As renewables surge and climate rules become stricter, are gas-fired power plants destined to become obsolete? According to Siemens Energy’s latest whitepaper Futureproofing Gas Power Plants: Modifications and Upgrades for the Energy Transition, a future for gas remains as tomorrow’s flexible enabler of a low-carbon grid.
Reshaping the future of gas power
GlobalData forecasts that solar PV will supply 20% of the global power mix by 2035, with offshore wind expanding at a 17% CAGR between 2025 and 2035. Furthermore, costs have fallen so dramatically that by 2023, 96% of new utility-scale solar and wind capacity could generate electricity more cheaply than new gas- or coal-fired plants.
At the same time, the International Energy Agency (IEA) expects nuclear generation to hit record highs by 2025, with more than 70GW of new capacity under construction, the most in three decades. In the IEA’s net-zero scenario (which describes a pathway for the global energy sector to achieve net zero CO2 emissions by 2050), the agency states that global nuclear generation capacity will need to more than double, rising from around 417 gigawatts today to approximately 916 gigawatts. While the net-zero scenario sees renewables making up nearly 90% of electricity supply by 2050, nuclear power will provide a significant and consistent baseload power source. This means heightened competition for baseload generation, even as carbon-pricing mechanisms add further cost pressures. EU Emission Allowances (EUAs), for example, increased past €100 per tonne CO₂ in 2023 before settling near €70 in mid-2025.
Alongside this changing landscape, electricity demand continues to climb. Global consumption is rising approximately 3 – 4% annually through 2027 and could be 50% higher by 2040, driven by electrification, data centres, and electric vehicles. That demand ensures gas still has a place as a flexible, fast-ramping complement to variable renewables that rely on the weather. Recognising the importance of this flexibility, capacity markets, such as the UK’s £20 billion scheme underwriting roughly 90 gas plants, now pay generators to stay on standby to ensure that electricity is always available, especially during periods of peak demand or grid stress.
However, for plant operators, this reshaping of the energy landscape requires making changes if they are to continue making profit. Analysts project that by mid-century, as energy-only prices decline, up to half of a gas plant’s income will need to come from capacity payments or grid-stability services rather than energy sales.
Traditional designs built for steady baseload operation are ill-suited to frequent start-stops, as thermal stress, accelerated wear, and efficiency losses at partial load reduce both performance and profitability. Without upgrades, many facilities will simply be too slow or too expensive to compete in merit-order dispatch.
In its new whitepaper, Siemens Energy demonstrates through detailed case studies how targeted modernisation can enable ageing assets to deliver the flexibility, efficiency and resilience that modern grids demand.
Case one: Flex-Power upgrades and agility
Siemens Energy implemented its Flex-Power Services™ portfolio at the Trianel Hamm-Uentrop combined-cycle plant in Germany. The package encompassed advanced burner controls, bypass improvements and “Hot/Warm Start on the Fly” capabilities that reduce warm-start times by 60% and shutdown times by 67%.
This plant, once tied to baseload cycles, can now switch on each morning to meet peak demand, then shut down by midday when solar generation floods the market, without excessive wear. This agility translates directly into improved profitability, positioning the plant to capture the most lucrative price windows.
Case two: Turbocharging efficiency
Siemens Energy’s Advanced Turbine Efficiency Package (ATEP) retrofits next-generation blade and vane technology into existing turbines to boost power output and heat-rate efficiency. Singapore’s PacificLight Power was the first in Asia to adopt this technology at its 800 MW facility, which has seen a 30MW (4%) output increase and a 3.5 percentage-point efficiency improvement. This has reduced CO₂ emissions by more than 60,000 tonnes per year, equivalent to removing 9,000 cars from the road.
Another example is the High Desert Power Plant in California, which applied the same upgrade to three SGT6-5000F units, adding more than 60MW on hot days while cutting NOx by 64% and CO by 50%. With fuel savings and extended equipment life, many operators recoup their upgrade investment within a few years.
Case three: Repurposing for grid stability
Siemens Energy’s Rotating Grid Stabilizer (RGS) converts existing turbine-generator units into synchronous condensers that provide inertia, reactive power and short-circuit strength.
At Uniper’s Killingholme plant in Lincolnshire, two retired steam-turbine generators were repurposed as carbon-free grid stabilisers. Fitted with flywheels, they now supply critical inertia to the UK grid without burning fuel. In another example, RATCH-Australia’s Townsville Power Station in Queensland adopted a Hybrid RGS system, switching seamlessly between power generation and grid-stabilisation modes. The unit can deliver up to 1,000MW seconds of inertia or return to power production within 20 minutes.
The pathway forward
Gas power may no longer dominate generation, but its ability to provide reliable, dispatchable power makes it indispensable during the energy transition. Learn more about how gas power plants can adapt to the energy transition by downloading Siemens Energy’s Futureproofing Gas Power Plants whitepaper for in-depth analysis, data, and real-world examples of successful modernisation.
