Spirit Yachts lifts the lid on its clean energy drive and solar sails

Aveento sailing yacht on the water - it has solar sails

Last year, Sean McMillan, founder of Spirit Yachts, announced that more than half the boats on order with the company were repeat orders for existing owners, but each repeat order owner was moving from diesel to electric. This obviously delighted him. It’s no industry secret that Spirit has been pushing hard on the sustainability agenda since it won British Marine’s inaugural environmental award at SIBS 2019. And, in a recent BBC documentary (Making Waves: Building Boats), McMillan lost no time in disparaging the state of the UK’s boat production.

“Look at this,” he said, gazing over a marina, the likes of which can be seen around the UK. “I find this really depressing. Acres and acres of white fibreglass.

“The problem with marinas like this is that 99 per cent of the boats in them are made from fibreglass. It’s leaving behind a really appalling legacy. Some of them might last 20/30 years but by that stage they’ll be very tired. It is indefensible and it cannot go on.”

Avvento features flexible solar panels

Without having to contend with the environmental issues of GRP – all Spirit Yachts are made with sustainably sourced wood (primarily Douglas Fir and Sapele from Canada) – the company is focusing its attention on re-genning clean energy used for the hotel load (interior lights etc), and electric propulsion.

Electric drive and solar sail boats

In April 2021, Karen Underwood was appointed Spirit’s MD and handed the baton for delivering even more effective, efficient propulsion systems on the high-end yachts beloved of James Bond film directors. She has a clear direction for the future. “Fundamentally we’d hope that any sailing yacht coming out of here would be having an electric drive system onboard,” says Underwood. 

“As an industry we need to be hitting global environmental targets and promote and facilitate the use of electric drive yachts. We need to be efficient in regeneration and power management, lowering the carbon footprint and having less of an impact on the environment. That’s where we all really need to be. And that’s what’s reflected in our yard. It’s something I can say, but it’s also something we can back up.”

Read more industry interviews in Marine Industry News magazine Issue 6.

That back up comes with an impressive legacy borne out of a desire to innovate, and clients’ interest in sustainable yachts. Underwood details Avvento; the owner lives totally off-grid in Canada in his electric 44CR (cruiser-racer design), built in the Ipswich yard in 2020. As well as an Oceanvolt sail drive system to generate power (through the propeller) while sailing, deck solar panels and a small wind turbine to make the boat as self-sufficient as possible, Avvento features flexible solar panels attached to the mainsail for maximising solar energy. 

“The panels are all either sewed in or glued onto the sail,” Underwood says. At the time Spirit was suggesting (and embracing) this technology, solar sails were almost unheard of. “Solar technology has definitely advanced and so we can shape the solar panels to capture sunlight to convert into energy at particular times of the day.”

The sails incorporate flexible solar panels

Underwood continues: “The owner of Avvento, is now working with OneSails’ John Parker and saying ‘actually at this time of day I could have captured the sun when it was lower to the water – could we look at having a different shape, or size of panel?’ He’s working with OneSails directly, and with us, to have best use of the solar panels.” 

As James Weller, Spirit’s head electrician, notes there is currently a significant cost in choosing electric over diesel. “The more it’s adopted, the more the price will come down,” he says pragmatically. He is a keen advocate of re-gen technology.

“Solar is currently the best way of continually charging the system,” Weller says. “Modern panels are getting more and more efficient even on a cloudier day. But when you’re sailing, if you get prime conditions, you can really put a decent amount of power back into the yacht by using the re-gen through the propeller.”

Solar panels embedded on deck on Avvento

While Weller is keen to stress that standalone data can be misleading as factors like the weather conditions and handling will affect that re-gen capacity, he says that, in great conditions sailing for an hour, he witnessed an average of 900 watts continuously being put back into the system.

Re-gen technology

Spirit is currently working with a few suppliers of re-gen technology and electric propulsion, testing new systems before fully committing. Currently in the mix is Torqeedo, Oceanvolt and lately ePropulsion (destined for the second Spirit 30).

“We can’t afford to be totally wedded to one supplier because of what’s going on in the world at the moment,” says Underwood. “Some owners like to keep all systems the same, other times they don’t. Some of our owners get incredibly involved with the supply element and deal directly with the manufacturers, which is great because we can all liaise together and there’s no mismanagement in the communication. It also means we’re pushing the supplier. We’re pushing boundaries all the time.”

Weller agrees: “We’re trying to make it so that their products are better, which purely makes our products better. We’re always trying to get suppliers to make their product as good as possible as they’re attached to our product. For example, we’ve done design tweaks with Oceanvolt regarding its installations and its battery management system, even down to the lighting on its throttles and how that’s programmed. It’s lots of little modifications that all add up.”

Custom electric boats

According to Underwood, Weller does a lot of R&D (mathematical problem solving) with suppliers and clients and has – over the past 21 years – become the ‘go to’ centre of knowledge on the East Coast for re-gen and drive tech advice.

Now Spirit is moving towards using MG Batteries. Underwood cites their performance on the P70 powerboat as being instrumental for making the decision, as well as the fact that “they work really nicely with the rest of the system.”

But while Spirit is openly advocating re-gen and electric drives, both Underwood and Weller note that not all owners are so open to moving away from fossil fuels. “I think it’s about changing perceptions, exploring avenues and spending time with people such as James who knows what he is talking about, who can direct and move people into the space of saying ‘actually I am going to go eco and it’s not going to cost the world and it’s very easy to manage’,” says Underwood.

“We have clients that come to us who might have something in their mind. Such as a client who wanted a 52ft sailing yacht with a diesel engine. He spent 45 minutes with James aboard one of our hybrid yachts, and one of our fully electric yachts, and came away thinking ‘no, I’ll have an Oceanvolt with possibly a back-up generator’.”

Like all traditional boatbuilders, this flexibility of adapting to changing decisions is key to Spirit’s processes. As a custom yacht builder and designer, Spirit can be really flexible in build. Without the restrictions of moulds the company an absolutely tailor all the systems onboard any of its yachts. 

“We can produce what people want as we don’t have the moulds. The problem for some of the GRP manufacturers is obviously their production is restricted with their mould tools. They try and create a standard one size fits all package as ultimately they have to,” says Underwood. “If you are dealing with something that is coming out of a mould, ultimately there’s not much you can change to it in terms of economy of scale. If like us you’re innovating throughout, it’s fine, you can have an electric 30 or an electric 111. We have the engineering capacity and electrical knowledge and knowhow to manipulate the hull to do what we’d like it to do, rather than the other way around.”

Weller says Spirit doesn’t just innovate at client request; he’s always looking at ways of powering yachts in the future. Currently he’s investigating hydrogen fuel cells to see if there is potential in using synthetic fuels. “We’re constantly looking at ways we can improve the yacht scene further. It’s not as if we’ve gone to an electric drive system and gone ‘that’s it now’. We’re always looking to make better. Electric drives are great but still have drawbacks in terms of range and having to have lots of batteries onboard. We’re always looking at new options.”

All images courtesy of Spirit Yachts/Richard Langdon.

Comments are closed.

This article was written and/or edited by the UK-based MIN team.

Skip to content