Sunday morning on the Guadiana river. We were about to finish our slow breakfast and we heared some tones of music. We looked outside.
Watch the movie and turn on the volume.
Enjoy peace and quiet.
Peace and quiet
Prevent spreading COVID and CO2
Even though we really like the Guadiana river, we want to move on eventually. But, in line with government policy, we would like to prevent contamination. The government however, wants us to get our vaccination in Holland.
We tried our favourite site Rome2Rio and found the quickest way.
Before we go from Sanlucar de Guadiana to Rotterdam we first have to get a PRC-test. So, a bus to and from Huelva. Then, to the Netherlands (provided the border with Portugal re-opens and we can fly from Sevilla). The trip would be: bus-train-plane-train-tram-house-tram-vaccinationscentre-tram-house. And vice versa for the return.
We would make 24 movements per vaccination. We will probably both need two injections each, so that makes 48 travel-moments per person. 48 environments to exchange the virus. 96 for the both of us.
And we thought of all the CO2, (Carbon dioxide) we would emit.
We found some nice (Dutch) sites we used to calculate the CO2 output of living, working and travelling, so here’s the math:
How much is that? What we would produce in extra CO2 equals, for example.:
- A yearly electricity consumption of two Dutch households (source Milieucentraal), or:
- The distance an average Dutch car makes in 1,8 years (source CBS, Dutch National Statistics), or:
- 230 train trips Amsterdam – Paris by Thalis.
If you would like to try some calculations for your own purposes, try for example those sites.
Rethink: the local solution
Considering the environmental footprint getting our vaccinations in the Netherlands would create, we started rethinking the situation. Our vaccinations could be restricted to 2 movements for each vaccination. That is: if we were allowed to receive them in Sanlucar de Guadiana. No PRC-tests needed, just a walk to get the vaccination in this village or somewhere nearby. This would prevent a lot of contamination moments, and also save fossil fuel and 3,2 tonnes of CO2.
So, we asked the Dutch Embassy in Madrid for advice.
From the skyscraper in Madrid came a quick and adequate response: “We understand your desire to be vaccinated. We have information from the Andalusian authorities about the steps you can take to be eligible for a call. These are as follows:
– You can use your Dutch or European health insurance card to access the nearest “centro de salud” (a public care center);
– There you can register in the “base de datos de usuario” (user database) as “desplazamiento temporal” (temporary displacement);
– According to Andalusian authorities, this will give you automatic a call for a vaccination, in order of age category.
– If you have a medical indication that puts you in a risk group we recommend that you find out how and whether this can be registered.
For timing, vaccination strategy, and further questions it is best for you to check with your ‘Centro de Salud’, but keep in mind this can be a matter of months”.
So, we went looking for our ‘Centro de Salud’. Would it be the ‘Consultorio Medico’ in the centre of Sanlucar de Guadiana?
The friendly nurse told us that it would not be that easy. We had to go to the “Trabajador Social” in Villanueva de los Castillejos, a village 22 km further east. We got an appointment 2 weeks later, at 9:45. There was a regular bus line to from Sanlucar the Guadiana.
The social worker in the Centro de Salud in Villanueva de los Castillejos gave us the form. In a restaurant we filled it in after our coffee, tea and a ‘tostada’. We got our copies in the papershop down the road, and we walked back to the Centro. We gave the social worker the form. He explained the rest of the procedure in Spanish, using arms and legs to explain the various paths the form had to go through the bureaucracy. This was a bit difficult to understand.
This visit could have been avoided if we could have filled in the form online. But the breakfast was great, and the 20 km walk was lovely and very healthy!
Now we are back in Sanlucar and await further instructions from the Centro de Salud. We hope Spain keeps its position as frontrunner of EU-countries vaccinating their population. And, we hope we soon can get our vaccination, our ‘ticket to travel’ in a CO2-friendly way.
Propelling to fossil freedom (3/3): the ideal hydro generation
In the two last articles we discussed two kinds of hydro-generation.
The first was the alternator-to prop shaft hydro generation: simple and cheap to make.
Second was the towing generator . This I would not recommend, because an extra propeller gives extra drag. And astern, the water is highly turbulent, which is not efficient for hydro generation. While the ships propeller is under your ship in a laminar current, so it would be common sense to use this prop instead. And, towing generator costs some 4000-5000 Euros. If you would add this money to a renewal of your diesel motor for an electric motor, you have a good business case. And technically it is very easy to change an electric motor into an alternator.
Most ideal is have the propeller directly on the shaft of the alternator. And this alternator can be switched into an electric engine with one button, bringing you to the harbour and motoring through wind stills. This ideal system is working on the ‘Ya’ and we show you how it is done.
Hydrogeneration starts with the propeller
You can use your existing propeller, but if you think of buying a new one, then read this.
The best props for energy generation are large, slow running props. So, the 34 foot-long Ya has two 17 inch (43 cm) propellers. But for a sailing yacht, the drag, the resistance of such big props could be terrible. Close hauled, this drag will seriously increase the leeway. Therefore, the Ya does not have fixed props, but 2 Autoprops, that will go into feathering position when not in use.
Also, a fixed propeller is not logical on a yacht, because it is generally designed for one speed. Mostly around 4 to 5 knots, and with an RPM (Rotations Per Minute) of about 1500. But when you are sailing and the prop is in generation mode, the prop will rotate slower. If you could adjust the pitch (the angle of the blades), it would generate more.
On a sailing yacht, also the speed will vary. So that would require continuous adjustment. You should adjust the pitch with every gust of wind and every wave running up and down. If the blades were continuously adjusted to the optimum position, it would be the most efficient for generation. (And also, for propulsion.)
Well, the Autoprop is the solution to this all. It adjusts the pitch automatically. Whether in propulsion or in generation mode, if the speed varies, the rotations vary, and the blades will vary the pitch to the optimum position and vice versa. And, when in propulsion mode, the blades are adjusted by the rotations and the speed through the water. This can be seen in the film below:
In its reverse mode it works just as efficient as in forward mode. The Autoprop therefore has the best generation efficiency, because the prop runs in reverse when it generates under sail.
The Autoprop adjusts the pitch on natural physics: the centrifugal force of the RPMs, and the impact of the water caused by the speed of the boat. So, no electronics, no chips or wiring, no hydraulic tubes, nothing. Just physics. The only maintenance is some lubrication every now and then. Isn’t it beautiful? It helps the Ya tremendously on its energy generation.
Want to know more? You find a very thorough explanation with an animation on the Bomarine site (Dutch spoken). The technology for the automatic adjustment is beautiful and makes our tech hearts run faster. But the economical hearts will start beating fast when you see the various tests. The Autoprop belongs to the most efficient props. Yachting did a prop test, or check the German Segeln. Underneath we show the outcomes of the French Voile Magazine.
The alternators
An electric motor with a permanent magnet can easily be switched into an efficient alternator. Just with one button. Technically, this type is basically the same as the old-fashioned dynamo on a bicycle tire. The rotations of the current electric motor (and so the dynamo) do not have to be very high. So, you don’t need a reduction box before your propeller and that makes it efficient, less complex and lower in costs. And a slowly rotating propeller is more efficient, in generation and in propulsion. But on slow rotations, the propeller must be bigger and should be designed differently to be efficient.
If you intend to buy an alternator and electric engine, consider these things that were decisive for Ya’s choice for E-Tech.
Low maximum rotation. The maximum number of rotations per minute can be adjusted by the factory. On the Ya the max RPM is only 1040 RPM, with a pretty high torque (Nm). Slower rotations of the prop have three advantages: more efficiency, less noise, less wearing out. It saves you a reduction box with its resistance and fast moving parts, and less reliability.
The motors are brushless. Just like most marine electric motors, they no longer have brushes that “drag” along the rotor. These should be replaced frequently. This feature saves us lots of replacements, because the motors make many hours as generators.
Double thrust bearing. A thrust bearing is put in between engine and propeller and absorbs the pressure the propeller emits. This prevents the propeller from exerting its force on the motor itself. A permanent pressure on the engine would cause wearing, so this is prevented. Most electric motors only have a thrust bearing on the propulsion side (to forward). But on the Sustainable Yacht the generating side (astern) is mostly used. So, the propeller does not “push”, but mostly “pulls”. The E-Tech engine is therefore equipped with a thrust bearing on both sides.
Synchronous motor. A synchronous motor is ideally suited as a motor and as a dynamo. He can, as it were, “flow” into it.
Liquid cooling. A cool electric engine works more efficiently than a warm one.
The practice and the numbers
As soon as we sail more than 4,5 knots, we give a little reverse power to the engine, and the Autoprop is ‘soft started’ for generation. We push the Charge switch. With the throttle in neutral, we see the RPM display showing about 300. Then we push the throttle slightly forward and the dynamo starts doing its work. Inside the cabin you can hear a light, friendly zzzzoommmm…. The dynamo gives electricity to the batteries in 48 Volt DC. This sound is not irritating at all. It gives peace of mind. A crew member once said: “Dynamo, Sweet Dynamo” ?
On 4,5 knots the energy production is not more than some Watts. But on 5 knots the dynamo delivers 50 Watts. On 5,5 knots it nears 100 Watt and when doing 6 knots it is over 150 Watt. Great fun it is when you reach the hull speed of the Ya of 7,3 knots and make over 250 Watts with each alternator.
In general, we are leisure sailors. At sea, especially the ocean, you sail your ship conservatively and for the 34 ft Ya a general speed of 5 to 5,5 knots is good. Some people find this a high average, but realize that we also have a Parasailor sail. It gives the power of a spinnaker, but is easy to handle with two persons, even when the wind gets stronger and you want to lower it.
Perhaps you find 100 Watts not much. Well, it is. This runs 24 hours a day, so count on 2,5 kWh per day. This is enough to cook an extensive meal with our induction cooker, oven and microwave. So, we are happy on the Ya. But it must be said that our speed is critical for obtaining this result. I would not recommend to seriously spend money on a prop and dynamo for a leisure yacht shorter than 30 feet, simply because you always have to sail too close to the hull speed for a good energy gain.
In 2012 we collected some statements from electric motor suppliers about the generation possibilities. The impression was created that with a propulsion prop, about 5% of the maximum propulsion power could be generated. That would be 650 watts with our 13 kWatt (2 times 6.5 kW) max power and therefore much more than our practice on the Ya. But still they can be right: you only need a larger yacht! For example, a 60 ft yacht would easily do 8 knots, and then the 650 Watts generation is a piece of cake.
But what really helps is that the hydro generation is the third leg of the tripod of our energy household. Now, there is always energy coming in from somewhere: sun, wind or our sailing speed. And, we have a light, reliable engine in our ship.
Propelling to fossil freedom (2/3) – towing generators
In last week’s blog we discussed the alternator-to-prop shaft as the good old way to generate your energy from the waterflow under your sailing ship. But there are more options. Here we discuss the towing options. It is great fun to see them working behind your ship. But are they useful for us cruisers?
A separate towing hydro generator
The general principle of a towing generator is simple: you connect the one end of a line to a propeller, and the other end to the shaft of an alternator. You throw the propeller overboard and when the line stretches, the prop starts rotating, thus rotating the line, and rotating your alternator. When the line is long enough, it evens out the difference of speed the boat has when climbing a wave, versus it gliding down the wave.
The yield and efficiency
Just as with any propeller, the physics, precisely defined in Betz’s law , also apply for the towing props. With the right propeller and alternator, and in normal, not turbulent, water, they start delivering from 4-4,5 knots. In the beginning, the yield is poor, just some Watts. The real yield starts from 5 knots and the yield grows steeply with every extra knot.
When making a lot of speed, the line will stretch, so it will be higher in the water. The closer to the surface, the less efficiency. This is because the waves cause turbulence in the surface; it gets even worse when the prop sprays water up into the air.
Another factor is the speed differences, that will tangle the line. The speed differs with every wave: climbing to the wave top the yacht slows down, and from the top down, she speeds up. When the speed slows down, there will be more slack in the line, so it can tangle. You can prevent this by using a (stainless) steel line, or an anti-torsion line. This is not cheap, especially the latter one. And both are difficult to coil up, so it will take a lot of storage space.
The Duogen is a special thing: this is a wind generator and a hydro generator. You simply change the wind blades for a propeller and let the pole go into the water from the aft of your yacht. The pole is perhaps too short for an effective wind generation (I would recommend at least 5,5, meter high, see here). But the pole is long enough to keep a small angle with the water flow, small enough not to affect the efficiency that much. It may not work as well as a long towing line, even though the length of the pole helps a bit to equalize the speed differences before and after the top of a wave.
When using the right propellor, the energy yield is a bit less than the oldfashioned alternator-on-prop-shaft. But it is not much more than 10% less.
Towing propeller on the transom
You can also mount a towing propellor on the transom of your yacht. There are many brands on the market. The three main manufacturers (Wattt&Sea, Eclectic Energy and Save Marine) make transom towing prop units that can deliver up to half a kilowatt. If you pick the right propeller. For a cruising yacht of 35-45 feet, the best is a big (40-50 cm) diameter, and a small pitch. Racing yachts can do with the small prop and a higher pitch.
The mounting needs serious attention. First, always choose the deeper one, because it runs on laminar flow, and not on turbulent ‘flow’.
- close to the surface there is more turbulence, so less yield;
- you’d better keep it as far as you can from the turbulent water flow leaving the hull of your ship;
- the prop must be really deep when you sail in steeper waves: mounted on the aft, the prop can come out of the water. If it does, it costs you much yield;
- don’t mount it in the ‘flow-shadow’ of your rudder or your existing propeller(s), because there is serious turbulence.
These deeper transom towing propellers weigh about 15 kg. Their cut-in is at 4 to 4,5 knots, just as any propeller (Betz’s law) and they can deliver 500 to 600 Watt at a speed of about 8 knots. The racing unit is smaller and can deliver more. They cost about 4000 Euros. With some wiring, adjusting to your battery management and the installation hours, it will be 4500-5000 Euro.
Towing generators – great for ocean racers
Towing generators are fun, for sure. But it is difficult to get a good yield out of it. It lies rather high near the surface. The long rope can tangle, which gives extra drag.
The Duogen, the prop on the pole with a hinge on the aft deck, deals with this problem sufficiently. But it is more vulnerable in heavier weather. The hinge must be very strong, and the weight is considerable if you want to hoist it out of the water with 6 or 7 Beaufort.
The towing generator on the transom is not logical to me. We need laminar flow, and especially directly at the transom is the most turbulence, from the hull of the ship and from the propeller(s) you just stopped.
The question is, why would you first stop the propeller(s) on your sailing yacht and then put another propeller overboard? Note that the propeller you just stopped, is usually of the right size and pitch just for your ship, and located deep, so in a laminar flow. A towing generator on board a sailing cruiser just makes no common sense.
And you pay nearly 5000 Euros for it. If I would like to spend money, I would prefer a mechanic in my engine room just making the alternator to the propeller shaft (see this article ), it will be three or even four times cheaper. OK, the towing generator misses the resistance of the V-belt, but no doubt that this will easily be made good by the better location of your propeller.
The towing generator only makes sense for ocean racers, simply because they don’t have a prop at all (to save drag!).
If you have the extra 5000 Euro to spend, and you reconsider to buy a new engine, then consider an electric engine/alternator. This, including the batteries and all, is cheaper on the long run, and can even be cheaper in the first investment. This is a sophisticated system and straight forward to a maximum yield. Like the Ya has. Next week we discuss this.
Propelling to fossil freedom (1/3)– simple and cheap
Hydro generation covers an essential part of a sailor’s energy need, next to solar panels and wind generation. This third way of supplying stabilizes your energy household. It is like sitting on a tripod instead of a chair with only two legs. When you are sailing and meanwhile the propeller generates electricity, you feel that unexplainable fossil freedom.
Hydro energy is free energy, who does not want that? I tell you: too many sailors.
Hydro energy is safer than a windmill (mostly set too low, so dangerous blades), than a solar panel (can blow away in a storm). Of course, it is also safer than a fossil fuel generator (fire, unhealthy). Who does not want that? Again: too many sailors.
Every cruiser, especially the long-distance cruiser, can get the energy really simple, and for low costs. You just connect an alternator to your propeller and you let it run when you sail. We will explain how.
To start with the result: there will be an alternator in your engine room, driven by a V-belt, which runs over a pully around the propeller shaft. When the propeller runs, it will make the alternator run, generating electricity, and a (built in) rectifier will give the voltage your battery needs (most yachts have 12 Volt).
Balancing RPM, (1) the alternator
The alternator is the most critical thing, so we start here. Most car alternators will start to generate electricity when making 800 rotations per minute (RPM). This so-called cut-in RPM, just tells you it would deliver its first Watt. We want more Watts; practice is to start from 1000 RPM.
If you buy an alternator, check some things:
- The rectifier. For most yacht systems it must be 12 Volt. Then it delivers till 14,5 Volt to load your battery completely.
- How heavy the alternator is. If it charges over 80 Amperes at 12 Volt, then make sure it has a double pulley (and double V-belt)
- Check the diameter of the pulley. It should be rather small; about 50 mm.
Now we go to the next step: how many rotations does the propeller make? Then we can we determine the final step: how many times bigger must the pulley on the propeller shaft be, to get that 1000 RPM?
Balancing RPM (2) the propeller
A propeller will start delivering a constant strong rotation when the boat sails over 4,5 knots. We take some extra and make it 5 knots. (If you are interested in the theory, Betz’s law tells you all about how much speed is needed to make a propeller run, in water, in wind, whatever)
Now comes the fun part.
There are two ways to learn the RPM of your propeller: by measuring it, or by calculation. Best is to try both methods.
First the measuring method.
You set sail and measure the RPMs when you sail e.g. 5 knots. You can buy an expensive RPM meter of 50 Euros or you measure it as follows:
- take a 20 cm line.
- Tape 5 cm of it on your shaft in the engine room
- When your shaft makes rotations, the end of the line will hit the hull skin: TICK
- Take the Dictaphone on your mobile phone
- When your yacht makes 5 knots, push the recording button
- After exactly 1 minute, you stop recording.
- Play the Dictaphone and you see a spike every moment the end of the line makes the TICK
- Count the number of spikes and you have the RPM of your propeller when sailing 5 knots.
Now the calculation method.
The number of rotations depends on the pitch of your propeller. You can read that on the propeller. This says for example: 14” X 16”. The first number: 14” stands for the rotation diameter of 14 inch. The 16” is the pitch. This 16-inch (or 0,4 meter) pitch means, that it will theoretically go 16 inches (0,4 m) forward in one complete rotation.
Suppose you make 5 knots.
5 knots is 5 X 1852 m = 9260 meter per hour. This is 9260/60=154,3 meter per minute.
So, your prop would make 154//0,4 = 385 rotations in a minute. So, it’s RPM would be 385.
But… water is not wood where a screw exactly follows its pitch. Water is ‘’thin’, ‘flexible’. When a propeller delivers propulsion, it pushes a boat forward, but also it pushes water to aft. It ‘slips’. An optimal propeller has 50% slip.
This makes the propeller’s RPM 385 *2/3 = 257 RPM.
Believe it or not, if you now check it with the measuring method, you see your results get pretty close to each other. If you measure less RPMs, you have more slip and so perhaps too much resistance. This can be a rough propeller, or friction in the reduction box or the bearing. If you have measured more RPMs, then this is great for your hydro generation, but you could have the disadvantage that the propeller doesn’t work well when you give much RPMs for propulsion.
To the right pulley size
OK, we have now:
- An alternator that must run 1000 RPM with a speed of 5 knots.
- A propeller making about 250 RPM at a speed of 5 knots.
So, the pulley of the propeller must be 4 times larger. Given the pulley diameter of an alternator of 50 mm, it means that the pulley on the propeller shaft must be 20 cm.
Most boats have that desired 10 centimetres under the prop shaft, but first check it before you start building. If not, there are alternator pulleys smaller than 50 mm. That saves you triple on the prop shaft pulley.
Next week we focus on efficiency and a more sophisticated system.
A bridge too close
There is a plan to build a bridge over the river Guadiana, to connect Alcoutim, on the Portuguese side, and Sanlucar de Guadiana on the Spanish side. We wonder if the bridge is a good idea. Because we adore the undisturbed beauty and silence of this place. Will it help these little towns? We are concerned that this bridge will not bring them the desired economic development. Then it would just be a waste of money, spoiling all that makes this place special.
The silent call of the Guadiana
A strong flood takes the sailing ship from the mouth of the river Guadiana, under the bridge near the cities Vila Real and Ayamonte, about 15 miles all the way up to Alcoutim and Sanlucar.
A sailor arrives here when the flood stream starts slowing down to a nice flow. You feel the calm, the peace here. Time to anchor. Easy, because the Guadiana has plenty good anchor grounds.
The village of Alcoutim has about 1000 inhabitants, Sanlucar about 400. Both places are located ‘at the end of the country’. Or even at the end of Europe. Well, at least it feels that way. Our Portuguese friends all see Alcoutim as the ultimate place of peace and silence in Portugal. They come here, over the little roads, and for them this area is the place to be. The Portuguese and Spanish tourists come to these far ends to enjoy the silence, the handful of friendly restaurants and bars and the idea to retreat in case you need a real still, buzz free holiday at end of the world.
You can kayak, swim, make a small river cruise. If you want to go to the town on other side of the river, you ask the man of the ferry boat to take you there.
There is also a cable from the one to the other side. Great for hikers. The Portuguese and Spanish walks are fabulous all year round, not in the least because of the undisturbed landscape and silence.
Our “Ya” is staying here in winter. For decades, there has been a small sailors population of some 50 sailing boats depending on these villages for their services. Each village has a small dockside, which guarantees an international ambience.
We like our walks here. The area around Alcoutim and Sanlucar is quiet. As long as we’ve been here, the silence is broken only by the occasional motorboat, a single car passing by, roosters crowing, birds singing, a barking dog and people talking. When the sun shines sometimes there’s music from people playing instruments, alone or together.
A bridge?
Once every three year there is a bridge during the Festival do Contrabando (Smuggler’s Festival). Small scale theatres, arts and artisans on both sides and a temporary bridge connecting the villages. This attracts lots of tourists.
Now, the Portuguese and Spanish local administration have made plans to build a bridge between the villages. This could help connect both sides. With a car it would take 10 minutes from village to village, instead of an hour. But which local would want that? If you would want to just cross the river, you can also go by ferry. This takes 10 minutes if you include the waiting. In general, there seems to be little exchange between the people of the two villages. The only ones crossing the border seem to be the sailors. There is one Spanish commuter regularly going up and down, and there are tourists, mostly hikers, crossing over by the ferry boat.
The sparsely populated rural areas on both sides would not generate a lot of traffic. There is already a bridge over the Guadiana in the north (near Mertola), and one in the south (near Castro Marim), both about 30 km away. Sanlucar could benefit from the fire brigade and the health services in Alcoutim, if there wouldn’t be institutional and language barriers to be bridged first.
We are asking ourselves: who is really going to benefit from this bridge. Will there be economic development because of the bridge? From what sectors? There’s hiker’s tourism, some small scale agriculture, no mining or other industry. So, tourism might be one of the viable sectors. But then the question is: what do tourists want? We think the tourist who come to this kind of remote area wants good food, nice walks and a pleasant environment.
The sound of a pleasant environment
A pleasant environment. Now we sailors and hikers get interested. Especially Peter, as an environmental scientist. He did a small ‘sound check on the spot’, as follows. He made a 10 seconds movie on a popular hiking trail. Just a random movie, so under the film you here the silence, with a footstep, some buzzing flies and a bird. This film-and-sound is recorded some 800 meters from where the bridge might be projected. We expect it will be a bridge with two lanes, with cars passing at 80 to 100 km per hour. So, then Peter put the noise of this kind of road under the same film-and-sound. Here under you see and hear the result.
The next 10 seconds is what you hear with a bridge near Alcoutim and Sanlucar with traffic.
This traffic noise is not loud. It would comply with the regulations about noise pollution, so don’t worry. But you would hear it. And it completely overwhelms the tiny sounds that a hiker, a sailor comes for, what many tourists enjoy. This region is one of the few where silence is not yet broken. Lucebert, a Dutch poet once wrote: Everything of real value is defenceless. We would say: the sound of nature is at least vulnerable. Maybe we appreciate silence more because we have lived in big cities and we know what it’s like when you’ve lost it.
A revaluation
So, let us reweigh the plan of this bridge against the loss of silence in this environment.
In the past decades, the roads to Alcoutim and Sanlucar have greatly been improved; they are small but good. You can easily travel to and from the tourist hotspots of Vila Real de Santo Antonio and Ayamonte on the coast. For tourists, there seems to be no particular added value that a bridge for cars might have. Also, the local inhabitants don’t seem to particularly need this infrastructure.
Perhaps an elegantly shaped bridge for pedestrians and bikes might be of true added value. Especially if the bridge itself would be worth visiting, like the hanging Geierlay bridge or the Pedro e Inez bridge in Coimbra. They would have to allow for sailing boats passing through, so the bridge should at least be 20 metres high. Other ideas to strengthen the local economy might also be welcome, like cooperation on cultural activities, development of the regional cuisine, crafts but also attracting digital nomads like the island of Madeira is doing now.
What to do?
Concerned locals have started a website with information and a letter you can sign (in English, French, Portuguese and Spanish).
.
Good Food
Every day we make beautiful walks, just where we moor or drop our anchor. As a bonus, we find amazing food on our way.
The picture above shows a selection of vegetables, herbs and flowers from our friends’ garden in Calstock. This was in August last year.
In September, in Brittany, we were stunned by the delicious, fragrant passionfruit and the quinces that nobody seemed to want. Which is weird, because quinces are perfect for stews and marmelades.
The flower of the passion fruit…
….and the fruit itself. You pick the ripe ones from the plant, it is the most delicious fruit you can ever get.
Bunches of quinces, ripe on the trees and inviting to pick,
In October, in Portugal , we saw a gem-like fruit that seemed much too beautiful to eat….
it was the fruit of the Medronheiro (Strawberry Tree).
From November, we walk in the area of the Guadiana river, the border river in the south of Portugal and Spain. Winter is actually a beautiful season to walk. It is pleasantly cool with 15 degrees Celsius.
In area around the Guadiana we see lots of almond trees along the roads and in the fields, with plenty of almonds.
You have to try first before picking them; some trees have sweet almonds, but some bear the bitter ones that you should be careful with.
The olive trees were heavy with olives in all varieties.
We met fellow sailors who have produced their own virgin olive oil. It took them three weeks to obtain 2 liters, but: it can be done.
For cooking and making infusions you can find fabulous herbs anywhere.
Fresh sage
Chamomile
Ever since we got on the Guadiana River, we have been seeing the orange trees, loaded with fruit. Harvesting season runs from September to March, so there is no hurry.
Walking along the Guadiana river, the orange trees invite you to pick a piece of fruit.
In Februari, after some rainfall, the oranges start falling off the trees. And if no one comes to pick them up, they rot in the fields.
These are the most juicy oranges in the whole world. And water’s always near, which is important according to a widespread European fairy tale on oranges. So, in the open fields, we pick and eat as many oranges as we like. We cannot think of a more sustainable way to stay healthy.
the Mystery of Moisture
We are happy sailors on the Guadiana river. But happy or not, above the 30th degree latitude the winters are cold. It gets wet, also on board. A first sigh, a complaint. But the moment the first mildew or mould pops up, sailors start to fight the moisture with dehumidifiers and dripping boxes, with bottles of bleach, mighty moisture catchers, and fans and vinegar…. But not the smart sailors. They don’t need to, they prevented it. You want to know how?
Here we reveal this.
The problem, the battle, and nature
Humid air feels uncomfortable. Living with moisture on board is like living in a shed. A humid cabin is difficult to get warm; it can easily double your energy costs.
So far you can survive. But once in November the first mould and mildew pops up, you are in shit. You smell it. You start sneezing. It feels unhealthy, and it is unhealthy. So, you start to fight it. You want to fight? The market offers you an endless arsenal of tools.
Here’s an article on how to spend your money. On 12-volt fans and wind scoops to make Jeff Besos richer, or buy this if you want to make him richer in a more fossil free way. The ultimate arm is the dehumidifier, because it has it all. This piece of technology costs serious money, it takes lots of space on your boat, and it consumes a considerable amount of electricity. And as a surplus, it needs maintenance, so you also have to work for the thing.
Not done yet? Here are plenty more arms to fight moisture, so don’t worry, you can fight endlessly.
In April you will think you won the battle, but you will experience reality when you go for your first sail and you open your sail bags. Black mould on your spinnaker, and sometimes even multiple servings of mushrooms in your sail bags and sails.
So, who won the battle? Nature!
If you battle the effects, good or bad, nature will win. For example, if you want to get rid of the effects of using fossil fuels, such as getting rid of the noise, the smell, the CO2, NOx and SOx, the fine dust, the worsening future for your children, then most people start to fight it. Then, the solutions are mostly paired with an awful lot of work and costs, and with slick but expensive technologies. And often you end up with half solutions and new problems. Don’t fight nature, because nature always wins.
Prevention, peace, and zero moisture
The best way to have no moisture is to prevent it. Just like we do on the Ya with the fossil fuel: we don’t like the effects of it, such as the noise of the engines, the smell, the bad future for your children, so we stopped using fossil fuel. Instead of the battle, prevention is like peace.
The preventive solution is not well known, because it is not exiting. There is nobody battling or working his ass off, and many times there is not even a demanding, complex, or expensive technology. A preventive solution is mostly a silent and cheap solution. There is actually nothing happening at all. For example, in case of a fossil free solution: there is no noise of an engine, no smell of fumes and diesel, no pollution of the lethal fine dust. You don’t hear, smell, feel, or even see the solution on the Ya. And, back to the moist, you can hardly find the moisture on the Ya.
How moisture is created and how fungus follows.
To start at the end of the physical process: moisture is condensed damp. Vapor is evaporated water floating in the air. Vapor condensates by three conditions:
- The more vapor, the more will condense.
- The stiller the air (no movement), the more it condenses
- The colder, the more it condenses.
Let us see what creates this vapor in your cabin. You can see the steam from your cooking water kettle. Or you see the dense steam from the pan you cook the potatoes in. For 15 minutes the dense steam is spreading into an invisible vapor.
It looks like this is a lot, but there is much more created by your gas (butane, propane, methylated spirits) stove in your galley or kitchen. Every liter of gas will create an average 7 liter of vapor!
You usually cook when it starts getting cold outside, so you keep the cabin closed. The vapor fills the air and goes into your mattresses, pillows, sleeping bags, linen etcetera. The vapor does not condense yet, because the temperature of the air and of the boats skin is still warm.
Inside the boat, all people breathe. Each adult in total exhales about half a liter of water till the next morning.
During the night everything cools down. The cold air hits the windows and the skin of the boat. Then, the vapor in the air cools down and condenses, leaving a film of water on everything. It gets into your cushions, your cloth and if a lot, it leaks down between your carpentry.
What helps is to evaporate it again. You can do that by heating up and by ventilation, to blow it away. That works on the open surfaces, but in cushions, corners and carpentry the moist remains. This is the ideal habitat for mould and all sorts of mushrooms and funguses.
Check here for the diseases mould brings you. The very moment you smell the first mould, it brings up the instinct to battle it. Don’t. You will lose it. Do better: clean up and prevent it from now on.
How Ya prevents moisture
We cook with a water cooker with automatic stop. So, the steam is limited to perhaps 10 seconds. The bulk of our food, we cook in a pressure cooker. The moment the pressure is on, we put the cooker in our ‘hay box’, an insulated box, where it slowly cooks till it is done. No steam at all. Most important is, that we don’t cook on gas. With the luxury of the electric engines/dynamos, we have a big battery bank. So, we have plenty of energy to cook with an induction cooker instead of a gas stove. This truly saves a lot of vapor.
The vapor we have while cooking, we let go directly through an open hatch. Cold is not a problem, because we have a hull with a panorama window. So, in the late afternoon and early evening, the sun shines in fully and heats up our cabin. This way, we can start our evening with a low humidity.
Every morning and evening the sun comes in abundantly and quickly the temperature rises to a comfortable level.
Ventilation
However, you can prevent what you want, also in the Ya the vapor builds up with every time we exhale. The two of us blow a liter of water into the air in an evening and a night. So, every morning we open all hatches and ventilate well, for about half an hour. This is refreshing.
Moisture can accumulate in all closed areas with still air. So, we have put little vent outlets under every couch and cupboard. You drill a hole of 4 cm and glue the outlets in.
But the real miracle is that we don’t have any moisture, mould or mildew on the carpentry, the ceiling, or anywhere else on the skin of our cabin. For many sailors this is a miracle. This is the miracle created by the insulation. It is 11 cm thick PIR foam and this makes the skin better insulated than the walls of a regular West European house. In The Miracle of Insulation you can read all details.
Windows on the Ya and what we do
All windows and hatches are single glazing . While here, in wintertime, they should be at least double. I remember I discussed this with the manager of the marine glazing company, but he only looked at me with glassy eyes; this was perhaps too visionary.
So, during this winter we simply put a cheap bubble plastic on the hatches and port holes with some tape. We still have the light, and the heat of the sun through it.
For our long single glaze (polycarbonate) windows, we simply accept that we take 5 minutes every morning to strip the condensation off. We remove about a quarter of a liter.
The top of the locker of the sails is not thickly insulated, and it has an open connection to the cabin. So, slowly, our sail bags get humid. When the winter sun shines and the sky is blue we put the bags open on deck. In that environment the air is extremely dry.
The mystery of moisture revealed
Moisture on board is caused by adding vapor to the air, that will condensate on cold surfaces. This is a great habitat for mould, mushrooms and other sickening stuff.
Fighting the moisture costs, time, money and is never ending. Best way is prevention. Prevent by:
· No combustion of fossil fuels inside. Especially gas cookers are very energy inefficient and create a lot of vapor.
· Insulation. The more seriously insulated, the better things stay warm enough to prevent condensation on it. Check here how it was done on the Ya.
· Ventilation. Refresh the air in your cabin and let the wind blow through it for a while. And put ventilation holes under your cupboards, berths, closets.
Fossil in paradise
We feel privileged to be on Guadiana river. We are on the Spanish side now, where there is no shore power, but a magnificent view on Alcoutim on the Portuguese side.
Until, after some days of fog and rainy weather, we noticed our batteries were on lower capacity than was to be expected. Trouble in paradise! Was this only the lack of sun and wind?
We realized that our batteries were deteriorating after 7 years of faithful service. Not unexpected, but nevertheless: bad news. Especially because we have a lot of them.
But, never waste a good crisis. We have been carrying around 25 liters of gasoline and a small generator the size of a sewing machine for in case of emergency. With too little sun and wind and lacking shore power, we decided to start using it.
During the circumnavigation we never had to use the generator, the trip was truly fossil free. The gasoline is now 5 years old. So, we had to filter it several times before we could use it.
We are grateful that this now helps us through the windstil, cloudy periods on the river. And we are grateful to our neighbours for not complaining about the noise. But, oh boy, what a nuisance, this fossil in paradise. It stinks, it disturbs the peaceful quiet on the river and we have had to repair it 2 times already because it had hardly been used.
We pray for the sun to shine and the wind to blow so we can use the generator as little as possible. As we write this we see the meter jump to charging 400 Watts on wind and sun so this is a lovely day.
We have started the search for new batteries to be able to continue our fossil free life.
In one of our next blogs we will tell you about our search and all that comes with it.
Nortada brings silent wind
The Nortada, the Portuguese Northern Wind, brought us to the Algarve. We have been here for a while now, happy victims of the Guadiana Glue. Since our wind generator broke down, we wanted to select a new one. Which one? In this article we compare the three most used quality wind turbines: Air Breeze, Superwind and SilentWind.
We compare these three wind generators because they are universal. They can handle all batteries, can be combined with solar panels and other generators, and they are available in 12, 24 and 48 Volt. They are often used on yachts and they are all good, high end generators.
We chose for the SilentWind for its light weight, low noise, the power in also the high range, and the low maintenance.
The yield is in the height!
If you really want a wind generator to deliver, then it needs height. Don’t put it on a 3 metre pole on your boat, but put it higher than 5,5 metre, away from wind obstacles. Then it delivers double, because that is where the wind blows.
This ‘higher-than-5,5’ metre rule dates from 17th century. They figured this out in the time that building high mills was difficult, while the wind in Holland was crucial for the industry there. In those days, the Zaanstreek was the innovation centre of Holland, the dominant and richest country of the world. It was full of windmills, for sawing wood, grinding grain, and they were pumping the water out of the polders around Amsterdam. They could use every sigh. This ‘higher-than-5,5-metre’ rule nowadays is interesting for us sailors.
Check the picture above. The wind blows from the left to the right. On the left side you see a diagram of the ‘clean’ wind. The wind is there if not too close to the surface. The wind blows over the buildings and creates turbulence above it. On the right side you see the influence of these obstacles. For good wind, you have to be far above that ‘stuff’. This also underlines the +5,5 meter rule from the 17th century, when obstacles in the field were not higher than the cattle and the grain. And this corresponds with our yacht: a hull on the water, with a railing and stuff on deck. So we’d better stick to that +5,5 meter rule.
If ever you want to remember anything about the yield of windmills: the height is essential. A cheap windmill put on 7 meter, gives a a far better yield than a high-end windmill put on 3,5 meter.
From here we go into the nuances and details.
More height – less weight
A sailing yacht should not capsize. The ‘Ya’ is an ocean approved yacht and complies with the highest standard; even with the mast top blown into the waves she still self-righting. So, all high things on board are necessarily light things.
There are two pretty light wind generators. The lightest is the Air Breeze (5.9 kg). SilentWind a bit heavier (6,8 kg). Heaviest is the Superwind (11,5 kg).
The Superwind is too heavy for a yacht like the Ya; we would have to put it two times lower and this is close to nonsense. But it is a good turbine for a bigger yacht.
The power – it is in the range, not at the peak
The peak power number only gives an impression for a first orientation. All three wind generators are in the range of a couple of hundred Watts. Instead of the peak power, you must look at the power curves. Then you understand the power of a windmill and what suits you.
Shrieking, madness….and then silence
We are cruisers. We love nature and the silence. We want our wind generator to deliver energy, not the noise.
All three windgenerators have 3 blades. This is a compromise between efficiency and noise. Interested in the technological reasons why? Rosie explains it simple and straight here.
On the Ya we started with the Air Breeze with the standard blades. From the first cut-in, it started making noise. First you like it, because it delivers. But when it really starts delivering and nears the 15 knots of wind, the blades produce a high shrieking sound. The first neighbour started to complain. At 20 knots of wind the neighbours got angry.
Then we discovered the silent blades. Made in Portugal by SilentWind. A high-end product, just as the price of over 300 Euros. But it was worth every penny. Now the same Air Breeze was making a bit of a whistle till 10 knots, a more serious whistle with more speed, and when the wind is somewhere between 15 and 20 knots, the wind generator’s noise drowns into the ambient noise of the wind blowing through the rigging of the boat.
Now we have the SilentWind. When the rotation is slow and you listen well, you can hear the sound created by the magnets or the new bearings. At 8-12 knots you hear a light low whistle and when faster it becomes a friendly lower tone with more volume. When over 15 knots, the noise drowns into ambient wind noises.
The Superwind you will not hear from 20 knots of wind. I listened many times to this mill in several situations in light winds, and it is really low noise. But nothing beats the SilentWind.
Brakes and no brakes
All three can be switched off manually, for example when there is not enough wind. The switch simply makes a short circuit. The Air Breeze and SilentWind also use this short circuit brake to prevent too much speed, which is near hurricane. Before the blade tips would reach bullet speeds, spin out of control and could be ripped from the turbine, the electronics create a short circuit and the blades will slow down to a near stop.
The SuperWind solves this differently, with smart blades. From 25 knots the blades automatically start to adjust their pitch and the rotation speed will not increase. So, in a severe storm, when there is not much sun for your solar panels, the Superwind keeps on generating energy for you.
One could say that the extra moving parts of the Superwind blades have more chance to fail than the simple fixed set of blades of SilentWind and Air Breeze. But this elegant mechanical solution is perhaps safer than the electronic shut off, because also electronics can fail.
Every windmill can be pre-set to stop generating electricity when a certain voltage is reached. Air Breeze and SilentWind simply use the same short circuit brake to prevent overcharging. Since Superwind does not have this brake, all the excess electricity is regulated to go into big capacitators that will get warm, or even hot, and will be cooled by the air around it in your engine room. I don’t like that for leisure sailors. In wintertime the consumption is low and the battery full, while the winds are strong. Then, when nobody is on board, the capacitators in the engine room or cabin cupboard get very hot. It doesn’t give me a safe feeling.
Keep your maintenance low
Superwind designed the mill to keep the maintenance low. The blade pitch against too much RPMs and the double bearings are two examples. Great, but all together it became too heavy for us.
Our Air Breeze broke down. It did not work properly in the medium wind range. Was it the circuit board? We lowered the mast, unmounted the shaft, et cetera and took the circuit board out. We sent it to the service. It was renewed. We remounted everything, put the mast up again, and it ran well. One week later, the same problem. We lowered the mast… to cut a long story short, we lowered and raised the mizzen mast six times (Thanks to Piet, Tulga, IJsbrand, Henk, Jaap, Mick, Inez and others). We also renewed a chip up there, and other things.
Then one morning, we were on the river Guadiana and I saw a strong breeze running over the water towards us. I looked up the mizzen, and saw the Air Breeze hardly responding. I knew, this was its last breeze. Our Air Breeze was no more. We declared it our late Air Breeze.
After these ups and downs, I learned what had to be down. That’s chips, diodes and circuit boards. They don’t belong in the top of your mast, where the rain and moist and salt from the sea reign and you can’t look after it. If you want to keep your maintenance low, then keep it low. Superwind and SilentWind put the electronics in a box (converter or MPPT) and you mount that box in your engine room or cabin or any other dry place. Ofcourse it can break down, but in that environment the chance is smaller and the (preventive) maintenance is easy there.
Why the SilentWind is Ya’s pick
Weight=height. On the Ya the windmill can be put on 7 meters high, on the mizzen mast. If…. the generator doesn’t weigh too much. The 6 kilograms of the Air Breeze and the Silentwind don’t influence the stability of Ya. The Superwind with its 11,5 kilograms should be mounted half way. But on 3-4 meters height there is simply not enough wind to justify such a high-quality piece of equipment.
Silence. All three are reasonably silent. (if the Air Breeze has the low noise blades). On the other hand, if you are on anchor somewhere in the middle of a creek enjoying the singing of the godwit, bluefinch and specked spoonbill, and then a light breeze picks up, you will enjoy the off-switch of your wind generator.
Which is the best on low noise? My private opinion is that the SilentWind -what’s in a name- beats the Superwind.
Power range. All three deliver well in the critical wind range we like to sail in, or when we anchor in a more open bay. The Air Breeze is best in ‘our’ leisure sailors wind range and falls back in the higher regions. The Superwind is doing about the same, but is cut on 350Watts from 25 knots. The SilientWind continues in the high range. We are also interested in the production in stronger winds, when the weather is bad and our solar panels don’t deliver. Then the 12 Volt delivers continually 420 Watts. The 48 Volt version -which is of our interest- delivers even 520 Watt, so much better than Superwind (350 Watt) and the Air Breeze (200 Watts). Our battery capacity is big enough, it is seldom full, so let it all come in, SilentWind!
Regulation You can look deep into the regulation. We love KISS, and then the Air Breeze comes close with a simple circuit board built in the mill. SilentWind’s regulation is based on the core business of the wind generator: to take all energy it can get from that wind, from the cut-in speed to the safety limit at gale wind. The only disadvantage is that you have a big MPPT in your engine room.
I do like the blade pitch solution of the Superwind to keep on running smooth in even a hurricane. But I don’t like that the mill keeps running when the battery is full and the capacitators can get hot. Batteries are full when there is no consumption, so mostly when nobody is there. Then we don’t want critical hot things on board.
Low maintenance. A special word to Superwind. They have put a lot of attention to durability and low maintenance. Unfortunately, this is also the reason that it became too heavy to be effective on the Ya.
I see maintenance, preventive or repairs, as a daily custom for the sailor. But our Air Breeze signed its death warrant when it had to be lowered from the mizzen for the 8th time to check the circuitboard. The SilentWind (and also Superwind) keeps this delicate stuff in the converter or MPPT, to be mounted low, e.g. in your engine room.
Conclusion: We chose SilentWind. Please mail info@fossilfreearoundtheworld.org if you have any comment. We’re curious what you choose and why!