Typical Use Case

[tpreitzel]

In the VERY near future, I suspect the following scenario will be a typical use case. Here's where the capability of solar will be essential. No, I don't want to get into another discussion of solar's viability on a bicycle, because I'm already convinced. ;)

Scenario (IC vehicles need not apply and I'm not a tree hugger):

John Doe needs to travel 120 miles per DAY (round trip) periodically. He leaves home at 8 am and wants to return by 4 pm. (*) He needs to AVERAGE 20 mph along the route. (**) He needs the storage capacity to travel over rolling hills with wind speeds averaging 15 mph. The 500w Cyclone kit seems like enough power to maintain the velocity. However, the storage capacity is another matter. Is John Doe supposed to recharge the batteries when he arrives at his destination 3 hours later, i.e. 11 am? If he must be home by 4 pm, he only has two hours to recharge the batteries.

What non-solar solutions make this scenario feasible?

(*) ~ 30 minute variability, i.e. 0730 - 1630
(**) Ideally, the speed needs to AVERAGE 30 mph to allow more time at destination, but 2 hour meetings, shopping trips, visits, etc. are not uncommon.

[Abneycat]

You'd need a fast charger and a battery capable of the 60 mile distance. A123s would probably be a good choice in this scenario. They can be recharged in measures of minutes instead of hours.

I don't personally think this is a "typical" case, but its not implausible. One vehicle I would suggest looking at is: http://www.powerinmotion.ca/superbike.php
here's a vehicle which exceeds the requirements you've set out. While its currently using NiMH, switching it over to a fast charging setup would be entirely feasible.

[tpreitzel]

I don't personally think this is a "typical" case, but its not implausible.

Frankly, this scenario occurs enough to myself and others living in our area to be a problem, and I suspect that many others around the world are in a similar predicament if they want to avoid IC engines. Spending 6 hours out of 8 on the road is a bit much even for the most important meetings and shopping trips, but workable on occasion. I'd much prefer a 30 mph AVERAGE. Let's include that option in this scenario as I'll be returning to it periodically as well.

[cerewa]

30mph or higher as an average speed should be viable for a 1000W cyclone kit or a Crystalyte type hubmotor-- I'm told the 4-- series (and 5 series) Crystalyte motors max out well over 1000W as long as you use one of their 72V controllers with good amperage.

The Dewalt/A123 battery cells can be set up to give fast charging and plenty of energy storage for a 120mile round trip@30mph with or without a recharge in the middle. (I'm not sure if we're assuming that John Doe will always have access to an electrical outlet at his destination.)

My 500W cyclone is geared so that I can't go much above 20mph, but an 8lb lithium/iron battery is enough for 40-45miles range at 20mph with moderate-strong pedaling. (to stay above 50% state of charge for better battery life that means ~25 miles on a charge, which is just a bit more than my distance to work). If you spent $1600 to $2000 on new DeWalt/A123 battery packs you could have enough to take you 120 miles at 20mph, maybe even at 30mph without pedaling. Recharge in the middle if you want to get closer to the 1000-5000 charge/discharge cycles that the batteries provide in ideal conditions... or if you want lower initial cost and vehicle weight by using fewer battery packs. I'm thinking that the maximum weight of lithium-iron batteries you'd have any use for when going after 120 miles of range is about 100lbs, which keeps your weight and cost more or less comparable to a new gas mo-ped (and way, way cheaper than a toyota prius, if our John Doe is one of the many people who can afford an automobile).

www.yesa.co.cn sells lithium iron packs that are cheaper and come with chargers and battery management systems already set up for this sort of use (very little do-it-yourself hassle compared to the DeWalt-A123 packs), but I'm not sure they are practical for charging in two hours... which is not a problem if you size the pack to handle the entire round trip.

[JeanCoutu]

Your typical use case scenario sounds well beyond absurd to me.

But whatever, how about demonstrating what solar solution makes your scenario feasible?

[cerewa]

But whatever, how about demonstrating what solar solution makes your scenario feasible?

If I could get one of those solar racer teams (http://www.wsc.org.au) to give me a free solar car, I'd be happy as a clam.

Or if I had a million bucks, I could probably get somebody to make one specially for me. Yeah, it's not a bike... (but our hypothetical traveler doesn't seem to care much about the number of wheels). The technology is there for solar vehicles to drive in this sort of challenging trip. But it appears to me that you have to be willing to shell out a lot more cash than it would take to put together a wonderful long-range battery-electric bike.

(okay, maybe i underestimated with that $1million figure, The U. of Michigan spent 2.5million on theirs (http://media.www.michigandaily.com/media/storage/paper851/news/2007/10/19/CampusLife/Solar.Car.Team.Preps.For.Race.Across.Outback-3043943.shtml) and it doesn't even have solar powered climate control)

[Abneycat]

If I could get one of those solar racer teams (http://www.wsc.org.au) to give me a free solar car, I'd be happy as a clam.

Or if I had a million bucks, I could probably get somebody to make one specially for me. Yeah, it's not a bike... (but our hypothetical traveler doesn't seem to care much about the number of wheels). The technology is there for solar vehicles to drive in this sort of challenging trip. But it appears to me that you have to be willing to shell out a lot more cash than it would take to put together a wonderful long-range battery-electric bike.

(okay, maybe i underestimated with that $1million figure, The U. of Michigan spent 2.5million on theirs (http://media.www.michigandaily.com/media/storage/paper851/news/2007/10/19/CampusLife/Solar.Car.Team.Preps.For.Race.Across.Outback-3043943.shtml) and it doesn't even have solar powered climate control)

I'm not sure on the cost, but personally I wouldn't want the solar vehicle to begin with. Been over this all already, but my word is KISS. Its not just a matter of the cost, but of dealing with your new invention in a practical manner. Don't add complexity, weight, fragility, and liability when you have other solutions that solve the same problem without *needing* these other things at all.

While IC vehicles "need not apply", I wonder why. Understandably, this is an electric bike forum, but everything has its ups and downs, and long range travel is one of the downs on the e-bike side of things. Undoubtedly after seeing vehicles like the superbike, its not only possible, rather simple with the right pocketbook, but still: I believe in the right vehicle for the right job, and I can't see anything explicitly *wrong* with considering the possibility of a small gas powered vehicle like a gasoline bike conversion kit or a small moped/scooter. These things get quite good fuel mileage, and are much more environmentally acceptable for single person use than a car, if all you need to do is scoot around for the odd meeting.

Would I build an electric over a gas? Certainly. I hate gas engines personally as well. But as a cheap, reliable solution, I admit that the gas engine has a lot to offer, and in a small scale application suited for the individuals needs (and, not dragging around the 3500lbs of extra car), these engines do well from an efficient and environmental standpoint.

[Sianelle]

There's been a lot of discussion over at motoredbikes.com as to whether having an on-board gas motor running a generator to supply a hub motor is a viable option or not. I'm sure that there's going to be an awful lot of discussion and experimentation around some of these ideas over the next couple of years.

[tpreitzel]

(I'm not sure if we're assuming that John Doe will always have access to an electrical outlet at his destination.)

I thought of including that possibility, but forgot about it. I thank you for reminding me. The possibility exists that John Doe will not be able to use the full 2 to 4 hour period for recharging the batteries. Naturally, this recharging period will vary with the circumstances for the specific trip.

I appreciate the information.

[tpreitzel]

If I could get one of those solar racer teams (http://www.wsc.org.au) to give me a free solar car, I'd be happy as a clam.

(okay, maybe i underestimated with that $1million figure, The U. of Michigan spent 2.5million on theirs (http://media.www.michigandaily.com/media/storage/paper851/news/2007/10/19/CampusLife/Solar.Car.Team.Preps.For.Race.Across.Outback-3043943.shtml) and it doesn't even have solar powered climate control)

Actually, with the newer type of cells, e.g. CIGS, you have much more flexibility in adapting your design. I can easily envision a type of aerodynamic, hybrid fairing including a canopy with removable arrays on them for a capacity of 200w (peak) with an additional weight approximating 25 lbs (~12 lbs above rider). Likely, this adaptation could be extended to exceed 250w (peak) without too much difficulty or additional weight.

[Saltydawg]

These guys say:
"We give LiFePo4 battery 2 years warranty, our battery can use 30A to charge in 20 mins"

http://www.cyclone-tw.com/order.htm

If they can really charge in 20 mins, problem solved...

[Abneycat]

I read up on CIGS, and currently the absolute best *flexible* panel is about 14%. If you were to build a fairing, it would only give about 70% of the output that a flat array in the same chemistry, and considering that the top of the canopy and not the underside is where it matters, you'd need more than just a fairing.

[JeanCoutu]

In the VERY near future, I suspect the following scenario will be a typical use case. Here's where the capability of solar will be essential. No, I don't want to get into another discussion of solar's viability on a bicycle, because I'm already convinced. ;)

Scenario (IC vehicles need not apply and I'm not a tree hugger):

John Doe needs to travel 120 miles per DAY (round trip) periodically. He leaves home at 8 am and wants to return by 4 pm. (*) He needs to AVERAGE 20 mph along the route. (**) He needs the storage capacity to travel over rolling hills with wind speeds averaging 15 mph. The 500w Cyclone kit seems like enough power to maintain the velocity. However, the storage capacity is another matter. Is John Doe supposed to recharge the batteries when he arrives at his destination 3 hours later, i.e. 11 am? If he must be home by 4 pm, he only has two hours to recharge the batteries.

What non-solar solutions make this scenario feasible?

(*) ~ 30 minute variability, i.e. 0730 - 1630
(**) Ideally, the speed needs to AVERAGE 30 mph to allow more time at destination, but 2 hour meetings, shopping trips, visits, etc. are not uncommon.


Since you don't want to get into another discussion of solar's viability on a bicycle, because you're already convinced, what solar solutions make this scenario feasible?

[tpreitzel]

Since you don't want to get into another discussion of solar's viability on a bicycle, because you're already convinced, what solar solutions make this scenario feasible?

Don't think it can be done, do you? Frankly, I don't like your tone or personally CARE whether you think solar is viable on the bicycle or not. I'm not at your beck and call, and I'm 100% convinced of the aforementioned scenario. With a little research on YOUR part and with average intelligence and imagination, the surface area required to place 200-250w of CIGS arrays on a hybrid fairing and canopy is totally workable within the weight limits that I've proposed. I'll definitely be working in this area for years to come, and I'm very excited about the likely applications of solar on the bicycle.

[Abneycat]

Well, i've already done the research. You might be able to do it, but I don't see *why* you'd want to do it, because my research indicates that it just isn't *practical*

But, good luck on your project regardless. If you do get it up and running, i'd still be interested to see it.

[cerewa]

I'll definitely be working in this area for years to come, and I'm very excited about the likely applications of solar on the bicycle.

I agree that it's completely possible. Just not as cheap&easy for the scenario proposed as battery power is given today's technology. Off-the-shelf lithium batteries are easy to use and carry. And generally you can charge them with renewable on-the-grid electricity if you're willing to pay an extra couple cents a month on your utility bill.

If we were talking about a multi-day bicycle tour or even an all-day one way trip, even the best batteries start to be awfully heavy, making on-the-bike solar seem pretty attractive given what is available today.

Both battery and PV technology will continue to improve, but it's anybody's guess as to how much they will improve. For example, I have been hearing predictions for a while now about how solar panels have the potential to become dirt cheap due to economies of scale, but I will believe it when I see it. The same goes for the idea that some new electricity-storage technology will make batteries give all of the energy storage advantages of a gas tank (quick filling, can last for a million miles of travel, lightweight compact storage of 500 miles of energy, discharge as fast as you want) without the disadvantages. Again, I will believe it when I see it.

[tpreitzel]

I agree that it's completely possible. Just not as cheap&easy for the scenario proposed as battery power is given today's technology. Off-the-shelf lithium batteries are easy to use and carry. And generally you can charge them with renewable on-the-grid electricity if you're willing to pay an extra couple cents a month on your utility bill.

If we were talking about a multi-day bicycle tour or even an all-day one way trip, even the best batteries start to be awfully heavy, making on-the-bike solar seem pretty attractive given what is available today.

Both battery and PV technology will continue to improve, but it's anybody's guess as to how much they will improve. For example, I have been hearing predictions for a while now about how solar panels have the potential to become dirt cheap due to economies of scale, but I will believe it when I see it. The same goes for the idea that some new electricity-storage technology will make batteries give all of the energy storage advantages of a gas tank (quick filling, can last for a million miles of travel, lightweight compact storage of 500 miles of energy, discharge as fast as you want) without the disadvantages. Again, I will believe it when I see it.

I never said or implied that solar on a bicycle was viable ECONOMICALLY for a massive production run. Rather, solar applications ARE viable on the bicycle in the context of areas that I've previously stated and for high-end, limited production runs that address some of those areas. Holding gold was not viable 10 years ago economically versus the dollar. The price of gold dropped somewhat from 1997 through the first part of this decade to a low of about $260/oz. Was it economically viable to hold gold from 1997 until it's bottom or hold dollars? From a strictly financial viewpoint, it was more economical to hold dollars (reinvested at interest) until the bottom. Does that mean that buying gold in 1997 was a bad idea? If you look today, the answer is obviously no. Although solar will continue to advance in capability and current products depreciate, does that mean investing in solar on a bicycle is a bad idea today? Again, the answer is relative to the final outcome. From a strictly financial viewpoint, investing in solar is a bad idea today. However, if a crisis arises (which ALWAYS rise SUDDENLY) where you might need an independent source of power and the infrastructure is disrupted forcing mobility, that investment in solar might look much more favorable...much more. CIGS arrays are generally PORTABLE which just adds to their flexibility for finite fixed applications and finite mobile applications. Personally, I agree with the notion that solar is economically non-viable on a bicycle with large scale production, but that is NOT an excuse to ignore the potential of solar on a bicycle NOW on a more limited basis INITIALLY. As you've indicated, costs will eventually fall allowing the ECONOMIC viability of solar on a bicycle on a massive scale. However, I should NOT need to really cover ANY of this subject as it should be obvious, and I've already indicated as much in my other posts if they're read carefully.

[tpreitzel]

Furthermore, in this thread, if people insist on wasting their time and mine, I want them to concentrate on overcoming the limitations presented here with IMAGINATION and design. Adequate storage capacity is one solution while solar is another with a likely combination of both.

[evblazer]

Wouldn't you need sun if not direct sun to get powered by solar. If we have to imagine that there isn't a power outlet at the destination of choice I think the OP has to take into account the possibility of clouds and not riding in a desert at high noon.
I rode 52 miles on a longer then normal commute yesterday. 95% of it was in pitch black the other 5% would have netted nothing for solar panels. Even if it was summertime I'd mostly be riding in the shade where it wouldnt' be great solar times.

I think the fairing that you propose of solar panels if shaped for efficiency of air flow rather then have sunlight exposure would do far more. Efficiency would greatly reduce the power requirements to get that 20mph average. A low or highracer recumbent with tailbox alone would greatly reduce the power vrs say a hybrid. You could put some cells on there and give them the ability to fold out into an array at the destination so you could point them at the sun?

This gives me nightmares of discussions on the EVlist about people converting an F150 pickup to electric and wanting to put some solar on it instead of converting something requiring half the power to go the same speed/distance.

[Abneycat]

Wouldn't you need sun if not direct sun to get powered by solar. If we have to imagine that there isn't a power outlet at the destination of choice I think the OP has to take into account the possibility of clouds and not riding in a desert at high noon.
I rode 52 miles on a longer then normal commute yesterday. 95% of it was in pitch black the other 5% would have netted nothing for solar panels. Even if it was summertime I'd mostly be riding in the shade where it wouldnt' be great solar times.

I think the fairing that you propose of solar panels if shaped for efficiency of air flow rather then have sunlight exposure would do far more. Efficiency would greatly reduce the power requirements to get that 20mph average. A low or highracer recumbent with tailbox alone would greatly reduce the power vrs say a hybrid. You could put some cells on there and give them the ability to fold out into an array at the destination so you could point them at the sun?

This gives me nightmares of discussions on the EVlist about people converting an F150 pickup to electric and wanting to put some solar on it instead of converting something requiring half the power to go the same speed/distance.

Well, you raise some excellent points. Not only would you get a lot more energy efficiency out of building a design that wasnt fighting as much wind, but riding a 'bent 120 miles would be a lot more comfy than riding an upright, to me. Unless you had a Brooks under your butt, and even then a good 'bent is like a lounge chair. An LWB would probably be good for something like this, very comfy long distance and with a lot of space in which to attach panels.

Solar is a widely varying beast. Depending on what angular factors (latitude, current declination of the sun, angle of the panel and so on), weather, cleanliness of the panels and many other factors, you can have days where reaching full panel output is as easy as not even trying, and days where its neigh impossible to get a decent output. The worst part is having those days multiple times in a row. Thats why solar *needs* to be paired with an auxiliary output in order to be effective on a vehicle like this. In this case, you would have a battery which charges off the solar, and then supplements the solar as its own output drops in such low output scenarios. However, if you reach the worst case scenario of say, having poor weather all day but needing a recharge, then you're looking at using the grid.

[Sianelle]

Having a multiple possibilities approach to recharging seems to be the way to go. I've found the discussion about solar recharging interesting, but I'm wondering how a small wind generator would work out. During my alternative lifestyle days I had a small wind charger based around a Sturmey Archer Dyno-hub and it was excellent for maintaining the charge on the 12 volt LA batteries I used to power the lights in my wee cottage.
I'm not suggesting trying to run a wind charger while in motion, but for recharging when miles away from a power point when the sun isn't shining I think it would be a good thing to experiment with.

[cerewa]

A low or highracer recumbent with tailbox alone would greatly reduce the power vrs say a hybrid. You could put some cells on there and give them the ability to fold out into an array at the destination so you could point them at the sun?

Well, when you put it that way, there are guys who were talking about their sub-4-hour century (100 miles) a year or two ago. They had unmotorized lowracer bikes, I'm not sure if they used tailboxes.

However, that was at very high pedaling effort so if you wanted to avoid the situation of needing to be in very good shape and ride really hard (and having to be on flat roads) an electric system of some kind is needed.

[evblazer]

Well, when you put it that way, there are guys who were talking about their sub-4-hour century (100 miles) a year or two ago. They had unmotorized lowracer bikes, I'm not sure if they used tailboxes.

However, that was at very high pedaling effort so if you wanted to avoid the situation of needing to be in very good shape and ride really hard (and having to be on flat roads) an electric system of some kind is needed.
I entirely agree for any casual rider to keep up with the OP 20mph requirement an electric system would be neccessary it just would need to be sized much smaller for a more efficient mode of transporation and possibly not need solar at all unless one were travelling across the desert without the ability to recharge although it could make long distance self contained electric assist commuting possible
A sub 4 hour 100mph is 25mph which requires alot more energy than 20mph. Plugging in numbers for a 200lb rider at kreuzotter I get:
MTB with racing slicks (basically a hybrid)
20mph 268watts 25mph 491watts with 15mph wind 20mph 695watts 25mph 1115 watts
Long Wheel bent base under seat steering, commuting equipped
20mph 239 watts 25mph 426 watts with 15mph wind 20mph 612watts 25mph 977 watts
Lowracer with tailbox
20mph 125 watts 25mph 201 watts with 15mph wind 20mph 254 watts 25mph 391 watts

when you throw in wind speed the lowrace with tailbox really shows the reduced power requirements of the more efficient machine.

I've been really on the fence about what electric assist to get for my 42 mile RT commute and this thread helped in making me look at some alternatives. I actually test rode a highracer recumbent light duty commuter with a tailbox this weekend and am going to do a test commute with it on saturday. So far it is exceeding what I was looking to get from an electric assist and I may go that route. If needed eventually getting an even lighter duty electric assist then I was originally looking at for my upright.

[cerewa]

I have a 35 mile round trip commute and for my commute, choosing between electric assist and an aerodynamic recumbent was a no-brainer--- most of my energy is expended going uphill, and starting up from stop signs/stoplights is also significant. Aerodynamics just wouldn't help all that much.