Energy and marine equipment manufacturer Wärtsilä South Africa on March 31 said the country would need more than 28 GW of flexible assets, including more than 21 GW of energy storage and more than 6.8 GW of flexible gas power capacity, to run on 100% renewable energy at the lowest cost.

The capacity needed to balance South Africa’s switch to grids powered by intermittent renewables must come from two key technologies, namely energy storage and flexible gas power capacity, capable of running on future fuels. Future fuels can be produced during periods when renewables produce more electricity than is needed, said Wärtsilä Energy South Africa business development manager Wayne Glossop.

“To decarbonise at the lowest cost, high levels of renewable energy must be scaled up by 2030. What we have learned from modelling over 145 countries and regions in our 'Atlas of 100% Renewable Energy' is that power systems with high levels of renewables need a significant amount of flexibility, through energy storage and gas balancing technology, to achieve the transition to a 100% renewable energy future,” he pointed out.

“By building high shares of renewables, we can create the conditions to produce carbon-neutral future fuels that can decarbonise all energy-intensive sectors, from power to mobility. To solve this final piece of the net-zero puzzle, the answer is to urgently build more renewables, supported by future-proof flexibility solutions.”

A significant degree of overcapacity is needed to account for the variability of wind and solar generation. Excess electricity is then used to produce future fuels with "Power-to-X" technology. The modelling finds that balancing the intermittency of the renewables production with a combination of flexible gas and energy storage would be 38% cheaper for Group of 20 countries, in comparison to relying on energy storage alone, he added.

“South Africa’s need for 28 GW of agile, flexible solutions reflects the country’s exceptionally high potential to meet its demand almost exclusively with wind and solar energy, and the requirement for significant power storage capacity when wind and solar is no longer generating,” said Glossop.

Wärtsilä on March 31 launched its grid balancing technology, powered by the upgraded Wärtsilä 34SG Balancer engine. It is optimised for renewable baseload markets and is an agile, fast-starting gas engine capable of ramping up to 10.8 MW in two minutes to seamlessly integrate with renewables. This could help to bridge utilities to a 100% renewable energy future at the lowest cost.

Wärtsilä’s power plant gas engines can currently run on natural gas, biogas, synthetic methane or hydrogen blends. The company is actively developing the combustion process to allow the burning of 100% hydrogen and other future fuels. Wärtsilä has a long record of successful fuel conversions for the global installed engine base.

Alongside the power plant solution, Wärtsilä offers its fully integrated GridSolv energy storage technology that is designed for ease of deployment and sustainable energy optimisation, and its GEMS Digital Energy Platform. GEMS dynamically optimises energy systems through a broad range of applications, like frequency regulation, to create revenue streams and enhance grid or system resilience.

“Currently, the industry is in a challenging situation. Investments need to be made today even if visibility of the future is not fully clear,” said Wärtsilä Energy Technology & Product Management VP Jukka Lehtonen.

Wärtsilä has developed the grid balancing solution based on existing, proven technology which is future-proof and flexible. The solution can be adapted to different operational profiles and running hours, along with the evolving needs of the system.

“Using our solution, renewables can be integrated seamlessly into different energy mixes as they become available,” said Lehtonen.

Wärtsilä’s grid balancing technology is part of a portfolio of products designed to cost effectively accelerate the energy transition. The portfolio comprises power plants, energy storage and energy management systems.

The power plant solution is based on lean design and it can be equipped with features such as unmanned standby, remote control capabilities, 24/7 data streaming and dynamic power management. Optimised performance and reliability are supported by Wärtsilä Lifecycle solutions, Lehtonen said.