Wärtsilä’s New ‘Future-Proof’ Engine

The growth of alternative power sources like wind and solar has, naturally, been a challenge to traditional engine manufacturers. The more GW produced by ‘green’ energy, the fewer are likely to be produced by recips.

But the challenge faced by engine manufacturers isn’t only about technology. Marketplace uncertainty is a factor as well. Globally, utilities are struggling with how best to achieve ambitious decarbonization targets, which is causing delays in investment decisions beyond renewables. After all, no one wants to make a ‘wrong’ bet on technology.

Wärtsilä believes its new 31DF multi-fuel engine offers a “future-proof” solution, said Antti Kämi, vice president, Engine Power Plants, Wärtsilä Energy Business.

“Customers today are very uncertain on the future, on what they should do,” he said. “We’re trying to relieve their uncertainty with this solution so they can execute for any type of future. You don’t have to decide anything right now because you can do anything with this engine.”

The 20V Wärtsilä 31DF engine, which was unveiled at the PowerGen Asia trade show, delivers 11 MW and is based on the company’s marine diesel 4-stroke Wärtsilä 31. The multi-fuel engine offers open-cycle efficiency, fuel choice flexibility, and dynamic operational features and is designed for markets where a gas supply is anticipated but not yet available, or where there are concerns regarding the availability or price of gaseous fuel, Kämi said.

It’s ideal for flexible power generation, providing a tool for the integration of higher levels of energy from renewable resources, Kämi said.

“The peaking gas market, given the growth of renewables, is really expected to grow,” Kämi said.

According to a recent report by Bloomberg, 1666 GW of non-generating, flexible capacity, such as batteries and demand response, will be installed globally by 2050. Overall, the report estimates that there will be a 350% increase in peaking gas plants, which will account for over 1TW of new capacity.

He said the Wärtsilä 31DF can synchronize with the grid within 30 seconds from start command and can provide full output within 120 seconds. That fast start-up facilitates the easy integration of renewable energy sources.

These features allow an overall higher level of system efficiency. The fuel flexibility of the engine improves energy security and increases resilience against unpredictable interruptions to the fuel supply. Should a reliable supply of gas become available following installation of the Wärtsilä 31DF, the engine can be easily converted to pure-gas operation because of its modular design, Kämi said.

“They can start operating with liquid fuels that they have access to, like diesel, and then transfer to gas when that becomes available, or even leap directly to renewable fuels—the Power to X technology is coming to the market more and more.”

Kämi said operation of the engine can be monitored and adjusted online, which is valuable in remote locations.

The engine has a bore and stroke of 310 X 430 mm and offers an open cycle efficiency of nearly 50%. The high efficiency of the engine reduces fuel consumption and costs, while minimizing carbon emission levels. The level of efficiency is retained even in partial load conditions, and the engine can resist output de-rating when operating in hot and humid conditions.

First deliveries of the 20V are expected in the second half of 2021 with 16V and 12V variants following, he said.

“This new engine is well proven already in marine applications and is now a conversion-ready solution for the energy sector. The key word to describe its functions is flexibility, meaning not only fuel flexibility but also operational flexibility to enable a variety of operations, including load following, balancing and flexible baseload. In all cases, the level of efficiency is outstanding,” Kämi said.