Thermal generation is returning to market relevance in a different form. It is no longer only a baseload story. It is increasingly a flexibility-margin story. Week 25 made that shift visible, with SEE thermal output rising 19.4% to 5.31 TWh, while gas-fired generation surged 32.3%.
This happened even as gas prices fell. That means the system was not simply responding to fuel economics; it was responding to the need for controllable output. Thermal plants filled the gap left by higher demand, lower hydro and weaker wind. In a market with rising solar penetration, that gap is concentrated in the ramp and evening hours.
A thermal flexibility margin monitor would track available gas, coal and lignite dispatch against residual load. The purpose would not be to celebrate thermal dependence, but to measure how much flexible capacity the system still needs before storage, demand response and grid reinforcements are large enough to take over.
Italy would be the core reference market. Thermal generation there jumped 66.7%, with gas-fired production rising by more than 61%. Hungary and Croatia also increased gas-fired generation, while Greece used gas to compensate for the complete absence of lignite generation.
Serbia requires a separate lens because coal and hydro remain central to system balance. When Serbian coal output weakens, the market can still be supported by hydro recovery or imports, but price exposure rises quickly when neighbouring markets are tight.
The monitor would help industrial buyers understand scarcity risk. It would help traders anticipate price spikes. It would help policymakers see whether the energy transition is adding enough firm capacity to support renewable growth.
Thermal flexibility is becoming a scarcity-hour product. Its value will be highest when the market is short of ramping, not when annual demand is stable.
