DIY Solar Ebike Goes Around The World, We Hope

[Mark Havran] is on a mission to complete a solo trip around the world on his bicycle. For such a long and arduous trip, unsupported by anything other than what he and his bike can carry, he has devised a unique vehicle with everything he needs to accomplish his journey. This bike has plenty of things we’ve seen before, such as solar panels and an electric motor, but plenty of things that are completely novel as well.

For such long-distance trips, the preferred style of bike for most is a recumbent. This allows the rider to take a more relaxed position while riding and is much more efficient than an upright bike as well. [Mark]’s bike also uses a hub motor in the front wheel powered by a set of lithium ion battery packs. The bike also utilizes four solar panels with three charge controllers (to reduce the impacts of panel shading) laid out with three of the panels on a trailer and a single panel above the bike to give him some shade while riding. [Mark] also built solar tracking abilities into each of the two arrays, allowing the solar panels to automatically rotate around the trailer and bike to more efficiently capture sunlight than a statically-mounted set of panels would be able to. They can also be manually controlled in case of high winds.

From the video linked below, we can see a number of other added features to the bike that will enable it to make such a long trip. First, he is getting a new motor which has a number of improvements over his old one, which he put over 30,000 kilometers on. Second, there are some safety features that deserve a mention such as his lighting setup borrowed from emergency response vehicles, and even includes a fire extinguisher for any catastrophic electrical failures. Of course, if you aren’t optimizing your recumbent electric bike for long distance there are some other modifications you could make to it as well to improve its off-road abilities. Best of luck, Mark!

47 thoughts on “DIY Solar Ebike Goes Around The World, We Hope

    1. Not true at all – lots of the electronics are handling more than enough current to potentially ignite their surroundings or themselves if things go wrong, and even a lithium battery fire is made manageable by extinguisher – also didn’t catch which style of Lithium battery he is using, some of them are much harder to burn than others…

  1. Fun idea, though got to wonder just how much or how often he ends up having to put in real effort. Its a long trip and at some points the weather is bound to be awful for solar, not like most e-bike rides where the battery could do the whole ride for the rider (probably multiple times over)…

    I think if I was planning such a cycle trip I’d stick with recumbent, but ditch the trailer, as it seems like more things to go wrong – if you make the whole bike frame thing a little longer and covered with a fairing plastered in solar cells shaped something like the helmets velodrome cyclists use I think you could get more than enough solar area on the two sides and top, get better aerodynamics, and because its more sealed and more aerodynamic you will have a little more power to spare so might be able to actively manage the riders little microclimate in response to the varied conditions of the trip. Ultimately I think my idea might then end up being a trike, or at least having stabiliser wheels built in to fairing to prevent excess tilt in a strong cross wind.

    I can see which path in optimisation he has picked and why, and it does seem a good one, but for such a long trip in the planning I think I’d side for making things more durable and comfortable.

    1. Actually I think your off on thinking about the trailer. Doing away with it and adding more to a larger bike frame only adds weight to make control harder. The fact that bikes make for horrible tow vehicles is another issue. It’s my opinion that the trailer is the most practical method and I would have used an additional wheel on the trailer to relieve balance issues from that part. There are a few different reason I would do this, one is to make his tracking system a bit more stable, another is if the trailer were to be modified slightly, it could be used to carry more of the load along with some added travel provisions like a little more food for out there, ETC. The additional wheel wouldn’t have to be used with a much wider spread, just a foot or so. I would use a little hydraulic stabilizing system at the connection to the bike to assist in keeping upright at key moments of unexpected need.

      1. Don’t need to add much weight at all (might even end up lighter), a largish fairing of Carbon or Glass fibre covered in Solar doesn’t need to weigh much at all. And I’d call it better placement for the added weight when thinking about control – as its mass you can directly counteract and feel its impact, trailers on the other hand do whatever they damn well please, and are behind you so if it wants to throw you for some reason you might not get any warning, or be able to do anything about it even if you do see it coming (this trailer might be light, but its got one heck of wind area to catch that shock gust or lorry shock wave)…

        I also did suggest it would probably end up a trike – which immediately means you can do almost whatever you want weight wise and have perfectly good control.

        But ultimately the reason to do away with the trailer is just that your most important asset for the long journey is hanging out behind you, where you really don’t have great control of it, the cables that make it useful are going to be flexing around often so quite possibly going to fail – its just not as durable an arrangement.

        Which to me, when the goal is to go so very far is more important, you need one of durability and very simple repairs (ideally both), this is two motors, solar panel, suspension, mechanical and electrical linkage all essential to functionality of the trailer, and none of it the easiest things to find a replacement or fix out in the sticks somewhere. The fairing concept will be much harder to damage, any damage is probably not terminal to the trip – you can live with it till you hit a city you can source parts or its a simple repair with the kit you’d have to carry on hand.

      2. If you two added wheels and handlebars to your engineering armchairs you could have your own recumbent bikes.
        “Well if I were doing this I’d build a teardrop faired trike with air conditioning”
        “I’d use hydraulic stabilisers to stop the trailer from tipping over”

      1. A fairing concept should have massively massively less drag than this, you only push the air out the way at the front once, and let it flow back smoothly behind you – this is all turbulence and air catching surfaces for maximum drag – though at slow air speed drag won’t matter so much, so if he is aiming to keep it slow being poorly aerodynamic won’t matter that much, only really in high winds – and most folk would choose not to cycle in those (though personally I always found that (within reason) to be the most fun cycling).

        Maybe a fairing works out worse against a cross wind – but then that trailer is such a massive lifting body if its angled even slightly wrong when the gust comes I’d rather have the fairing – directly feeling the action of the wind against something you are directly connected to and probably right at the centre of mass and pressure so all the forces don’t have great leverage over your ability to shift your weight means you should have good control – being yanked about by the wind actions on the trailer all acting through the pivot point a distance behind you is going to be much harder to control.

    1. Yes this occurred to me too – what the different regulations will be for each country he attempts to travel through…

      At least it can charge up while he waits for customs clearance at each border.

    2. I’m disapointed in myself that this didn’t occur to me at all, I’ve been moaning how stupid the rules on Electric personal transport is for ages – like in UK its legal to hire and use a powered personal scooter thing, but you can’t own one and use it… The power limit as an idea seems sound – but really its the wrong approach, doesn’t matter how much power it can draw really, just how fast it can go electrically and how much it weighs- as those are what defines the damage you will do in an accident and once you get beyond a sensible cycling speed and weight you really are a motorbike. So should be under motorbike legislations.

      I expect being all software controlled he will just state it is set to x – whatever the rules of that nation require, even show the border folks the settings, then silently turn it back up once he is through, as long as you don’t ride like an arse or really go too fast so you look like a motorbike nobody will ever know…

      1. okay, let’s assume that weight of the machine and max speed are the definitive factors in the rules on electric personal transport. Then how would that work out for a person of 50kilo versus a person of 150kilo? In other words, the person riding the machine might contribute the most to the total weight of the moving mass. Using the engine power is not a bad idea at all, since this truly limits the amount of power you can add to the system (motor power combined with overal friction (which is liked to be higher for the heavier person) will determine the max. the speed, which is also limited by other rules). Having no power limits would certainly be a bad idea anyway.

        1. Down here at least, it’s already mandated that electric assist must cut out at 25 kph. It would be technically trivial to electronically regulate or just limit the maximum rate of acceleration also, so that is a parameter that could be legislated instead of the currently piddly 250W power limit. Then you could actually have e-bikes that can power up hills without being pedestrian-mutilating drag machines.

        2. A bicycle has multiple sources of power so a 50W motor with a 50W elderly person will have a different top speed to a 50W motor and a 400W tour de France contestant. Even that 50W motor may have a peak power of 1000W. I much prefer speed limits and weight categories, they’re harder to fudge and are how we govern cars.

          1. Oh and you mention rider weight varying, yes that makes weight a harder measure of danger but for vehicles it’s accounted accounted in your Gross Vehicle Weight Rating I.e. what’s the maximum this vehicle can safely carry including itself. If you’re over that rating you’ll get pulled over and fined. If you crash while over it your insurance is invalid. The same can sort of apply to bicycles since they have a maximum load rating. Say to meet the ebike category your unladen weight must be less than 30kg and your gvwr must be below 180kg.

        3. As I could go 30mph (traffic permitting) carrying 20kg+ of crap and on a heavy hybrid mountain bike on road tyres, seems like 30mph (or slower) with a max bike weight of say 40KG is reasonable to still be a bicycle. Its well within human ability to do just that…

          Just ban Twist and Go throttle – you must pedal and keep the top speed and max weight reasonable, then it is fair to keep it the less regulated Bicycle over a motorbike/moped – remember those things have 30Kg or more of engine and a big steel frame, massively heavy wheels, even hitting you at 5mph its going to be nastier than the ebike in the above ballpark going quickly, and those mopeds can go faster too, motorbikes much much faster…

          Remember all rules are basically arbitrary – so picking any number that seems reasonable to prevent abuse of the tech is good enough – no such thing as a good reason why all vehicles in the UK can be 2.5M wide, but you get to be 2.55M, (or was it more – definitely wider) if you are a refrigerated van (yes there are wide loads etc but any old vehicle can be that wide) – yet with how narrow many UK roads are legally locking most vehicles types down to 2M, or 2.2, 2.3, heck down to 1.5 etc might make more sense, and why should a cold van get to be wider than legal for anything else that can just use the roads normally (I’ve not looked at these rules in a while, so numbers are perhaps erroneous and maybe they have been updated at some point, but arbitrary they definitely are).

          1. Why would you ban “Twist and Go” throttle?

            I’d say if anything, were to be banned it would be pedal controlled throttles, as they’re usually pretty imprecise, and there’s no safety benefit that I can think of.

            Only the most expensive pedal controlled throttles are proportional to pedal torque. Most are simply a magnet sensor that applies a fixed throttle (Low, Medium, High) whenever the pedals are turning. With the higher end torque based sensors, most people turn them up to the point where they’re effectively full throttle any time the pedals are turning anyway, so they’re not all that different in general practice.

            On my commute, the majority of ebikes are essentially just running full throttle with the rider turning the pedals at 50RPM. Because there’s no proportional control on most of them, you can’t actually ride at lower than full throttle unless you stop the pedals and coast, and just turn them to boost your speed back up, etc. Seeing as the speed and power limits are pretty low, usually 24, or 32km/h depending on region, most people would probably ride at full speed anyway, but at least with a thumb or twist throttle, you can have some finesse at lower speeds instead of being all or nothing.

            When I’m riding my ebike, and following a non-motor cyclist up a hill, I’ll ease up on the throttle, and make a nice wide pass at a reasonable speed. This would be impossible with most pedal controlled setups. you’re either off the throttle, in which case you’ll be decelerating, or you’re on full throttle, in which case you’re probably going to blow by at maximum power. It’s actually difficult to ride this kind of bike smoothly.

            The two types of control are actually reversed from how they’re typically perceived. A pedal controlled throttle is basically just forcing you to ride with little effort, and as fast as the controller will push you (unless you change the power settings up and down constantly). A manually controlled throttle actually lets you more easily adjust how much, or little pedal assistance you want.

          2. You ban twist and go IMO so you remain a bicycle – rather than having legal, license free ebikes that are really just unregulated electric motorbikes – stripping things like pedals and the human motive element, to make the best motorbike they can while fitting whatever the rules are – as you give Bicycles and I assume even electric ones to those too young to be trusted with a motorbike/car etc it to me seems important for such an unregulated form of transport to remain as idiot and child proof as possible…

            Also I’d never heard of such primitive pedal control, so didn’t know there was actually a potential controllability issue – I’ve had one experience on an e-bike, and it was great to ride – while young, fit, with no trip I’d take proving too much at the time and broke, its all been normal cheaper end bikes personally..

          3. That’s the problem, though. Cycling purists trying to impose their ideals on everyone else.

            It’s almost as if they see anything that could make them better(in a particular situation) than a normal bike as if it’s unfair competition.

            It shouldn’t be seen as competition to bicycles, but to cars.

            There’s always lots of cyclists boasting about how they’ve never needed a motor, and it’s somehow wrong to remove/reduce the requirement of leg power, yet very few of them ride as their primary, or only form of transportation.

            ebikes make it possible for people to get around without cars in a lot of situations where they would be unwilling or unable to on a standard bike, whether due to injury, lack of fitness, or just lazyness (if that’s even the right term).

            I’ve seen lots of fair weather cyclists call e-bikers fat and lazy, and then drive to work any time it’s cold or cloudy or they don’t feel up to it, while the ebikers are still commuting on their bikes regardless.

            Removing the requirement to turn the pedals doesn’t make it any more of an “electric motorcycle”. If it has the same motor and controller, it will be just as safe. Does it really matter if they’re turning the pedals with minimal effort, or holding down a thumb throttle? Either way they’re getting the same few hundred watts from the motor, with whatever they want to add with their legs.

            I don’t think there’s anything that makes the vespa style scooters any less safe than something that looks more like a bicycle, so forcing them to put pedals on to keep it legal as a bicycle is super dumb, especially when they’re so wide and weirdly positioned to be completely impractical to use, and potentially dangerous to other cyclists.

            IMO, the biggest danger to ebikes is giving inexperienced cyclists the ability to ride fast, before they’ve gained the riding experience to do it safely.
            I think this is what gives people a natural dislike for twist/thumb throttles, or scooter style bikes.
            The reality is that even with pedal throttle, that rider’s going to be just as inexperienced, and bad to ride around.

            Arguably, if we take away all the advantages of an ebike, and make it as much like a normal bike as possible, people won’t ride them, and we won’t have those inexperienced riders flying around at 32km/h. The problem is that instead, they’ll be flying around in their cars at 60km/h instead.

            Trying to turn people away from ebikes is often the same as turning them away from bikes.

            Most people aren’t going to go straight from driving, to being a hardcore cyclist overnight. Ebikes are a great way to get into biking, and many of those riders will probably get more into bikes in general.

            I’ve always liked bikes, but was never an every-day cyclist until after I got an ebike. Now I mostly ride my road bikes, leaving the ebike for bad weather, or days when I really don’t feel up to riding.

          4. I have nothing against e-bikes, I just have never needed to travel a sane distance to cycle through terrain that was too much for me, and being forever broke won’t cough up for the e-bike as I don’t need it. It is not at all about making e-bikes more like ‘pure’ cycling, just keeping enough requirements in their build process that they do not end up become motorcycles in all but name – as you don’t want to go letting any age and any skill level zoom around on ‘motorcycles’ – there is a reason they have licence requirements and are regulated.

            And if you take away all the cycling elements as a requirement for unregulated electric bicycle you will end up with bikes that are effectively unregulated motorbikes – and that is bloody stupid as an idea, as being unregulated its what you give those kids that are no where near mature enough adults yet to be trusted with a moped/motorbike, but probably old and responsible enough the parents don’t follow them round keeping them in check and would rather like them to haul themselves around more often – and we all have been younger and stupider, even a grumpy old man in outlook decades early like myself was stupid on occasion…

        4. I don’t know why no power limits would “certainly” be a bad idea.

          The main speed-related danger I see with ebikes, is when I’m climbing a steep hill at 10km/h, and and ebike makes a close unexpected pass at 25. If I were to swerve to avoid a pothole or something, it could cause a crash, because I’m not expecting riders from behind to be approaching with that much speed differential. The funny thing is, that a few hundred watts of continous output is plenty to make this kind of speed differential on a long hill. I’ll might do around 300w sustained on a long steep hill, so an ebiker pedaling at 175w of leg +350w of motor will have a huge speed advantage.

          I’ve never been bothered by another bike accelerating from a stop too quickly. If anything, the opposite is true. Often ebikers have their bikes in a stupidly high gear and rely on their motor to get them moving. It’s not unusual for them to be pretty wobbly and slow if they ever need to start on a hill where the controller is holding them at the current limit. A more powerful motor would quickly get them up to speed quickly and avoid the wobbly starts, especially on larger cargo-bikes, etc.

          I would begrudgingly agree that some form of speed limiting is probably a necessary evil, but there’s really no need for power limiting on a bike with a 32km/h top speed, IMO.

      2. Really, I don’t think even fast acceleration causes any danger on ebikes. A speed limit, sure, so you don’t have people flying past other cyclists at 50km/h, but if it’s limited to 25 or 32km/h depending on the region, it shouldn’t really matter if you’re doing that with 300w, or 3kW.
        In a lot of cases, more power is actually going to be safer, because it’ll let you get rolling with a lot less wobbles if you have to start on an uphill, etc.
        It would also be nice if you could ride faster with a license, etc. I can ride my 75kW gasoline sportbike around with no technological limiters on the speed or power, but it’s illegal for me to do 40km/h on my ebike. Really, why is one okay, and not the other?

        1. Because of dumb politicians who not only don’t know anything about what they’re writing laws about, they refuse to learn, wallowing in their ignorance like pigs in mud.

  2. why on earth does he have that bracket for the top panel orientated that way.

    Huge amounts of aerodynamic losses! Why bother carrying so many panels if you are just sacrificing efficiency

    1. While I do somewhat agree his head would fill much of that bracket zone creating drag, you don’t want it in the way visibility wise, and he has mounted all the running lights to the back of it – so it is probably the best way to mount it building this style of bike – and going slowly its not going to be that bad as drag and velocity are not a linear relationship, nice and slow the drag won’t count for that much.

      I’d rather a more proper fairing, but to each their own, engineering compromises no matter what you build…

  3. I see he used a sensible recumbent design- short wheelbase and low steering position. I see so many with the steering tube coming up between the rider’s legs where they have to hold the weight of their arms up as long as they are riding. Ugh! In a crash you know where that tube is going, and your arms will get tired in a matter of hours.

    Long wheelbase bikes, especially loaded ones, suck at going slow, especially up hills.

  4. Is there really that much to be gained by sun tracking? I’ve seen some work where it looks like a flat panel still gets you about 85% of the output regardless of sun orientation (perpendicular to sun is 100%), And of course I cant find it now!

    1. What you can get off axis is very panel dependant – some of them have interesting mico lens etched into the glass front, or better optic properties of the covering etc, and the actual silicon beneath can be of a few different forms, with different feature types – it all makes some difference.

      I can say with certainty that the particular panels on our roof don’t do near that well off axis, probably between 40-60% once you get into acute angles…

    2. You can get reasonable efficiency on a static panel which is initially oriented for the maximum average power.
      If you’re rolling around, the best you’re going to do is straight up, which is going to be far from ideal when you’re anywhere but the equator.

      1. If you can’t rely on any orientation, then the best is actually flat – like is done on boats. A vertical orientation would result dead spots.
        According to the paper I linked to, flat isn’t as terrible as it sounds.

    3. The best all around angle if you son’t have a 2 axis tracking mount is to aim the panels due south (or north for southern hemisphere) and match the north/south tilt angle to your latitude.

      If you’re depending on the panels for winter heating then it might be best to set them at the angle where the sunlight will hit them straight on at winter solstice to maximize the % conversion from the reduced winter light.

      Or do a three position manual mount to change four times a year. Low for Winter, High for Summer, center for Fall and Spring. Change at each equinox and solstice.

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