[Project] Solar Powered Bitcoin Mining Rig

[NoahWL1]

Last Updated: 6/3/15

Intro to the Project:

While working on my Bitcoin miners that are far past obsolete because my power cost is 11 cents per kilowatt, the thought occurred to me that no miner is obsolete if power is not a concern.  Thus, the idea to create a solar powered Bitcoin miner.  I did some research on the subject and found that there really weren't a lot of things on it.  Probably because it's highly inefficient considering the cost of the solar panels and batteries.  However, who cares?!  This is for fun, and maybe in 2 or 3 lifetimes I'll get my money back.

The Goal:

The goal of this project is to power 3 Antminer U2s I have laying around collecting dust.  They are outdated, but in all will make about 1 cent a day on free power.  Definitely worth the fun of the project!  The miners will be able to run 24/7 and stable with minimal downtime.

How it's Going to be Done:

The way this is going to be accomplished is fairly simple.  The basic idea is to use a 2.4 amp USB phone charger solar panel rig to charge a 30Ah battery bank (which also has a solar panel built-in that will trickle charge it).  The battery bank will be powering a controller that controls the Antminer U2s.  The controller has yet to be decided, as a Raspberry Pi is a bit more expensive and power-hungry than I'd like it to be.  However, if I can't find anything else I'll resort to it.  (If anyone has any ideas, please, post a comment on a controller I can use!)  The controller will be connected to the internet either through WiFi if the controller supports it, or with an ethernet cable that goes inside to the router.  So technically it's not 100% free Bitcoins, but we're not counting the cost of the internet here.

Parts list:

Right now I'm still searching for parts for this project so this post is going to be updated frequently as I find the right components.  Right now, I have ordered the solar panels and I already own the battery bank and Antminer U2s.  As I mentioned before, I am still looking for a controller.

Battery Bank: http://www.banggood.com/30000mAh-Solar-Charger-Battery-Power-Bank-For-iPhone6-Smartphone-p-919239.html (Not really 30,000mAh, but still a good 8,000.  Works well.)
Antminer U2s: http://www.amazon.com/BITMAIN-ANTMINER-U2-Bitcoin-Overclockable/dp/B00ITD5NV6/ref=sr_1_1?s=office-products&ie=UTF8&qid=1433208426&sr=8-1&keywords=antminer+u2 (The U2s can be purchased for cheaper, search "Antminer U2" on eBay.com)
Solar Panels: http://www.amazon.com/SUNKINGDOM-trade-Activities-Compatible-Accessary/dp/B00MTF70AC/ref=cm_cr_pr_product_top?ie=UTF8
Controller: Yet to be decided!  Post ideas in the reply section.  Must have low power consumption, cheap cost, and ability to run Antminer U1 or U2 miners.
(UPDATE) I have decided to go with the Raspberry Pi 1 B+ because of the low price, power efficiency, and the ability to be used in future projects. http://m.newegg.com/Product/index?itemnumber=9SIA4641T69520
Raspberry Pi WiFi Dongle (optional): http://ebay.com/itm/201363255068?_mwBanner=1
Controller Storage: Class 10 4gb SD card to run Minepeon on the Raspberry Pi.  http://www.ebay.com/itm/131508561008

Cost:

This project wasn't meant to be super expensive.  At least not at the start.  I chose the cheapest but trustworthy products I could find for this project, and I might end up changing them out if they don't work right.  Here's the cost of the parts and the total cost:
- 30Ah Solar Charged Battery Bank: $15
- 3x Antminer U2: $20 for one, $60 for three (already owned)
- Raspberry Pi 1 B+ Miner Controller: $33
- Class 10 4gb SD card for Raspberry Pi: $4
- Adapter for micro SD to full SD: ~85 cents (already owned)
- Raspberry Pi USB WiFi Adapter (optional, uses more power): $5
- 2.4 amp Solar Panels w/ 2 built-in USB ports: $40
Total cost without including already owned devices (so far): $97 (with optional USB WiFi adapter)
Total Cost including no already owned devices: $158
All prices are in USD.

Yes, the cost is large, and the chance of making an ROI is basically nothing, but it's a very fun project and can be endlessly upgraded or used for something else.  I will continue to look for better and cheaper components in the future for anyone that wants to build this project on their own.  An instructional guide with pictures and a video will be posted once all the parts have arrived and I've successfully set everything up.

So, what are your guys' thoughts on this?  I'll be updating this post as I advance with pictures, comments, and more.  Hopefully by the end of the month I'll have a fully free energy powered Bitcoin mining rig, no matter how small!

Are you a tl;dr kinda guy?  Here's the main breakdown! Fold-out solar panels meant for camping or hiking rated 2.4 amps @ 5 volts will charge a battery bank that also has a 300mAh built-in solar panel.  Battery bank will provide backup power in case the sun gets blocked out for a bit and at night.  The Raspberry Pi controller and Antminer U2s are directly connected to the battery bank, as the bank can be charged and supply power at the same time.

[valkir]

Nice funny project! I will follow this for sure! 

[NoahWL1]

Nice funny project! I will follow this for sure! 

Glad to hear that!

[NoahWL1]

I've opted in to go with the Raspberry Pi 1 B+ as the controller.  It should work great!  I've updated the original post with the new information and purchase link.

[NoahWL1]

Also went for a cheap WiFi dongle for the Raspberry Pi since this is going to be outside.  Ethernet cords can be a bit hard to run to the roof!  The original post has been updated with the purchase link.

[notlist3d]

Very neat idea please keep us updated.  If you are able to please keep a total cost tally, would be interesting to see total cost.

And ouch I did not realize U2's were still that high.  USB miners most use for learning bitcoin mining at this point.  If your looking at this area might consider Avalon Nano - https://ehash.com/product/avalon-nano/  .  Can get over 4 GHz each on those.  They are not really ROI miners, but few are still selling new.

But with yours having them already is definitely a bonus to keep costs down.  Nice project though.

[ezeminer]

I wouldn't mind selling my u2's in my sale post.

Or other USB mining supplies.

[NoahWL1]

Very neat idea please keep us updated.  If you are able to please keep a total cost tally, would be interesting to see total cost.

And ouch I did not realize U2's were still that high.  USB miners most use for learning bitcoin mining at this point.  If your looking at this area might consider Avalon Nano - https://ehash.com/product/avalon-nano/  .  Can get over 4 GHz each on those.  They are not really ROI miners, but few are still selling new.

But with yours having them already is definitely a bonus to keep costs down.  Nice project though.

Yeah, when I went to grab a link for them I was pretty surprised too!  I'm glad I already have 3 of them.  I'll check out those Avalon Nanos and keep you posted!  When I get back from school I'll make a price list of everything, thanks for the idea.

EDIT: I've found some cheaper U2s on eBay but I'm not going to post the links since eBay links tend to go dead pretty fast.  Just search Antminer U2 on eBay.com, and avoid the person selling them for $150!  (wat)

I also checked out the Avalon Nanos.  Not really sure how stable they are, although the price is good.  The real killer is the power usage: 5 watts!  On 5 volts USB, that's drawing an entire amp of power whereas the U2 only draws 600 milliamps of power even when overclocked to 2.2gh/s.  I don't know where you saw 4gh/s but I only see 3.6gh/s.  Either way they draw more watts per gh/s, so just not worth it.

[NoahWL1]

I wouldn't mind selling my u2's in my sale post.

Or other USB mining supplies.

Well maybe if I can get some more power running in the near future I'll take them off your hands .  I don't think I can run more than 3 right now.

[valkir]

The wifi dongle is a energy killer. Take max 2 watt for the pi and if you had a wifi dongle, take 10w. So maybe start with a rj45 cable to see if everything work before adding a wifi dongle.

[NoahWL1]

The wifi dongle is a energy killer. Take max 2 watt for the pi and if you had a wifi dongle, take 10w. So maybe start with a rj45 cable to see if everything work before adding a wifi dongle.

Will do, thanks for the info! 1 wire is certainly worth more miners.

[NoahWL1]

I'm working on how the miner will be powered at night.  With the 4000mAh battery, it's not going to be possible.  The total amp draw is going to be around 900mAh.  That's 300mAh minimum for the Raspberry Pi and 600Ah for the U2 running overclocked.  According to some simple math of 4000/900, at best the battery backup power will only last around 4 and a half hours.  In my area, it can go days without much sun, so I want the battery backup to last at least 24 hours.  Assuming the setup uses around 1amp, as I doubt it will be exactly 900mAh, I will need a 24Ah battery pack preferably with solar charging built in.  This 30Ah pack seems to be like a good fit for the job at a good price from a site I use quite often: http://www.banggood.com/30000mAh-Solar-Charger-Battery-Power-Bank-For-iPhone6-Smartphone-p-919239.html  This pack also has 2 USB ports, which will come in handy if I need to use an external powered USB hub for more miners.  I'll update the links and costs in the main post now.

EDIT:  It appears that bank was waaay too good to be true.  I thought something was off with 30Ah for $15...  I guess I'll have to try and find something else for full overnight power, but for normal use not overnight it should be okay as it seems to have around 4000mAh of battery in it.  I'll keep looking.

[valkir]

you only got 1.5w on this charger. You will burn the battery because you will take more than waht he can charge. Be careful when using lithium battery there is some stuff you need to know.
You cant discharge it too much and you need the exact voltage and amp to be sure not to surcharge it. 

[NoahWL1]

you only got 1.5w on this charger. You will burn the battery because you will take more than waht he can charge. Be careful when using lithium battery there is some stuff you need to know.
You cant discharge it too much and you need the exact voltage and amp to be sure not to surcharge it.  

Are you talking about the battery power bank I just posted or the one I already have?  They're both rated for 2.1 amps/10.5 watts, plenty for the miner and the controller.  I updated the post with the new battery pack with some more information though.

[TheRealSteve]

Two notes:
1. Buyer beware when it comes to mAh ratings on power banks.  tl;dr: they're rarely what is claimed.  Try to look for online reviews where people at least tear it down or even better run a capacity test on it.
2. That solar panel is underpowered for the suggested capacity.  You spoke earlier of fold-out models, those would almost certainly be more suitable as they tend to have higher solar output.

Just to give you an idea.. here's a fairly large solar panel for use in electronics (never mind the cost) supposed to be rated at 2.5W (yours is claimed to be 1.5W): https://www.sparkfun.com/products/7840 .  9.15V / ~4.2V (rough charge voltage) * 280mA ~= 610mA (ignoring the losses in the buck circuity and all that).  610mA is less than what your setup draws.  Over time, the battery would eventually be drained.

Not raining on your parade - I love me some StickMiner fun - just saying you might want to look around some more

As for battery safety, if you're already using a power bank, they tend to have over- and under-charge protection either in their own circuit, or on the pouch battery / the 19670 batteries.  If you were doing it yourself, a battery management chip is pretty cheap.

[NoahWL1]

Two notes:
1. Buyer beware when it comes to mAh ratings on power banks.  tl;dr: they're rarely what is claimed.  Try to look for online reviews where people at least tear it down or even better run a capacity test on it.
2. That solar panel is underpowered for the suggested capacity.  You spoke earlier of fold-out models, those would almost certainly be more suitable as they tend to have higher solar output.

Just to give you an idea.. here's a fairly large solar panel for use in electronics (never mind the cost) supposed to be rated at 2.5W (yours is claimed to be 1.5W): https://www.sparkfun.com/products/7840 .  9.15V / ~4.2V (rough charge voltage) * 280mA ~= 610mA (ignoring the losses in the buck circuity and all that).  610mA is less than what your setup draws.  Over time, the battery would eventually be drained.

Not raining on your parade - I love me some StickMiner fun - just saying you might want to look around some more

As for battery safety, if you're already using a power bank, they tend to have over- and under-charge protection either in their own circuit, or on the pouch battery / the 19670 batteries.  If you were doing it yourself, a battery management chip is pretty cheap.

Ah, I understand your confusion.  I was wondering why you were saying that the panel only had 1.5 watts.  Now I see you're talking about the one in the power bank.  The fold-out one is going to be connected to the battery bank, which also has a solar panel that will provide a bit more power.  Sorry the post was too long, I like going in-depth on explanations .

Here's the break-down of it if you don't want to read it: Fold out solar panels rated 2.4 amps @ 5 volts will charge a battery bank with a built-in solar panel.  Battery bank will provide backup power in case the sun gets blocked out for a bit and at night.  The Raspberry Pi controller and Antminer U2s are directly wired to the battery bank.  I updated the post with this now in case anyone else bored by my life story wants an overview

[NoahWL1]

you only got 1.5w on this charger. You will burn the battery because you will take more than waht he can charge. Be careful when using lithium battery there is some stuff you need to know.
You cant discharge it too much and you need the exact voltage and amp to be sure not to surcharge it.  

Are you talking about the battery power bank I just posted or the one I already have?  They're both rated for 2.1 amps/10.5 watts, plenty for the miner and the controller.  I updated the post with the new battery pack with some more information though.

I understand what you're saying now, that the solar panel in the battery bank only has 1.5 watts of output power.  You must have missed that I was also using 12 watt solar panels (2400mAh @ 5v) to charge the battery bank.  The battery bank is used as backup power and to supply more stable current to the controller and miner, in case the sun is hidden by a cloud for a period of time or something.

[valkir]

oh ok nice 12w solar panel. Which one ? Do you have a link, Im searching a 12w panel. 

[aarons6]

this looks like a good project.. you can stick them on a solo pool and just let them run pretty much maintenance free..

but there is one or two issues you havent really addressed yet..

1 is a major one.. on the power pack i have, it auto shuts off after about an hour and you have to press a button to turn it on..

the other is you might need 2 of those solor panels.. the 12W is PEAK watts.. you probably wont even get close to that most of the time.. maybe 6 or 8.

[NoahWL1]

this looks like a good project.. you can stick them on a solo pool and just let them run pretty much maintenance free..

but there is one or two issues you havent really addressed yet..

1 is a major one.. on the power pack i have, it auto shuts off after about an hour and you have to press a button to turn it on..

the other is you might need 2 of those solor panels.. the 12W is PEAK watts.. you probably wont even get close to that most of the time.. maybe 6 or 8.

I have used the power pack for quite some time now and I've never has any problems with it turning off.  I specifically chose the panels because of that peak voltage.  I knew I wouldn't get close 2400mAh on most days, and I know I won't need more than 1200mAh to run one U2.  I plan to buy some traditional panels with no USB cables in the future and wire them in parallel with the existing panels that have the USB port.  Then I'll be able to run a powered USB hub and more USB miners.