Solar bike trailer with automatic sun tracking (version 1.0)
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- เผยแพร่เมื่อ 26 ส.ค. 2024
- Convert your own bike: bit.ly/2PSOEyh
Why is my 100 watt solar panel only giving me 75 watts? bit.ly/2DGzauR
Here's how the solar trailer performs under challenging conditions. Instantaneous readings of solar, motor and pedal power are displayed across the top of the screen. This is about 2-3 hours before sunset on a hilly, twisty, tree-shaded road. I picked this route and time of day not because they're representative of typical touring conditions but because watching a rear view camera going in a straight line with no shading would be boring.
Huge thanks to Justin, Teklektic and everyone who worked on the solar firmware for the CA over at Grin Technologies. I've logged over 2000 miles (3000 km) with various solar setups over the years but I've always used two CA's and mostly had to make do with quick glances at the CA's while riding and jotting down totals at each stop. The combination of video and telemetry overlay is a game changer for solar bike design.
I hope this helps others who are looking to build their own solar rig.
I've uploaded the log data to the Grin Trip Analyzer here: www.ebikes.ca/t...
Note: The Wh totals are a bit out of step with each other. The solar and motor Wh are from the start of the trip while the human Wh are from the start of the video (3 km into the trip). This is because the log contains Ah for solar and the motor controller but only instantaneous human watt readings. I power cycled the Analogger and CA at the start of the video to make it easier to sync the data with the video.
Tools used: CA3 with solar firmware, modified GPS Analogger with Hall sensor for solar charge current, Sempu Gen3 bottom bracket (uncalibrated), GoPro Hero 5 Session for video capture, DashWare for telemetry data screen overlay (running on a 12" MacBook under VMWare), Final Cut Pro to add the yellow markup and to edit the footage down to 5 minutes (from about 25).
Convert your own bike: bit.ly/2PSOEyh
Why is my 100 watt solar panel only giving me 75 watts? bit.ly/2DGzauR
Details about the solar tracker here: endless-sphere.com/forums/viewtopic.php?f=6&t=94721&p=1424869#p1424869
Crazy frog has invisible bike 😭
sorry new placements don't make you chosen because I feel it in my body 😂
What the hell is this 😭
The solar panel article was quite informative, witty and friendly! 👍
I was just picturing this EXACT thing in my head, complete with the graphic overlay of all the power metrics! I am so impressed by your build!!! holy crap! After finding out about the Sun Trip last week, I already can't get the idea of long distance solar e-bike touring out of my head, and now I see this amazing video?! Also, thank you for your excellent documentation. What an amazing resource.
Sweet! Always nice to hear when someone finds it useful. Thanks for letting me know.
This thing is epic. You generated 25% of what was used, not bad. Guess at lunchtime these number would be equal.
Nice clean design, looks like a product someone could put on the market.
Yeah, I don't think there's any solar panel currently available that could provide 100% of what's used, unless it's a really weak 250 watt motor. Still, just take a break, eat lunch, you can basically bike an infinite range with this setup.
Correct. Sizing a solar panel for an ebike by trying to match peak power requirements would be a terrible design. You select the solar panel size based on your daily watt-hour requirements. For long distance touring, you need 200W to 400 W of solar. If you’re just looking to top up your battery for short local trips, you can get away with a much smaller panel.
I’m heading out on a tour around the US in a few days. My 330W solar array will provide more than half the power for this 4500 mile journey.
250 watt will get me where I want to go, even with some decent luggage. Average use is 10 wH/km extra above my own physical range as long as I keep the speed limited to 25 km/h
I am testing a Powerbutler.de charger to use 12 volt from solar to charge my battery. Works only when battery is not in use, but I have two of them anyway.
Regen is not an issue here in the Netherlands although riding at higher speeds sometimes involves more breaking. At the same time, charging from AC is not a problem either.
Panelsize will also depend on available space on trailer and what is allowed. A single wheel trailer can only be 75 cm wide.
This does make me wonder how long a bike trailer is allowed to be.... ;-)
Brilliant invention. Terrific, and a bit surprising, to see regenerative braking on an e-bike. Happy traveling.
Thanks, Phil. Most ebikes can’t implement regen because they use mid-drives or geared hubs with an internal clutch. My bike has a direct drive hub.
yes my golden motor direct drive has ebrakes too.. ebrakes are a must have
Very cool. The tracking is great.
Now _that_ was fascinating. Thanks.
I didnt know stuff like shown in this video would interest me, but the power of recommendations made it happen. Thanks, super cool :)
Great rig! Will have a look at ur site too, thanks for sharingw us!
wow, crazy impressive! ... can't wait to build me a solar setup.
Go for it!
That's a great video
Wow, very cool! From what I've seen to get meaningful power you need a trailer and can't get away with small panels in the front and back. Maybe some kind of cage with a solar roof would work.
I like the shots at 0:40 where you overtake struggling cyclists :D
That’s really cool and practical use for technology.
I love this auto solar tracking device and the way how you can speed up hill. Any transformation to the bike? would like to see it... wish you all the best
Right. It looks like I didn't think to put a link to the project site in the description. Here it is: www.solare.bike.
The bike is a recumbent with front hub motor and batteries on the bike so it still works as an ebike without the solar trailer. Leaving the trailer at home is much more practical for short trips around town. The big solar trailer is really just for long distance touring. You could attach such a trailer to just about any kind of ebike or even put the motor and batteries on the trailer if you don't want to convert the bike, although you might have issues with loss of traction if the trailer is lightweight like mine.
bro this is amazing
Mi sono costruito anche io la mia bicicletta elettrica . A mio avviso sarebbe da lasciare in piano e evitare una macchina che lo muova .. poi va detto che una alternativa sarebbe di fare un pannello “ ripiegato “ anche solo su un tessuto formato da più pannelli 30x40 in serie e stenderlo per terra e lasciare ricaricare le batterie nella pausa durante il giro in bici ... va detto che andando in strada ( come faccio anche io) con una buona batteria LIFEPO4 da 36 V 30 ah ne hai per un giro di più di 80 km .. per il tempo che ho io a disposizione è più che sufficiente. Inoltre attento alla rigenerazione! Che utilizzo anche io con motore GEAR LESS se vedi la tensione delle batterie salire oltre il limite rischi che si incendiano.. limita la corrente di rigenerazione.. considerando che in carica rigenerativa non usi il BMS della batteria .. ATTENZIONE...
This is so cool I love it
Very cool. I am planning a world bike tour currently. I would love to do it on an ebike with a cool solar power set up...but I am afraid I am the least mechanically inclined person on the planet. Athletic yes. Mechanically inclined? No. Lol. So it will be pedal powered only for me. But i will bring a foldable solar panel to charge my iphone. Lol. 😉
Have you considered riding or aiding a rider in the Sun Trip event? Cool innovation.
One of the best video about solar ebike. Short, self explanatory with a lot of info. Can you share reliability issue you had since you have been using the solar bike for some time?
A bit tricky to answer because I’ve kept replacing every component as I keep coming up with better ideas. Just about the only parts of this build I’m still using are the Rohloff hub, the Cycle Analyst and the solar charge controllers. Everything on my current build has survived 15 to 30,000 miles. I’ve had to replace one of my four current solar panels because it failed, likely due to excessive flexing of the rear-most part of my trailer.
@@solarEbike thanks for the feedback buddy. For 30000 miles, only replace one solar panel is good.👍
This is amazing.
Wowo this is an excellent project :) I like data over the video :) nice.
This project is amazing, and I've watched virtually all your videos. Can you tell me how you collected the data and what software did you use to overlay them on top of the video?
Amazing work bro. Keep it up.
Very cool solar bike！
Any calculations regarding benefit to overhead ratios? Also, diffused lighting conditions? Would it be beneficial to center & shut off in heavy overcast/foggy conditions? This is a wonderful development, btw...
Assuming you mean benefit of a motorized tracker vs a solar panel tilt you set manually, my advice to first-time builders is to skip the added weight, cost and complexity unless you enjoy the engineering challenge. I've attempted to quantify the gains and found it's difficult to generalize because there are so many factors. Are you traveling mostly north-south or mostly east-west? The gains are the greatest when the sun in directly left or right of your direction of travel and least when the sun is ahead or behind. There's no gain when the sun is overhead or when it's overcast or when you're stopped and can manually position the panel. Time of year, your latitude and daily weather patterns can make a big difference. The overall gain can be more than 30% or less than 5%. I've created a calculator to help estimate for any location or time of year. Link below.
You are correct that heavy overcast generally dictates a center position and my light sensors figure this out automatically. However, I was a bit surprised to discover that during overcast conditions, you can gain a few watts by tilting 10-30° away from trees or buildings on one side of the road if the other side is clear of obstructions because you want the panel to point at the center of the visible "sky dome." Fortunately, the light sensors also pick up on this and generally find the optimal angle.
docs.google.com/spreadsheets/d/1Za-3a4wOQHfdXC8ih5EQkNvv1A90bd7S-pbzUT162c4/
You are a beast 250w of human power is a lot
Well, I was well rested and I think those were just peak values during a short sprint. I certainly can't maintain that output. Also, the human power measurements are through a relatively inexpensive bottom-bracket torque sensor. It's useful as a way to control the motor power relative to pedal input but not terribly accurate. I hope to get it calibrated against a better power meter if I ever get my hands on one.
Cool video! Great seeing the live stats. How are you recording human wh? That's something i would love to play around with!
Hey Jack. I'm using a Sempu bottom bracket torque sensor from Grin Tech. It works great for controlling motor torque with pedaling effort but isn't terribly accurate for measuring human watts.
I looked for ways to at least measure human watts while I had my Bafang mid drive but didn't like any of the options. The Sempu became possible for me after I switched to a direct drive hub motor. I'm loving the silent operation and regenerative braking.
@@solarEbike thanks for the answer! Would love to meet you in a future SunTrip! :)
@@JackButlerVideos That would be a blast. I've got the next 2-3 years mapped out with my own 6 continent solar ebike adventure but I'm open to doing a SunTrip after that. Glad to hear you're hungry for more after your China trip.
@@@JackButlerVideos Yeeeeah! That would mean we re getting more of them great videos! Go jack go!
Try yo add some super capwcitors they are great to hold inrush voltage and current and use that to feed the motor on peak power and charge the battery smoothly.
Sehr interessant! Liebe Grüße aus Österreich
very good info, thanks
Imagine trailing 3 of these
Vraiment super cette vidéo ! On aimerait en voir d'autres avec plus de précision sur le montage :)
Bonjour David. Here's a short video clip showing how the linear actuator is mounted: th-cam.com/video/DKka3gzXPWI/w-d-xo.html
And a new post with lots of details about the solar tracker here: endless-sphere.com/forums/viewtopic.php?f=6&t=94721&p=1424869#p1424869
Very interesting, thx!
0:33 to 0:40 Why does the panel not turn to the right ie toward the sun?
Ha! Good eye. Couple of possibilities. The tracking algorithm has some delay built in to avoid excess wear on the tracking motor. Also, this version of the trailer has only 2 light sensors and they’re both on the top side of the panel. Occasionally, the sensor facing away from the sun would pick up more light due to light reflection from the ground (albedo), particularly if the sun is hitting the panel at a steep angle or even shining in the back of the panel. My new trailer has 4 sensors to fix this.
Is it possible to help me built one like yours to put on my bike trailer sir Need some info for your set up
Great video, I would be interested in seeing the solar tracking mechanism and how it works.
endless-sphere.com/forums/viewtopic.php?f=6&t=94721&start=100#p1424869
@@solarEbike
Thanks for that, do you have any details about the tracking mechanism?
@@benpar8120 I'm confused. When I click on the link I posted above I see a long post with detailed description, video, photos and links related to the tracking mechanism. Are you seeing something else?
@@solarEbike
Ahh yes found it, Linear Actuator....I thought it was one that you have bought ready made...
@@benpar8120 If you're looking for a ready made tracking add-on to an existing trailer, I posted some kit options at the end of the post above. These are designed for stationary solar panels so they may not update the position frequently enough to be useful on a moving trailer. If you're looking for a complete solar ebike trailer, these French guys posted a video and it looks like they're planning to sell it as a product: th-cam.com/video/jqowchDKIK8/w-d-xo.html
Brilliant.
That is amazing!!
Cool!
Mega cool!
Very cool
Cool sun tracking! Is it possible to use two directional trackings?
Thanks. I assumed from the start that anything other than single axis tracking with the tilt axis parallel to the direction of travel would have undesirable aerodynamic consequences but I’ve never tested that assumption.
Was the voltage really to high @4:00 or was it the BMS that found one cell stage over its max. voltage and opened up ending charge for the whole pack?
I'm still trying to figure it all out but I believe what happened is that the charge current got too high at 3:35, spiking to 33.8A @ 40.0V when the motor controller overshot the set 30A limit on regen current. I'm guessing the BMS cut off the battery to protect it from excess current. Once the BMS cut off, the motor voltage was free to float above the 42V (4.2V/cell) BMS high voltage cut-off limit which caused the BMS to keep the battery disconnected until voltage dropped below 42V.
My note at 4:03 is about the solar charge controller seeing more than 42V on the output side and not charging. You'll see that solar watts immediately dropped to 0 starting at 3:35 even though there's full sun. Putting the note later was just an editing choice. Both the BMS and the charge controller resumed working as soon as voltage dropped below 42V again. The full log data is available here but the timestamps won't match because the log data isn't edited for time: www.ebikes.ca/tools/trip-analyzer.html?trip=vQbjaL
Hello, how did you made the video overlay showing the watts, voltage and other parts of your system ?
Please see video description.
Did the regenerative braking break when you hit the high volts?
Was the battery filled to the top when going downhill?
I believe that the battery BMS cut out to protect the battery from excess charging current. When that happened, the regen braking action stopped but the motor was still spinning and generating the high voltage we see (back EMF) which in turn stopped solar charging because the charge controller detected the higher voltage. The BMS reconnected a few minutes later and everything worked fine again with no damage. I have since reduced the max regen current setting and increased the battery from 400 to 600 Wh and the problem has not happened again.
Awesome.
Pauze at 0:57, not very effective if i see the shadow on that car.
Doesnt that become a sailor panel with wind?
Still great invention anyway
Thank you. I just completed a 2100 km trip with a newer version and wind only gave me trouble for about 2 km so not really a showstopper problem.
There are some tracking errors here. Some I fixed by using 4 light sensors instead of 2 and some are a deliberate design decision to delay reaction time to reduce the tilt motor duty cycle to prolong it's life.
@@solarEbike in the netherlands wind would be a major problem 😂
This is so smar idea
Awesome stuff. A few quick questions - how many square meters of panels is that, and what's the total 'wattage' of the PV set up? And secondly - the 'regenerative braking' - stupid question, but just to check, is this putting energy back in the batteries? What's that actual mechanism, how does it work? Heat from the friction or what? Thanks very much.
This trailer has 2 panels each rated at 94 watts. Link below has the specs for a similar solar panel from the same manufacturer. Keep in mind that the “rated” or “STC” watts refers to ideal laboratory conditions and is not intended to represent a real-world output which will be somewhere between 10% and 90% of the rated value, depending on several factors.
www.solbian.eu/en/sp-series/22-sp-104.html
Regenerative braking: Simply put, an electric motor is a device that converts electrical energy into mechanical energy. It works in both directions. If you input electrical energy, the motor spins. If you spin the motor, you get electrical energy.
With the appropriate mechanical connection between the motor and the bicycle wheel, the motor controller can slow the bike to a stop, converting some of its momentum into electrical energy and storing it in the battery. It’s far from 100% efficient. Maybe half of the energy is lost as heat (in the motor, controller, wiring connections, internal battery resistance, etc.)? With traditional friction brakes, all of the momentum is converted to heat and “lost” by radiating out to the environment.
Many ebikes don’t have regenerative braking because their designs prioritize motor weight, cost, gearing, weight distribution, etc. over the benefit of regenerative braking. In my case, I wanted a direct drive hub motor for long-term reliability and regen is relatively simple to do on that kind of setup. I do 80-90% of my braking with the motor and my brake pads last about 5 times longer than they did on a previous setup without regen. On hilly rides like this one, regen typically adds about 20% to my battery’s range. On flat rides like my work commute, it’s more like 9-10%. If you don’t have many stop signs and traffic lights along the way then the gain is even smaller because you’re not using your brakes much.
I am building a 2 meter long trailer, but I am worried about the instability and the "sail effect" that panels with lateral winds can produce. Have you noticed any instability?
Hey Sergio. I logged about 500 miles with this trailer and wind was never a problem. One time when it was very windy and the panel was fully tilted to one side I could feel the wind pushing so I just turned off the automatic tracking and returned the panel to the horizontal position. I was able to keep riding.
If it gets so windy that it becomes difficult to walk or ride a bike without a trailer then a big solar trailer will not fare well. If most of your riding involves very large vehicles passing close to your bike at high speeds then this might be a problem. For all other times, you'll probably be fine.
Trailer geometry can be tricky. Total weight, location of center of mass, frame rigidity, wheel location, hitch type, etc. all play a role. I recently posted about my failed designs and how I fixed them here: bit.ly/2PUlPRb
Here's an illustration of the difference in wind exposure with and without tilt for the trailer in this video.
solarpoweredbike.files.wordpress.com/2019/05/area-exposed-to-wind-full-tilt-vs-no-tilt.jpg
Good point. He had thought about the side winds, but not about the jolt caused by vehicles passing too close. so I think I'll place the panels horizontally and I will not install the solar tracker until I see that I can control the trailer correctly.
I’m a big believer in building the simplest possible version and testing it. Add complexity a little at a time and test some more. Even if you decide against motorized tilting I would still recommend having a way to tilt manually when you are stopped.
Good luck with your project.
Excellent R&D for a better future for our planet!
One question, how do you manage to embed the parameters in your video? Does the data come from Cycle Analyst? I would like to understand and ... do the same with my Veloks tricycle.
Thanks, Giles. See the video description for details.
@@solarEbike Oops, sorry, I hadn't seen.
No problem. Let me know if that doesn’t answer all your questions.
Hey, this is awesome. Can you share the tracking app that you use to overlay the data onto the video?
I wish it was just a simple app. Video is recorded with a GoPro and data is logged separately then combined using DashWare (free, Windows only). Details in video description.
Pls can you tell me how much voltage das your solar panels have and how much watt and your electric motor how much voltage and watt are the energy directly from panels to the electric motor or they charge a batterie first i want to build one am travel 3000km my dream
Ebikes typically have 36V, 48V or 52V lithium battery packs (mine is 36V). Solar panel voltage just needs to be lower than your battery: search "boost solar charge controller" to learn more. 200 watts of solar panels will give you 50-150 km of daily range. More info here: solare.bike
nice!
Is your speed sensor set up correctly? Because your 38kph seems closer to 45kph.
Interesting, how can you tell? Are you just guessing from the way the scenery goes by? Because the wide-angle lens tends to make things look faster than they really are.
Also, I measure speed using both wheel speed and GPS and they agree with each other pretty closely so it might be off but not by that much.
Ola onde comprar esse digital. E o rastriador de sol
This is a one of a kind home-built prototype so it's not available for sale. However, I posted a bunch of information about the build and some useful links here if you're interested in pursuing a similar project: endless-sphere.com/forums/viewtopic.php?f=6&t=94721&p=1424869&hilit=tracker&sid=da03feddfcf088f7f4f2ad943e26b842#p1424869
Do you have webstie / blog ? , i want to see how wiring system works , it seems very efficient bike
Assuming you’re asking about the sun tracking tilt mechanism that is unique to this trailer, I’ve posted info here: endless-sphere.com/forums/viewtopic.php?f=6&t=94721&start=100#p1424869
I'm french I liked this idea I want to see more video of you with your machine ! (Google translate ^^')
Does it just need the date and time of day and general location and direction? Or is there a sensor?
I'm using an Arduino to control the tilt and I bought a GPS module (time and latitude) to go with it but never got around to hooking it up because my first approach using two light sensors worked pretty well. It still needs some fine-tuning. I talk about it some more in this video: th-cam.com/video/7RGBBNctWNA/w-d-xo.htmlm18s
You were faster than that car. That car couldn't overtake you, Where did you go quickly? by the way, how did you add the live status of the energy, first time saw that kind of video, thank you for sharing your experience with us, but be careful when you drive in downhill roads,
I think maybe that driver was being considerate and giving me extra space or maybe they were just slow. I don't usually try to race cars with my solar ebike, especially not with the trailer attached. The live data overlay was created by combining the video (from any camera) with log data captured with a Cycle Analyst and creating the overlay using Dashware software later ("in post"). More details in the video description.
@@solarEbike thank you, I need to build a e-bike, now days I save money and design the project, after I build the bike I will send you a message. Thank you again.
Ebikes are great for fun and for daily transportation. Converting an existing bike is a good way to save money and to learn at the same time. Good luck with your project.
Hi do you not need a BMS or are they typically included with battery pack?
Every ebike battery I’ve ever used had a BMS included. I wouldn’t mess around with lithium batteries without a BMS. But if you’re looking to connect solar panels to your battery you also need a solar charge controller.
@@solarEbike Another aspect of solar bike builds I havnt seen covered is the connection from charge controller to battery. Can you just connect to the batteries standard power input?
Usually, yes. The input port may be limited to 2A or 4A or 6A of charge current but the cells inside can usually handle more so with larger solar panels you may need to charge through the discharge port. Connectors are another issue. You will likely need to find one to match your battery.
Круто
How many cells per battery
I take it you're running lithium polymer
10s 6p LG MG1 18650 cells. LiPo is rarely used on ebikes.
Cool
I have also read that there are 2 different panel qualities, only one of which is affected proportionally by a shadow
Cool! Of course the question everyone has: How much energy does the sun tracker motor take?
I was wondering the same thing when I was putting this together. The tilt tracking motor draws around 1 amp at 12 volts and has a duty cycle of around 1-10% so it averages less than 1 watt usage under most circumstances. The solar production gains are much higher than that - easily 10 watts or more gained by adjusting to the optimal tilt angle.
However, the added weight, cost and complexity are harder to justify. Although automated tracking on a bike trailer has significant gains under ideal conditions there are many times when it doesn't add much value such as when it's overcast or during stationary charging when you can set the tilt angle manually. I carried the tracking feature into my new design mostly because I like the engineering challenge and it's a cool visual, not necessarily because it was worth the trouble.
what motor you are using to change position?
i need something 12v 1A
On this trailer I’m using a 12v linear actuator made by Progressive Automations. On my new one I’m using one of these with a torque limiting shaft coupler (clutch): a.aliexpress.com/_mNDpQWX
Are you building a solar tracker?
@@solarEbike yes, in theory^^
Oh an actuator, these things aren't cheap
I thought more of a normal motor with a gear and direct drive. Unfortunately, I only have these RC car motors that have far too high rpm.
I also thought about a stepper motor, but they have too many cables, I just need plus and minus for the sensor ^^
I want to use this sensor - but it has only 1A Output for the Motor (12V) is that enough?
www.aliexpress.com/item/32814172509.html?
I am still unsure how to build the drive unit
Bergwacht The first link I gave you is for a motor/gearbox combo but if you already have a motor try searching AliExpress for “planetary gearbox” to see if one of those might fit your motor.
12v 1a is enough to move some solar panels provided you have sufficiently low gearing and don’t mind that it’s slow. Make sure you know the minimum update interval for that tracking controller you’re looking at. If it’s designed for stationary applications and you plan to use it in a mobile platform then you may not like it if it only adjusts once every 5 or 15 minutes.
Linearmotor eBay: www.ebay.de/sch/i.html?_from=R40&_nkw=linearmotor+&_sacat=0&rt=nc&LH_PrefLoc=2
А в чём прикол все время едет в низ....
That's great. And then we could show the test video without the 25kph uphill and then 66kph downhill mostly in the shade of trees.
From the video description, "I picked this route and time of day not because they're representative of typical touring conditions but because watching a rear view camera going in a straight line with no shading would be boring."
Here's another one without hills or trees: th-cam.com/video/5O2JbZug4oo/w-d-xo.html
I've "read" that inclination of panel doesn't affect wattage (see KREOSAN videos) May be that's another panel
Toi idee sowas
Ya pedaling what's the sense of that gonna case more accident than results of not pedaling tha things. Dangerous on the back what's that too much wattage?? I can't understand having solar if you can't use motor all the time
4:16 you found a tesla model 3!!😛
Looks that way. That was Berkeley, California. Probably more Teslas per capita than most places.
Here in europe we dont see them yet😭😭
Охуенно.
Hummmmmmmmmmmmmmm, wind? Gear, food, water, collision insurance?