Changing propulsion demands to reshape marine engine market

The marine engine market is being reshaped by a combination of emissions regulation, alternative fuels, and electrification. The transition is unlikely to follow a single path, with diesel still playing an important role as practical and infrastructure constraints limit how quickly some sectors can move to electric propulsion.

Engines Plus managing director Hedley Beavis also says that some areas of the market are shifting from inboard diesels to outboards.

According to Beavis, this is becoming increasingly visible in both commercial and leisure boatbuilding, particularly as higher-powered outboards broaden their applications. Commercial operators are moving towards outboards because they are “easier to maintain” and cheaper to replace. Seven-metre catamarans aimed at the fishing market that would previously have used inboard diesels are now being fitted with outboard pods, he says.

The same trend is evident in leisure production, he says. Some Beneteau fishing/dayboat models that previously used 150hp inboards moving to outboards because they are “easier to fit from a production point of view”, as well as being “cleaner” and “probably cheaper”. MIN has previously reported Beneteau models, including the Gran Turismo 36, being offered with both inboard and outboard engine options.

Marine engines follow construction’s development

Engines Plus was established in 2009 as an independent engine distributor, with a portfolio spanning industrial applications, including diggers and excavators, as well as marine engines for both commercial and leisure markets. The company has been primarily focused on diesel engines for the past 10 to 15 years.

Beavis notes the marine engine market follows what goes on in the construction and industrial engine market. The sub-100hp marine diesel market is increasingly based on industrial diesel technology that has already had to meet emissions requirements.

“The small stuff, all below 100 horsepower, is coming from the industrial engine market sector, which is emission compliant, it’s got DPF filters on it and fully common rail. They’re either Mitsubishi, Kubota or Perkins-based,” he says.

“The larger engines above 100, 150 horsepower are coming from the automotive sector.” This matters because automotive engines have had to deal with increasingly stringent emissions regulations, so marine manufacturers can use an existing, developed engine platform rather than developing an entirely new marine-specific engine.

Current development in conventional outboards is focused largely on meeting emissions legislation, improving existing models and extending the power range.

Selva, for example, which Engines Plus represents, has introduced new 30hp and 9.9hp models, alongside updates to its 150hp and 200hp engines, while the company is also developing a small 4kW electric outboard.

Electric propulsion meets an infrastructure problem

While electric propulsion is advancing at the smaller end of the market, Beavis is sceptical about the practicality of electrifying the larger outboard-powered boats found on beaches and in small coastal harbours around the UK’s coastline. He says some can use outboards of up to around 115hp, but there is often no shore power available to recharge them. With up to 50 boats on some beaches, he questions where the necessary charging infrastructure would come from, arguing that the same problem would apply across numerous small harbours around the UK.

Thus electric propulsion is more straightforward for smaller engines –  particularly below 10hp, where batteries could potentially be charged at home or on the boat –  but the infrastructure challenge becomes much greater as power requirements increase.

Solé targets replacement and genset markets

Engines Plus has worked with Solé Diesel for around 15 years, supplying its marine engines across the leisure and commercial sectors. Beavis says the relationship has increasingly included supporting customers looking to replace older engines, with Solé recently launching its SK80, a four-cylinder, turbocharged and intercooled mechanical diesel aimed at yachts and small leisure craft. The engine offers a straightforward replacement option.

“They do a nice marinisation as well . . . people comment that it’s a quality product rather than some of the other marine engines that are chucked together.”

Beavis says Solé is now very much focusing on gensets. “They see opportunities with the larger vessels in the leisure industry with variable speed gensets. They think the small yacht market is tough.”

HVO offers a faster route to lower emissions

He notes that if the industry eventually goes down the electric propulsion route, owners will still need a generator on board.

“But what frustrates me more is that you’ve got things like HVO fuel. That could reduce emissions massively overnight.”

Earlier this week, Forth Ports, owner of the Port of Tilbury, voiced similar concerns. Chief operating officer Paul Dale pointed to the continued taxation of HVO, saying: “Despite the environmental benefits and the investment businesses are making to move to renewable fuels, HVO is still taxed in the same way as diesel.”

Existing policy doesn’t adequately incentivise businesses to move away from conventional fuels.

Uber Boat by Thames Clippers has also called for vessels operating on tidal rivers and estuaries to regain eligibility for Renewable Transport Fuel Certificates (RTFCs), arguing that current rules are making HVO significantly more expensive than conventional marine diesel.

Thames Clippers estimates that using HVO across its fleet could save 17,152 tonnes of CO2e, but says the fuel is currently nearly 50 per cent more expensive per litre than marine diesel because of the policy position. The rules make lower-carbon fuel less attractive while the industry develops hybrid and other alternative propulsion technologies.

Beavis says that all the engines the company currently represents work with HVO, and “a lot of the older engines do as well.”

Fishing grants support cleaner engines

Although the government is being pressed by many to do more, a new scheme recently revealed is set to
“kickstart cleaner, newer engines,” says Beavis.

In mid-September England’s Fisheries and Seafood Scheme expanded to provide grants towards new engines and gearboxes on fishing vessels. Support is 65 per cent for the small scale coastal fleet installing new petrol or diesel engines, 50 per cent for other vessels installing new petrol or diesel engines, and 90 per cent for electric or hybrid engines, regardless of vessel or business size. The scheme is administered by the Marine Management Organisation and funded through the £132m Fishing and Coastal Growth Fund.

“The problem is, it’s only for English fishermen,” he sighs.

For Beavis, the marine engine transition is therefore less about one technology replacing another. Outboards, diesel, HVO, hybrid and electric propulsion all have roles to play — but cost, infrastructure and the practical demands of boat operation will determine how quickly each develops.