Catamaran with solar panels

It so happened that I got into a kayak for the first time only in 2015, having turned 47 years old by that time. I picked up an oar, tasted the aroma of romance from river rafting and realized – this is mine! In one breath the Klyazma was passed from source to mouth, and then, on long winter evenings, plans for future trips began to arise in my head: along the Volga, along the Kama, along Chusovaya. Also, the long-standing desire to take a “cruise” along the Don (of course, from the very upper reaches of the Central Russian Upland to its delta flowing into the Sea of ​​Azov) did not leave me alone. I started the 2016 season with a hike along this river. I’ll immediately clarify the specifics of my “expeditions”. Although I am not an extreme hiker, I prefer to travel alone. And due to the impossibility of finding a lot of free time at once, I am forced to break long routes into separate stages (sometimes two or three days), starting each next one from the finishing point of the previous one. As a result, by July I reached the city of Zadonsk from the source of the Don in several stages. And in August, having decided to add a little geographical diversity, I set off for the Volga, aiming for a 400-kilometer (according to the route picket data) section from Nizhny Novgorod to Kazan.

However, my rapid acquaintance with the world of water tourism was suddenly stopped by an injury received mid-distance. The two-month stay in a cast that followed this event forced me to seriously rethink the concept of my travels. And first of all, I wanted to reduce the risks associated with searching for parking spaces. A catamaran with inflatable cylinders and an aluminum frame was seen as a suitable option for providing overnight accommodation directly on a ship moored near the shore. But it is heavier than a kayak, therefore, rowing it alone will be difficult and inconvenient due to its large dimensions. And since there was no desire to disturb the river silence with the crackle of a gasoline engine, obsessive thoughts appeared about using an electric motor powered by solar energy as the main driving force.

Studying the characteristics of various solar panels and watching many videos on the Internet about their use instilled confidence and theoretical validity of the plan. My reasoning was that one 100 W solar panel produces a little over 5 A of current, and a 360 W electric boat motor requires about 30 A, which means that five or six of these panels are needed to guarantee its operation at full power. But this is just a theory, and I’m not a professional power engineer, so in order to test the calculations in practice and before spending money on very expensive equipment, it was decided to conduct a preliminary multi-stage test on what was already available, that is, on a kayak.

Solar panels come in three types: monocrystalline, polycrystalline and amorphous crystals. I immediately rejected the latter and did not consider them anymore due to the high cost. Comparing the potential capabilities of mono- and polycrystals, I came to the conclusion that there is no clear opinion about which of them is better. Moreover, the effectiveness of one or another panel largely depends on the angle of incidence of sunlight on them. Some give maximum effect at angles close to 90 degrees (perpendicular to the sun’s rays), while others allow wider tilt ranges. At the same time, the majority of practitioners whose reports were found on the Internet tended to think that there was no particular difference between them, especially in non-stationary conditions. The sun is moving across the sky. The panel installed on the vehicle is also in constant motion, and in different planes. In the end, this is what it turns out to be. Therefore, without further ado and guided solely by intuition, I made a choice in favor of monocrystal plates (outwardly they are distinguished by slightly cut corners) and began assembling my first solar battery.

The front side of the plate under the sun’s rays has a negative charge, and the back side has a positive charge. Each of the plates, according to the manufacturer, produces approximately 0.5 V and 5 A at peak. Accordingly, 40 such elements connected in series give a total of 20 V and the same 5 A, providing a calculated 100 W.

It is convenient to assemble the plates into a battery using a conductor, which will allow you to solder the chain evenly, but for the experiment I limited myself to the simplest template from a piece of plywood, drawing cells on it. The connections were made using a tinned copper busbar 2 mm wide. A bus cut to size was soldered with one end to the upper part (to the “plus”) of the first plate, and the other end to the lower part (to the “minus”) of the next plate, and so on, until they formed a single battery. The process turned out to be simple, and even such a “great specialist” in soldering like me could easily cope with it: it was enough to run a hot soldering iron along the busbar, having previously moistened the contact point on the plate with an alcoholic rosin solution. In April 2017, the homemade solar panel was ready to be installed on the boat.

In any trip, and especially on an inflatable kayak, weight is of no small importance, therefore, if possible, any additional equipment should be multifunctional. Guided by this principle, I used a folding cart as a transom for mounting the electric motor, which serves on land for transporting the boat and camping belongings. I supplemented its cargo platform with plywood plates connected to each other with self-tapping screws, and secured the trolley itself in the stern of the vessel, pulling it from the front with a nylon cord to a crossbar made of polypropylene pipes that remained in the house after installing the heating system. I tied the sub-motor frame to standard eyelets glued to the sides of the kayak and to a loop on the stern post. It turned out simple, easy and, as subsequent tests showed, including a 400-kilometer hike, quite reliable.

Of course, I couldn’t wait to quickly test in real conditions what the solar battery I had assembled was capable of. Although it was immediately clear that if it could “pull” the boat, with a power of only 100 W, then it would have to spend more time charging than actually being in motion. The ideal solution for a “solar power plant” lies in a competent combination of solar cells of sufficient power, energy storage in the form of a battery, a special controller that monitors the charging and release process, and consumers of this energy. Moreover, the correct collaboration of all components is important. And not only in the presence of the sun, but also in cloudy weather, as well as in the morning and evening hours, when the angle of the rays cannot be considered effective. Understanding this and preparing for the first test output, in addition to the homemade battery, a lightweight laminated solar panel was purchased – model TPS-105(32)-100W-SF. A frame was made of polypropylene pipe around the perimeter, which made it possible to secure it to the transom trolley using clips rotated at 90 degrees to each other. The cost of the panel is about 13 thousand rubles. – it is more expensive than analogues on an aluminum frame, but the determining factor was its low weight (only 2.2 kg).

A small motorcycle battery with a capacity of 12 Ah was used as a buffer. Motor – Minn Kota ENDURA C2 30 with a power of 360 W (12 V, 30 A). It has five forward and three reverse speeds. The average price for October 2017 is approximately 15,000 rubles.

Special mention should be made about the controller. Today there are a huge number of them on the market from different manufacturers, but there is no fundamental difference among all this abundance. For installations with a power in the range of 500 – 600 W, the design diagrams of such devices are very close, and often the same. For testing, I purchased an inexpensive Chinese controller costing only 700 rubles, and it quite successfully coped with its tasks over the course of several tests and three trips. And to make it more convenient to select gears on the electric motor, maintaining the optimal “speed-load” ratio, I supplemented it with two ammeters: one shows the discharge current, and the second the charge current. To combine all these elements into a single complex, you do not need to have any special knowledge, just look at the external panel of the controller and figure out which terminals, observing the polarities, to connect the panels to, and to which batteries and the load.

The testing ground was a 5-kilometer circle around the lake, “calibrated” using a navigator. On a not very clear May day, I managed to walk 15 km along it only due to the sun! The effect was more than obvious! I will give the timing of the tests. The start of the first lap took place at 7 o’clock. This was followed by 50 minutes of driving and a stop of 1 hour 10 minutes to charge, after which the movement continued until crossing the finish at 9:40. An hour and a half of exercise and the start of the second “race” at 10:30, and at 12 o’clock, slightly before reaching the control point, another pause. After a 40-minute “refueling”, the second circle was closed and the third began. It had another stop at 14:00 for 30 minutes, and then the final finish at 15:00. In total, without using oars, 15 km were covered in 8 hours. The driving time was 4 hours 50 minutes, and charging time was 3 hours 10 minutes.

The results of the first test were encouraging. Firstly, I had the opportunity to feel, so to speak, the “driving force of the sun” with my own back for the first time – this was an unforgettable experience! Secondly, they made it possible to draw important practical conclusions that it makes sense to increase the total power of solar panels to 300 W, and at least double the battery capacity. I was also noticeably disturbed by the wires randomly stretched across the kayak, so it was decided to combine all the electronics into a single unit in the form of a plywood box: two motorcycle batteries were placed inside it, and a controller and ammeters were located outside. Also, a standard 12 V “cigarette lighter” socket was mounted on the front wall of the case, which was then actively used on hikes – a satellite navigator is constantly connected to it, recording a track, and phones are charged. To charge the camera battery, a 12-220 V voltage converter is permanently installed – a Mobile SP 150 inverter with a power of 150 W.

The power plant has also undergone modernization. In the new version, it already consisted of three solar panels, for which we had to purchase another TPS-105(32)-100W-SF. To mount them in the bow of the boat (the first longitudinally, the second transversely), a structure similar to the previous one was assembled using frames made of polypropylene pipes. It turned out to be very functional – in the working position, the transverse panel protects camping equipment from rain, splashes and dew, and to load the bow and cockpit it is enough to fold it forward, like a trunk lid. And behind it, in the most visible place, there was an electronics unit with a tablet-navigator; next to it there was a place for a camera, a paper map and other things needed on the road.

The second series of tests was carried out during a real trip along the Don on a section of about 140 km (from Zadonsk to Voronezh). There were only two days of free time, but the unexpected sunny weather in the middle of the rainy summer did not allow me to sit at home. I arrived at the place where the last stage of the “pre-solar period” had ended a year earlier. I assembled the boat. Equipped with three panels, it began to resemble a small aircraft carrier, and the glowing lights of the controller and the navigator screen emphasized its connection to clearly “unearthly” technologies. However, during the first rafting, I decided not to give up the oar, using muscle power simultaneously with the traction of the electric motor. This tactic made it possible not to lose speed during snacks and rest from rowing, and also significantly helped in areas with a headwind.

When hiking, I very often wake up before dawn. The sun has not yet risen, there is fog over the water and all the most interesting things are ahead… I enjoy nature, but I don’t forget about the technical side. I found out experimentally, for example, that solar panels begin to reliably supply energy to the batteries when the sun rises by 20-30 degrees, which corresponds in our middle zone to about 7 o’clock in the morning in the summer. And the results of the running day were the following indicators: distance traveled – 99.6 km, travel time – 15 hours 10 minutes, maximum speed – 11.9 km/h (taking into account the passing current), average speed – 6.6 km/h , the average speed including stops is 6.3 km/h.

Never before have I been able to travel more than 60 km in one “throw”, and never before has the overall average speed exceeded 5 km/h! Unfortunately, neither this day nor the next allowed me to draw clear conclusions about what share of these results is due to muscular efforts and flow, and what share is provided by solar energy. Since I was in a hurry to meet the allotted time, I actively worked with the oar, increasing the mileage, but also personally introducing a constant “error” into the statistics.

The answer to this question was received during the August 2017 rafting from Voronezh to Belogorye. The distance was 250 km and was covered in three days. And already in the very first hours on the route, analyzing the objective readings of the instruments, it became clear that when the oar and motor are simultaneously operating in 3rd gear, the speed of the kayak is lower than when rowing with the motor raised. The movers began to change alternately: first to row until the controller shows the maximum charge of the battery, then turn on the motor in the 5th gear and move on it until the “smart electronics” prohibits connecting the load (there is such an indicator on the controller).

In the combined mode, “only the oar is only the motor”, it became noticeably easier and the time was released for the contemplation of the surrounding landscapes, which on the average Don are very picturesque. Once he admired the beauty, while manipulating with the navigator, and … accidentally removed the total statistics of the campaign in two days from the memory of the device. Only the track of a little less than a 100-kilometer section remained fixed: the path traveled is 95.13 km, the movement time is 14 hours 50 minutes, the maximum speed is 9.3 km/h, the average speed is 6.4 km/h, the average speed Movements taking into account stops – 5.4 km/h (there were quite a lot of stops).

Despite the fact that these indicators were quite comparable to the data obtained in the previous campaign, I was tired of noticeably less. Although it has not yet been possible to confirm this “visibility” with objective data. For this reason, it was decided to conduct a new experiment on the third running day: to turn on the motor as soon as the sun allowed, and move exclusively on it, choosing a transmission that will be enough for solar energy. True, in order to ensure the “purity” of experience and not to lag behind the schedule, just in case, it rose at night and manually waved almost 35 km manually. I met the dawn on the water, but it was not possible to turn on the motor due to the too sharp angle of sunlight illuminating the panels. Finally at 7:40 the screw spun. Oar aside! I only had to move a troops, stare around and reflect on the intricacies of using alternative energy sources …

So, the movement began in 2nd gear. Closer to 10 o’clock in the morning of the battery, the battery was confidently enough to switch to the 3rd gear, and in the middle of the day, when the sun was approaching zenith, even the fourth “speed” is used for about an hour! The results of the site passed only on the electric motor: the path – 35 km, the movement time is 6 hours 35 minutes, the maximum speed is 8.5 km/h, the average speed of movement is 5.3 km/h, the average speed, taking into account the stops – 4 , 9 km/h. Not bad! Moreover, before the onset of dusk, when the angle of decline in sunlight will cease to be effective, at this pace it was possible to move another three to four hours. And this means that there is an opportunity to bring a daily mileage without the use of cheerful to 50 km.

Of course, do not lose sight of the fact that the current also worked for the total result. It usually adds several kilometers to the piggy bank for each hour spent on the water. But such assistance from nature does not detract from the achieved result. Yes, and this does not always happen – there is also a counter wind, “compensating for the fastest passing course. By summarizing, it can be concluded that the energy issued by three solar panels with a total capacity of 300 watts allows us to compete with the kilometers of daytime crossings demonstrated by conventional cays in hikes on plain rivers. But they are constantly rowing, and here you can pick up oar only occasionally. Plus, the presence of its own power source, which provides energy to all electronic equipment taken with you.

The successful experience of using the solar panels on the kayak served as a good motivation for activating the work on the equipment of the catamaran, and by the beginning of September 2017 it was ready.

A little about the design of my ship. It is based on the RAFTMaster K-4 catamaran “People’s” (length-4700 mm, width-2000 mm, cylinders diameter-550 mm, weight-28 kg, carrying capacity-550 kg). It is produced by a Moscow enterprise and in winter I visited production to clarify its features. The meeting turned out to be useful – I was immediately offered to make individual specimens of cylinders with a bruised feed part, which would reduce the diphthant when moving under the motor (initially the nose and feed have equally pointed forms necessary for the thresholds of four people).

As I already mentioned above, the main idea to switch to a larger craft was the desire to provide the crew with greater safety and comfort at the parking lots. Now you do not need to look for an even and secluded site under the tent where you can relax. And also to exclude any undesirable meetings with the local population – it is sometimes very difficult to do this on the crowded shores of large rivers. Most of the comfortable places are built up on them, occupied by beaches with noisy discos until morning, or occupied by fishermen. Everything is much easier with the catamaran: I moored near any wild shore, even the narrowest strip of land, separated from civilization with an impenetrable wall of thickets, and calmly relax until the morning. Yes, and the tent is now not needed – you can sleep on board. To this end, I equipped a catamaran cabin.

The cabin frame is assembled from boards with a cross section of 100 × 15 mm. Its lower part is deepened from the level of the standard “springboard” of the catamaran to about the middle of the floats and lined with a plywood with a thickness of 10 mm, forming a dry closed cockpit. It serves for cooking, storing things and equipment. On the right and left on the floats, plywood decks are fixed -you can sit and you can walk on them. The nasal part of the cabin is equipped with soft waterproof and non -proceeding walls of reinforced PVC material with a density of 800 g/m2, on top – a roof protecting from the scorching sun or rain. It is possible to install mosquito nets on all sides. At night, the side decks are covered with fastening wings-tents, and a large tent is obtained.

The design of the cabin is modular-distinct. For transportation, the elements of the upper part of the frame are unbuttoned and laid in a cockpit box. So that you can manage alone – a folding unit with wheels is provided on the transom. They allow you to transport not only the cabin to the place of assembly, but also help to move the entire catamaran entirely – to let it into the water and pull it ashore. The total weight of the cabin assembly is about 75 kg.

Having evaluated a positive forecast in the Voronezh region to the second decade of September, a weekly vacation was taken in order to check the new ship on the water. The weather was real summer and sunny. Of the minuses is a strong wind of the southern directions, that is, oncoming. Such winds are not uncommon on the Don, but this time their impulses reached 15-19 m/s. They interfered, of course, to advance forward, but for a comprehensive testing of running qualities, they turned out to be very useful.

In general, the idea looked a little adventurous: a 360 W engine and a total battery capacity of 22 A h did not initially allow actively maneuvering in conditions of insufficient illumination. The calculation was built in the hope of five solar panels with a total capacity of 500 W, paired with the new MRRIR 3210A MRRI controller, which has an advanced indication mode and most importantly, an effective charge algorithm. Also, possible risks were minimized due to the fact that there were many nodal transport points on the way, from where it was possible to safely withdraw and which, in the event of technical problems, it would be possible to get along the flow.

And on September 10, the Don River in the area of ​​Belogorye, the first descent of the vessel. It took about three hours on its full assembly, installation of energy weapons, loading of things and provisions, which I think it was quite acceptable – many newcomers have more time to assemble ordinary frame kayaks.

They walked together with their wife, so they did not set record tasks for themselves, rather it was a “research rest”. At times, they rafted in the raft, and sometimes I had to take up the oars so as not to slip a convenient parking place. It fell and compete with a very strong oncoming wind, but maneuvering on the motor with tacks made it possible to successfully overcome complex areas. We checked themselves and the “ship” for strength.

In four days in such a relaxed rhythm, 85 km was passed. From the point of view of technical statistics, the most indicative was the second chassis: the passed the path is -25 km, the movement time is 5 hours 45 minutes, the maximum speed is 7.6 km/h, the average speed is 4.4 km/h.

Main conclusions. The catamaran, equipped with five solar panels, moves slower than a kayak with three. 1 km/h. In principle, this is explainable, since the weight of the equipped vessel with the crew is almost four times more. In this campaign, I was not able to evaluate its potential to reach the maximum daily distance. But the possibilities for organizing life directly on board during movement on it are significantly higher compared to the kayak – this is an undeniable fact! It is possible to lie down or stand in full growth, which significantly reduces fatigue from monotonous sitting. The second “fat” plus is the presence of a roof over your head, which saves time to search for parking, installing and removing the camp, and the weather becomes a noticeably smaller obstacle.

Having received a certain experience, I understand that now I will find a lot of work on refinement of both the catamaran itself and additional equipment. There are thoughts to engage in the construction of a wind generator, which will increase the energy potential of the vessel, and therefore increase the margin of its course in conditions of insufficient illumination. Be sure to increase the capacity of buffer batteries at least 200 A – this will remain mobile at least five hours in the most unfavorable conditions, even without sun and wind. It also makes sense, probably, to install 500 or 1000 watts on the second engine with a second engine – it will add confidence when performing maneuvers in windy weather. And I really want to try the floating anchor in the “underwater sail” mode – I hope it will come in handy in the fight against a strong oncoming wind due to the more efficient use of a fair flow.

Well, instead of conclusion. It is known that in Australia, the traditional multi -day “Solstemobili” races made by the hands of fans have been taking place for several decades. Or maybe we will organize something similar? In 2018, for example, on one of the beautiful reservoirs of central Russia, the festival or rally vessels set in motion by solar energy. Do not wave up for the competition so far, but for starters, just meet to chat and hold joint test races. I am sure that such a full -time exchange of experience could become very interesting and useful to many! If there are unusual enthusiasts, write to the editor and tell about your designs.

O. Snegovskoy