Wärtsilä Oyj : Without balancing technologies, renewables won’t decarbonise the energy sector

"Decarbonisation will fundamentally change how electricity is generated," says Nette Lehtinen, Director of Strategy and Business Intelligence at Wärtsilä Energy. "Most of our demand will be met using electricity generated from clean sources, such as solar and wind. As the share of renewables increases in generation, volatility of the system will increase, which will frequently mismatch supply and demand."

One way of managing this variability is to build energy systems that use fast-ramping flexible technologies that can quickly respond to sudden drops in renewable energy generation, or sudden increases in demand. Here, innovation in the energy industry has led to solutions that can make the leap from theory to reality.

"This is what Wärtsilä's energy storage systems and grid balancing engines do," says Lehtinen. "They're flexible. They balance volatility and make sure that the power supplied by renewables always matches the demand thanks to short reaction times and the ability to turn on and off many times in one day. Plus, when the level of renewable generation is high, flexible balancing engines can quickly ramp down and still run in an efficient way."

Renewables must remain cost-effective

Not only is flexibility good for the climate, it's also good for investors. It makes renewables the most profitable way to power the grid and ensures that backup power is available when adverse weather conditions don't generate enough electricity.

"It would seem at first glance that we could simply design power systems that generate electricity through wind and solar and then store excess generation in batteries to use when the weather turns," says Lehtinen. "But while that works in theory, it doesn't work in reality."

First of all, she says, there would be no way to secure enough investment in the sheer number of excess plants we would need to build. "The economic attractiveness of investing in excess plants would certainly be low. This would raise the cost of the entire system as most of the renewables would be excess to requirements most of the time. But meeting demand using grid balancing engines overcomes this problem and makes renewables the most cost-effective power source."

Second of all, the battery life of energy storage currently exists on the scale of hours, which isn't suitable for running an entire grid during extended periods without wind or sun. "Energy storage in form of batteries is a vital solution. It responds in milliseconds, which means it can smooth output, store excess energy and re-dispatch power when needed. But when renewable supply goes to zero, we need to have a long-term source in place, otherwise blackouts will happen."

The energy transition needs hybrid solutions

To maintain grid stability, to ensure energy security, and to reach ambitious decarbonisation goals, it's clear that global society cannot rely on a single solution or technology and must rather build power systems using flexible hybrids.

"We need to understand how technologies mix and match," says Lehtinen. "Different countries have different energy backgrounds, which is why it's important to perform country-level modelling to understand which types of energy mix would benefit which countries, to more rapidly increase their share of both renewables and less carbon-intense options. This is what Wärtsilä has done for different regions to support utility companies and political decision-making."

Wärtsilä's experts have modelled for example the immediate next steps for three key African markets-Nigeria, South Africa and Mozambique-to lay the foundations for decarbonisation and electrification at the lowest cost and risk while maximising reliability and affordability. By building a stable base over the next decade that's ready for a significant addition of renewables, countries can leapfrog to renewable energy systems and avoid the costly carbon-intensive mistakes made by the Global North.

"Africa is home to 60% of the best solar resources globally and solar PV is already the cheapest source of power in many regions," says Lehtinen. "Yet the continent has only 1% of the world's installed solar PV capacity. Unlocking this resource will have a transformative impact."

To optimise the economics of the energy transition in general, flexible solutions must be tailored to the unique environmental conditions in which they'll operate. Wärtsilä's engines can already run on multiple fuels and are ready to be converted to new carbon-neutral or carbon-free fuels when they become commercially available.

"Our engines and energy storage systems enable our customers to quickly scale up their use of renewables over the course of the next decade," says Lehtinen. "Plus, the engines can continue to play the same clean role in the future when they're fuelled by hydrogen and other sustainable fuels, which will further enable them to build entire net-zero power systems."

Timing is everything

Renewable energy is a necessary but insufficient part of the energy system of the future. A 100% renewable energy future is only possible when supported by a range of balancing technologies, such as utility-scale energy storage, flexible power generation, and energy mix optimisation software-all of which Wärtsilä offers.

The energy transition will only be successful if we make the right decisions at the right time. This is why Wärtsilä's GEMS Digital Energy Platform is crucial. It answers complex interdependent questions to dynamically adjust the energy assets such as storage, renewables and engines based on market conditions.

"Because of the Russian invasion of Ukraine, we must be even faster with the energy transition," concludes Lehtinen. "After adding renewables, we should balance the grid by using engines and storage. By supporting the growth of renewables, we can phase out inflexible plants, such as those that use coal. When sustainable fuels start to become cost-competitive, our balancing engines are ready to run on sustainable fuels such as hydrogen. That's how we'll reach a 100% renewable energy future."

Written by

Harry Lawrence