How decentralized gas power plants are making energy supply more stable

The energy transition faces a double challenge worldwide: How can the power supply remain stable when renewables hardly feed into the grid for days on end and demand is rising at the same time? Recent examples such as the large-scale power outage in Berlin, the current blackout in the US, and record electricity prices during prolonged periods of low wind and solar power in Europe show that extreme weather and structural weaknesses can push even modern power grids to their limits. Particularly critical are periods with little wind and sun—so-called dark doldrums—during which feed-in drops massively.

Oliver Hoch, Expert Energy Policy and Regulatory Affairs, and Michael Stipa, Senior Vice President Strategy, Business and Product Development Stationary Energy Generation in Rolls-Royce's Power Systems division, explain why modular gas engine power plants make the grid more resilient thanks to their flexibility and decentralization, thereby enabling a secure and sustainable energy supply.

The German government's power plant strategy

The German government has set a clear course with its power plant strategy: gas-fired power plants with a capacity of up to twelve gigawatts are to be put out to tender this year in order to guarantee security of supply. These are then to be used when solar and wind power do not provide enough electricity. 

Oliver Hoch: "A resilient and cost-efficient power supply is the backbone of our social stability. If critical infrastructure such as hospitals, waterworks, data centers, or public administration fails, irreparable damage threatens. That's why this power plant strategy is absolutely necessary."

But what does such a strategy look like in practice? And why are modular gas-fired power plants particularly suitable here?

Michael Stipa: "The key factor here is technological openness. Our electricity system needs a mix of different solutions to efficiently meet varying requirements and maintain a balance between the energy triangle of security of supply, economic efficiency, and sustainability. True resilience comes from decentralization, not centralization. An energy system based on many distributed, modular generation units is less susceptible to large-scale disruptions and bottlenecks. Modular gas engine power plants offer exactly this structure: they consist of individual gas engines that can be flexibly combined and built with 30, 60, or more megawatts of power, depending on requirements."

Scalability and efficiency

But how exactly does this scalability work? And what advantages does it offer for operations?

Michael Stipa: "You can tailor a power plant precisely to the power demand required. A 50-megawatt power plant does not have to activate all of its units if only 30 megawatts are needed. Instead, you only start up the number of engines that are actually necessary – and these then run at full load with optimum efficiency."

This flexibility has a direct impact on economic efficiency—a crucial factor in an energy system that is increasingly characterized by volatile renewables. With their high flexibility, they are therefore an ideal complement to wind and photovoltaics. 

Economic efficiency in dynamic operation

With the increasing share of renewable energies, the operating profiles of gas-fired power plants are changing fundamentally. Whereas conventional gas-fired power plants used to run at full load for 4,700 hours a year, today they often only run for around 2,000 hours. At the same time, they have to be started up much more frequently – around 100 times a year – to close short-term generation gaps.

Michael Stipa: "Modular gas engine power plants are optimized precisely for this dynamic operation. Their flexible modularity avoids inefficient partial load ranges, thereby achieving significantly higher overall efficiency with variable loads. In this scenario, they become the more cost-effective solution – not only in terms of plant cost calculation, but also when viewed over the entire life cycle."

But the advantages don't end with efficiency. Another often overlooked aspect is geographical flexibility.

Geographical flexibility and grid relief

The compactness of the individual modules is a decisive advantage: a gas engine unit fits on a truck and can be relocated as needed. This means that modular gas power plants can "migrate" geographically with the energy transition – they are built and used where they are actually needed. This avoids expensive grid expansion infrastructure.

Oliver Hoch: "Many smaller, decentralized power plants generate electricity where it is needed. This reduces the need for long transmission lines and relieves the burden on the overall energy system. This saves costs, not only for grid expansion, but also for the end consumer."

This flexibility is particularly relevant in a country like Germany, where electricity demand varies greatly from region to region – and where grid expansion often fails due to acceptance problems.

Rapid implementation is key

Time is a critical factor in the energy transition. While the construction of large power plants often takes years, modular gas-fired power plants can be connected to the grid within 12 to 18 months of approval. This not only speeds up planning, but also reduces costs.

Michael Stipa: "Modular gas power plants are ready for operation very quickly. This is possible because our gas engines are standardized and mass-produced products. They literally roll off the assembly line at our engine factory in Friedrichshafen and our system factory in Augsburg. This significantly accelerates the implementation of the energy transition."

This is an advantage that is particularly important at a time when the energy transition must progress rapidly – without jeopardizing security of supply.

Experience from the UK

Since 2014, the UK has been relying on a capacity market to switch its energy supply from coal to renewable and gas-fired power plants. Rolls-Royce has been supporting the British energy transition with highly efficient gas gensets ever since – around 500 mtu gas gensets are now in use to support the power grid.

Michael Stipa: "The UK shows that gas engine power plants are not just theory in the overall energy system, but work in practice. They step in when renewables are not sufficient – reliably, flexibly, and cost- ly. This experience is proof that our technology is not only technically feasible, but also economically viable."

Sustainability through alternative fuels

The great strength of modular gas power plants lies in their sustainability. They can already be operated with biomethane or biogas today – and are therefore more than just a temporary solution. As soon as green hydrogen is available in sufficient quantities, they will be able to operate in a climate-neutral manner. This is a feature that sets them apart from many other bridging technologies.

Oliver Hoch: "Yes, our gas engines can already be operated with biomethane or biogas today. It is also possible to add up to 25 percent hydrogen. As things stand today, however, we still have to rely largely on natural gas, as there is simply not enough biogas, biomethane, or green hydrogen available. Once hydrogen is available on a large scale, they can be powered 100 percent by it. This makes them a genuine bridge technology that actively supports the energy transition."

This means that modular gas-fired power plants are not only a solution for today, but also an investment in the energy supply of tomorrow.

Conclusion: Opportunity for the energy transition

The energy transition is one of the greatest challenges of our time – but also one of the greatest opportunities. With modular gas engine power plants, we are showing how this transition can succeed: through flexibility, innovation, and a clear vision for the future. They are not just a stopgap solution, but a central building block for an energy system that is resilient, affordable, and climate-friendly.