{"id":47330,"date":"2021-11-08T22:05:07","date_gmt":"2021-11-09T03:05:07","guid":{"rendered":"https:\/\/www.cruisingworld.com\/?p=47330"},"modified":"2024-01-04T16:03:20","modified_gmt":"2024-01-04T21:03:20","slug":"the-promises-and-pitfalls-of-an-all-electric-yacht","status":"publish","type":"post","link":"https:\/\/www.cruisingworld.com\/story\/sailboats\/the-promises-and-pitfalls-of-an-all-electric-yacht\/","title":{"rendered":"The Promises and Pitfalls of an All-Electric Yacht"},"content":{"rendered":"\n
\n\n\t\t\t
\n\t\t\t\t\t\"Arcona <\/div>\n\t\t\t\n\t\t\t\n
\n Imported into the US \u00admarket by Green Marine, the Swedish-built Arcona 435Z is a rarity: an all-\u00adelectric cruising sailboat.<\/span>\n Jon Whittle<\/span>\n\n\t\t\t\t <\/figcaption>\n <\/section>\n\t\t\n\n\n

This past October, I saw one of the most interesting exhibits in more than 500 new cruising sailboats<\/a> I\u2019ve reviewed over two decades. It was the Arcona 435Z, built in Sweden and introduced by Graham Balch of Green Yachts in San Francisco. Balch describes his business as \u201ca new brokerage dedicated to the electric revolution on the water,\u201d and it was the \u201cZ\u201d in the boat\u2019s name, which stands for \u201czero emissions,\u201d that made this boat so interesting. This was the first electric propulsion system\u2014not hybrid but all-electric<\/i>\u2014I\u2019d ever seen on a cruising sailboat.<\/p>\n\n\n\n

Electric propulsion isn\u2019t new. Since 1879, electric motors have propelled boats; a fleet of some four-dozen electric launches transported visitors around the 1893 Colombian Exposition in Chicago. But cruising sailboats are not launches, and the open sea is not a protected canal. When we\u2019re using cruising boats as they\u2019re meant to be used, they seldom end their day plugged into a shore-power outlet. Cruising boats comprise many devices \u2014stove, refrigerator, freezer, windlass, winches, autopilot, radar, lights\u2014whose power typically comes from a tank of fossil fuel. And today\u2019s cruising sailors are accustomed to using diesel auxiliary power to motor through lulls or punch into headwinds and seas.<\/p>\n\n\n\n

Starting about 15 years ago, we saw a wave of diesel-electric and hybrid propulsion systems on production and custom cruising boats (see \u201cPerpetuated Motion,\u201d CW<\/i>, March 2005<\/a>). Both of those systems ultimately start with an onboard internal-combustion engine. A diesel-electric propulsion system relies on a running genset to directly power the electric motor that turns the propeller. A hybrid system relies on batteries to power the electric motor, plus an internal-combustion genset to recharge the batteries. One of the promises of a hybrid system is the ability to regenerate electrical power. Regeneration means using boatspeed under sail to turn the propeller, whose spinning shaft sends electrons from the electric motor back through an electronic controller to recharge the batteries. In such a system, the boat\u2019s propeller is both an electrical load (when running under power) and a charging source (when sailing in regeneration mode).<\/p>\n\n\n\n

The Arcona 435Z was different from both of these systems: It incorporates no onboard fossil-fuel engine at all. Instead, it has a bank of lithium batteries, several solar panels, and a proprietary propulsion leg that looks like a saildrive. \u201cThis boat,\u201d Balch said, \u201chas the very first production unit in the world of Oceanvolt\u2019s newest electric propulsion system, called the ServoProp.\u201d<\/p>\n\n\n\n

\n\n\t\t\t
\n\t\t\t\t\t\"lithium-ion <\/div>\n\t\t\t\n\t\t\t\n
\n On the Arcona 435Z, the space where you\u2019d normally expect to find a diesel auxiliary is occupied by a bank of lithium-ion batteries.<\/span>\n Tim Murphy<\/span>\n\n\t\t\t\t <\/figcaption>\n <\/section>\n\t\t\n\n\n

For our sea trial, Balch was joined by Derek Rupe, CEO of Oceanvolt USA. \u201cIf you can sail the boat and you have some solar, you can go anywhere in the world, and you can make all your power underway while you go,\u201d Rupe said. When we spoke in October 2020, he touted three high-profile sailors who were using the Oceanvolt electric propulsion system: Alex Thomson, for his Hugo Boss<\/i> Open 60 Vend\u00e9e Globe program; Jimmy Cornell, for his Elcano 500 expedition; and Riley Whitelum and Elayna Carausu, who had been teasing their new boat for months on their popular Sailing La Vagabonde YouTube channel.<\/p>\n\n\n\n

The efficiency of Oceanvolt\u2019s ServoProp and the regeneration from it is the promised game-changer in each of these boats. The ServoProp is a leg with a \u00adfeathering propeller that can be set for optimal pitch in three modes: forward, reverse and regeneration.<\/p>\n\n\n\n

\u201cYou don\u2019t need fuel,\u201d Rupe said. \u201cYou don\u2019t need to dock; you can go anywhere you want to go and always have the power for living and propulsion.\u201d<\/p>\n\n\n\n

That\u2019s the promise. But are there also pitfalls?<\/p>\n\n\n\n

Innovation and Risk<\/h2>\n\n\n\n

Marine electric propulsion is an emerging technology. Compared with the mature and settled technology of diesel engines and lead-acid batteries, electric-propulsion systems\u2014with their electronic controllers and lithium batteries\u2014are in a stage of development best described as adolescent. Every sailor has his or her own tolerance for technical innovation. For the promise of fewer \u00adseconds per mile, grand-prix-racing sailors willingly trade a high risk of expensive damage to the sails, rig or the boat\u2019s structure itself; cruising sailors, by contrast, tend to favor yearslong reliability in their equipment as they seek miles per day.<\/p>\n\n\n\n

Folks who identify as early adopters take special joy in the first-wave discoveries of a new technology; if they\u2019re clear-eyed about supporting an ongoing experiment, they see themselves as partners with the developers, accepting failures as opportunities for learning. Sailors motivated primarily by changing the trajectory of climate change might be especially willing to modify their behavior to limit their own output of greenhouse gases. Investing in any emerging technology asks you to start with a clear assessment of your own risk tolerance. We\u2019ll return to this theme with one or two real-life examples.<\/p>\n\n\n\n

\n\n\t\t\t
\n\t\t\t\t\t\"Oceanvolt <\/div>\n\t\t\t\n\t\t\t\n
\n Lithium batteries have far greater power density than lead-acid batteries, meaning they\u2019re lighter for a given capacity. The Oceanvolt system allows you to monitor batteries at both the module level and cell level.<\/span>\n Tim Murphy<\/span>\n\n\t\t\t\t <\/figcaption>\n <\/section>\n\t\t\n\n\n

The American Boat and Yacht Council, founded in 1954, sets recommended standards for systems installed on recreational boats. For decades, ABYC has published standards related to installations of diesel and gasoline engines, as well as electrical systems based around lead-acid batteries. By contrast, it was only three years ago that ABYC came out with its first electric-propulsion standard (revised July 2021). And only last year it published its first technical-information report on lithium batteries (a technical-information report is an early step toward a future standard). The takeaway is that if you need help servicing your diesel engine or electrical system built around lead-acid batteries, you can pull into any reasonable-size port and find competent technicians to help you. With electric propulsion and lithium batteries, that pool of skilled talent is significantly scarcer.<\/p>\n\n\n\n

\n\n\t\t\t
\n\t\t\t\t\t\"ServoProps\" <\/div>\n\t\t\t\n\t\t\t\n
\n This fall, Green Marine introduced a new all-electric yacht to American sailors: the Salona 46 with two Oceanvolt ServoProps, and the ability to hydrogenerate twice as fast. The Salona features twin control panels and throttles.<\/span>\n Herb McCormick<\/span>\n\n\t\t\t\t <\/figcaption>\n <\/section>\n\t\t\n\n\n

To say that a technology is mature simply means that we\u2019ve learned to live with it, warts and all, but that it holds few remaining surprises. Certainly, diesel-propulsion and lead-acid-battery technologies each leave plenty of room for improvement. When a charge of fuel ignites in the combustion \u00adchamber of a diesel engine, some three-quarters of the energy is lost in heat and the mechanical inefficiencies of converting reciprocating motion to rotation. Lead-acid batteries become damaged if we routinely discharge more than half of their capacity. During charging, they\u2019re slow to take the electrons we could deliver.<\/p>\n\n\n\n

Lithium batteries are comparatively full of promise. Their power density is far greater than that of lead-acid batteries, meaning they\u2019re much lighter for a given capacity. They\u2019re capable of being deeply discharged, which means you can use far more of the bank\u2019s capacity, not merely the first half. And they accept a charge much more quickly; compare that to several hours a day running an engine to keep the beers iced down.<\/p>\n\n\n\n

\n\n\t\t\t
\n\t\t\t\t\t\"Oceanvolt <\/div>\n\t\t\t\n\t\t\t\n
\n A pair of dedicated Oceanvolt motor controllers.<\/span>\n Herb McCormick<\/span>\n\n\t\t\t\t <\/figcaption>\n <\/section>\n\t\t\n\n\n

But the pitfalls? Let\u2019s start with ABYC TE-13, Lithium Ion Batteries.<\/i> Some of its language is bracing. \u201cLithium ion batteries are unlike lead-acid batteries in two important respects,\u201d the report says. \u201c1) The electrolyte within most lithium ion batteries is flammable. 2) Under certain fault conditions, lithium ion batteries can enter a condition known as thermal runaway, which results in rapid internal heating. Once initiated, it is a self-perpetuating and exothermic reaction that can be difficult to halt.\u201d<\/p>\n\n\n\n

Thermal runaway? Difficult to halt? Self-perpetuating?<\/i><\/p>\n\n\n\n

\u201cTypically, the best approach is to remove heat as fast as possible, which is most effectively done by flooding the battery with water,\u201d TE-13 continues, \u201calthough this may have serious consequences for the boat\u2019s electrical systems, machinery, buoyancy, etc.\u201d<\/p>\n\n\n\n

If you were following the news in January 2013, you might remember the \u00adstory of Japan Airlines Flight 008. Shortly after landing at Boston\u2019s Logan Airport, a mechanic opened the aft \u00adelectronic equipment bay of the Boeing 787-8 to find smoke and flames billowing from the auxiliary-power unit. The fire extinguisher he used didn\u2019t put out the flames. Eventually Boston firefighters put out the fire with Halotron, but when removing the still-hissing batteries from the plane, one of the \u00adfirefighters was burned through his \u00adprofessional protective gear.<\/p>\n\n\n\n

\n\n\t\t\t
\n\t\t\t\t\t\"Victron <\/div>\n\t\t\t\n\t\t\t\n
\n A Victron Energy Quattro charger\/inverter.<\/span>\n Herb McCormick<\/span>\n\n\t\t\t\t <\/figcaption>\n <\/section>\n\t\t\n\n\n

Samsung Galaxy cellphones, MacBook Pro laptops, powered skateboards\u2014in the past decade, these and other devices have been recalled after their lithium batteries burned up. In that period, several high-end custom boats were declared a total loss following failures from lithium batteries. In March 2021, a 78-foot Norwegian hybrid-powered tour boat, built in 2019 with a 790 kW capacity battery bank, experienced thermal runaway that kept firefighters on watch for several days after the crew safely abandoned the ship.<\/p>\n\n\n\n

Yes, experts are learning a lot about how to mitigate the risks around lithium batteries. But we\u2019re still on the learning curve.<\/p>\n\n\n\n

ABYC\u2019s TE-13 \u201cSystem Design\u201d section starts, \u201cAll lithium-ion battery \u00adsystems should have a battery \u00admanagement system (BMS) installed to prevent damage to the battery and provide for battery shutoff if potentially dangerous conditions exist.\u201d It defines a bank\u2019s \u201csafe operating envelope\u201d according to such parameters as high- and low-voltage limits, charging and discharging temperature limits, and charging and \u00addischarging current limits.<\/p>\n\n\n\n

Graham Balch takes these safety recommendations a step further: \u201cTo our knowledge, the BMS has to monitor at the cell level. With most batteries, the BMS monitors at the module level.\u201d The difference? \u201cLet\u2019s say you have 24 cells inside the battery module, and three of them stop working. Well, the other 21 have to work harder to compensate for those three. And that\u2019s where thermal events occur.\u201d<\/p>\n\n\n\n

Balch followed the story of the Norwegian tour boat this past spring. He believes that the battery installation in that case didn\u2019t meet waterproofing standards: \u201cThe hypothesis is that due to water intrusion, there was reverse polarity in one or more of the cells, which is worse than cells simply not working. It means that they\u2019re actively working against the other cells. But if the BMS is monitoring only at the module level, you wouldn\u2019t know it.\u201d<\/p>\n\n\n\n

On the Green Yachts website, Graham lists five battery manufacturers whose BMS regimes monitor at the cell level. \u201cIf I were sailing on an electric boat, whether it be commercial or recreational, I would feel comfortable with having batteries from these five companies and no other,\u201d he said.<\/p>\n\n\n\n

The broader takeaway for today\u2019s sailors is that lithium batteries bring their own sets of problems and solutions, which are different from those of conventional propulsion and power-supply technologies. A reasonably skilled sailor could be expected to change fuel filters or bleed a diesel engine if it shuts down in rough conditions. With lithium-ion batteries aboard, an operator needs to understand the causes and remedies of thermal runaway, and be ready to respond if the BMS shuts down the boat\u2019s power.<\/p>\n\n\n\n

Real-World Electric Cruising Boats<\/h2>\n\n\n\n

When we met Oceanvolt\u2019s Derek Rupe a year ago, he and his wife had taken their all-electric boat to the Bahamas and back the previous season. Before that, he\u2019d been installing electric-propulsion packages for six years on new Alerion 41s and other refit projects. \u201cMy real passion is on the technical side of things\u2014installations, really getting that right. That\u2019s half the picture. The technology is there, but it needs to be installed correctly.\u201d<\/p>\n\n\n\n

When talking to Rupe, I immediately encountered my first learning curve. I posed questions about the Oceanvolt system in amps and amp-hours; he responded in watts and kilowatt-hours. This was yet another example of the different mindset sailors of electric boats need to hold. Why? Because most cruising boats have just one or two electrical systems: DC and AC. The AC system might operate at 110 or 220 volts; the DC side might operate at 12 or 24 volts. On your own boat, that voltage is a given. From there we tend to think in terms of amps needed to power a load, and amp-hours of capacity in our battery banks. Going back to basics, the power formula tells us that power (watts) equals electrical potential (volts) times current (amps). If your boat\u2019s electrical system is 12 volts and you know that your windlass is rated at 400 watts, it follows that the windlass is rated to draw 33 amps.<\/p>\n\n\n\n

But an all-electric boat might comprise several systems at different voltages. A single battery bank might supply cabin lights at 12 volts DC; winches and windlasses at 24 volts DC; the propulsion motor at 48 volts DC; and an induction stove, microwave and television at 110 volts AC. A DC-to-DC power converter steps the voltage up or down, and an inverter changes DC to AC. Instead of translating through all those systems, the Oceanvolt monitor (and Derek Rupe) simply reports in watts coming in or going out of the bank.<\/p>\n\n\n\n

\u201cWe keep all our thoughts in watts,\u201d Rupe said. \u201cWatts count in the AC induction. They count in the DC-to-DC converter. They count the solar in. They count the hydrogeneration in. And the \u00adpower-management systems tracks it that way for shore-power in.<\/p>\n\n\n\n

\u201cOn a boat like this, maybe I have 500 watts coming in the solar panels,\u201d he continued. \u201cSo then I can think: \u2018Well, my fridge is using 90 watts. My boat has an electric stove. When I cook a big meal, I can see that for every hour we cook, we lose about 10 to 12 minutes of our cruising range.\u2019\u201d<\/p>\n\n\n\n

During his Bahamas cruising season, Rupe observed that on days that they were sailing, the combination of solar panels and hydroregeneration supplied all the power he and his wife needed. \u201cWhen we weren\u2019t sailing,\u201d he said, \u201cwe found that we were losing 8 percent each day, in the difference from what the sun gave us to what we were using for the fridge, lights, charging our laptops, and all that stuff.\u201d<\/p>\n\n\n\n

Rupe\u2019s solution? \u201cTwice in Eleuthera and once outside Major\u2019s, we went out and sailed laps for a couple of hours because the batteries were below 30 percent of capacity. It was good sailing, and the wind was coming over the shore, so we didn\u2019t have any sea state. We did a couple of hot laps on nice beam reaches, and generated about 700 watts an hour.\u201d<\/p>\n\n\n\n

Of the three sailors Rupe touted in October 2020\u2014Alex Thomson, Jimmy Cornell and the Sailing La Vagabonde couple\u2014only Cornell can report back on his all-electric experiences with Oceanvolt. Alex Thomson ended his circumnavigation abruptly last November, just 20 days after the Vend\u00e9e Globe start, when Hugo Boss<\/i> collided with an object in the South Atlantic. And at press time in early fall 2021, Riley and Elayna had just recently announced the build of their new Rapido trimaran; keep an eye on their YouTube channel for more about their experiences with the Oceanvolt propulsion system.<\/p>\n\n\n\n

\n\n\t\t\t
\n\t\t\t\t\t\"Oceanvolt <\/div>\n\t\t\t\n\t\t\t\n
\n The Oceanvolt ServoProp has a feathering propeller that can be set for optimal pitch in three modes.<\/span>\n Courtesy Oceanvolt<\/span>\n\n\t\t\t\t <\/figcaption>\n <\/section>\n\t\t\n\n\n

As for Cornell\u2014circumnavigator, World Cruising Routes <\/i>author, creator of the transoceanic rally, and veteran of some 200,000 ocean miles\u2014he suspended his planned Elcano 500 round-the-world expedition solely because of the Oceanvolt system in his new Outremer catamaran. His Aventura Zero Logs on the Cornell Sailing website, particularly the Electric Shock<\/i> article posted on December 2, 2020, are essential reading for any sailor interested in sailing an electric boat. \u201cSailing around the world on an electric boat with zero emissions along the route of the first circumnavigation was such a tempting opportunity to do something meaningful and in tune with our concern for protecting the environment that my family agreed I should do it,\u201d Cornell wrote. \u201cWhat this passage has shown was that in spite of all our efforts to save energy, we were unable to regenerate sufficient electricity to cover consumption and top up the batteries.\u201d<\/p>\n\n\n\n

Cornell\u2019s experience in that article is raw, and his tone in that moment bitterly disappointed. We recommend it as essential reading\u2014not as a final rejection of the electric-boat concept or of Oceanvolt\u2019s system, or even as an endorsement of Cornell\u2019s own decision that the system didn\u2019t work. I suspect that I may have arrived at the same conclusion. Yet given the same boat in the same conditions, one imagines that a new breed of sailor\u2014a Graham Balch or a Derek Rupe\u2014may have responded differently to the constraints imposed by an all-electric boat, as nearly every cruising sailor today habitually responds to the inconvenient constraints of diesel engines and lead-acid batteries.<\/p>\n\n\n\n

\u201cIf you bring electric winches, electric heads and an induction stove, and then sail into a high-pressure system, you\u2019ll set yourself up for failure,\u201d Balch said. \u201cYou have to balance your power inputs and your power outputs.<\/p>\n\n\n\n

\u201cSailing an electric boat is a return to the tradition of sailing that the crutch of a diesel engine has gotten us away from,\u201d he added. \u201cMagellan\u2019s fleet got all the way around the world, and they didn\u2019t have a diesel engine.\u201d<\/p>\n\n\n\n

Tim Murphy is a <\/i>Cruising World editor-at-large and \u00adlongtime <\/i>Boat of the Year<\/i><\/a> judge.<\/i><\/p>\n","protected":false},"excerpt":{"rendered":"

The Swedish-built Arcona 435Z – with its lithium-ion batteries, Solbian solar panels and new Oceanvolt ServoProp drive leg- is the first all-electric cruising boat we\u2019ve ever reviewed. How does it measure up?<\/p>\n","protected":false},"author":1,"featured_media":47220,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"BS_author_type":"BS_author_is_guest","BS_guest_author_name":"Tim Murphy","BS_guest_author_url":"","hydra_display_date":"November 8, 2021","hydra_display_updated":false,"_yoast_wpseo_primary_category":"167","_yoast_wpseo_metadesc":"The Swedish-built Arcona 435Z - with its lithium-ion batteries, Solbian solar panels and new Oceanvolt ServoProp drive leg- is the first all-electric cruising boat we've ever reviewed. An all-electric yacht has several huge advantages, and some downsides.","_yoast_wpseo_title":"","_yoast_wpseo_meta-robots-noindex":"","arc_story_id":"TLMRWCN5KJH55MGHQMS2QIAMJE","arc_website_url":"story\/sailboats\/the-promises-and-pitfalls-of-an-all-electric-yacht\/","custom_permalink":"story\/sailboats\/the-promises-and-pitfalls-of-an-all-electric-yacht\/","arc_subtype":"right-sidebar","arc_exclude_from_feeds":false,"sponsored":false,"sponsored_label":"Sponsored Content","sponsored_display_label":false,"sponsored_image":false,"post_right_rail":true,"post_right_rail_ad_1":true,"post_right_rail_ad_2":true,"post_right_rail_ad_3":false,"post_right_rail_ad_4":false,"post_right_rail_recirc":true,"fixed_anchor_ad":true,"post_top_ad":true,"post_off_ramp":true,"post_taboola":true,"labels":false,"apple_news_api_created_at":"","apple_news_api_id":"","apple_news_api_modified_at":"","apple_news_api_revision":"","apple_news_api_share_url":"","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_is_hidden":false,"apple_news_is_paid":false,"apple_news_is_preview":false,"apple_news_is_sponsored":false,"apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":"\"\"","apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"footnotes":"","ad_settings_ads_on_this_page":true,"ad_settings_automatic_ad_injection_into_the_content":true,"ad_targeting":"","sponsored_url":"","social_share":true},"categories":[167],"tags":[357,1225,515,1831,255,227],"acf":[],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/posts\/47330"}],"collection":[{"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/comments?post=47330"}],"version-history":[{"count":0,"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/posts\/47330\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/media\/47220"}],"wp:attachment":[{"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/media?parent=47330"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/categories?post=47330"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.cruisingworld.com\/wp-json\/wp\/v2\/tags?post=47330"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}