Converting our yacht Skylark
As lifelong sailors who feel a great responsibility to preserve our beautiful environment for the next generation we recently converted our Parker Super seal to zero emission sailing. It has proved a great transition in so many ways, taking our sailing experience to the next level. We want to encourage others to take the leap, we feel you won't look back. We recognise it is a bit scary as it feels unknown, so the purpose of this article is to share our story to encourage you.
Our Parker Super Seal - Skylark
Skylark is our eco Parker Super Seal. She is an accomplished sailing boat, quick, safe and fun. We can regularly get 8.5 knots through the water, she is a joy to sail. Our cruising range is generally the south coast between the Solent and the West Country plus the Channel Islands and France. We have aspirations to take her round Britain, (we just need to prioritise the time).
Skylark is primarily powered by sail, a main and genoa (140%) and a couple of asymmetric spinnakers. Her motor is a 6kW electric engine, with a 9kWH lithium battery, both made by ePropulsion. Leisure power is supplied by SuperCool 12v lithium batteries with SuperCool 100w Solar panels..
Installing an Electric Pod Engine
Last winter we took what seemed to us a big step to convert Skylark (our Parker Super Seal) from diesel to electric propulsion. We haven't looked back and would certainly never go back to burning noisy, smelly, dirty, hydrocarbons with all the damage that they do to our fragile environment.
A brave step? Well somehow taking a serviceable engine out and going to an emerging technology is always a bit scary, especially when it involves drilling holes through the bottom of a hull. Interestingly having done it we have two observations about the process:
The most complex part was taking the old diesel out
If you can put together an Ikea piece of furniture you can convert a yacht to electric
We will never look back, nor go back to a diesel
Out with the old
Our Bukh 10 had been in Skylark for 40 years, still going strong but getting expensive to run and maintain. As you can imagine, it was well bedded in. Taking it out wasn’t something to be rushed. All the bolts had secured themselves for the long term. Getting the spanners into what is inevitably a very restricted space is an art that takes a while to master. Persuading the fixings to loosen is not for the faint hearted, a little cussing and the odd cut, the use of WD40 giving time to allow it to work does the job.
We set to removing the Bukh over a couple of days with a few hours each day. The bits we were worried about, the engine mounts and the drive shaft, actually turned out to be easier than expected. The numerous hoses and cables felt a bit ‘Forth Road Bridge’ we never quite seemed to be able to get to the end. In reality it was a relatively straightforward task, just painstaking and on occasions painful.
Having taken everything off the engine the next task was to lift it out. At 140kg this was not a light load. We constructed a frame ove the boat using scaffold poles. Attached a chain hoist and lifted her gently up and out. It was a dream, all went without a hitch. Once in the air we had the advantage of having the boat on her trailer, so simply rolled the trailer forward and lowered the engine onto a wheeled pallet. Job done.
With the engine out, there was so much space. We then added to the space by taking out the exhaust system, actually a real ‘five minute job’. This revealed a massive space, now used for extra storage. The came the fuel tank, and its attendant tubes, another space saving, but most of all the joy of saying goodbye to smelly diesel.
Next was to fill the several holes in the skin of our ship, the water inlet and outlet, the exhaust outlet. That felt good, the fewer holes in the hull the better!
Finally the Big Clean: the bilges of any boat are always a bit grimy, but years of oil and muck warrant a really good scrub. Traffic film cleaner worked well as a degreaser, then loads of soap and water. A task made so much easier knowing that it was the last time our lovely hull would be subjected to those yesteryear hydrocarbons, yuk.
Finally, we had a clean slate. Perfect foundations for the new install
In with the new
Well, this proved to be so straightforward, though a little daunting at first, hence the Ikea comment earlier. A good read of the instructions, marshaling the right tools, and with an engineering chum (to bolster our confidence) we set to.
First, we spent a good amount of time planning. Second, we glassed a 50cm by 50cm marine ply pad onto the inside of the hull, as belt and braces to spread the load of the engine fitting. Essential: no, but diligent, it ensures our engine will be safe and secure for the coming decades.
The pod engine is totally external. The pod is simply bolted to the hull with three 10mm bolts to secure it, surrounding a 66mm hole for the cables to feed through. Carefully working out how, and where, to position the engine took a good amount of time. We actually had to cut off the last 15 cm of the drive shaft cowling, otherwise, our propeller would have been too close to the rudder. The cutting was easy (in retrospect). The one item that did take time was the shaping of the spacer to the shape of the hull, allowing the engine to sit vertically. In retrospect, a better cutting edge and more confidence would make it much simpler next time.
The engine fitted, we moved to the interior and set to putting in the controller, the charger, the morse and the control panel. All very straightforward. One tip, put the control panel in an eas to see position with the instrument cluster on the forward cockpit. The data is really useful and benefits from easy viewing whilst at sea.
Next: the battery. Our E175 9kWH battery is compact at 52cm by 55cm by 27cm but heavy, at 87kg. It fits perfectly on the engine mounts, the load spread by a piece of marine ply. It takes up only half the space of the engine. We introduced it into the boat by reversing the process of removing the old diesel, lowering it gently into the cabin, then sliding it forward on an old mountain skateboard that I happened to have in the garage. It was so much simpler than we had dared hope.
Finally connecting it all up was a steady logical process that needs to be approached methodically though it is very straightforward. Then, the big switch on. A press of a button and all springs to life. I still marvel every time I switch it all on, apart from a few lights, little to show, push the morse forward and silent powerful thrust results.
12v leisure system
Prior to conversion, Skylark carried two 12v batteries. These worked well for day sailing, charged by the engine …. When motoring and trickle charge solar when at rest. However, with an electric engine there is no alternator! So for living aboard, after a couple of days out, running instruments, charging phones, lighting etc, without a means of recharging power gets a bit short. A new solution was required.
After much experimentation, we have gone to 12v lithium batteries. These have many advantages, you can use all the capacity, as opposed to 50% with lead-acid. They can run 240v appliances, as well as 12v. Data screens provide all information live. They weigh only a few kg, less than a quarter of the weight of lead-acid. All in all they are just so much more flexible
We now run a pair of 266W batteries and a 500w unit for the fridge. This provides so much power and is easily maintained by the solar panel
We carry an experimental 48v wind generator. So far it is proving most successful. It is powerful, quiet and neatly out of the way. The great benefit is that on a swinging mooring, or at anchor, it means we rarely have to use 240v. Right now we continue to research which brands we want to work with until we have enough data to make informed decisions. Always good to have an ongoing research project.
We carry a 100W solar panel with a 120w in reserve as we have been experimenting with different solutions. This does mean that we can charge the fridge battery in parallel with the leisure. In reality we have much more 12v than we need, however there is now always ice on tap!
Tenders and Paddleboards
As you would expect to complete our set up both our tenders and our Sandbanks Style paddleboards have electric propulsion powered by hydro regeneration and solar, enabling us to extend our range in an eco fashion
Electric boating - the experience?
Electricity is generated by the engine hydrogeneration system whilst sailing plus our wind generator, and on occasion 240v mains power. We carry solar panels for the 12v system when living aboard. She resides on a swinging mooring in the harbour; on the odd occasion when we want to charge from the mains (usually before a long passage) Chichester Harbour Master and MDL Marinas are kind enough to supply 240v electricity free of charge to electric boats at four points around the Harbour (we continue to encourage other ports to take up this positive eco practice).
In reality we rarely use more than a small proportion of the engine's potential. Skylark weighs approximately three tonnes, loaded. We normally cruise at about 975w at just under 4 knots, which gives over nine hours of motoring. A full 6kW gives around 8 knots for a much shorter time (for the boy racers out there)! We lived aboard for a three week stretch in the summer, charged just three times (as there was very little wind), and never went below 50% on the battery. Motor sailing back from Southampton Town Quay in under 4 knots of wind, a distance of 29 miles used less than half the battery.
What is it like to live aboard? Well, our three weeks were an absolute joy. Silent eco sailing. Everyone stops us wanting to know how we do it, as we silently cruise past 38 footers! Silent motor sailing in the many days of calm this summer. Range anxiety - we are totally over it! We did passages of up to 40 miles in no wind, and never went below 50% of our battery. We motored from the Solent into Poole Harbour where we spent several days pottering, wing boarding (with limited wind) and kayaking, only regenerating just before we embarked on our next long passage, and that was because we were pretty well totally becalmed most of the time so our wind generator was limited.
We have found that as with all-electric engines there is a huge amount of torque giving fabulous maneuverability and the joy of silent motoring. At steady speeds she uses very little power, then faster speeds seem to push the effort up on a roughly cube basis. This is great at encouraging us all to be traditional and work with the wind and tides not despite them.
Having an electric engine also totally changes the way one sails, tacking upwind with just 2-300w hundred watts gives an extra couple of knots and an additional 10 degrees of pointing angle (as the apparent wind shifts), and all this silently, wow!
Learning points? Take courage, go electric now. We haven't found anything to fear and it takes our sailing to the next level. The one thing it took us a while to suss out was how to run our leisure systems as lead-acid batteries only last a couple of days with no alternator at hand! Our learning was to ditch lead-acid in favour of lithium, a quarter of the weight and you can use the whole battery not just 50% of it. We now have so much power that we happily run a SuperCool fridge solar-charged, breakthrough!
In summary we would never go back to hydrocarbons, it is such an all-round better experience as well as making a significant difference to the fragile marine environment. Downsides? The only one we have found is that folk seem reluctant to race us, as they claim they can't tell if we are running the engine - as if we would!