Southerly 47

Southerly 47

“We’re surprisingly happy with the diesel-electric. Day sailing is very easy, typically we use less than 15% of our battery capacity leaving port and the regen and small solar panels enable us to put a little back over a day’s sailing. We use another 15% getting into port. The batteries are easily fully charged overnight. In two weeks sailing around Northern France we used the generator twice for around three hours in total, when we couldn’t recharge overnight.

Motor sailing is fabulous with an electric motor. It appears that 1.5kW to 2kW of power is sufficient for us, which means we can motor sail for many hours before any diesel is required. Moreover, the lack of noise makes motor sailing a real pleasure.

The generator is much quieter and pleasant to use for charging than the engine ever was.” – Owner of the Southerly 47

Doris is a Southerly 47 whose owners specifically came to Sail Electric to accomplish a detailed modernisation and prepare the yacht for a planned round the world expedition. She has since undergone a full transformation package with Sail Electric, to ensure the least possible environmental effect during her travels, whilst supporting the crew on board to work with the natural resources available.

Seeking a way to fully achieve sailing with minimal impact, harnessing both wind and solar power, phase one for Doris has been completed with the installation of a 30 kilowatt AXC modular motor system from Oceanvolt. This drive system is powered from a 28-kWh lithium phosphate battery storage system and further supported with a 15-kilowatt onboard DC generator. The ship’s wide monitoring and control link to the internet provides real time and historical data capture, so that the owners know what’s happening at any given time anywhere on the planet. Essentially, it also means that their system can be relayed back to Sail Electric’s central server in the UK. This level of remote support, combined with Doris’s state-of-the-art electric propulsion system, will provide her owners with full confidence to embrace next generation sailing.

Phase two will include the installation of a 1.5-kilowatt solar display mounted on a custom stainless-steel arch, located to stern and powering the main energy storage facility,  on the coach roof will house a 12v solar array that will optimise the vessel during the hours of daylight, and support the the recharging of the 12v element of the vessel after using the lighting, freezers and refrigeration at night. This comprises a set of durable, high efficiency, flexible solar modules which will support both the vessels energy storage  systems.

The vessel also has battery to battery charging, and with the monitoring system onboard to view in real-time, a decision process is easy to understand and adaptable to whatever natural resources are available at any given moment. With the regeneration function available under sail available at sailing speeds over 6 knots, coupled with both solar arrays, this means that renewable energy is always prioritised.

Over some three years, Doris’s programme of works has interrogated every section of the vessel, preparing her to sail on an expedition of a lifetime. In preparation for this global adventure, her owners will initially be sailing more locally, adapting to life on board and learning how to manage their new and very much improved boat. Thanks to the advice and experience of the Sail Electric team, Doris will sail with little impact, as she first tours the UK, and with her diesel generator there  if needed as a backup. Doris truly is a go-anywhere, off grid expedition yacht.

The owners of Doris commented, “When we decided to convert our Southerly 47 to electric propulsion, we did our homework, and discovered that lots of suppliers wanted to do it but none seemed to actually know how to.Then we found Sail Electric. After our very first conversation with Wayne we came away knowing we had found the right people for the job. Nine months later and our beautiful Doris has an electric propulsion system powered by regeneration and we are looking forward to the most beautifully crafted aft solar array. The team at Sail Electric have been an absolute joy to work with, incredibly knowledgeable, communicative and flexible. They have navigated post-pandemic supply chain challenges and demanding clients with good humour and hard work, regularly going the extra mile to ensure everything is perfect. We honestly couldn’t be more delighted with the result and can’t wait for our round the world electric adventure to begin.”


"With long-distance passage planning, weather is always on top of the agenda, but when racing, you are told when to leave, whatever the weather! The AZAB is a Category 1 offshore race, some 2400 NM plus qualifier, a fully electric yacht had never entered before. Along with the owner of this Southerly 47, one of our agents co-skippered the race to the Azores and back in 2023, the ultimate test of the method and technology. Although this Southerly 47 is hybrid electric, the challenge was set by both skippers not to use the diesel range extender, instead competing in the offshore race using only the power of nature. A first for the AZAB and the skippers, zero diesel used and nearly 3000 miles of racing, the yacht never missed a beat."

Technology used in the electric Southerly 47 sailboat:

  • Length overall: 14.35 m
  • Boat beam: 4.46 m
  • Light displacement: 17256 kg
  • Electric motor system: Oceanvolt AXC30 shaftdrive motor
  • Electric motor system nominal power: 30kW
  • Electric motor system voltage: 48 V
  • Propulsion batteries: 28.8 kWh Lithium battery bank


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