The energy balancing act: How to cut costs and deliver the benefits of net zero

Balancing engines and energy storage are essential to unlocking the full potential of renewables, as well as combatting the narratives positioning green growth at odds with economic growth.

By Anders Lindberg, Energy President at Wärtsilä

The energy sector is at a crossroads. Over the past year, conversations around net zero and the cost of energy have become increasingly polarised, dominating political discourse and driving diverging policy priorities across the globe.

At the same time, global renewable energy development has continued to grow rapidly, with 90% of new power capacity added in 2024 coming from renewables.

In recent years we have seen significant energy price rises, despite record renewable energy roll out. This has left people and businesses asking when they’ll begin to feel the benefits of investment in renewable energy.

One area where we can make an impact quickly is by cutting energy wasted through curtailment, by investing in balancing technologies such as grid balancing engines and energy storage.

Have you read?
Wärtsilä Energy’s Frederic Carron on Asia’s diverse energy transition

Planning future energy systems

Energy systems, in the way that we think of them today, emerged from connecting legacy fossil fuel power generation to industry and local communities. These grids, underpinned by large shares of coal and nuclear power, required little flexibility.

Renewable sources of energy, like wind and solar power, are less predictable than fossil fuels as they rely on changeable weather to generate electricity. While renewables are essential to driving down carbon emissions, reaching global climate targets, and are already the cheapest form of electricity in many regions, grids across the world are not equipped with the necessary balancing and storage capacity to fully harness their potential.

Electricity demand is also set to skyrocket with the electrification of the hard-to-abate, energy-intensive industrial and transport sectors. Additionally, forecasts predict that by 2030, AI and data centres alone could account for 13% of global power consumption.

Installing the right mix of balancing engines and energy storage technologies to improve the efficiency of grids is essential before energy systems are confronted with the challenges of an ever more electrified economy.

Also of interest:
Powering the transition: Why hybrid energy storage is the backbone of a resilient energy system

Energy waste is an existential challenge for global decarbonisation

The International Renewable Energy Agency reports that a record 585GW of renewable capacity was added in 2024 alone. This is more than the annual power generation capacity of India. While this is cause for celebration, it has also exposed a problem in global energy systems that needs to be addressed.

On bright, windy days, much more electricity may be generated from wind and solar power than can be used by a grid. This has led to markets across the world switching off wind turbines and solar panels, often at a cost, wasting potential energy generation.

Costs to consumers from constraints in Britain’s electricity network surged by 60% to £253 million ($353 million) in the first two months of 2025, as wind farms were paid to switch off and curtail renewable energy, gas plants were used to support the wider network when renewables were not generating enough power or if there were issues in transmission systems.

Last year almost 30% of Northern Ireland’s planned wind output, 5% of Germany’s renewables output and 2.5% of France’s solar was curtailed. In China 58.7TWh of renewable power was wasted, enough to power 24 million households.

Conversely, when renewables can’t meet sudden demand spikes, countries risk steep price hikes or even blackouts in the absence of energy storage or flexible balancing capacity.

With renewable energy projects requiring significant investment, seeing these assets work sub-optimally has stoked narratives positioning green growth as at odds to economic growth. Investing in balancing engines and energy storage technologies is the fastest, most reliable way to optimise renewable systems, cut energy waste and slash bills for consumers.

Energy Transitions podcast: Applying grid resilience lessons from Spain’s blackout

The need for balancing engines and energy storage

Energy storage systems, in the form of batteries, have proven invaluable – absorbing surplus power and releasing it when needed. Energy storage growth has accelerated rapidly and as of 2024, global cumulative capacity has reached 150 GW.

While balancing engines receive less visibility than energy storage, they make a huge impact on energy systems across the world. These units can provide power on demand for minutes, hours, or longer periods of time. They can also power up more quickly than gas turbines – providing higher levels of grid flexibility, have improved efficiency, cut costs and emissions.

These engines represent a low-risk, high-impact investment. They are ready to support today’s grids and seamlessly adapt to tomorrow’s sustainable fuels. When paired with renewables and storage, they ensure every megawatt generated is put to work.

Read more: Wärtsilä to trial ethanol-fuelled engine for power generation

Solving the energy balancing act

Problems with energy waste, compounded by a lack of secure supply, threaten to get worse with the demands of a fully electrified economy.

Wärtsilä has modelled over 200 power systems globally and found that a combination of renewables, energy storage and future-proof grid balancing engines offers the quickest, lowest cost and lowest emissions pathway to a net zero future. This integrated approach could unlock cumulative savings of €65 trillion ($76 trillion) by 2050, compared to a renewables and energy storage only scenario.

Without balancing engines and energy storage, an area the size of Europe will be needed to be covered with renewable power to realise clean energy goals.

The energy sector must act swiftly to upgrade grids, secure supply and eliminate waste. Doing so will drive down bills, prove beyond doubt that renewable energy spurs economic growth, and maintain public confidence in the net zero transition. Balancing engines and energy storage are essential to unlocking the full potential of renewables – and delivering net zero benefits for all.

ABOUT THE AUTHOR

Anders Lindberg is President, Energy, Executive Vice President and a member of the Wärtsilä Board of Management. He has extensive experience in leading international project businesses in the energy and rail industries. He joined Wärtsilä from Dellner Couplers AB, where he was President and Chief Executive Officer. Prior to that Lindberg was the Executive President EPC and QHSE in Ørsted and also held several international managerial positions in Bombardier Transportation.