Solar/electric road assist for cross country trip

[veloman]

I posted an add on craigslist Austin where I am, looking for others to join me. I got a few responses, some people think it's impossible with electrics. I beg to differ.

http://austin.craigslist.org/bik/1787502134.html

What I need help on:

Locating quality, lightweight solar film / panels. Can anyone point me in the right direction for instructions on how to wire them to charge my battery, as well as how to wire them in with my controller to directly power my motor (more efficient)?

I need 40 volts to charge my Fatpacks, and I'm going to be very creative in where I place the solar panels.... possibly to shade myself from the sun.....

Is anyone knowledgeable with wiring in the Austin area who would like to help on this project?

 

[piersdad]

not quite what you want but some good ideas here when a sighted and blind couple wanted to tour the country
a 4 wheeled tribrid
has solar panels as a sunshade and dual pedal power as well as electric power

http://www.storydad.com/forum/index.php?topic=611.0

 

[veloman]

OKay, so I've been thinking about this cross country trip idea. What if I used a velomobile? Coat the body with solar cells, and/or have foldouts for charging time during stops. The aerodynamics would allow me to go 30mph on about 400 watts draw, realistically (could be even less).

Now for the kicker: the biggest problem with cross country by bike is - where to sleep? Well would it be possible to just sleep in the velomobile? You could retrofit the inside to have a nice wide seat/backrest, maybe with additional foot/leg rests for sleeping. You would be completely self contained, and could use a top cover over your head opening to protect from the weather. The idea is that you'd park at campgrounds for cheap, where you can shower and all that. But no need to haul a tent? Or you could stash a tent if you really wanted, since the velomobile would have tons of storage area.

Battery: you could carry LOTS, like 2kwh. You'd be able to top off at some campsites (the ones with electric hookup) if you didn't solar charge enough before sundown.

Now, of course this whole setup wouldn't be cheap - but I think it'd be the best way to travel cross country. Think huge cushy seat, full suspension trike, with a perfect aero streamlined body for efficiency at speed. Maybe your motor system could do regen for those big downhills where you'd be burning up your brakes since you are so aero.

If you were really worried about not being seen, then just make a really good 360 degree lighting system, think utility vehicle orange flashers, in addition to massively bright front and rear lights. At night, you would be more visible than a motorcycle. Just keep your speed to 25+mph to reduce closing speeds from behind. Would need a fairly powerful motor to do such speed up big hills, but it's doable.

Man, I need to do something like this, at some point in my life! It would be great to do it with 1 or two others as well!

 

[dogman dan]

There is a recent thread on the same subject where lots was discussed about how it could be done, etc. It's hard, in my opinion, to carry enough panel to charge a largish battery. Much lighter to just carry more battery. I feel about the same way about trying to carry a very fast charger. Just simpler to carry enough battery for a 80 mile ride. About 30 ah of 48v or 20 ah of 36v does the trick. 30 pounds max.

80 mile range will get you from plug to plug, even in some of the most desolate places in the SW desert. Out in the desert, if you aren't making it to a plug, you aren't making it to water either. Not such a problem in winter though.

A recumbent is a good idea even without the velo fairing. I see lots of cross country riders on the highway here, taking state 70 west. Lots of em on bents.

You have a place to bunk in any town with an ES member with a high post count, pretty much.

 

[John in CR]

I don't think you want to go full velomobile. That would make for a torturous trip, hot and very noisy inside. I know I'd want the wind on my face and barely any noise.

You don't need to worry so much about the voltage of you solar panels/cells hitting a target, because you'll need a charge controller no matter what due to the wide voltage range put out by a given panel based on how much sun it's getting. You just need a charge controller that takes whatever the panels put out and outputs the 40 volts you need.

Panel weight is going to be an issue unless you spring big bucks for the limited thin film stuff available to consumers, or you DIY. I'm going DIY, which will be really cheap 50cents/watt for the A grade cells I got. I should have some results for my lightweight and slightly curved panels (for rigidity) pretty soon. If it works then the bulk of my on-bike cells will be on a tailbox that also folds out to double the exposed cells and get them all facing the sun instead of just half of one side at best while riding. A shade canopy would be nice, but I worry about the wind.

You're a real cyclist, so don't listen to anyone saying it's not possible, because you could do it with no assist, so there's no reason you can't pick up really useful assist with a smallish amount of watts while riding, and some hundreds of watts while stopped, which would of course be at the best sun times, which is the worst for riding anyway (other than while raining).

I look forward to your build. I'll be sharing my stuff too in the alt energy section of the forum as soon as I have something to share. We're still in rainy season so my progress isn't hurried. This kind of humidity isn't so good for getting really clear results with epoxy.

John

 

[veloman]

Okay, maybe velomobile is out. I didn't realize they were that noisy, but it makes sense. I'm thinking something like this, with a good size tailbox for all your storage, maybe a rear suspension model.

I've test rode recumbents this summer, they are crazy comfortable, but I don't feel I'd like being in heavy traffic with one. But 99% of the time on a cross country trip, I think they'd be ideal, ESPECIALLY with electric assist. It's something I'd really like to do if I could get a few others to join me. Midracer recumbents drafting at 30mph, the ones in the draft might be needing a whopping 200watts. Imagine how far you could go in the absence of headwinds or mtns? It'd be cake on the flat parts of the route.

 

[dogman dan]

I'm seriously impressed with this gals bike for a crosscountry journey. If you built lightweight panels about 2x2 or so, they'd stack right on the back of it.
http://endless-sphere.com/forums/viewtopic.php?f=6&t=21333&start=0

BTW, if you didn't know it, thin film solar is not very efficient. So it takes close to double the square footage to equal the output of silicon PV cells. But it sure would be cool some day, to shake out a lightweight blanket weighing less than a pound and start charging the ebike. Something about like the solar sun shields for cars. Someday,,,, we will have it.

But even then, panels will have to get 10 times more efficient to gather enough power to charge an ebike with a single panel of say 3' x5'. To gather the power while riding is really hard, since it's not easy to keep the panel pointed at the sun as a road twists and turns. If you rode away from the sun it would especially be a problem with aero. About all you can do is mount the panel horizontal, which is not very optimum unless you are at the equator, at noon.

So you really do have to think in terms of a set of panels you can break down to carry, and set up facing the sun for midday. Then ride evenings or mornings.