Grid balancing technology shaping our renewable future

We are at a turning point in the energy transformation.

By the end of this decade, the amount of renewable energy sources used globally will double and inflexible energy production will decline significantly, with production of coal and oil alone falling by 2,300 TWh.

The availability of cheap renewable energy sources and the climate targets set by the government mean that change is happening at a breakneck pace.

But this puts a strain on our energy grids as we move away from inflexible, centralized power generation towards large amounts of decentralized, intermittent wind and solar power.

To adapt to this new reality, we need flexible power generation that can respond rapidly to fluctuations in renewable energy.

The optimal technology to drive this transition is grid balancing engines.

A remarkable increase in wind and solar power

While the above renewable energy projection is striking, the ambitions of governments around the world are even bolder.

At COP28, governments committed to tripling renewable energy by 2030 to meet our climate goals and keep global warming below 1.5 degrees.

Increasing the share of energy from renewable sources is the most important solution we have in the fight against the climate crisis. To enable this transformation, the cost of solar power fell by 88% and onshore wind power by 68% between 2010 and 2021.(1)

However, the influx of low-cost renewable energy is already creating challenges for our electricity grids.

Restrictions – in the case of switching off renewable energy in favor of inflexible generation – are a significant problem. It wastes energy, emissions and money.

To illustrate the scale of this challenge: in California, curtailment of wind and solar generation reached a record high of 606 GWh in March 2024.(2) that’s enough to power Los Angeles for over a week.(3)

These problems are common in power systems that use only 30-50% renewable energy. Imagine the impact when we reach 50-80% wind and solar energy.

Simply put, it is not possible to support renewable energy with inflexible technologies such as coal, nuclear and combined cycle gas turbines (CCGT), which take time to rise and fall and cannot adapt to fluctuations in renewable energy.

We need the right kind of flexibility and balancing technology to accelerate the development of renewable energy sources and ensure stable, reliable energy every minute of every day – without skipping a beat.

Engines vs. Eros

The key question to ask is: what is the right type of flexible power generation – the optimal technology – to balance renewables and accelerate the energy transition?

Two leading solutions are grid balancing engines, such as those supplied by Wärtsilä, and aerospace gas turbines (aeros).

In almost every respect, our technology wins.

The easiest way to understand the difference between engine and aerodynamics is to compare a car engine with an airplane turbine. The car’s engine starts instantly and can be ramped up and down efficiently. The plane’s engine idles when you board, takes time to start, and then once you’re in the air, it can only operate within limited parameters.

You wouldn’t use an aircraft turbine to get you to the shops, you need something more flexible and efficient at different speeds.

The same applies to managing our power systems. As we transition to intermittent wind and solar energy sources, we need power generation that can adapt and match fluctuations in renewable energy generation at the touch of a button. We need engines.

Our motors can accelerate in as little as two minutes to support or balance power systems with minimal downtime. They have high efficiency and performance under all loads, even in extreme conditions, and generate 10% lower greenhouse gas emissions than aero.

They perform better than eros when sent to real-time markets (i.e. 15- and 5-minute energy trading intervals). The study, titled “Uncovering the Hidden Value of Piston Engines in Today’s Energy Markets,” found that over 20 years, engines could capture 60% more value than eros.(4)

Crucially, the engines are also ready for a net-zero emissions future. By using natural gas today as a transition fuel, they will be able to use renewable fuels, which will be the most abundant in the future and will not become stranded assets in the coming decades.

Misunderstood role of gas as a transition fuel

There is a common misconception of gas as a transition fuel.

This is seen as a step between highly polluting production such as coal and renewable energy sources. At Wärtsilä we see things differently.

We believe that gas should be used to enable the transition.

We have created power system modeling for nearly 200 markets around the world and have consistently found that a small number of grid-balancing gas engines in a system can provide the balancing and flexibility for renewables to flourish.

Crucially, the price of electricity does not have to increase once electricity systems reach net zero. Utilities are moving away from a high-cost operational (operating) expenditure model in which capital is continually attracted to power and maintain older, inflexible coal, oil and gas plants, to a new model in which capital expenditures (capex) are invested upfront in predictable , low maintenance costs, renewable energy technology.

Flexibility creates the conditions in which renewable energy is the most cost-effective way to power our networks: it ensures the availability of backup energy when wind or solar power is insufficient, reduces supply constraints, and capitalizes on the benefits through efficiency mechanisms.

These are not 24/7 power plants, they can be adjusted and quickly sped up and shut down when renewables are not providing power or when there is a high demand for power. This way: a small amount of gas makes a big difference to the system.

At Wärtsilä we have a five-step plan to ensure a 100% renewable energy future anywhere in the world, based on this model. The steps include: 1) adding renewable energy sources, 2) increasing flexibility through engine balancing and storage, 3) phasing out inflexible power plants, 4) switching to sustainable fuels, and 5) phasing out fossil fuels.

Our grid balancing engines are essential in this context to provide the required flexibility and balancing and to enable renewable energy sources to dominate our electricity systems. Excess renewable energy can then be used to create sustainable fuels for our engines to create fully renewable power systems.

Delivering our renewable future

This decade will be crucial in laying the foundations for the clean energy future we envision. This gives us a unique opportunity: to add more renewable energy to our networks than ever before, to ensure the right level and right type of flexibility in our electricity systems, and to phase out inflexible assets by switching to sustainable fuels.

With our grid balancing engines, energy storage and optimization, Wärtsilä provides the beating heart of our future power systems.

The question is not whether we have the technology to enable the energy transition, but how quickly can we do it? The answer to this question will be repeated for generations.

(3) Calculations: Los Angeles consumes 22,000 GWh per year (https://planning.lacity.gov/eir/StudioCity_SeniorLiving/DEIR/04-N.1_Utlities-Energy.pdf), so the average consumption per month is 1,833 GWh. 606 GWh is 33% of 1,833 GWh.

(4) https://www.wartsila.com/energy/pages/reuters-white-paper—uncovering-the-hidden-value-of-reciprocating-engines