How to convert a small blue water, sailboat to an electric vessel on a budget

by Fiona and Kevin Horig 5 Dec 2018 06:26 UTC

In January of 2016 we purchased "Clipper". Prior to this we had not sailed or owned a sailboat. In October of this year, 2018, I successful installed an electric motor into my 28ft, 50 year old wooden sailboat.

The exercise has taken two and a half years of research and has in its entirety cost under $10,000, this includes batteries, solar panels and electric motor.

Clipper the EV (vessel), leaning into the future

Clipper is moored on the Brisbane River, and is a classic Alan Buchanan design. Steeply raked stern post hiding a 1.7m full length keel. Clipper was built in 1967. She sweeps up at the bow reducing freeboard, but designed for more buoyancy when beating to windward. Clipper is strip planked in American Mahogany with Oak beams. The plans state a 4hp Sturt and Turner 2 stroke, but her builder Clive Rouse opted for a two cylinder 10hp.

When Clipper passed into our hands, she was not in the best condition. She was powered by 40hp Buhk diesel. The motor was so big the companionway steps had been removed along with the engine inspection cover. Rope had wrapped around the prop which had then been jammed into the rudder. The engine mounts had twisted and the engine was at an acute angle.

This is an account of how we successfully converted our internal combustion engine (ICE) wooden sailboat into an electric vessel. I have recorded YouTube videos relating to each section of this article. You can find the video links at the end of each section. Or go to the Living our Lifestyle YouTube channel to see the videos there.

After purchasing Clipper, her first journey was to the hardstand for an inspection. The hull was sound but there were a number of problems especially around the mast. And of course the engine. The engine had to go. It was too big and powerful for such a small boat. The question was how to find a replacement within our price range? So we decided to have an external mount, custom built to fit an outboard to get Clipper from the hardstand to her mooring on the Brisbane River. From there we could make repairs and research our propulsion options.

Diesel engines are expensive, but to go secondhand would be asking for trouble. The only other option which seemed feasible was to go electric. So I began to research whether becoming an electric vessel was possible. There are no EV's (electric vessels) around us, so there was no one I could ask about the practicalities of going electric. In fact everyone was telling us of all the electric vessel failures they had heard of. So it was up to us to do some research. We were in no hurry and had a limited budget.

There were a lot of questions to be answered. AC or DC, what sort of batteries- lithium or wet cell, weight distribution, how to recharge.

This is our journey of making Clipper into an electric vessel bringing her into the 21st century.

"It is our belief that technology has shifted enough that the change to electric will be swift and if we are not acting with the change we will be left behind".

Why we decided to convert our sailboat to an electric vessel

We test drove a Tesla in May of this year, 2018. We don't own a car, but we are fascinated by the technology, and wanted to learn more about it and the experience it can give. Well, what an experience! The Tesla test drives are free, book one, you won't regret it.

Driving the Tesla reinforced our belief that the electric disruption is here and available now. Nearly three years ago when we talked to others about the EV movement, we were thought of as "one of them", and to some extent this is still true. Though recently we are finding that attitudes toward electric vehicles and vessels are changing rapidly.

Technology has shifted and it is our belief that technology has shifted enough that the change to electric will be swift and if we are not acting with the change we will be left behind. Fiona and myself like to lean to the future, not be dinosaurs waiting for extinction because we did not have the courage and ability to adapt.

The process of converting Clipper to electric drive has been slow. This is because we live on a small income and there was a need to balance the cost of renovating Clipper with our lifestyle. There is no doubt that it has been challenging at times.

Cost - Reason 1

The cost of going electric is comparable to that of fitting an ICE (internal combustion engine). The total cost was less than Au$8 000. This included the sailboat kit consisting of a:

• 10kW engine, electronics for the motor, gear reducer, display unit, speed control,
• 9.5kWH of usable battery storage
• 6 *160W solar panels.

The batteries were second hand but will give five years use. The batteries cost $150, Clipper has eight of them, total $Au1,200. The batteries weight 400kg in total. This seems comparable to the weight of a diesel motor and the weight of the fuel to run the motor.

The maintenance cost is greatly reduced as the electric engine and reducer have two moving parts. Compare this to a diesel engine which has hundreds of moving parts. We often hear that the weakest part of a sail boat is the engine. Our fuel costs are nonexistent and there is no such thing as dirty fuel for us. The batteries are recharged as you sail through our solar panels. The energy storage (batteries) are used to power the house and motor. This spreads the initial cost.

We are living on the power generation that would otherwise be discarded.

Freedom - Reason 2

Firstly there are no prestart checks before using the motor to leave the mooring. We just turn the key and the motor starts. The only water we check is the depth sounder. No oil check, no concern about dirty fuel, no air lock in the fuel line and no dirty fuel filters. Just pull the anchor up (we do not have an anchor winch) and go.

The EV (electric vessel) allows you to go anywhere with the potential of unlimited range and to motor quietly. We are not constrained by fossil fuel needs, and spending our money on diesel with our budget was a very real limiting factor. Remote islands are going solar because diesel is too expensive to import. We have the freedom to head into a port and visit because we want to go there, not because we need to refuel. This allows us to spend our money on items that are necessary or important to us.

Our electric sailboat will allow us to visit remote locations, we don't need to worry whether there is diesel to fuel up. We just need a few good sunny days and we have recharged our batteries. We intend to have a small generator as a back up, but so far, on the Brisbane river we are generating more power than we can use and our battery bank is fully charged each day. Visiting remote locations is a large part of the sailing experience, and without the fuel concern this is made much easier. We will bring a sense of respecting the fragility of the eco systems to these remote locations. And not be a contributor to the rising sea levels.

We have the freedom to be powered by our solar panels during the day. And at night time we run off the stored power in our battery bank. We won't be disturbing those anchored near us or the peace and quiet that we enjoy ourselves. There is nothing worse than a wind turbine or generator at night disturbing the very peace and reason you would sail to remote locations.

It is time to go electric

The perfect time to go electric has been with us for some years. Having spent two years investigating the electric option, we have found that it is only our reluctance to take the first step and lack of reliable information about what is available that is the deterrent.

Batteries are often the reason given for not going electric. We are using AGM batteries which is technology that has been with us since the 80's. After speaking with the Arrow electric racing team, we were advised that if weight is not a problem, then they are better than lithium. More reliable and easier to maintain when things go wrong. Especially if you intend to voyage to remote locations. But the time is nearing when this will all change and lithium solid state will hopefully be a game changer in battery technology.

There is enough information on the internet to calculate the displacement and force needed to push Clipper along at 4 knots. Each boat is different so I will not go into the details on whether electric will work for you. Needless to say, I am confident that I have made the right decision and electric will push Clipper along at four knots drawing eight amps an hour with the tide. Or 15 to 30 amps/hr without tide assistance. The batteries we have can quite easily allow the motor to draw its maximum of 120 amps an hour. The motor in general does not rapidly deplete the batteries.

We often read about the Tesla or Nissan Leaf EV's. But very little about what is happening with electric vessels. I think we should start paying attention. The EV business is growing, two strokes are being banned and pollution laws are becoming stricter. Who wants to hear a screaming outboard when watching the water life. or how about autonomous navigating. Using Pixhawk to connect the electric motor so you now have auto navigation with auto speed control.

The future of yachting is here now and it is silent.

Cost of batteries

The cost of batteries is the most limiting factor. Not only now but in the future when it is time to replace the batteries. We also needed to consider the cost associated with getting power from the sun through solar panel and the cost of the regulator which regulates the power from the panels into batteries. Wind, solar and a backup generator were the power options open to us.

We purchased a 400 watt wind generator to see for ourselves the realities of wind. The generator is noisy and dangerous. Needless to say, wind generators are not for us and it was quickly relegated to the lock up. Solar on the other hand is very affordable. We have been able to acquire 4 * 160 panels for less than $400 and they are getting cheaper all the time. This is more than enough to keep the 8, 12650 CSB absorbed glass matt batteries fully charged. Even on a cloudy day the panels do far better than the wind generator.

We were lucky to get the batteries at the right price from a business that refurbishes old batteries. The batteries were previously used in an uninterrupted power supply (UPS) setup. Five years old with five to seven years useful life left in them if looked after. I was only going to install four batteries for the 48 volt motor but ended up with 9.5 kW hours of useful storage for AU$1200. Twice what I needed but at that price I couldn't resist getting eight batteries.

Batteries are the most complicated part of the system. Getting the right batteries and the ability to keep them operational is difficult.

Advantages of a 48v system

There was no electricity on Clipper when Clive and Margaret set out to discover the world. In the photo taken as they passed through the Panama Canal, the oil lamps used for navigation lights can be seen fitted forward of the coach house each side of the mast.

Times have certainly changed. The availability of power has meant that the number of electrical appliances available for yachts has greatly increased. On Clipper we power a microwave oven, slow cooker and even use an electric milk frother for making the best cappuccino. But yachts are commonly fitted with a 12v battery system for the house and a 24 volt system for the anchor winch. All the batteries are recharged from an alternator on the diesel which is also 12 volt. We have found the 12 volt system is lacking and out of date. It is not able to provide the power of living with modern conveniences.

However, we find there is a reluctance among yacht owners to convert to a 48 volt electrical system. Boats have always been 12 volt, why change ?

We have fitted a 48 volt system and Clipper now has a micro wave oven.

The electric motor is 48 volt so we had to decide how to set up the electrics. The choices were to have either two electric systems. One 12 volt battery set for the house and another 48 volt system for the motor and the electronics that go with it. Or to have just one 48 volt system.

I decided to go with one 48 volt system. The advantages in using a 48 volt system has become more apparent. Why have all this stored power in Clipper, which is now essentially a portable battery pack for the motor, and not use it. Using all of the stored powered is where the 48 volt system is amazing. having only used 12 volt over the years, learning about 48 volt has been a great learning curve.

I am not an electrical engineer qualified to give advice. But put in layman's terms there is 4 times less current while accessing the same amount of power. This means you can use wire with a smaller diameter to run appliances with a high power specification. The microwave is a classic example. How many yachts use a microwave and do not have a generator or use it only when at a marina ? Not too many I would think.

We can only run high energy draw appliances because of the higher amperage we can draw from the battery. The 48v system means I can run thinner wire from the battery bank in the stern to the bow. It is cheaper, less risk of fire and I can run more appliances. I step down the voltage to run the 12v wire a short distance to each appliance.

There is the great advantage of having a constant power supply with the 48v system. The most power fluxuation we have had has been only 0.2v. That is from 11.9 to 12.1v. This is nothing compared to running a 12v system where voltage fluxuation can be anywhere from 10.5 to 14.5v. The fridge runs more efficient and the lights are brighter. After all, they are designed for 12v and not 12.7v. Running LED's at 14v requires a heat sink. They simply are not designed for higher voltages. The risk of fire is always present on a boat and any management of of this risk is highly advantageous.

All this free power, saving money instead of doing nothing with it while waiting for the motor to be run. Completely opposite to having a tank of diesel sitting there.

As the journey continues we are discovering more advantage of the 48 volt system

Fitting the electric motor

One question everyone asked about installing the electric motor was: Who is going to fit it? To me this was an odd question.Fitting the motor to me was probably the easiest part. All you had to do was line the shaft up and make some engine mounts to fix the position. There was no 200kg diesel engine taking up all the space to crawl around, plenty of room to move, if the shaft did not match lift the gear reducer with one hand while placing the spacer the other hand.

The only engineering i needed done was having the shaft cut, cutlass bearing replaced and stern gland fitted. I left this to P&W marine engineers who did a very professional job. Why would you have the hassle when it is a lot easier getting people who know what they are doing and at a very reasonable cost.

Sounds simple, and in reality it was. Fitting an electric motor is easy. making the engine mounts was the real surprise. Thanks YouTube. The place where you can find almost anything. Here you can find out how to make auto suspension mounts. It is where i got the idea for the engine mounts.

The engine mounting holes in the hull were 19mm and I was using 12mm bolts to secure the electric engine to the hull. This caused a vibration so to solve this problem I used polyurethane to hold the bolts in place. As i held the bolts in place I poured the poly into the hole. It only takes about 90 seconds to set. Making for an easy process. I made some moulds out of wood to hold the gear reducer at the correct horizontal height, then used two turn buckles to align the gear reducer shaft to the prop shaft.at the correct angle up and down.

Where to from here

This our story of the adventure we have chosen to go on. It is far from finished as we plan to test to learn how to sail Clipper, the EV. Going electric has been done before and gets easier as time goes by. We are happy that we are among the first in Australia to not be reliant on fossil fuel technology. Clipper is a classic, but this does not mean that she is too old to lead the way in new technologies and be among the most advanced.

Nos to make an auto pilot that can connect to the electric motor to give constant speed and direction. Who knows, connect a camera to give navigation by beacons or avoiding collision by changes in light conditions.

It is all possible and exciting because we are living in exciting disruptive times.

This article has been provided by the courtesy of livingourlifestyle.com.