Power generation upgrade

Warning! Technical article. Lots of data and numbers and not funny.

Last year we wrote about our regenerative electricity production and about our Aquair towed generator which we use as a second wind generator. As long as the wind blew everything was working perfectly but when it stopped (as in Columbia) then we realized that our batteries were no longer working properly and the solar was under-dimensioned especially with our water maker now running. There were even a few days that we had to run the engine and that is awful.

So, while in Panama, we rebuilt and rewired things again.


The HRDi controller from Marlec regulates the power from the wind generator and can optionally work as a controller for 160 Watts of solar panels. It works but lacks an absorption phase during the charging which is not good for the batteries. Additionally only 12V modules can be connected which is not enough to allow the MPPT (max. power point tracking) to function efficiently early and late in the day or when the sky is overcast. We bought a Victron Energy SmartSolar 30/100 which has a three phase charging algorithm and can deal with a higher voltage. Really nice is the Bluetooth connection which allows us to see the actual and historical data on the smartphone.

the blue line in this screenshot from our data logger on 5. Feb. shows the controller working perfectly. Bulk, absorption and float. (All times are UTC and we are UTC+5 so sunrise is about twelve.)

We doubled our solar power by buying two new 80 Watt panels from a Chinese electrical store. With four panels rated at a total of 320 Watts, we could connect two strings of two panels and thus double the voltage available to the controller.  All four panels are mounted and wired above the cockpit and nicely hidden from below by the bikini sun cover.

Our batteries were sourced by Ardfern Yacht Center two years ago and, according to the manufacturer, were unsuited for use in a regenerative energy system. They were not deep cycle batteries and were not helped by the few times we ran them nearly empty. The lack of an absorption charge phase in the controller also shortened their life. We bought three deep cycle marine batteries – two for the services and one just to start the engine – manufactured by East Penn. They have a great document that describes which charging voltages to use and a competent and quick customer support who actually answer emails and wrote that we should use a float voltage of 13.8V and absorption of 14.7V.

Information_SignThe batteries are Deka DC31DT Marine Master manufactured by East Penn. Their data sheet for regenerative systems is online here. Gabriel Schneck is their great customer support person who helped us.

In Panama the system worked well despite us being anchored facing north and thus with shadow on the panels. Sailing south to Ecuador we produced 1400Wh of solar power one day and the next day – with absolutely no sun – 360Wh but our average after 33 days is about 700Wh. Each wind generator produces an average per day of about 200Wh and when on passage the towed generator produces between 150 and 800Wh depending on our speed.

Screenshot from Android App. Per Bluetooth we can see what is happening in the system. In real time and as a daily summary.

The first month suggests that we are now self sufficient in electricity and therefore also water production. Another piece of freedom.

Dinghys

The perfect cruiser’s dinghy packs up really small and can be stowed away for passages. At the same time it should be stable in use and capable of carrying people and cargo safely and relatively dryly.

Our inflatable Avon fulfils the first specification perfectly. It takes a little time to install the wooden slat floor and rowing seat then blow it up and just as long to reverse the process but it stows in the aft locker. Unfortunately it fails on the safe and dry requirement. If we use it to go up wind against waves of any size, the only suitable apparel is bathing clothes and everything we take needs to be extremely well packed. More than once it turned over in the wind and once set the outboard under water. When we visit another boat, we need to remove the motor and hang it on their boat if we want to relax.

Our Avon dinghy fully stocked

In the Caribbean the Avon was ripped directly next to a seam. Four attempts by us to repair it all failed and when we found an expert in Panama, he could only solve the problem by lifting part of the seam and glueing under it. His repair worked but we needed a more reliable tender.

The selection of small dinghys in Panama is not huge but with the help of Sheila (an American lady rebuliding her boat at Port Linton) we bought an AB dinghy with a fiberglass bottom. This is safe and stable but impossible to stow any where but between the mast and inner forestay. Sailing is, of course, a series of compromises so we have now developed a way of doing that. Once we have the AB dinghy in the water she is great fun. We bought her just before Annalena and Daniel arrived and “test drove” extensively in the San Blas Islands. In the Las Perlas archipeligo we completely filled her with water when a breaker swamped us just off the beach but, even full of water and sand, she can be rowed home.

With the dinghy, we received a free dinghy chap (a material cover to protect the dinghy from sun and rubbing). It was for a different size and type of dinghy and had no holes for the carrying handles or anything but did come with a bag of “blue bits” to sew as protection around any holes. Luckily we have a Heidi on board and she and her sewing machine can do anything. After hours and days of hard work, perspiration and many many broken needles, we had a cover that fitted and a matching bag to stow items while in transit.

Another sailor told us he had been quoted one thousand US dollars for such a dinghy chap and Heidi now says she fully understands why they cost so much. She doesn’t plan a production series.

Water maker. Katadyn 40E

A boat is freedom. Freedom to go where you want, when you want. With Artemis full of food and a fair wind, we can travel far away from civilisation and visit otherwise unreachable places. But you need water. Until now we have filled our tank where ever we have found a supply and, in the worst case, bought bottles. But the logistics detract from the enjoyment and, as we head out in to the Pacific, good drinking water will become a scarce commodity.

So we have invested in a small Katadyn 40E water maker. This magic device takes fifty liters from the surrounding sea and five ampere hours of electricity with which, through the miracle of reverse osmosis, it produces five liters of drinkable fresh water. We use about ten liters a day so in two hours we can produce all we need for that day.

This is one of the smallest devices used on boats but it has the advantage that we can power it from wind and solar power. It also fits nicely in our “bathroom” which is now the “water works”. We bought this model as every one wrote that it “just works”. Andi Blenk installed one this year and his positive feedback convinced us to invest.

Unfortunately our system didn’t “just work” as it had been incorrectly assembled in the factory. We needed many emails, lots of tests, much frustration and hundreds of extra dollars before we tasted our first fresh water but now it works and it was worth it.

We use a pre-pump to take sea water from the ocean and pass it through a sieve and two pre-filters. The standard system uses one filter but this way we can run it in silty anchorages. The filtered water enters the Katadyn and is then compressed and forced through a membrane which removes most of the salt leaving less than 200 parts per million which is far less than we can taste.

Produced and cooled with solar and wind power.

Another piece of freedom!

In the bowels of the boat

Boats have marine toilets. They look a lot like the toilets you are used to on land but work a little differently. You don’t just press a button and empty a days drinking water down the drain. Instead you pump a lever which sucks sea water out of the ocean and uses that to wash everything clean. At the same time the pump empties the contents out of the bowl. There is a switch with which you decide if you would like to empty straight in to the ocean – the preferred solution out at sea – or in to a holding tank on-board – when in a harbour or a bay. The contents of the tank can later be pumped out once you are back out in the middle of nowhere.

Artemis plumbing – with blockages

A great system that is flexible and reliable – until it breaks. The first indication we had that something was amiss was when it became harder to work the pump to empty the bowl. Shortly thereafter the pump to empty the tank began to sound as if it was working harder and then stopped working.

I was pretty sure the problem was a blockage in the outlet pipes as this is a “standard” problem on most boats that occurs every couple of years. I disconnected the outlet from the tank pump and was rewarded with a spume of dirty looking slurry. After that is was “just” a case of bending myself in to the hot, tiny space in front of the toilet, dismantling all the other pipes, beating them on the dock to break the calcium build up, washing them through and re-assembling. Really important was to assure that absolutely everything was very tight as most of the piping is below sea level and a break could lead to a sunken boat. Four hours later, and with Heidi’s help to feed hoses through tight spaces, everything was working again.

Once I had showered off the sweat and the all pervading smell of slurry, I was happy that everything was working. I drew a plan of the system so I would know how everything works next time and searched the Internet for some way to avoid the problem. Unfortunately the expert opinion seems to be that it is just a part of boat ownership so learn to like it.

Bosch power tools

“I wish I had a set of tools like Heidi and Neill!”

How often have we heard this from tradesman that we have had on board? They work on boats all day but arrive with a motley assortment of tools and when they need “something special” they need to go back to the workshop to find it. Or – they borrow ours 🙂

Before we left we bought a set of Bosch power tools and they have definitely been one of our best investments.

Bosch power tools

We charge the two 12 Volt batteries up using the excess power that we generate with wind and sun and most of the time they are plugged in to the torch and vacuum cleaner both of which get used all the time. Vacuuming up dirt is so much better than redistributing it with a brush and a good torch is vital for looking in to the dark corners or searching for Artemis in the night with the dinghy.

We also have two drills, one of which can also be used as a power screw driver, and a reciprocating tool which we can use to saw woods, plastics or metal and use as a sander. Very useful when maintaining a boat with so much wood work.

After sixteen months of use, the power tools are still paying for themselves every day and hopefully will continue to impress tradesman all over the world.

New fridge

Our Rustler had a fridge in the galley (sailor speak for kitchen area). It was a quarter of a century old, badly insulated and didn’t regulate properly. It was slowly rotting the surrounding woodwork and sometimes stopped cooling but still took 60 Watts from the batteries. We decided it had to go.

We ordered a Vitrifrigo TL20 top loading fridge. The manufacturer ignored our emails and the USA dealer quoted three months delivery so we ordered it via Ocean Chandlery. It has a capacity of 20 liters which is plenty for us. The technical data claims it is category A+++ and uses only 28 Watts of power.

Unfortunately Rustlers are hand built boats so nothing is easy. The work top was glued to the cupboards below and ran under the cupboards above. It had to be cut in to little squares before being hacked off. The fridge was also jammed in and held in with liters of insulating foam. Both fridge basin and foam had to be cut out in tiny blocks. New saw blades were needed which involved an 18 km bike ride to the tool shop.

We needed a new work top and Heidi had the brilliant idea of making one from wood stained white and then sealed with epoxy. Not only did she have the idea, she also made it happen – despite the ambient temperature being 15°C above the recommended temperature for working epoxy. The new top looks better than the old one and is more functional and has a fridge fitted and working.

The fridge has now been working for a week and works as hoped. The only “problem” is that it appears to take 36 Watts rather than the advertised 28 Watts. That is a major difference when you are running an autark system as we do.

Anchoring – a complete overhaul

When we bought Artemis, we changed to a Rocna anchor and it has been doing a fantastic job of holding the boat each night – the statistics are here.

But there is more to anchoring than just the anchor. There is:

  • the anchor
  • the chain
  • the anchor winch with it’s gearbox and motor
  • the switch that you press to work the motor

The all important switch rusted and fell apart in Grenada but we managed to clean it up and put it together so that it worked (mostly) until friends brought a new one to the Grenadines. The new one fitted perfectly after we modified it a bit.

repairing the anchor winch
Continue reading “Anchoring – a complete overhaul”

“Anchor Pro” app

Last week we wrote about how often we used our Rocna anchor and relied on it. Maybe just as important is an anchor watch program or App that lets you know when the anchor is not holding.

When we anchor we set our position in the Android app “Anchor Pro” We tell it where the anchor is and how much chain we have out. It immediately starts to monitor our position relative to the anchor. If we move outside the radius we have defined, the batteries on the tablet run low or it loses GPS signal, it lets out a very loud alarm.

The app is very easy to use but loaded with clever options. Really useful is the ability to define only a segment of a circle as being “OK”. Here in the Caribbean the wind comes from the east so you can anchor “a little bit closer” to an object to your east and then input a larger radius to the west than to the east.

Also nice is that when you leave the boat with the tablet you can switch the app off and, on your return, tell it to use the old position. You can also switch on the “heatmap” view and see all the positions that have been logged. A nice tidy grouping (as shown here) suggests that you are holding well and can enjoy a run ashore.

Anchor Pro showing the heatmap

A well set anchor, a good mattress and this app are our secrets to a good nights sleep.

Review of our Rocna Anchor

When we bought the boat we knew we were going to be spending as much time as we could at anchor. The most beautiful places in the world don’t have marinas or pontoons. Real freedom relies on a solid dependable anchor.

Before we left Scotland we installed a new 20kg Rocna anchor. Rocna recommended a 15kg anchor for our size and weight of boat but the extra 5kg is nice to have on board. The anchor is attached to the chain with a Kong connector.

In the last year we have spent 240 days at anchor. Often the pilot book has written that an anchorage has bad holding or that the anchor may need to be set a few times. Once – in Spain – we had problems setting the anchor because the bottom was a mass of weed. And only once it has not held when set and that was very strange. We anchored in Friendship Bay, Bequia and the anchor held perfectly all night. The next morning we started to drift and didn’t stop. Unfortunately we didn’t dive on the anchor when we set it to check if it was really set and in to what. We just pulled back and checked the chain tensioned.

So the numbers are:
– set 239 times from 240
– held 239 times from 240

In Spain, in a thunderstorm we once had 30 knot winds blowing us in all directions. We only had 20 meters of chain out as we were in a protected fishing port and the weather forecast was 5 knot winds from the west. We were being blown in circles and the anchor held us through it all. As you can see on the anchor watch, we swung within a 30 meter radius and the tablet was in the middle of the boat so the anchor was turning over and resetting within about five meters. Impressive!

anchor watch after the Spanish thunderstorm

Having watched a lot of people anchoring over the last year, it is obvious that a lot of badly set anchors are more a “crew problem” than an “anchor problem”. We regularly see big white charter catamarans sail to a point, stop and dump twenty or thirty meters of chain on top of their anchor. I am not sure that even a Rocna would help much if set in this way.

Marking the dinghy

Our insurance policy states that our dinghy needs to have an “identifiable mark”. When we bought the boat, the dinghy already had “Artemis” written on it in three places so Heidi brushed up the lettering a bit and we sent a photo to the insurance.

Here in the Caribbean everyone says “always lock your dinghy up!” and “don’t write the boats name on the dinghy!” The logic being that when your dinghy is on the beach, the bad guys know your boat is empty. We explained this to the insurers who agreed and said they would never mark the dinghy with the boats name (?)

Even the police lock up their boats in Martinique

Half a day with Acetone and Heidi’s work had been destroyed. Now we had a naked dinghy and needed an “identifiable mark” that had nothing to do with the boat but clearly said “It’s ours!” Sounded a bit contradictory.

Our solution is a generic email address that is now “permanently” marked on the dinghy and which passes any mails received on to both our email accounts. In addition, any one who writes to us on this address gets an autoreply with a thank you and our mobile phone numbers. The address has nothing to do with the boat or us so the potential thieves can spend an enjoyable evening looking for a fictive boat called “Soseies”. Hopefully if the dinghy is stolen and discarded some one will contact us. If not, at least we have complied with the insurance policy.

Amazing what good solutions we can work out when we have so much time to think about the problem. And thank you Gremmel lending us the generic address.