing prices for the first quarter of 2016, a 55pc-efficient gas plant held around a ?0.60/MWh advantage over a 38pc-efficient coal plant.

Coal-fired generation rose in October, owing to the return of several units from annual summer maintenance, and as prompt European coal swaps dropped to their lowest in several years. Coal-fired units planned for closure at the end of this winter — the 2.3GW Longannet, 1.9GW Eggborough facilities and the final 490MW unit at Ferrybridge — may also operate regardless of generation economics this winter if they have coal stocks to burn.

Coal-fired output reached 12.7TWh in October, accounting for 27.5pc of generation, up from 8.5TWh in September. This was the highest monthly amount generated by coal since April's 14.2TWh. But output was still down compared with last year, when coal generated 16.4TWh in October and accounted for 38.3pc of generation.

The increase took coal back above nuclear to second in the generation mix in October, with nuclear plant generating 11.6TWh — around a quarter of overall output. Nuclear was the UK's second-largest source of generation in May-September.

Nuclear availability has been higher this year compared with 2014, when four units, equalling more than 2GW of capacity, were shut down in August after a boiler spine defect was discovered in the units' design. Total nuclear generation in October last year amounted to just 7.7TWh, or 16.5pc of overall generation.

The lower output from coal and CCGT plant this year is partly down to a rise in renewable generation, following growth in wind and solar capacity over the past year. Wind output metered by the grid between January and October totalled 35.4TWh, up from around 33TWh a year earlier.