solar bike

Great advertising for green-tech, but unless its parked in full sun all day and you have a very short commute, that square footage of PV might not give your battery a full top-off.

Better for a businessman to put tracking panels on the roof of his business, and let E-biking employees charge up from the sun for free. Like Lithium batteries, the PV panels are sometimes worth more than the bike, and easily steal-able.

I would suggest that because of the natural lean of the bike (on its kick-stand) to put all 3 panels on the non-kickstand side. Then park the bike to get max sun (of course). I'd have 2 panels open to the left and right, to be as vertical as possible, while the reflectors fold down like a lap-top on all three panels (as they do now). The central rack-attached PV panel can be hinged at the top, and prop-able so the bottom of all 3 panels will swing outward so they can be set at a more optimum angle to the sun.

There was some discussion a while back at builditsolar.com and also otherpower.com about reflectors adding to the panels output. The reflectors are cheaper than added panels, and can be made of polished metal so as to be more hail and wind-blown tree-branch resistant (compared to common glass-mirrors). The big problem was the added heat. Early experimenters melted their PV panels before they realized that heat could be a problem.

Next step was to add a surface-mount heat probe and a simple circuit to gradually change the angle of the reflector to diffuse the solar reflection, and eventually remove the reflected light. (Google Redrok tracker)

Adding heat sinks to the backs of panels raised the reflectors useful solar harvesting time. Adding a plate to the fins enshrouded the heatsinks, creating a chimney effect (thermosiphon, heat rises) and that helped even more (the reason its good to have the panels near vertical). It is debateable if adding a small fan to the chimney-row of enshrouded fins would raise the heat-shedding enough to make the fans watt-draw be worth the added solar reflecting time.

In hail/tornado country, there was a design that had all the panels facing down for their protection, and all solar harvesting was from pivoting reflectors. Due to the near horizontal angle of those PV panels, they had a vertical liquid-filled thermosiphon loop alongside the panel for its cooling (similar to whats found alongside municipal electrical supply transformers.

In the pic below, hot coolant enters the hollow fins at the top, and as they shed heat the coolant will sink, re-entering the hot transformer at the bottom (no pumps). The shape of the tube-fins allows more of them to be added as neccessary (of course, air would be a better coolant for a mobile E-bike!).

All that being said, in spite of several concerns needing to be addressed, reflectors work...

oimg_GC00273793_CA00273899.jpg
 
Check out this page about a solar scooter build.
http://www.builditsolar.com/Projects/PV/pvscooter.htm

He drives it to work, leaves it in the sun and drives home where he again leaves it out side. Never needs to plug it in...so yes you can run your ebike by solar charging.
 
sk8norcal,

Thanks for sharing that trailer. It's the first trailer I've considered borrowing a number of ideas from, such as:
1. That's a proper bike hitch.
2. Nice and long for lots of cargo, and/or lots of solar panel, with good handling
3. Detachable front wheel for the trailer so it becomes a stand alone trike.

:idea: The things I'd do different are:
a. Much lighter and lower construction of course.
b. Make it aerodynamic (I need to go at least fast enough to feel the wind)
c. Use geared hubs in small wheels on the trailer, so they'd really only be powered for big hills and when operating as a trike, but would have inconsequential drag. Primary drive on flat roads would be my powerful and fast ebike.
d. Several kwh of my lithium stockpile to ensure I can make the trip back from the beach non-stop.
e. Seating for at least 2 kids with a roll bar
f. Several hundred watts of solar panel that folds or slides out to full size and can be raised for double duty as sun shade.

I can just see the two boys and I zipping 50 miles to the beach to our friend's hotel. Then I've got 2 vehicles there, the fun and powerful towing bike, and a load hauling trike with a solar canopy that I can bring right on the beach loaded with ice chest and people. I like this idea so much that I may have to put off plans for another cargo bike in favor of this trailer/trike solar powered RV. :mrgreen: :mrgreen: :mrgreen:

John
 
I think the idea of folding out the majority of the panels when parked is the best idea. At least here in CT, we get lots of tree shade, so even on a sunny day on back roads, you wouldn't get a lot of sun when riding.

I'd really like to make a 200-300watt array that I could carry and fold out on the bike. That was my idea for a cross country trip - as it would provide shade during rest stops. As long as it's compact and lightweight when folded for easy carrying, then I think it'd be great. Ebike 20 miles to the beach, fold out panels, charge back to 100% while enjoying the beach. No worrying about finding an electric outlet.

Ebikes will be the first vehicles to be able to effectively recharge and power themselves with no 2nd party power source (gas station, electric outlet). Motorcycles and cars will just require way too much power with today's technology.

I think there is just something really REALLY awesome about traveling on nothing but pure natural power from the environment.
 
I agree with all that except I think a lightweight emoto could pull it off too when run conservatively, since they can pretty easily stay under 100wh/mile. A narrow, lightweight and aerodynamic micro van with a couple square meters of PV cells on top that multiplies by 4 with slide out panels when parked could pull it off too, but the problem would be the requirements to get registered for licensing, so it would have to be a big trike. Patrick's thread about a solar only ebike really got me thinking about how to pull it off, especially since I have 500W of brand new PV cells in the raw to try to make something small work.

Now this trailer thing has me thinking about how to come up with something really slick looking with some sexy aero curves that can function as a rainy day etrike for bringing the kids to school, and has a removable front wheel so it works as a trailer for cargo and/or passengers. It would also function as a mobile ebike solar charging station for both itself and my main bike. Then I can do up one really powerful 2wd ebike for me that's a scream to ride and can pull the trailer. I just need to verify that the 2 wheels on the trailer don't somehow kick me into some kind of motor vehicle definition here. I'm so lucky with the current lack of electric motor rules, that I want to take full advantage of it while I can.
 
You guys still don't understand. It takes alot of weight of solar panels to truly make a solar bike go very much distance. The one guy in this thread only goes five miles a day round trip and he has a big disclaimer in his ad. The other trailer says it is not viable at the end of their video. But I guess we can still dream! Anyone can mount solar panels to their bike and say it is solar powered. But because of the additional weight and drag you did not really gain anything. What you need to have is a fixed solar setup mounted at home, and one fixed or ready to fold out at work, that you leave at work if you need it, but do not carry with you. By the way, I charge my bikes with solar. I just don't take my solar panels with me on my bike. You would be better off taking as much battery as you need for your ride and then charging it up again at your solar charging station.
 
John, out here in the campo, the "Trafficos" are stopping and fining drivers that have people riding in the back of pickups. Doesn't seem to bother those in BIG cattle type trucks.

Might need to check and see if the boys will be legally riding or if you get "Towed" by MOPT wrecker. Living in Paradise is getting more restrictive all the time. :roll: :roll:
 
Evoforce said:
You guys still don't understand. It takes alot of weight of solar panels to truly make a solar bike go very much distance. The one guy in this thread only goes five miles a day round trip and he has a big disclaimer in his ad. The other trailer says it is not viable at the end of their video. But I guess we can still dream! Anyone can mount solar panels to their bike and say it is solar powered. But because of the additional weight and drag you did not really gain anything. What you need to have is a fixed solar setup mounted at home, and one fixed or ready to fold out at work that you leave at work but do not carry with you. By the way, I charge my bikes with solar. I just don't take my solar with me on my bike.
Click to expand...

Evoforce,
No, it's you who doesn't understand. My 500W of cells weighs only 3 lbs and cost a whopping $250. I would not attempt this with store bought panels that are either very heavy due to glass, or weigh about half that (still heavy to me) and cost a fortune. The static portion of my panels will be part of the shell of my bike that would be there even with no solar panels, so the added weight will be only a few pounds per 100W. The fold out, slide out panels will be of a very lightweight composite construction, and will add little weight (My concern there is space, not weight). My bikes all have batteries and can go as far as I choose with no sun. My bikes averages about 500wh per day in energy use in their roles that have replaced the use of my car by about 90%, so I could easily get by with 100W of PV for charging during our 5-6 month dry season if I chose to do a few position changes for solar tracking. The rest of the year I could get by on 150-200W of PV, leaving a few weeks of days of clouds all day where plug in would be required. I understand my power requirements quite well, and I also understand the power source and would approach that supply using quite conservative estimates.

I'm not talking about meeting average American daily driving needs. I'm talking about me and my power needs. In Patrick's thread I was talking about his, which was a far more difficult task, but possible with decent roads. Evoforce, do you understand the low power consumption of electric bikes? They are the most efficient form of transportation known to man. Do you understand that I am DIY'ing my own lightweight panels, not using some 25lb per 100W store bought panels? Which utility or oil company do you work for, because I want to understand the motive for your insistence on multiple occasions that something won't work, that I know perfectly well will work if constructed properly? Or is it that you build an electric car or motorcycle that had no range or performance because you filled it with lead batteries? Don't tell me you're one of the guys who tried putting a 20W panel on something thinking you could get useful transportation energy out of so little.
 
Harold in CR said:
John, out here in the campo, the "Trafficos" are stopping and fining drivers that have people riding in the back of pickups. Doesn't seem to bother those in BIG cattle type trucks.

Might need to check and see if the boys will be legally riding or if you get "Towed" by MOPT wrecker. Living in Paradise is getting more restrictive all the time. :roll: :roll:
Click to expand...

Kids would have roll bar protection, seat belts, and helmets, so no Traffico would mess with me. That is as long as that trailer doesn't put me into some motor vehicle classification, something I already called my lawyer friend about to research for me. Plus I'm a gringo and know how to use the Costa Rican equivalent of a $10 bill quite effectively. :wink:

John
 
No John, What I am referring to is, unless you have a ton of money for space age materials, and tracking devices, it makes more sense to have your charge panels set up at your major destination(s). Please don't take it personal. Once you figure out what you are going to do (what materials that will work for the long term) and daily use to see if it is truly practical, you may come up with something unique and untried that may lead to something that actually will be viable. People are always saying something can't be done. That makes me personally try harder. In this case I am not saying that it can't be done, it needs to have a viable way of doing it. Your solar cells may be cheap but containing them, building a unique structure, and keeping them directed at the sun may be a little more hassle and expense. But don't take it as though i'm not hoping that you will invent a way where noone else has really yet succeeded! Well, at least not at a down to earth price or convenience. And no, I do not work for an oil company. :lol: I have the same hopes and desires as you but I have been experimenting with this for years. You are a noobie and are just learning. More power to you but you cannot put down my years of experience by claiming I may be the enemy. I just want to try to keep you from making some of the mistakes that myself and others have made. Maybe avoid some of our pitfalls so you can focus in other directions. Even though I have been through what you are now experimenting with, you have not wanted or even asked my advice. You may think you are a pioneer at doing this but many many before you have and are trying. This should not discourage you but should clue you in to truly and objectively look at the pitfalls and not just have a love affair for the sake of desire. I have built panels and the rest of the materials in addition to the cells can add up. Then if you have to figure in your labor... I realize that if you need a custom structure that it then becomes cost effective to build it yourself.
 
Well, having a home solar charging station would be the best use to start off with. That's #1. And if you could have a setup at your work too, then you're prob set. But I'm still going to try building up a worthy solar array to charge my ebike, and be able to take it with me.

The guy on the EVT scooter, his ride weighs 286lbs. Adding even a heavy ready made panel of 30-50lbs wouldn't be a very significant drag on normal terrain.

Now if you try adding that weight on an ebike, then hauling it 40 miles each way to your destination and recharging with only 200watts, then it becomes a problem.
 
I agree that stationary with solar tracking is the best use of solar panels, but only when looking at it from an economic point of view of electricity production replacing drawing from the grid. For mobile use I'm looking at it from a whole different perspective, which is convenience and utility. Cost to me is just sunk cost this go round, ie I want the panels to last a long time of course, but more due to my labor and time involved than anything else. For me it's an experiment.

I want and need some kind of light weight EV with some type of covering for both rain protection and aerodynamics, so if it adds very little weight why not cover it in solar cells? They're cheap enough. I understand much of the time many of the cells will generate very little electricity, but ambient light produces some, and some is better than none. That also ensures that on a sunny day some cells will be getting full sun at all times, and here at less than 10°N latitude even early morning sun is powerful, especially at 1km of altitude where I live.

Now to get some real autonomy with more distance capability it's going to take more surface area, unless I make the tailbox taper down to a horizontal point instead the typical vertical. That's definitely on the table, but it's typically windy here during good weather, so I worry about the potential of lift from a wind gust...more research required in that regard. Another way to get that extra solar surface area is with additional panels that slide out or fold out. I like the convenience of slide out with a hinge at full extension for adjustable angle to the sun. Then they are separate from the body panels and can be flat instead of slightly curved like I want the body panels.

I love my ebikes and they meet the majority of my family of 5's transportation needs. I've gotta come up with a rainy day solution no matter what, and with relative ease I can make that solution rarely need charging in daily use due to our low daily average consumption at 500wh. My bikes are no fuss, just plug in to charge when I get home, but I'm the type who always searches for the absolute easiest route, and what could be better than just put the key in and go, and rarely need to plug in? If I can do that, why not go a bit further and incorporate more range? Why not go for the gusto and add more cargo and passenger capacity too?

I know it's technically feasible, so the hatching plan is killing my sleep with my mind racing through variations and improvements ever since the seed was planted. To me the hardest part will be to do it in a form pleasing to the eye instead of being functional but an eyesore. Being just a novelty that's a curious eyesore to most is no skin off my back, but doing something slick and beautiful would do much more for the cause. Plus slick = aerodynamic, so more speed and range and economy and better use of the same solar surface area.

Freedom and utility are my primary goals, not economic ROI.

John
 
That's true, I think we sometimes base decisions on economic ROI too much. There is great value in your idea to incorporate PV cells onto fairings, I hope your project is a great success and I look forward to following along!

I spent a good while tonight just staring at my bikes, trying to think how I can add fairings to keep myself warmer in the winter. It gets quite cold up here in northeast US, and I want to use my bike as much as possible. I love tackling challenges and doing the unconventional to achieve superior results.
 
Plus, I look at my ebike stuff for the past couple of years as far into the plus side economically. I'm not even considering the wear and tear saved on the family minivan, or that it still has 1/4 tank of it's 4th tank full this year. My big plus return in real dollars saved is that this is by far my cheapest hobby ever, as well as the most rewarding and up near the top in terms of fun. Solar powered would just be the icing on the cake in whatever form it takes. Sure I could make a normal solar panel that no one see's and does its job day in day out, but where's the fun in that? I'm too impatient to wait on recouping the $30/yr I spend on ebike electricity. The other route I can at least dream that I might be able to turn a hobby into a business and learn a bunch of new stuff in the process. I've been wanting to try my hand at some vacuum forming of composite materials, so this is as good a chance as any. :mrgreen:

It's really just research anyway for the 10-12m electric sport fishing catamaran that is the next big project. It's the real reason I want to try my hand at slightly curved lightweight DIY composite solar panels. If it works, the boat will get multiple kw of solar as an integral part of the structure, and you guys will all be welcome to come down and hook up some sailfish and tuna, maybe even a marlin. Don't worry it will be a multi-way hybrid, so there won't be any getting stuck if gets cloudy.

John
 
I would look at inflatable, I would look at satalites and space station panels, they are designed with space considerations in mind. Reflectors with the panel itself cooled by water onsite , or a ground-cooled rod. There are lots of neat things you could do IM SURE

Now what really should be happening is the roll out film. why cant we get enough of this stuff!!!!! I mean its out there,,,where?

KEEP IT UP ,

I saw the pure solar cars race go by me in central manitoba, It was AMAZING, watching these cars zoom by at 80km/h. it was a nice sunny morning.......

edit: the cars also have 30kg of LITH ION.....ok mabye not as amazing as i thought will have to look into this,.
 
Crazy thought, but since the hub motor makes such a super generator at low speeds (no gearing needed), what about carrying a set of detachable blades and a telescoping pole which would convert your rear wheel into a 200-500 watt wind generator? If the rear wheel could detach from the bike easily, and there was some method of quickly attaching the pole and blades, it might only add a few pounds to the wieght of the bike, and in a windy area you could charge anytime, day or night.
 
Not crazy, but not with the bike's motor. I'd use an RC motor with a simple gear reduction and some kind of brake. The headaches from a practical standpoint would be a stable tower and removable blades as well as launching and taking down the turbine. Spinning blades are so dangerous that proper engineering is critical. Maybe some kind of VAWT is best, a collapsible helix (don't know if that even exists) or VAWT that when disassembled is a couple of metal disks and nearly flat stackable blades.

An inflatable turbine that provides it's own lift or is lifted by an air foil instead of using lighter than air gases would be ideal for the beach, but you're looking at a lot of engineering and testing since it's not something you can just look up how to do online.

A portable wind turbine would be cool, but the setup and take down time and effort along the inherent danger make it impractical for several hundred watts of power generation. Down here the best wind is typically when it's sunny, so the quick and easy setup of extra PV panels is a big plus. Now that I think about it, I'd want the PV also flexible enough to provide shade at the beach, because this sun is brutal. LFP was milk white before 30min in the sun and a lobster afterward, and that happened at about 8 o'clock in the morning on one of his first days here.

John
 
heh LFP is from Seattle like me...we don't really know what sun is..but I heard from other states it is some star near earth.

We get a lot more wind than sun here, so I can't immediately discount the 24 hours of wind production vs 5 hours of hazy light that may or may not cause you to cast a shadow.

I had in mind a slower speed "Dutch?" type windmill using the very slow winding 9C hub motor. Perhaps make the vanes out of ripstop kite material and fiberglass rod, in a sail fashion, and have it designed to spin with a lot of torque but very slow. My experience with this is nil, so it may not even be possible. (How do they get those big Dutch windmills to spin slowly btw?)
 
KTP said:
heh LFP is from Seattle like me...we don't really know what sun is..but I heard from other states it is some star near earth.

We get a lot more wind than sun here, so I can't immediately discount the 24 hours of wind production vs 5 hours of hazy light that may or may not cause you to cast a shadow.
Click to expand...

That's understandable. The easy answer is move. Do it now before the prices where the sun is skyrocket due to the higher inherent energy value. Wind energy is great if the wind is consistent enough to count on...even better than solar in some locals because it works at night.

KTP said:
I had in mind a slower speed "Dutch?" type windmill using the very slow winding 9C hub motor. Perhaps make the vanes out of ripstop kite material and fiberglass rod, in a sail fashion, and have it designed to spin with a lot of torque but very slow. My experience with this is nil, so it may not even be possible. (How do they get those big Dutch windmills to spin slowly btw?)
Click to expand...

Inefficient blades is a big factor, but also the bigger diameter stuff turns slower for the same power. With a DD hubbie you're still talking about hundreds of rpms, and you really don't want to go removing your drive wheel with frequency. It's just asking for problems, especially in the cabling. On my main bike I installed the hubmotor in Dec '08 and haven't touched it since. It works today the same as it did when new, and I use it virtually every day as my family's primary transportation.

I still say a small and light motor, and gear it to whatever speed you need.

John
 
OK - I hate to throw some inspiration at ya - First after reading the messages I agree that it aint easy BUT - I disagree that a bike is the most efficient means of transportation - I think that would be Ice Skates - sounds funny but google "Wing Skate Sailing" and after looking at the design - imagine a bike - yes two wheel under that cover - yes this would be the most aerodynamic design. Now take the back part of that sail - the part you do not have to see out of - and coat it with hydroponic mirror type plastic (very light) and concentrate it on two solar panels specially made for high intensity light extending out from the bottom of the bike at 45 degrees starting at 2 inches from the ground. Mount the batteries high enough that you can use the weight to counteract the wind flow when leaning into the wind to gain the most energy. Add a super set of tires and shock absorbers and test it first on some salt flats. You could probably get some serious regen out of this, as skate sails speed is limited to 75 miles per hour which is upwards of 4 times wind speed. OK - imagination mode turned off... http://sites.google.com/site/wingskatesailpict/
 
Dave Sloan said:
OK - I hate to throw some inspiration at ya - First after reading the messages I agree that it aint easy BUT - I disagree that a bike is the most efficient means of transportation - I think that would be Ice Skates
Click to expand...

A sail boat is far more efficient than a bike. I routinely travel hundreds of miles on 0 gal/hr (so that would be 200/0 = infinity miles per gallon :mrgreen: )

So we could either freeze all bike paths or we could dig them out and replace them with canals.
 
While we're throwing crazy ideas out there, I may as well throw in another more efficient form of transportation. A worm hole in space MIGHT be as efficient as your boat, since 999999999light years/0gallons = infinite mpg. If I could only build one....where is my flux capacitor
 
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