How Clean Can We Get? Solar E-Bike Discussion...

Xase

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A couple of questions for the electronically inclined among us:

1. Would it be possible to drape a flexible outdoor-weatherproof solar photovoltaic panel over the rear rack/pannier bags of an e-bike in order to charge the batteries?

2. If so, how many volts/watts would be needed to accomplish this task?

From googling “solar portableâ€￾ and quickly rummaging through the first page of links I found these panels in 12v-24v & 6.5w-55w varieties. Surely this is can be done. :D

solaris-26--for-web.jpg


When I did a forum search for a similar thread I only came up with a thread about a bike with solar panel wheels and a few threads mentioning photovoltaics only in passing, so I assume this is a new topic.
 
Xase said:
A couple of questions for the electronically inclined among us:

1. Would it be possible to drape a flexible outdoor-weatherproof solar photovoltaic panel over the rear rack/pannier bags of an e-bike in order to charge the batteries?

Possible, yes. Practical, no. At 20-30%, solar cell efficiency is pretty low already. Factor in that about half the draped cell will be pointing away from the sun, and the other half at an angle, and you'd require far more solar cell area than with cells always angled towards the sun.

2. If so, how many volts/watts would be needed to accomplish this task?

For example, you'd need at least one of these 6-foot by 1-foot 12V 1.2A cells for each 12v battery:

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2705
Thumb_20W_Flex%5B2%5D.JPG

Say, 4 for a 48v 10ah SLA pack. Because the cells wouldn't be facing the sun, recharge time would be -- guessing from my experience with solar cells as a kid -- at least 30 hours (during sunny days, obviously).

It's more practical if you have an enclosed bicycle (like a velomobile) so you can coat the entire surface with solar cells.

U_of_T_Solar_Vehicle-2.jpg


Or rig some kind of fold-out, tilt-able platform:
DSCF2187.jpg
 
Ok i'm having a stab at this - please correct me because i assume i'm wrong :p

to recharge a pack you'd have to match the charging voltage for a pack... an example for you:

36v battery
so roughly 3 12v solar pannels required.
now for the amphour / wattage part...

if the battery is a 36v 15ah pack, its going to need 36x15 = 540watts to charge the pack (ignoring that charging efficiency is below 100%)
if your 3x solar pannels are 55w 12v panels (which won't be exactly small)
55w / 12v = 4.3a max

so your 3 12v panels would be providing 36v at 4.3a max then it would take these 3 panels in parallel 3.4 hours to recharge them - is this right?.

now here's where it gets bad. thats assuming that the panels are running at nominal power output - which they will most likely only do in direct sun, therefore if its cloudy add a lot of extra time :(... and add that to the charging inefficiency.

I'd think unless you were camping at a site for a couple of days it *might* be worth while, but you're better off finding an electricity point.
 
BiGH said:
Ok i'm having a stab at this - please correct me because i assume i'm wrong :p

to recharge a pack you'd have to match the charging voltage for a pack... an example for you:

36v battery
so roughly 3 12v solar pannels required.
now for the amphour / wattage part...

A DC/DC converter and diode could be used as the charger (I think).
 
BiGH said:
if the battery is a 36v 15ah pack, its going to need 36x15 = 540watts to charge the pack (ignoring that charging efficiency is below 100%)

If you use 540W , the charging current wil be 15A for the 36V battery. Full charge will be done in 1 hour. But not all battery could stands 1 hour Full-charge rate.

If you use 36W (1A charging current). Full charge is done in 15 hours.

So it is not necessary to use 540 watt.
 
The7 said:
BiGH said:
if the battery is a 36v 15ah pack, its going to need 36x15 = 540watts to charge the pack (ignoring that charging efficiency is below 100%)

If you use 540W , the charging current wil be 15A for the 36V battery. Full charge will be done in 1 hour. But not all battery could stands 1 hour Full-charge rate.

If you use 36W (1A charging current). Full charge is done in 15 hours.

So it is not necessary to use 540 watt.

sorry wasn't clear with that - i realise now its not a required calculation :p Thanks :) i didn't think i was right there :)
 
I think its quite a fun, if expensive (vs the grid) project to do. I imagined the way I'd do it is to build a small bike shed with the roof at a an optim angle to the Sun. Have, say, a 50 watt panel on the roof float chariging a few old car batteries. Then get a battery charger that runs off 12 volts such as the astroflight. Alternatively if you have an unusual battery pack/charger then get an 12 volt to mains voltage inverter to plug into the usual charger.

The avantage of having a few old car batteries as backup means there's no problem if its not sunny for a few days, all that the typical energy output of the solar panel matches the energy demands of the bike over a period of time.

Charging a battery directly with solar panel is a little tricky without a regulator that protects the panels overcharing the battery. All though, if its only small panel it would be possible to trickle charge the battery directly.
 
Thanks for the responses everyone.

What do you guys think of these passages:
“The P3 Portable Power Pack is used worldwide to provide users an alternate power generator for charging lead-acid, Nickel Cadmium (NiCd), Nickel-Metal-Hydride (NiMH) and Lithium Ion rechargeable batteries.
Using the P3 Portable Power Pack and charge controller, the solar generator can be used to charge any range and chemistry of rechargeable battery. In addition, the P3 charge controller and battery can become a solution for portable remote power needs.
Continues to power under cloudy/overcast skies.
Re-charges batteries or directly powers.
Powers field electronics; sensors, laptops, phones, radios, GPS, portable lighting.â€￾
http://www.affordable-solar.com/solar.portable.htm
“Offers higher cell efficiency than other flexible solar cell technologies at a reduced cost. Functions with many devices even in cloudy and rainy skies.â€￾
http://tacticalwarfightergear.com/tacticalgear/catalog/product_info.php?cPath=84&products_id=174
I know, I know, it just says “functions… in cloudy and rainy skiesâ€￾ but does not specify at what efficiency, but I'm actually lucky enough to be in a very sunny location and we hardly ever have such cloudy days.

I could be wrong here but 30 hours seems like a bit of an exaggeration for charging bicycle batteries. I think these panels may have had some technological improvements in the past few years-decades. Plus, keep in mind that I’m in the market for a weak commercial production e-bike, like the new Schwinns that have a Protanium Mini Motor, 24v, 250 watts with a 10 AH battery.
http://endless-sphere.com/forums/viewtopic.php?t=1954
How do you guys think this 25w, 12v, 41.25â€￾x21.50â€￾ module would do? I’d need a couple I assume.
http://www.affordable-solar.com/gse.sunlinq.25watt.12volt.flexible.solar.panel.htm
There’s also a 48w, 24v, (that has to get the job done, but it’s bigger) 52â€￾x29â€￾
& a 55w, 16v, that’s 55â€￾x32â€￾ (getting’ a bit expensive & large though).
http://store.altenergystore.com/Solar-Panels/Foldable-Solar-Panels/Global-Solar-Cigs-Technology/Global-Solar-P3-48-48W-24V-Portable-Power-Pack-Desert/p566/

If mounting it on the bike wouldn’t work would this be a more practical suggestion: spread the panels out on the ground or roof of my home and workplace for recharging the batteries while the bike is not in use... ??
 
NickF23 said:
I think its quite a fun, if expensive (vs the grid) project to do. I imagined the way I'd do it is to build a small bike shed with the roof at a an optim angle to the Sun. Have, say, a 50 watt panel on the roof float chariging a few old car batteries. Then get a battery charger that runs off 12 volts such as the astroflight. Alternatively if you have an unusual battery pack/charger then get an 12 volt to mains voltage inverter to plug into the usual charger.

The avantage of having a few old car batteries as backup means there's no problem if its not sunny for a few days, all that the typical energy output of the solar panel matches the energy demands of the bike over a period of time.

Charging a battery directly with solar panel is a little tricky without a regulator that protects the panels overcharing the battery. All though, if its only small panel it would be possible to trickle charge the battery directly.
Nice! I like this idea!
 
You can also use concentrated solar (CSP). Thin-film amorphous panels can tolerate heat better than silicon.

Harborfreight has amorphous 45W panel sets for $199USD. Mirrors are cheap.

If you get enough reflected energy to cook the panels, you can cool them with fluid circulated across their backs and use the warm fluid to preheat (temper) your home's hot-water system.
 
it's going to be expensive most likely i'd say....

if you use a bank of batteries, i'd have to ask the question:

if you recharge your batteries, how often would you do it? becuase you need to match your energy requirements with the energy outputs. ie no good taking 2 days (of overcast weather) to charge up a bank of batteries to charge your bike if you need to charge it daily ( for commuting).

don't underestimate how variable solar panels can be:
summer in london - about 250W per day from a 60w BP solar panel
winter in london - about 27W per day from the same panel.

http://72.14.253.104/search?q=cache...t+day+BP+80w&hl=en&ct=clnk&cd=1&client=safari



I think you'd have a bit more sucess making a hybrid setup - ie wind and solar.:) wind works during the night too - solar only during the day.

or there is the alternate of grid tied panels. If you don't have access to free or 2nd hand car batteries, grid tied is kinda cool. It means you don't have to buy batteries (thus having more SLA batteries produced etc). Baically the electricity you make is fed into your mains power, so if you consume it, great. If you're consumption is less than you produuce, you sell it back to the electricity company for someone else in your local area to use.

I actually think this is the way to go beucase all your solar generated power goes to use even if your bike doesn't use it, your home doens't use it - someone will. However the panels are $$$ but you can buy a single panel at a time whenever you can afford it. The panels usually take about 10 years to pay for themselves, but come with a 25 year warranty and are hail proof (unlike many smaller panels)

(check out Kyocera 200w grid tied panels)

I have a vision that eventually all power will be generated from the roofs on our own homes - much like a distributed power generation plant :) where the power company buys power from houses during the day, and provides power during the night when its dark - interruption free! I think thats REALLY cool :)
 
last time i checked solar panels were about £3/watt on ebay.

thats a £450 battery charger for me :cry:

if thieves steel lead off church roofs then you can bet they will nick these!

better to let the electric company do the work for you and simply pay for green electric.
 
I think the easiest way to do it is simply install a grid tie system for the average power consumption of the charger. IE: If you use 3kwh a month charging it (watt meter comes in handy) you get a system that returns 3kwh a month on average.

Bike already has enough stuff on it without trying to cram monster solar panels on it.

An even cheaper solution would be a windmill, but harder to install if you don't have acreage.
 
My two cents...

:arrow: Focus on building an electric bike that is worth riding, then worry about the electricity afterwards.

Electricity for an electric bike is near zero compared to everything else we use. (my computer is probably now using nearly as much energy as my charger) So now is not the time to be focusing on where to get the electricity. If you are going to be focused on something make it be the bike or the batteries.

:arrow: Those are the weakest areas right now.

Nuclear power is safe and clean and if we build more of them we will have all the power we need. Also, now with the recently acquired new law that allows the recycling nuclear fuel (since 2004 or so) we have a near infinite supply of fuel. (we used to send 90% of the fuel to nuclear dumps which was stupid)

So don't worry about electrical energy... with the right resolve (nuclear power) and a sprinkling of other stuff like solar and wind we will have enough. :)
 
safe said:
Nuclear power is safe and clean and if we build more of them we will have all the power we need.

You must be logging in from a different planet, Safe. In the time I've been on Earth, we've had Three-Mile Island, Chernobyl, Whoops, and numerous other nuclear powerplant failures. Fission excrement is dangerously radioactive for thousands of years. We bury it where it builds up, leaches into groundwater, damages the ecosystem, and poisons communities. The enriched uranium and other nuclear fuels fuel terrorism, enrich the military-industrial complex, and feed humanity's ubiquitous fear of mutually assured destruction.
 
All in favor of noo-kew-lur power can store the waste and byproducts in their backyard.

Step right up... no pushing... there's enough for everybody...

:lol:
 
I see nothing wrong with Nuclear power, coming from a Coal state (guess where my power comes from?) Chernobyl was a piece of trash even when it was built, and 3 mile island no one was exposed to more radiation than a microwave lets off. Yucca mountain also has pretty tight regulations for dealing with the waste material. Sure, bad things can happen and it doesen't win for 'greenest' but nuclear energy can supply what we need right now in a very cost effective way.

Sorry for getting off topic, I still say wind is the way to go if you have the land (we have a 500w windmill at the farmhouse)
 
TylerDurden said:
All in favor of noo-kew-lur power can store the waste and byproducts in their backyard.

Step right up... no pushing... there's enough for everybody...

:lol:

There you go... I like that measure!

Would I put a windmill out back? Sure.

Solar cells on my roof? You betcha.

Nuclear waste buried in my yard? Not on your life.

Why do most people feel it's OK to shovel some of the most demonstrably dangerous, provenly poisonous materials into somebody else's living space? It's the same attitude people who encourage their dog take a shit in your yard show.

Now let me tell you how I really feel....
 
From the figures I've read, it takes 35 years for a Nuclear Powerplant to pay back the energy required to build it.

And they have a lifespan of 40 years. Hardly worth the bother.

And this doesn't count the cost of DISPOSAL. Like there's somewhere to stick the waste...not in my backyard.

Nuclear is a fiasco. We can do it smarter than that. And I come from country that sells Uranium hand over fist, but we aren't dumb enough (yet) to use it.


Sun and wind complement. What we need is small, neighbour friendly turbines for suburbs. I'd love to cover my roof in tiny little turbines and solar panels.
 
Anybody read the news lately?

http://www.cbsnews.com/stories/2007/08/21/national/main3188894.shtml

Tenn. Nuke Accident Hidden From Public
Government Secrecy Over Fuel Plant Hid 2006 Accident That Could Have Caused Nuclear Reaction
image3188955g.jpg

KNOXVILLE, Tenn., Aug. 21, 2007

(AP) A three-year veil of secrecy in the name of national security was used to keep the public in the dark about the handling of highly enriched uranium at a nuclear fuel processing plant — including a leak that could have caused a deadly, uncontrolled nuclear reaction.

The leak turned out to be one of nine violations or test failures since 2005 at privately owned Nuclear Fuel Services Inc., a longtime supplier of fuel to the U.S. Navy's nuclear fleet.

The public was never told about the problems when they happened. The Nuclear Regulatory Commission revealed them for the first time last month when it released an order demanding improvements at the company, but no fine.

In 2004, the government became so concerned about releasing nuclear secrets that the commission removed more than 1,740 documents from its public archive — even some that apparently involved basic safety violations at the company, which operates a 65-acre gated complex in tiny Erwin, about 120 miles north of Knoxville.

Congressmen and environmental groups have criticized the policy, and now the commission staff is drafting recommendations that may ease its restrictions.

But environmental activists are still suspicious of the belated revelations and may challenge the commission's decision not to fine Nuclear Fuel Services for the safety violations.

"That party is not over — the full story of what is going on up there," said Ann Harris, a member of the Sierra Club's national nuclear task force.

Nuclear Fuel Services has been supplying fuel to the Navy since the 1960s. More recently, it has also been converting the government's stockpile of weapons-grade uranium into commercial reactor fuel.

While reviewing the commission's public Web page in 2004, the Department of Energy's Office of Naval Reactors found what it considered protected information about Nuclear Fuel Service's work for the Navy.

The commission responded by sealing every document related to Nuclear Fuel Services and BWX Technologies in Lynchburg, Va., the only two companies licensed by the agency to manufacture, possess and store highly enriched uranium.

BWX Technologies has not experienced any problems as serious as the uranium spill at Nuclear Fuel Services, commission spokesman David McIntyre said. But its operations were included in the order to seal documents because it produces nuclear fuel for the Navy, too.

Under the policy, all the documents were stamped "Official Use Only," including papers about the policy itself and more than 1,740 documents from the commission's public archive.

The Associated Press first reported the policy in May after the commission briefly mentioned in its annual report to Congress a March 6, 2006, uranium leak at Nuclear Fuel Services. The leak was one of three "abnormal occurrences" of license holders cited during the year.

Agency commissioners, apparently struck by the significance of the event, took a special vote to skirt the "Official Use Only" rule so that Nuclear Fuel Services would be identified in the report as the site of the uranium leak.

Some 35 liters, or just over 9 gallons, of highly enriched uranium solution leaked from a transfer line into a protected glovebox and spilled onto the floor. The leak was discovered when a supervisor saw a yellow liquid "running into a hallway" from under a door, according to one document.

The commission said there were two areas, the glovebox and an old elevator shaft, where the solution potentially could have collected in such a way to cause an uncontrolled nuclear reaction.

"It is likely that at least one worker would have received an exposure high enough to cause acute health effects or death," the agency wrote.

"We don't want any security information out there that's going to help a terrorist," agency Commissioner Edward McGaffigan Jr. said in a newly released transcript from a closed commission meeting May 30. But "that's entirely separate" from dealing with an event that could have killed a worker at the plant.

"The pendulum maybe swung too far," agreed Luis Reyes, the commission's executive director for operations. "We want to make sure we don't go the other way, but we need to come back to some reasonable middle point."

Agency spokesman David McIntyre said it may be difficult to separate Nuclear Fuel Service's secret work for the Navy from its public work converting bomb-grade uranium to commercial reactor fuel. The leak happened on the commercial reactor side.

In a stinging letter to the Nuclear Regulatory Commission chairman in July, two Democratic congressman from Michigan also blasted the policy.

"We agree that NRC should withhold from public view any sensitive security information of this nature. However, NRC went far beyond this narrow objective," read the letter from John Dingell, chairman of the House Energy and Commerce Committee, and Bart Stupak, chairman of the Oversight and Investigations Subcommittee.

McIntyre defended the commission's decision not to fine Nuclear Fuel Services, even though the agency rated the uranium leak last year as its second most-serious violation.

Instead, the agency ordered Nuclear Fuel Services to conduct a full review of its "safety culture" and make changes using outside experts.

"If we can get long-term permanent changes and improvements in their process it is better than slapping them with a fine every time something goes wrong," McIntyre said.

Nuclear Fuel Services Executive Vice President Timothy Lindstrom, a Navy veteran who joined the company in September, said the company had already made "significant progress."

"I think it is important that the public recognize that we do have a very robust safety program at NFS. We live in this community and take our stewardship very seriously," he said.

"I think if we were to have an event like this again, we would push to make it public," he added. "Clearly it would have been better to have this discussion 18 months ago than it is to have it now."

Meanwhile, NFS told its 700 employees this past week it will be "exploring the possibility of a sale" over the next 12 months — not because of the commission's disclosure, but because of the company's increasing value to a booming nuclear power industry.

"We are in a position of strength," company spokesman Tony Treadway said.

By Associated Press Writer Duncan Mansfield
 
hmmm, so its possible to provide all the energy requirements of the US via nuclear power with the aid of fast breeder reactors.

But does anyone know many nuclear power stations you'd need to cover transport, heating and electricity in the US?

I imagine it would over 1000, or 50 for every state. And if the US went down this route then could they really expect all the other nations of the world not to.

If every country did this then all every country in the world would have the ability to produce nuclear weapons or alterantivley would be totally dependent on other nations for their fuel supply.

Sounds to me like a good formula for a species to ensure its long run extiction :shock:
 
I was under the impression that fast breeder reactors were vapourwear?

Like Fusion..
 
http://en.wikipedia.org/wiki/Uranium-238

Breeder reactors
Uranium-238 is not usable directly as nuclear fuel; however, it can be used as a source material for creating the element plutonium. Breeder reactors carry out such a process of transmutation to convert "fertile" isotopes such as uranium-238 into fissile plutonium. It has been estimated that there is anywhere from 10,000 to five billion years worth of uranium-238 for use in these power plants . Breeder technology has been used in several reactors.

As of December 2005, the only breeder reactor producing power is BN-600 reactor at the Beloyarsk Nuclear Power Station in Russia. The electricity output of BN-600 is 600 megawatts. Russia has planned to build another unit, BN-800, at Beloyarsk nuclear power plant. Also, Japan's Monju breeder reactor is planned for restart, having been shut down since 1995, and both China and India have announced intentions to build breeder reactors.
 
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