Based on the Spirit cruiser racer (CR) design, the 44CR (e) was commissioned for an eco-conscious customer who set Spirit Yachts the goal of “near total energy self-sufficiency”. The ‘e’ denotes the yacht’s electric drive system.
The project is the first fully electric yacht to be designed and built by Spirit Yachts. At the request of her owner, the yacht has zero hydrocarbons onboard. She is also the first yacht in the UK to be launched with solar panels integrated into the main sail and deck.
The 13.4-metre sloop-rigged sailing yacht, named Avvento, has a lightweight Oceanvolt ServoProp15 sail drive, which is powered by Oceanvolt 48VDC batteries (total capacity 30.4kWh, made up of x16 1.9kWh batteries). The electric drive system uses hydro generation via the electronically controlled pitch propeller to regenerate the batteries whilst sailing. Regeneration is boosted by solar panels on the mainsail and the aft deck.
Spirit Yachts managing director Nigel Stuart commented, “The original brief from the owner was for a yacht that would sail well in the light winds of British Columbia.
The yacht also needed to deliver the lowest possible carbon footprint during its build and when operating, as well as having the flexibility to upgrade its systems when technology advances.”
Nigel continued, “Without a generator onboard, the owner will need to be mindful of energy consumption, but with careful management of battery power there will be no sacrifice on any luxuries. The yacht has air-conditioning, heating and electric toilets, all of which make life onboard very comfortable.”
Regeneration depends on sailing speed, but Spirit Yachts has calculated it will be realistic to see 1.5kW at 8 knots of speed. Weather dependent, the solar deck panels on the deck and the mainsail can regenerate a combined total of 1.47kW.
Two Solbian solar panels are integrated into the aft Lignia deck and support the drive system by recharging the batteries. The panels (that can be walked over) serve as the hatch covers for two large lazarettes below, one of which houses a tender with an electric motor.
To deliver on the brief of a yacht capable of performing well in especially light winds, Spirit Yachts fitted a taller mast and a larger mainsail than on a standard 44CR rig. Spirit Yachts also worked with OneSails GBR (East) to develop a solar solution for the yacht’s sail wardrobe.
John Parker from OneSails GBR (East) explained, “We have collaborated with Solar Cloth System to integrate thin cell PV panels into the yacht’s 4T FORTE™ main sail as a source of electrical generation.”
French company Solar Cloth Systems developed the technology, which is officially named Powersails®.
John continued, “Due to the high modulus construction of the 4T FORTE™ composite material, the impact of the PV panels will be minimal in terms of the sail’s characteristics and performance. The technology is cutting edge and to my knowledge it is first project of its kind in the UK.”
OneSails’ 4T FORTE sails are currently the only sails made from a cloth that can be stripped of its hardware and recycled at commercial recycling plants.
On deck, a wide cockpit offers ample space for six guests crewing, socialising or al fresco dining. Manual Lewmar winches give a nod to more hands-on sailing, whilst a carbon mast and boom from Hall Spars ensures her rig remains lightweight. A 40” Sipo Mahogany and stainless-steel steering wheel was fitted for smooth handling.
Down below, a reversible heating/air-conditioning Webasto pump heats and cools the yacht using minimal power. All lighting is LED and a Webasto 4.2gallon 115v/750W heater provides hot water. At the owner’s request, there are no hydrocarbons onboard and any cooking will be done on a stove that uses alcohol for fuel.
Spirit Yachts founder and chief designer Sean McMillan commented, “One of the great joys with this particular yacht was the creative freedom afforded by the lack of a large diesel engine, which would normally need to sit on the centreline and take up a considerable amount of space. By having a much smaller electric drive system, the owner is able to have a twin aft cabin and a more spacious central living area for living aboard and entertaining.”
The interior layout accommodates four guests across two cabins. A forward double V berth with ensuite serves as the owner’s cabin and a starboard aft cabin sleeps two guests in twin berths. A fold-down chart table has been built into the forward bulkhead of the guest cabin to maximise space.
A central saloon has a port-side, u-shaped sofa around an American Walnut dining table, complemented by a second sofa to starboard. Aft of the saloon, to port, is the open-plan galley. White bulkheads, Sipo mahogany ringframes and exposed yellow cedar planking give the interior a warm, natural feel.
The owner of the Spirit 44CR (e) is Vincent Argiro, a retired technology entrepreneur living, sailing, racing, and exploring in British Columbia.
When asked what he enjoyed most about the design and build process at Spirit Yachts, Vincent commented, “The sense of freedom to create a truly white sheet design, with Sean’s brilliant vision and the rest of the team’s wide experience and substantial advice and expertise. It has been a true collaboration.”
Vincent went on to say, “Avvento is meant to be a defining prototype of an energy self-sufficient and sustainably-built sailing vessel— a living laboratory and research platform for proving out all the technologies and practices that make eco-sailing attractive to many others. She will soon be live on the internet for all to study her “energy metabolism” wherever in the world she is!”
Vincent Argiro plans to launch a website, which will track the yacht’s energy usage and regeneration.
Nigel Stuart added, “Vincent (the owner) is knowledgeable and experienced when it comes to eco-friendly technology and its capabilities. His unwavering ambition to live sustainably onboard has allowed us to be bold with innovation and push the boundaries of eco-friendly yachting.”