How to Solar Charge an Electric Bicycle

[LockH]

VTA GM & CEO Nuria Fernandez, Los Altos Mayor and VTA Board Member Jeannie Bruins and Swiftmile.com CEO Colin cutting the ribbon on an e-bike charging station at our River Oaks campus. These solar-charged e-bikes will help our employees get around during the day without a car and without getting too tired. The station and four bikes are part of a partnership with Swiftmile to test these bikes in North San Jose.

 

[LockH]

"Did this town REALLY ban solar panels for hogging sunlight?"
http://www.theweathernetwork.com/ne...-ban-solar-panels-for-hogging-sunlight/61132/
Daniel Martins
Digital Reporter

Tuesday, December 15, 2015, 12:29 PM - Stop us if you've heard this one: A town in the United States banned solar panels due to fears they would 'suck up all the energy from the sun.'

That's been the lead of most international coverage we've read about the town of Woodland, North Carolina, whose council rejected a new solar panel installation 3-1 after a public meeting this week, as well as approving a moratorium on future solar developments.

Going to the local paper, the Roanoke-Chowan News-Herald, resident Jane Mann, whom the News-Herald identifies as a retired science teacher, told the gathering solar panels prevent photosynthesis, keeping plants from growing. She also expressed concerns over cancer.

Another resident, Bobby Mann, also said he thought solar panels "suck up the sun" (as the paper reports it. The piece as a whole is a bit light on direct quotations).

However, the Manns' outlandish concerns have dominated international coverage of the meeting, or at least the headlines, making it sound like the project was dismissed out of hand for staggeringly unscientific reasons.

In fact, according to the News-Herald, Woodland has been quite good to solar power companies, such that three other solar farms have been approved, with one already under construction.

And the proposed new installation wouldn't actually help the town much. The News-Herald says the proposed build site isn't actually within the town limits, so tax revenues would be unaffected, and any electricity generated wouldn't be fed into the local grid, leaving power bills unaffected.

So when you get into the rest of that meeting, the concerns of the citizens start getting a lot more practical.

One, for example, said all the added solar panels in the area had caused her property's value to drop. Another said the economies of area communities had dried up as a result of traffic diversion due to a nearby highway, and feared solar farms would similarly drive people away.

Your mileage may vary as to how valid any of their concerns were, and the company reps at the meeting said property values should be unaffected. The online article lacks pictures, so unfortunately we don't have any idea of the look on the reps' faces when the "solar panels suck up sunlight" issue came up.

As bizarre as that concern was, however, the rest of the issues raised by the citizens have given us an interesting insight into the local politics of the renewable energy revolution.

:?

 

[craneplaneguy]

Here's how I do it, hardly portable however! A 2.5 KW wind turbine, and about 4 KW of solar. Unshown is the .9 KW micro hydro system as it's shut down for the winter. Everything is grid tied.

So, I have it covered when at home, but I need to figure out a way to recharge my 52 volt battery off my planes 12 volt charging system, that has about 10 amps available while in flight. I need to go over this entire thread and see if this has been covered already, and if I understand it. I'm thinking a custom made module from SolarConverters may be the most efficient and easiest way to go.. I've dealt with them in the past using one of their voltage controlled switches to use the same solar array to charge batteries after a buried water tank was filled, on an off grid home I used to have. They are a big name in the renewable energy field.

The Trail Viper was maxxed out by this snow depth, and only going downhill (that's my 400' long runway) made it possible at all. NO kickstands were used in either photo! A little later I took my Montague mountain bike down the same way, and it's skinnier tires, larger dia. also, did much better.

 

[Ykick]

Plane can deliver about 120W in flight? After losses using either inverter or step-up dc-dc convertor you'll be lucky to deliver 100W (2A) into 52V battery pack. Probably more like around 85W. Not much, gonna need to be a long flight if the battery pack's depleted.

 

[LockH]

For US folks "U.S. extends solar and wind tax credits to boost clean energy by $73 billion over 5 years"
http://inhabitat.com/u-s-extends-so...oost-clean-energy-by-73-billion-over-5-years/

First paragraph:

Renewable energy pundits heaved a huge sigh of relief yesterday, as Congress agreed to extend solar and wind investment tax credits for an additional five years. The credits were initially set to expire in 2016, which had caused concerns about the immediate future of the clean energy industry in the United States. Now, the five-year extension is expected to create a $73 billion boom in clean energy projects. The full impact of this decision can only be described by one word: massive.

 

[craneplaneguy]

Agreeded, I guesstimated about 2 - 2.5 amps. Engine h20 amp charging circuit but I need to kee about 5 freeed up for other uses. Slow charge for sure but better then nothing. The Luna charger puts out twice that so I figure twice as long at half the rate, hopefully.

 

[Ykick]

You’ve probably seen these before? http://www.ebay.com/itm/Boost-DC-DC-Converter-Power-Supply-Step-up-Module-12V-60V-to-12V-80V-600W-10A-US-/111803816137?hash=item1a0806d8c9:g:RrcAAOSwPcVVk4lG

I’ve used ‘em on occasion and IIRC got around 1.7A from 12-13V 10-15A into 50V pack?

Trick is to be careful setting voltages and trimming current. I burned Turnigy power meter inadvertently putting out around 80V.

 

[craneplaneguy]

That looks like about right, and the price is low enough to make it a no brainer. Thanks, ordered! The multimeter is my friend in setting this up safely. Worth a shot anyway, for $15.00.

 

[LockH]

http://www.artdelic.com/store/p16/130W_lightweight_portable_solar_panel.html

 

[LockH]

http://inhabitat.com/13-year-old-ma...rough-by-harnessing-the-fibonacci-sequence/2/

"... Aidan Dwyer created a solar cell tree that produces 20-50% more power than a uniform array of photovoltaic panels."

 

[LockH]

"How Germany Became a Solar Superpower"
http://www.triplepundit.com/2015/08/germany-became-solar-superpower/

"... in some ways, America is late to the party by about 25 years."

 

[LockH]

[youtube]exs4gbDRiiA[/youtube]

 

[markz]

"How Germany Became a Solar Superpower"
http://www.triplepundit.com/2015/08/germany-became-solar-superpower/

"... in some ways, America is late to the party by about 25 years."

Are not they always late for most things?
I just need to look at Japans cell phone market.

 

[craneplaneguy]

I've taken to refering to my 3 different E- bikes as " my solar powered bikes." In addition to my home wind/ mostly PV/ hydro power grid tied system, which provides in excess of my consumption. I recently put another grid tied array down in town at my crane yard, which will also supply 100+% of my power needs. So, charging at home or in town, they are in effect solar powered, though admittingly in directly. It makes people think...
..

 

[LockH]

^^ MUCH better than "coal-powered". Here in Ontario, Canada has stopped coal 100% for electric generation already. (But lots of nuclear now/still. Eeeek! So technically our "ebikes" are half and more nuclear-powered.)

 

[LockH]

"Panasonic Beats SunPower’s New Solar Module Efficiency Record":
http://cleantechnica.com/2016/03/02/panasonic-beats-sunpowers-new-solar-module-efficiency-record/

The new world record, for a 23.8% solar conversion efficiency mark, bests the previous one set just recently by SunPower (22.8%). The achievement means that Panasonic now holds the conversion efficiency record for both crystalline-based solar cells (25.6%, set in April 2014) and modules.

A new press release provides more: “Panasonic developed a unique silicon heterojunction structure composed of crystalline silicon substrate and amorphous silicon layers, and has continuously improved its photovoltaic module HIT using silicon heterojunction since the start of commercial production. This new record was achieved by further development of Panasonic‘s proprietary heterojunction technology for high-efficiency solar cells and modules adopting a back-contact solar cell structure.”

For those who are unaware, “heterojunction” refers to a technology “for junction formation required for solar cells that covers the silicon base surface with an amorphous silicon layer. This technology has the key feature of superior passivation to compensate for the many flaws around the silicon base surface area.” And “back-contact structure” refers to a technology “for eliminating the shadow loss on the front side electrode with the electrodes on the back of the solar cell, which allows the more efficient utilization of sunlight.”

 

[craneplaneguy]

If it comes down to carrying a module on a bike, that top efficiency is great. Otherwise, for me it comes down to dollar per watt at the time of the initial purchase, when ground mounted there is usually plenty of room, so adding a few modules is a cost effective way to use more common and cost effective ones.

 

[LockH]

[youtube]0801_K7VZGo[/youtube]

(Brings up the idea of using water to cool the cells to improve inefficiencies a few %.) Dunno if or how much solar tracking they put in this design.

http://cleantechnica.com/2015/04/27...pletes-two-floating-solar-power-plants-japan/

The 1.7 MW floating solar plant at Nishihira Pond and the 1.2 MW plant at Higashihira Pond were built using Kyocera modules fixed to specially developed floating platforms which are attached to the lake-beds. The power plants, inaugurated in late March, are expected to generate an estimated 3,300 MWh annually.

 

[parajared]

What happens if I just y-splitter my battery lead off my 12s lipo pack (44 volts) directly to the raw 48volt lead off my solar panel and just manually keep an eye on the voltage levels? Would that work? Maybe a dumb question, sorry.

Nevermind: found the answer

If, however, you connect the solar panel directly to a battery, then the voltage on the terminals of the solar panel will always be equal to the voltage over the battery (if there is light). This is given by ohms law, V=R*I. If there is no resistance between two points (a wire from + on solar panel to + on battery) then the voltage is also 0. This means that the voltage over the connected solar panel will be equal to the voltage of the battery, and climb slowly until the battery is fully charged. The rate of this "climb" depends on the current the solar panel can deliver, battery type etc. Such a direct connection is not for practical use, and could damage the battery or solar panel or even be dangerous.

There will be a place in between, the Maximum Power Point, MPP, where the product of voltage and current is at its largest value. The voltage and current are called VMP and IMP respectively.
The Isc and Imp values will be more or less directly proportional to the amount of light hitting the cells of the panel, and Vmp will be about 80% of Voc (for silicon cells).

The problem is that to draw Imp for different light levels on the panel requires a different effective load resistance. A straight connection to a resistor or to a battery cannot do this. So the MPPT (MPP Tracking) Charge Controller, CC, or inverter will take the incoming DC from the panel at Vmp and draw just enough current, Imp, to maximize the panel output power

 

[parajared]

Also along that same line of thought why not just have a voltage activated alarm?

Instead of notifying you that you have hit your target voltage with a "beep" the voltage that would have been sent to the "beep" buzzer instead activates a single throw single pole relay and the relay cuts power from the solar panel?

 

[parajared]

Oh well,
I took the "sane" route and just used a charge controller. I was inspired by people building PVC pipe lawn furniture and built a solar rack out of PVC pipe.

My plan: serialize 4 "ultra thin, high efficiency" 12v solar panels together to make 48 volts and run them to a 48v charge controller. Charge controller uses a buck converter to charge my pack which is 44v nominal.

 

[LockH]

"This beautiful electric bike will charge itself with built-in solar panels"
http://www.businessinsider.com/this...-itself-with-its-built-in-solar-panels-2016-2

With medium usage of up to 20 km/day, LEAOS is completely self-sufficient, that is to say, independent from conventional power sources. Activating the solar charging requires no action on the part of the user.

 

[LockH]

"Take a peek inside Nevada's new solar farm that generates power 24/7 with molten salt"
https://www.yahoo.com/tech/peek-inside-nevada-solar-farm-231848184.html

[youtube]pK9-Q92KYns[/youtube]

The Crescent Dunes plant relies on more than 10,000 sun-tracking mirrors. These mirrors store the solar energy in a pit of salt that is heated to about 1,000 degrees Fahrenheit. In order to provide power to the grid any time of day or night, the heat stored in the molten salt is used to turn water into steam that powers energy generators.

 

[LockH]

[youtube]sN6mlzL1ckA[/youtube]

 

[LockH]

Hello Buffalo, NY!
http://www.assemblymag.com/articles/93310-solar-panel-assembly-plant-nears-completion

Solar Panel Assembly Plant Nears Completion
In an industrial park near the shore of Lake Erie, hard by the Buffalo River, the future of the solar power industry is under construction. SolarCity’s sprawling Buffalo factory, built and paid for by the state of New York, is nearing completion and will soon begin producing some of the most efficient solar panels available commercially. Capable of making 10,000 solar panels a day, or one gigawatt of solar capacity a year, it will be the largest solar manufacturing plant in North America and one of the biggest in the world.

Pic captioned "The gigafactory covers some 27 acres, making it the largest solar production facility in North America."