Staycation Electric Motor Progress

So we are coming to the end of our staycation. Managed several walks, one food shop, one visit to the pharmacy.

Cushions

Plus Jane has made lots of progress on the cushions. She has nearly finished all the ones we have foam for. That is all the backrests for the U-shaped part of the saloon finished. Also nearly finished the cushion that goes behind the log bench on the starboard side to make the a great sea berth.

Electric Motor

Meanwhile, I’ve continued to make progress with the electric motor frame. both end frames are complete.

Front and rear motor end plates (outside faces)
Front and rear motor end plates (inside faces)

So I have been able to attach them to the motor, add the shaft, belt pulleys and belt drive (and tension it).

Motor in the frame with the belt tensioned.
Note that the back is deliberately lower as the propeller shaft is not horizontal.

Remaining motor tasks

So just a few tasks left.

While it is already very rigid (each end frame weighs about 10kg) I do want to make sure there is no twisting or other movement between the motor and the shaft).

  • so I need to cut and drill the 4 angle lengths to attach the front and back together at the corners (all but two of the bolts already fitted to the end plates)
  • add one diagonal flat bar per side.

I need to cut a keyway in the shaft to lock the large pulley to it. Then fit both pulleys with keyways.

I haven’t got the right spanner for the big bolts on the bearings yet, that will have to wait until we can get to the boat.

Once we have sorted all that we have a much larger angle length which will be for the two cross bars that rest on the engine mounts (which we have not got yet).

Of course I’ve still got to build a battery box and do all the wiring and fitting. The box for the 4 x 300AH batteries will be positioned just forward of the pulleys. As the box will drop between the original grp coated engine bearers the batteries (2 layers of 2 batteries) will end at about the same height as the motor frame.

Weight comparisons

I’ve done a quick estimate of some of the weights. I can check what we have take out more accurately later. But

Electric Motor + Frame + Batteries (1,200AH) = approx 220kg

Diesel Engine with gearbox approx = 180kg
Two huge stainless steel fuel tanks? Guess more than 80kg (will check)
All the exhaust components, fuel filters etc etc? Guess at least 30kg
Original engine bearers (not being replaced) 20kg
Full load of fuel. Guess 70 gallons which is around 220kg
Starter battery approx 30kg

Total being replaced is over 560kg

So the new Electric motor fully fuelled is 1/3 the weight of the diesel engine fully fuelled. Even compared with empty diesel tanks the electric motor system is 1/2 the weight. And that weight is all in the centre of the hull with a much lower centre of gravity than before. So our boat trim won’t vary as much.

Space gains

Beyond all the weight comparisons there is the space issue. The entire electric motor and battery bank easily fit in just the old diesel engine compartment (with space for house batteries, inverters and solar charge controllers). So we gain 1 fuel tank plus old battery box (for 4 lead acid batteries) into the cockpit locker. Plus we gain the 1 fuel tank space at the side of the corridor to the aft cabin.

And more gains

Then there is the smell! Diesel smells horrible and inevitably over 42 years there have been leaks of fuel and exhaust soot in the boat. All that is going to end up cleaned off and painted. We can already tell the difference, by the time we are finished it will be lovely 🙂

The need for Active Solar power generation

With the our commitment to Zero fossil fuel sailing we have been having to review and update our initial Solar plan. Designing our Solar Arch has been part of that.

The traditional “passive” approach to solar is not going to work for us. By that I mean the idea of putting up a few solar panels and forgetting about them. We need to generate far more electricity from solar than this approach achieves.

So what do I mean by “Active Solar power generation”. Unlike shore based like people living on boats are used to being proactive about energy use and supply. So the mindset includes managing consumption and keeping an eye on battery state. However, for a long time this has been done with the expectation that you can always charge the batteries by running the diesel engine or a generator or by going into a marina and using the shore supply.

We are making a determined effort to keep electric consumption down through a number of deliberate choices:

  • Wind vane self steering, keeping the electric autopilot only for redundancy
  • No freezer. Yup it does constrain the food you can take and keep but fridge and freezer are huge electrical power hogs.
  • Reduced Computer consumption. We are going to be minimising laptop use by having Raspberry Pi single board computers for navigation, entertainment and “office work”. They run on 12 volt.

However, by committing to Zero fossil fuels we are increasing our electric consumption significantly and reducing our energy sources.

Increased consumption:

  • Electric Motor. This uses a lot of energy and is the opposite to the norm. When we motor we will be drawing lots of energy from our batteries rather than putting it in. While we will have regen (charging the batteries when the propeller spins while you are sailing) the change is incredibly significant as the norm is to see the diesel engine as a provider of almost unlimited “free” electricity and hot water. Of course it isn’t free at all, but more a desirable side effect that has resulted in a significant increase in the number of hours the engine is used. So has become a norm to motor whenever the wind speed drops because at the same time you will charge the batteries and heat the water.
  • Electric cooking. All forms of electric cooking (Induction hobs, Microwave, Pressure Cooker) use a lot of power (although mostly for a relatively short time). The norm is to burn bottled gas (occasionally diesel or paraffin). By cutting out another fossil fuel we increase our electric consumption.
  • Dinghy Outboard. We have an electric dinghy outboard engine. So far the boats we have seen with electric motors (Sailing Uma, Beau and Brandy) have not switched to electric outboards (despite the hours they spend maintaining their petrol outboards). In part that is because they want to be able to go faster in the dinghy (see this video from Sailing Atticus for a good reason for this) but it is also about the need to charge the outboard engine battery.

Increased generation

So this is the heart of the challenge. By committing to no fossil fuels all our energy needs to come from renewable sources. We have three options:

  • Engine regen. We are hoping this is going to be significant for us. On longer passages it will do more than recharge the motor batteries from leaving harbour but will contribute something to the daily consumption. It also has the potential to provide power through the night. However, it is only available while sailing and only while you are sailing fast enough (probably won’t contribute much below 5 knots). As liveaboard cruisers typically spend the vast bulk of their time at anchor the contribution isn’t that great.
  • Wind generators. These have the significant advantage of potentially providing significant power at night and through the winter. However, there are problems. Many people complain about the noise and vibration. Fitting them without causing shading on solar panels is a challenge. They do require a lot of wind, probably more than you would normally be looking for in a sheltered anchorage. We’ve looked at the Rutland 1200 but at the moment feel the cost and installation challenges are too great.
  • Solar. The typical installation of solar has been changing quite significantly. For liveaboard cruisers the norm now seems to be to have a solar arch with between 300 and 600 watts of solar panels. That is enough for minimal electric motor use (see Sailing Uma, Beau and Brandy or Rigging Doctor) but not for electric cooking, electric outboard etc.

So Active Solar

This is where our plan differs. We are going to have to be far more active about our solar generation. That means a number of things.

Our solar arch needs to be tiltable to increase it’s efficiency (both Sailing Uma and Beau & Brandy do this but the vast majority of solar arches do not).

When sailing we will need to be active in adjusting our solar generation. Some panel positions will be pretty much setup and forget (such as covering the upturned dinghy on the foredeck with panels before leaving harbour). Others will only be possible in lighter conditions (some along the guardrails for example).

The goal will be to have enough permanent solar when sailing (solar arch and wheelhouse = 510 watts) so that with the regen and battery bank we will be able to get through a gale when we have to put all the other panels below. That shouldn’t be too hard as in those conditions you are not likely to be doing much cooking and you can put off charging the dinghy outboard.

When conditions improve we should be able to sail in light to moderate with an additional 1,050 watts (2 x 175 watts on the dinghy, 4 x 175 watts on the guardrails from the cockpit to the stern. Some of this is going to suffer from massive shading at times so we are assuming it will be about 1/2 as efficient as the solar arch.

Then at anchor we need to have lots of solar panels that come out and are positioned dynamically. We will need to have solar panels positioned above the mizzen boom, around most of the guardrails and possibly above the deck. How many of these we will need is still uncertain (it depends so much on where we sail – if Coronavirus and Brexit mean we have too stay around the UK then we are going to need a lot more solar in Scotland than the Caribbean).

So far we are planning on a total of around 2,400 watts (13 x 175W + 4 x 40W) which so far I have only heard of on large catamarans.

We will need to be active in working with these panels. We will need to adjust the tilt during the day so that as the sun and boat move their efficiency is kept as high as possible. We will need to move them if other boats come alongside or if we are in a marina. We will need to put a lot of them below when sailing.

So I’m going to be building a standardised wooden surround for each panel. This will provide attachment points so that any panel can be fitted to any section of guardrail (and be tilt adjustable) or to the supports above the boom and dinghy. The edging will provide bump protection when moving them around and allow panels to be stacked without scratching the glass. We have chosen the 175W Victron panels as our standard because they are about as large as we can lift, manoeuvrer around the boat and fit through the main hatch into the cabin.

Exactly, where we will store all the panels that need to be “reefed” (taken down) in a gale is currently not fully sorted. Some might go on the aft deck or aft cabin. Some in the corridor to the aft cabin where one of the diesel tanks was. Some in the forecabin (which is likely to be mostly storage when there are only 2 of us).

We are under no illusions that we can achieve zero fossil fuel without ongoing, daily labour to maximise solar generation. But while that might seem a lot of work remember that we won’t spend any time (or money) finding and visiting fuel docks or carrying jerrycans around in the dinghy.

In summary

We believe we can capture several orders of magnitude more solar power than is generally the norm for monohull cruising yachts. But it will require us to work at it every day.

Staycation Progress 1

So on holiday this week but still at home. Very much trying not to take risks or push boundaries of the rules.

So today Jane has finished another Saloon backrest:

We have also been making more motor progress. Working on 2 frame back plates, I finished drilling the end stop holes for the 4 slots that are used to attach it to the motor with it’s height adjustment.

The one end plate at a time we started using the Dremel to connect the holes into slots.

We managed to finish all 4 slots in one of the plates and do a test fit. Perfect first time 🙂 On this plate we now need to notch the edge (marked in read) to clear the control wires that come out the back of the motor.

Then repeat the slots in the 2nd back plate.

Once we have the front and back plates all done we can start adding the lengths of angle stainless steel to the edges, plus more to connect the front and back plates at the four corners. Then one flat stainless steel bar per side as a diagonal cross member.

At that point we should be able to add the bearings for the shaft that will connect to the propeller shaft, then the shaft, the belt drive pulleys and the belt drive itself.

The motor throttle is due later this month and the 4th battery (so we will have 4 x 12 volt 300AH batteries connected in series to give 1200AH in total, delivered at 48 volts.

Hopefully it won’t be too long before we are able to get to the boat, at least for a day trip, so that we can collect all the battery cables and crimp connectors. Then we can get it all wired up and tested at home.

Sustainable Sailing and Human Power

I’ve been quiet on here during the COVID-19 pandemic so far. More urgent priorities and has seemed inappropriate when so many have been dying, ill or struggling in other ways. However, some countries are now starting to move beyond lockdowns and it now seems more appropriate to focus on building a better future. One that is more human in scale, more caring of people and planet, more sustainable. So here are some thoughts of another aspect of bringing Humans into Sustainable Sailing

With a goal of zero fossil fuels being central to our understanding of Sustainable Sailing there is a big gap in what we have been planning so far.

What about using human power?

I’ve come up with a number of potential uses for human power when Sustainable Sailing. Let’s see if any make sense.

  1. Moving the boat
  2. Replacing electric powered items on the boat
  3. Generating electricity
  4. Getting to/from shore
  5. Getting around on shore

Now we have a list, time to consider them in some detail.

Moving the boat

The best examples I know of for actually moving a yacht by human power come from two races. In the UK The Three Peaks Yacht Race (run to and climb the highest peaks in Wales, England and Scotland; sail between them; engines only allowed within specified areas of the ports) and the Race to Alaska (No motor, no support, all the way to Alaska.
The physical endurance, saltwater know-how, and bulldog tenacity to navigate the 750 cold water miles from Port Townsend, Washington, to Ketchikan, Alaska). There are great videos from Race to Alaska 2019

My conclusion is that if you want to be able to make any real progress with human power to move a yacht then 3 conditions need to be met

  1. You need a large crew so that you can have people who are rested enough to cope with a storm that follows a long calm where you have been using human power.
  2. The lighter and easier the boat to move the more practical it is. A racing multi-hull is the best option, a live-aboard heavy displacement mono-hull very bad.
  3. So far the most effective solutions for speed are also fragile and take up a lot of space. Neither good for long term cruising.

Therefore, it seems to me that it is better to invest in improved sailing performance in light winds to minimise the amount of time that human power could improve your speed. For shorthanded cruising (eg a couple living aboard) an electric motor is going to be far less risky in harbour situations where you don’t have spare crew or where you need to be able to cope with tides and headwinds while manoeuvring.

Replacing electric powered items on the boat

Probably the only electric powered item that we plan to have that we could easily (and more cheaply) replace with a human powered version, is the windlass for raising and lowering the anchor.

The electric windlass we are fitting can be used manually. However, having an electric windlass seems to us to be a great safety feature.

It allows us to have a much heavier anchor and chain,

it means we won’t put off moving to a more sheltered anchorage because we don’t want to manually raise the anchor,

if you need to leave an anchorage in bad conditions we won’t start sailing while physically exhausted from raising the anchor.

It raises the anchor much faster, which with the saving in physical effort makes sailing on and off anchor much easier

So we think investing in better electrical capacity is a better option here.

More and more yachts, particularly larger ones now have electric winches and/or electric sail furling. We plan to stick to manual as long as we are physically capable, possibly getting an electric powered winch handle rather than a whole winch when we need help.

Most of our other electrical systems are cooking or water related. So far no obvious human powered options (water-making would be great but falls far short of daily needs for a lot of effort).

Generating electricity

How about using a bike or something to generate electricity while we exercise? Our conclusion is that it can’t generate enough to be worthwhile (especially when you factor in a small crew). Time and money better spent ensuring maximum power from your solar by keeping it clean, shadow free and pointing at the sun.

Getting to/from shore

This is where I believe it starts to get very interesting.

We have gone for probably the most popular dinghy style (A rigid inflatable with aluminium hulls). Having inflatable hulls makes getting on and off the boat so much easier and safer with no risk of damage. An aluminium hull is both lighter than the traditional grp and much tougher for dragging up beaches (it is also fully recyclable). Ours is a Highfield Classic 290 which we should be able to store on our fore deck when sailing (just in front of the main mast), it also fits inside our van for transport to and from home (nowhere to keep it near the launching place near our mooring).

Ribs are pretty rubbish to row (the hull is too wide with too much water and wind drag, plus the seating position is inefficient. So we have an electric motor, but that means we sacrifice speed, it won’t be possible to plane (but we don’t expect to want to zoom to fantastic diving spots for example).

Could human power provide an alternative? We have looked at various “toys” to use when at anchor. SUP’s (stand-up paddle boards) are very popular and the inflatable ones easy to store. But practical and useful they are not, unless it is warm enough to wear just a swimming costume and you don’t need to go far and it is smooth water without much wind and you don’t want to carry anything. An inflatable kayak is a little better in practicality.

So instead we are wondering about carrying something designed to row well. The best option that we have found is from Angus Rowboats, they have an amazing track record (first human powered circumnavigation, rowing across the Atlantic, coming first in the under 20 feet category of the Race to Alaska). They have this beautiful Oxford Wherry available as plans or a kit. I’ve had a chat with Colin Angus and we agree it should be possible to make a minor adjustment so that the wherry can be divided into 3 nesting parts for storage on deck (we think it would fit on our aft cabin). We think that this would be the most efficient human powered dinghy that you could carry on a yacht. With a sliding seat you will be able to carry yourself and a passenger to explore rivers and harbours at a similar speed to our outboard engine on the rib.

We don’t think this would be suitable for our only tender, the key issues is that with the sliding seat you have to have outriggers for the oars and this makes coming alongside a yacht very difficult without causing damage (so instead we will use the rib as a dock/boarding platform). The lack of an engine option makes carrying large amounts of shopping or fighting the fast tide in the Menai Strait unattractive.

Getting around on shore

It amazes us how few of the sailing YouTube channels carry bikes with them to get around on the shore, particularly to go shopping. In a recent video Beau and Brandy had a 30 minute walk to the supermarket. They then had to push the loaded trolley back before an hours round trip returning the trolley.

Matt and Amy on Sailing Florence seem to be the best sorted with two Brompton bikes but we think they too are missing a key thing to transform using bikes for shopping. What they need is a trailer. For us there are two stand-out options (they need to fold and they need to be suitable for any bike and they need to resist corrosion). If we didn’t already have a trailer then the Cyclone Range from Radical Design are brilliant. The other option (and yes we have one) is from Carry Freedom We have an old Large Y-Frame but there are other options now. Here is mine in use (Cargobike sadly not so suitable for fitting on board boats, plastic box is just bolted on, anything else could be used). It works as a hand cart too for getting right to the loading point.

Conclusion

By far the most cost effective and transformative use of human power in Sustainable Sailing is a bike with a trailer.

A good rowing dinghy (probably in addition to a RIB) comes second.

For everything else your energy is better used improving your boats sailing ability and electrical generation and storage.

Friday progress #18

So we came to the boat late last night to spend time off with plenty of Social Distance. Didn’t come within 50 metres of anyone last night (apart from those in other cars). Today we spoke to Richard working on the boat next to us in a howling gale from at least 5 meters distance. I did buy one thing from the chandlery but at an appropriate distance from the staff. Now it seems we have the boatyard to ourselves. Will return home tomorrow.

It feels like slow progress today. More clearing out of the diesel engine remains (fuel pipes, exhaust, wiring) and cleaning of the space. We have managed to get the very heavy steel engine bearers out (not sure yet if we will reuse them at half the length or not need them).

The slowest part has been trying to sort out the Stuffing Box. This provides a seal around the propeller shaft. We want to replace it for 3 reasons

  • It needed a fair bit of work doing a) the “stuffing” replacing anyway as it was apparently leaking consistently b) the grease gun needed servicing c) there is a pressured water supply from the engine cooling which we won’t be able to maintain.
  • We want a modern leak free alternative to keep the area around the electric motor as dry and salt free as possible.
  • We want to keep reducing maintenance and the newer dripless seals go for years without any servicing (and without needing to take the boat out of the water to do that servicing).

We haven’t managed to do this yet. We can’t undo the last of 4 bolts holding the stuffing box outer casing in place. Thanks to the Rival Association Facebook page we think we have a couple of potential solutions to look at.

So some photos. All looking a lot cleaner and more empty but not finished yet.

Most of the fuel pipes plus assorted other engine bits
Fighting the stubborn bolt (it is still winning)
What remains of the outer shell of the stuffing box.
That last bolt, always the least accessible one is the one that won’t undo (a stainless steel bolt in a bronze shell is a recipe for getting stuck due to galvanic reaction between dissimilar metals)
Aft wall of the engine compartment looking very empty. Note also the “missing”, heavy, metal engine bearers, they are not needed for a 40 kg engine that runs smoothly compared to a 180kg engine that tries to shake loose all the time.
The cockpit locker, looking from across the engine bay. The dark stain is where the port side diesel tank was. The batteries were on the left between the engine bearer (foreground) and the fuel tank. On the right was the hot water, the fuel for the heater, the water pump and the fridge condenser.

The whole space should now be free of diesel and we have vacuumed all the worst mess out. Won’t smell properly clean until the last bits have been removed, it has been cleaned, sanded and painted. But at least until then we have 6 big holes (from seacocks, propeller, exhaust, bilge pump) for ventilation.

We didn’t get to eat until 9:30pm, so am feeling very tired now. Not sure what if anything we will manage tomorrow before heading home.

Another not Friday progress

We won’t be making direct progress on Vida this Friday as I’m working. Still we have been making some progress at home.

Jane has ordered more foam for the saloon (dinette backrests and the outboard portion of the sea berth).

I’ve been collecting a few more parts for the remaining jobs. Now that we have discovered the bilge, I’ve got a water level sensor and an electric bilge pump that it will control. That will mean that should there be a leak we can focus on finding and solving the cause while the pump keeps the water at bay as much as possible. Also if water comes in while we are off the boat then at least it will get pumped out for a while (given that the only holes below the waterline will be for the cockpit drains we have massively reduced the chances of this, unless sea lions attack us). However, there are some problems.

Firstly, at the moment we don’t have good enough access.

Secondly, it looks disgusting. We can’t allow water to get contaminated with all this yuck get pumped out into the sea.

So I’ve got some heavy duty bilge cleaner to try to get it clean enough to not contaminate any water that sits in it. Plus we want to get it clean enough for epoxy resin to stick to it, so that we have options for reducing it’s size and adding some strength (more bio-epoxy arriving soon).

Another area of progress has been towards more visible progress. We’ve ordered everything to fully refurbish our two hatches (one over thee aft cabin and the other over the saloon). Currently, the acrylic is so crazed that you can’t see through it, we had thought we would leave this until later but there are leaks between then acrylic and the frame, leaks in the seal in the frame and leaks between the frame and the deck. At the same time we have ordered a new acrylic panel for the roof of the wheelhouse, you couldn’t see through it and it was also leaking. All of that from Hadlow Marine for less than half the cost of one new hatch.

Finally, a spot of good news is that while the extra batteries are delayed due to the Coronavirus our electric motor has been shipped and we should have it in a couple of weeks (I’m by no means minimising the terrible effects of the virus and fully recognise that a bit of inconvenience for us counts as nothing).

I’ve also corrected the part of the drivetrain that I’d got wrong (maybe I’m on the way to becoming a tapered bush bearing expert) and we should have that soon. There are still some decisions to make and parts to order before we will be ready to connect the motor to the propeller but no rush as I don’t want to make mistakes.

So much space gained by switching to an electric motor

Now that our engine compartment is empty we have been able to more accurately work out where everything will go.

We can fit the motor batteries (each 300AH) at the side of the motor. By stacking two batteries each side we can have the entire motor and it’s “fuel” in about 600mm length from the end of the existing propeller shaft. Plus we could add a 3rd layer of batteries if we needed to double the motor battery capacity (while that would be higher than fully desirable the tops would be about level with the top of the existing fuel tanks so not much impact on stability). .

Forward of the motor and batteries we can fit up to 7 x 120AH house batteries within the existing engine compartment (we are starting with 4). These will be nice and low in the boat (considerably lower centre of gravity than the existing engine and tanks). Our busbars will also be mounted here.

Above the house batteries there is plenty of space for our two Victron inverters. Aft of the motor, where the fuel filters are we will be able to fit all our Solar MPPT controllers so they have short cable runs to the batteries.

All this means that we won’t need to use the original wet locker for the inverters and MPPT controllers, so we get that back.

When the fuel tanks are removed we will gain a huge amount of space in the cockpit locker (which used to lose space to 4 batteries, fuel tank, hot water tank, water pump, fridge compressor). We will also gain in the corridor to the aft cabin which we will be able to make a bit wider and have a huge storage area with shelves for boxes of clothes (maybe one day a redesign of this and the chart table will create space for our bikes).

So not only did the diesel engine fill this large space (and leak fumes out all into spaces in every direction), it also took lots of extra space for fuel, starter battery etc.

The electric motor doesn’t just bring all it’s systems into the one space it also allows a whole load of other things to fit into the same space, thus creating yet more space elsewhere.

In all this we will be able to see and reach every battery’s cable connection and LCD battery monitoring display. We will be able to remove every battery (although we will have to remove several to get to the furthest ones). We will be able to see and reach the last two remaining seacocks (for cockpit drains). We will have access to the propeller shaft and whatever shaft seal we end up with. We will also have better access to the deepest part of the bilge for the manual and electric bilge pumps that we plan to fit.

For a boat that we intend to live on when we retire all this extra space and accessibility are two reasons that alone would make going for an electric motor a great improvement. But we still have all the other benefits too.

The biggest Electric Motor difference compared to Diesel

The biggest difference is availability.

With an electric motor instead of a diesel in your boat you can achieve the same/similar performance in power/speed. At the same time you can get better reliability and lower maintenance.

However, the biggest difference is that you have to manage availability.

With a diesel availability is taken for granted. We assume that if you have fuel the engine is available:

  • whenever you want it
  • however long you want it
  • at whatever speed you want it

these are not the same with an electric motor as everyone of them depends on your management, preparation and planning around availability of the battery bank.

Note that here I’m talking about electric motors that use battery banks that are charged primarily from renewable energy. If you have a generator (usually diesel in this case) that can generate the same power as the motor uses then you are in the same situation as with a diesel engine.

What affects availability?

There are three key variables that affect how much electric motor availability you have at any particular time. All these need to be managed and none of them can be changed instantly at the point of need.

Hence, using an electric motor requires a mindset, especially changes in how you manage the boat and the plans you make.

The three variables are:

  • Technical specifications (particularly of battery bank and renewable energy generation)
  • What you have been doing up to this point (ie what state is your battery bank in at this moment)
  • What you are planning to do (and what contingency plans you have made)

What makes things easier?

Spending more on the technical specification increases your capacity and reduces the amount of management and planning you need to do. For example a bigger battery bank or a larger solar panel array both mean you will have more capacity available and so less need to manage the capacity and the plans become easier to make.

Choosing a catamaran makes things easier as there is always going to be more space for solar panels.

Cruising less often or less intensively makes things easier as you have longer between passages to charge your batteries.

Cruising is warmer climates makes things easier as there will be more sun to get more power out of your solar panels (at the extreme, solar panels are going to be of zero use in a polar winter with 24 hours of darkness).

Longer passages (as long as there isn’t a tight schedule) makes things easier as you can sail for days while charging the battery bank ready for the next landfall.

Better sailing performance with special focus on light winds and going to windward (when people are most likely to motor or motor-sail)

What makes things more difficult

Tight and fixed deadlines.

Wanting hands off systems where you pay someone to do the maintenance and then have instant and complete availability 24/7.

Always available “luxury” (air conditioning, hot water, heating, large freezers and fridges, electric autopilot, electric winches)

Complicated coastal waters (tidal inlets, long and narrow harbour entrances, big marinas, headlands with big tidal streams, lots of traffic)

Managing availability

Diesel inboard engines have managed to create a reputation of always being available and for most weekend sailors this has been the reality. The engines get professionally serviced each year, they are not run many hours, people avoid bad weather and they keep their boats where high quality fuel, parts and expertise are all available. As you go further and for longer, especially to remote places, this changes a bit with care needed over fuel quality and parts availability being more challenging as well as having to be more self sufficient in maintenance skills. So management of availability with diesel engines is only an issue for more adventurous, intensive cruisers.

On the other hand Electric motors require a far more hands-on management process for all cruisers as the battery capacity is far less than a fuel tank and the rate of charge from renewable sources far slower. This means planning ahead and that has a much bigger impact on those who have not had to do this least with diesel engines.

If I motor-sail now to speed the passage, will I have enough battery left to motor into the harbour or up the river? That means thinking about tides/currents and the weather (how much solar power will I generate during the passage).

It means thinking about what might be needed in the next few days. Suppose the wind gets up from a different direction, do I have enough battery left to motor away from the anchorage if it becomes unprotected tomorrow.

It means being very aware of both consumption and generation. If I run the watermaker then when am I going to recharge the batteries, might it reduce the ability to get in or out of a harbour.

It will mean changing passage planning. Probably needing to be more flexible. If the wind drops you might not be able to motor fast enough for long enough to make a tidal gate.

Many sailors using harbours such as Chichester, have a working assumption of motoring from deep in the harbour to the open sea whatever the tide is doing. That might fully use your battery capacity with an electric motor.

If you are cruising outside the tropics in the winter your solar generation might only be 10% of what you would get in the Bahamas. The total power you can use over a period of time will be dramatically reduced so you will need to pay far more attention maximising the generation eg adjusting the angle of your panels (actively pointing them at the sun to increase their effectiveness), to keeping them clean and free of shade.

In some ways this is going back to ways of the past when yacht engines were unreliable and not powerful enough to push you against an unfavourable tide so that you didn’t factor motoring and consistent/predictable passage times into your plans.

What we are doing to handle this?

On the technical side

  • Efficiency is key everywhere. A brushless electric motor is better than one with brushes. Switch to low power everything eg LED, self contained solar powered wind sensors, wind vane self steering.
  • Lithium batteries. At the moment Lithium-ion phosphate (LiFePo4) technology has the edge with higher capacity, faster discharge and charge rates, able to be more fully discharged without damage.
  • Simple and basic. We are starting with no fridge or freezer in the UK. No electric winches, no electric toilets.
  • Improve the sailing performance as much as possible. So we are replacing a back of mast furling system with slab reefing on a longer boom with a larger sail area supported by battens. We are looking to changing from a single point mainsheet to a track. We are cutting lots of weight from the interior and systems.
  • Adjustable solar panels that allow extra capacity be deployed at anchor and in calm conditions.
  • We are keeping separate banks of batteries for house and motor while having the ability to transfer energy from either bank to the other
  • We have invested in a significantly oversized anchor to reduce the chances of having to evacuate anchorages.

Management

We are using Victron monitoring tools (battery bank monitor, mppt controllers) that give us the most data possible on past and present energy generation and consumption.

We are following a revised version of the tradition that the engine starter battery should be kept separate from the house bank. This requires larger battery capacity overall and some extra components, however, we believe that this complexity does give us the reassurance of being able to protect our motor availability. At the same time, when in a protected anchorage we can choose to charge the house bank from the motor bank if you have a few cloudy days and are using a lot of power (maybe for clothes washing, cooking, or hot water). On the other hand when leaving an anchorage we can charge the motor bank (albeit not very fast) from the house bank although with the understanding that might mean we need tot turn off the house items such as electric autopilot, or fridge & freezer or no induction cooking. So our version has has some separation but also allows us to run DC to DC chargers at anytime to be able to “steal” power from one battery bank to charge the other.

Expectations

More than anything else having an electric motor with a fossil fuel free goal means having realistic expectations. We expect to

  • sail on passages, using the electric motor for marinas, rivers and tight harbours
  • have more variable passage times as we won’t be using the motor to keep consistent average speeds
  • work more closely with the tides rather than be able to motor against them
  • work hard at maximising solar generation by using additional panels that have to be moved around, by tilting panels to their most efficient angles
  • work hard at minimising consumption of all appliances
  • by motoring more slowly to significantly increase range

Conclusions

I’d started this several times as a post about the disadvantages of electric motors, but I’d struggled with it. That is because, unless you have an unlimited budget, the issues are all about attitudes and expectations.

If you believe in reducing fossil fuel use then the differences are entirely manageable.

If you are not concerned about fossil fuels and the climate emergency then the inconvenience of managing availability is going to appear a deal breaker.

The technology is changing fast and modern boat design trends (such wider beam carried aft, fewer ketch rigs) make it simpler to fit larger solar capacity. It is likely that over the next few years there will be further gains in battery capacity. Monitoring and Management will be more sophisticated and automatic. So gradually the need to manage availability will diminish, especially for weekend sailors as a battery bank that is fully charged at your home marina will cope with a weekend of sailing and motoring.

A beyond our dreams yacht

The sailing channels are full of amazing boats. What used to be the sailing magazines that my Dad would buy have been replaced by YouTube channels like Yachting World.

Consistently they present, as if it were normal a world view that everyone will be buying a brand new boat and that these days nobody would consider anything smaller than 40 feet (and that only if it is a “modern” shape which gives about 50% more accommodation than a more traditional design).

So the boats they show off start at about £ 1/2 million (over 20x more than we paid for Vida and nearly 10x what we will have spent by the time we retire to live on her).

So they are far, far beyond our dreams, expectations and none of them have much focus on sustainability in any form.

To be honest not many of them are very attractive to us either. We absolutely do not need or want so much space, we absolutely do not want our sailing to be totally dependent on electrical power for sail control (especially as they all require fossil fuel electric generation).

Yes, nearly all of them will be much faster than Vida (so what, we are not planning to race). Their huge, flat wide sterns and twin rudders will be give more control downwind. Yet the costs of these benefits are huge (mooring/haulout/storage/repairs/complexity etc etc). With our experience a 38 foot boat still seems huge and daunting, we don’t want more 🙂

Yet, I admit that I have just watched a video of one boat that if you happen to give me would be awesome (even if I’d want you to give me the money to make her fossil fuel free).

Actually, I think you would need to give me about £5M. I could buy a 5 year old Garcia Exploration 45 for about £1/2M, keep another £1/2M to keep her and ourselves in luxury for the rest of our lives and then give the £4M away to assuage my guilt at such indulgance 😉

However, there is a lot we can learn from such experienced sailors as Pete Goss and Jimmy Cornell that we can and are putting into practice with our work on Vida. Plus others that we feel they and the rest of the sailing world need to learn about sustainable sailing in the light of the Climate Emergency and connected issues such as plastic pollution.

So what are we trying to learn and implement?

  • Redundancy: For example by adding a Hydrovane wind vane self steering we have 2 rudders, 3 self steering options, 3 hand steering options. Similarly with two battery banks, multiple solar panel circuits, two inverters, two electric hobs etc we have few single points of failure. See my post “The problems of interconnected systems
  • Insulation. Very clearly the levels of insulation make the Garcia Exploration 45 very quite and comfortable. We can’t get anything like as much but we are replacing the traditional ply plus foam backed vinyl with a minimum of 10mm closed cell foam and we already see it making a significant difference.
  • Understanding. Garcia do a week of training for new owners and provide lots of documentation. We are building up complete hands on experience of just about every single part of the boat.
  • Maintenance. A boat you don’t have to keep fixing things on. Our route to a similar goal is quite different. We are doing it through simplicity. eg changing from 3 fossil fuels + electricity to renewable electricity only, removing every seacock (apart from cockpit drains), composting toilets, no refueling or concerns with fuel quality.

What can’t we do?

  • An Aluminium hull and watertight bulkheads making the boat pretty worry free where there is ice in the water (but we can’t see a fossil fuel free heating system that would cope with such climates anyway)
  • A swim platform at the stern. Going to “make do” by sorting the best possible boarding system on the side of the boat.
  • A full deck saloon. We will be making sure we can enclose our wheelhouse for full water protection if not as warm as being “indoors”.
  • Have as much storage space. But we are creating more by getting rid of the diesel engine and tanks, the gas cylinders and the paraffin tank. Also by having less space for long term guests.

What they can’t do?

  • A brand new boat can’t have the same low carbon footprint as a 42 year old boat. We are keeping a cost the planet has already paid from being thrown away rather than using new resources (I’m guessing that everything we put onto Vida in new resources will be dwarfed by the fossil fuel impact of a few tonnes of diesel used each year).
  • Make a brand new 45 luxury boat as unattractive to thieves as a 42 year old 38 foot boat.
  • Reduce the cost to get to ocean crossing by a factor of 10

Maybe it is just self-delusion but we really don’t watch these video’s of new or larger boats and feel we wish we could have one. Well maybe except occasionally a Garcia Exploration 45 with an electric motor 😉

Making Electric Motor plans

So, if we do decide to fit an electric motor what are we looking at?

We follow five sailing channels on Youtube who have fitted electric motors:

Our plans are different, in part because we are in the UK and so pricing and availability is different. In the UK there are a small number of suppliers who will fit complete systems but they are outside our price range (about the same cost as the boat). Unfortunately we have not found UK suppliers of sailing boat specific kits.

So we are looking at buying parts and installing it ourselves. However, we are also not wanting to be too adventurous, so we are looking at components that have been used for marine applications by others.

This is where we are at so far:

How powerful should the electric motor be?

Calculating what size of engine to get is quite complex. The nature of a boat moving through water is that the power required to move faster rapidly increases with speed, until the point where adding more power does not give more speed (probably around 7 knots/13kph for Vida). So there is no point in buying a really powerful motor.

On the other hand, when you are motoring into a strong headwind more power is needed for the same speed. While we intend to be cautious and avoid dangerous situations where we can, however, we recognise that the time when a motor increases your safety most, is when you have to motor away from a shore in a strong headwind (and if that is somewhere with a restricted channel or an adverse tide then sailing will be most difficult). At these times more power is needed for the same speed.

In the end a sensible rule of thumb seems to be to replace a 39hp diesel with about the same hp in an electric motor (although the two hp figures are not directly comparable for reasons I still don’t understand).

Fortunately, at slower speeds (using less power – so that the batteries last longer), a 40hp engine at 25% power isn’t very different in efficiency than a 20hp engine at 50% power (and will be less likely to overheat).

So we are looking at a 40hp motor, unfortunately that restricts the options in the UK as the most widely available motors are less powerful than this (or are designed for speedboats rather than heavy cruising boats).

Voltage

Most 40hp DC electric motors run at 72 or 96 volts. A few run a 48 volts. Higher voltages mean that at the same power the wires can be thinner as the current is reduced. Electric motors draw a lot of power and so with lower voltages the current can be very high.

However, there are two disadvantages of higher voltages. Firstly, they get more dangerous. Secondly, they need more batteries. You get high voltages by connecting batteries in series. So four 12volt batteries in series gives 48colts. You need 6 batteries for 72volts and 8 for 96volts. That gets expensive! If you decide you want to increase your range you can add extra batteries in parallel to your battery bank, but if your bank is 96volts you need to buy 8 batteries at a time.

So we have decided to look for 48 volt motors and start with a relatively small bank of batteries that we can add to in the future.

Brushless

Unlike Kikka and Dan on Sailing UMA we have decided to go for a brushless motor. More expensive, hard to find secondhand but safer as they don’t have the same risk of sparks (some authorities and insurance companies won’t insure boats with motors with brushes, especially if they have gas on board due to the risk of explosions).

Cooling

Some electric motors are water cooled (typically using fresh water with a sealed system and a radiator). Others are air cooled, some with integrated fans.

Our preference is for air cooled for simplicity, we will have to make sure we provide an adequate supply of dry air to the engine room.

Motor of choice

So we are looking for a 40hp, 48volt, air cooled, brushless motor.

The US supplier used by Beau and Brandy is Thunderstruck-ev and they have a HPEVS AC35 motor kit. I’ve have found a UK supplier of these HPEVS AC motors. So yesterday I was able to pop in and visit Falcon Electric who are focused on electric cars. That takes us a few steps forward.

So we are looking at an HPEVS AC51 motor package from Falcon Electric which gives 40hp at 48volts. It comes with a lot of the stuff we need (Controller, Wiring harness and display).

Other stuff

Of course we don’t just need the motor, there are lots of other bits too.

Drivetrain

We hope to be able to reuse the propeller and the propshaft (after the existing coupling has been cut-off).

We will need to replace the cutlass bearing (this is the bearing through which the propeller shaft enters the boat, it is typically water cooled by the sea). Once the existing engine is out this should be straightforward.

We are looking at replacing the original stuffing box (this is what stops water from entering the boat through the propeller shaft opening). There are much more modern, drip free, reduced maintenance options now available.

We will need a thrust bearing as electric motors are not designed to resist the push of the propeller.

We will need a way of connecting the motor drive shaft to the propeller shaft. This will probably need to be a belt with pulleys as the motor has a maximum speed of 10,000 rpm and the propeller is much less (probably in the region of 3,000). This is something we need to calculate as the propeller speed needs to be matched with the propeller itself and the boat hull shape/speed. In the US Thunderstruck-ev sell these, I’ve not found anything but suppliers of parts here.

The engine will need a mounting (at one end part of the gear reduction). Fortunately, there is a stainless steel fabricator at Beaumaris we should be able to use. With the gear reduction we should be able to position the motor reasonably high so we can be confident it won’t get flooded even if the boat took on a lot of water. We will sort out some form of cover to direct cooling air and make sure that air is as dry as possible (and it might be nice if we can choose to divert the warmed air outside in warm climates and inside in cooler places).

Power

The dimensions of the electric motor are far smaller than the current diesel so we will be able to fit the battery bank in the same space (giving us loads of extra space where the fuel tanks are at the moment). We will start with a small battery bank, probably four 12V 100AH Lithium-ion Phosphate. When we see how that works for range we can decide how much more to add.

We need to plan exactly how we will handle charging. Probably the simplest (but not most efficient) will be to install a DC to Dc charger so we can keep all our renewable energy charging our house battery bank and then charge the engine bank from that. Otherwise the voltage switching and balancing gets a bit complicated.

Controls and monitoring

We want to end up with a simple, single lever control that controls both direction and speed (eg push forward to go forward with speed controlled by how far you push, pull backwards for reverse). We will need to sort out displays of battery and range that we can see outside. Obviously, these are slightly different for boats than cars (speed is an order of magnitude different for a start).

Timing

This is going to need more thought. There are lots of dependencies to work out. For example, we are going to need the yard to lift the old engine off the boat at least (we probably need to get it out from under the cockpit floor which is under the wheelhouse roof ourselves). However, as the yard is very full that will need to wait until some other boats have been launched in the spring. At least this will allow us to workout all the details before rushing into it.

Other advantages

  • We don’t have to learn how to maintain diesel engines 🙂
  • We should be able to sell the existing engine for more now than in a few years time.
  • We gain lots of space in the cockpit locker
  • We gain storage space in the corridor to our aft cabin.
  • We don’t have to replace the water coolant seacock, we can get rid of it.
  • Access to the cockpit drain seacocks and bilge will be much easier
  • The boat will be lighter
  • We should reduce the amount of maintenance we need to do in the future
  • Fossil fuel free 🙂
  • Much quieter when motoring
  • No Diesel smell (brilliant for helping reduce seasickness)
  • Zero fuel cost and much more independence from harbours when cruising

Disadvantages

  • Cost (rough budget about £12,000)
  • Reduced range (depends on the size of the battery bank but certainly only a few minutes at full power initially)
  • Renewable generation limits. How fast can we charge everything? We are going to need to cover the boat with solar and move them around to maximise power generation.
  • Restricted cruising grounds by availability of enough sun to charge everything – we might need to go south for the winter 😉
  • With electric cooking, electric dinghy motor and this electric motor we will need to carry petrol generator in case we can’t keep up through renewable generation.