CCGT

In the European power markets briefing series, CCGT sits at the nexus of the gas-storage and carbon stories. The clean spark spread, the margin after fuel and carbon costs, is the key signal for whether German CCGTs run or stand aside. In the June 2026 period this spread swung through an extreme range. On 15 June the spread was approximately -EUR 44/MWh with TTF at EUR 43.8, EUA near EUR 78/tCO2 and German day-ahead near EUR 74, pushing German CCGTs off-merit and eliminating their gas-for-power bid from the prompt market. Two sessions later, on 17 June, German day-ahead power jumped 59% to EUR 117.63 while TTF fell to EUR 41.12 and EUA rose to EUR 79.78, producing a +EUR 15/MWh clean spark spread and restoring positive CCGT running margin for the first time in weeks. At +EUR 15 spark, gas-for-power demand immediately competes with EBN, CRE and ARERA mandate-injection for prompt TTF molecules, putting an additional demand signal into the prompt market at exactly the moment TTF had broken below EUR 43. The EUR 59/MWh swing across just two sessions illustrates the three-variable feedback loop that defines CCGT economics: when TTF falls and German day-ahead rises simultaneously, running margin can shift from deeply negative to materially positive within 48 hours. Germany's StromVKG capacity bill, which cleared its Bundestag first reading on 11 June with a September 2026 first auction, is designed to fund 10-12 GW of hydrogen-ready CCGT-class capacity, with the Greens demanding a conversion-pathway condition on any capacity contract.

The 22-24 June heat wave drove the spread to its 2026 high of approximately +EUR 110/MWh: German day-ahead cleared at EUR 207.84/MWh as heat load surged while EUA broke above EUR 80/tCO2, raising CCGT marginal fuel-plus-carbon cost to approximately EUR 98/MWh (at TTF ~EUR 40.75 and 0.52 tCO2/MWh efficiency). French reactor curtailments under the 28C river-discharge limit on 22-23 June removed cross-border nuclear supply and concentrated the heat demand signal on the German gas stack. Heat-burn gas demand competed directly with EBN, CRE and ARERA mandate-injection for prompt TTF molecules, compressing storage injection at a critical refill moment and briefly lifting the gas-for-power claim on available molecules above that of storage operators.

The 9-13 July window squeezed the clean spark spread from the other direction: both cost inputs firmed at once. TTF round-tripped back above EUR 50/MWh on Gulf shipping-risk sentiment, and EUA broke EUR 81/tonne on MSR-driven tightening, lifting CCGT marginal cost on both fuel and carbon legs simultaneously just as CCGTs were being asked to pick up load curtailed from French nuclear (Chooz, Golfech, Bugey off cooling-water limits). That combination, higher input costs arriving exactly when running hours needed to rise, is the tightest version of the spark-spread squeeze CCGT operators have faced this summer.

A Combined-Cycle Gas Turbine (CCGT) plant generates electricity by running a gas turbine on natural gas combustion, then capturing the exhaust heat in a heat-recovery steam generator (HRSG) to drive a second steam turbine. This two-stage recovery lifts efficiency to 55-62%, significantly higher than the 35-40% of a simple-cycle open-frame gas turbine, and reduces fuel consumption and carbon emissions per MWh of output. CCGTs typically reach full output within 30-60 minutes, faster than coal or nuclear but slower than open-cycle gas turbines used for peak shaving. Their combination of efficiency, dispatchability, and moderate capital cost made them the dominant new-build thermal technology in European power systems through the 2000s and 2010s.

In electricity merit-order terms, CCGTs typically sit mid-stack: they operate more cheaply than older open-cycle gas plant or oil-fired capacity, but are undercut by nuclear, hydro, and renewables on marginal cost. On high-demand days with low wind and high industrial load, the last CCGT running is often the market price-setter, the 'marginal unit' whose short-run marginal cost clears the Day-ahead market. That cost has two principal components: the gas fuel input (indexed to TTF or NBP) and the carbon cost of emissions (priced via EU Allowances under the EU ETS at approximately 0.52 tonnes CO2/MWh for a modern CCGT). The clean spark spread, the margin after fuel and carbon, is the key profitability signal for CCGT operators.

Energy transition planning in Europe gives CCGTs a dual role: as the dispatchable backbone supporting intermittent renewables in the near term, and as a potential hydrogen-burning asset in the longer term once green hydrogen costs fall sufficiently. Germany's government approved a 12 GW hydrogen-ready gas capacity tender in 2024, explicitly specifying plant designs capable of co-firing or switching to hydrogen. The economics of that transition depend critically on whether hydrogen can undercut CCGT marginal cost at scale.