Micro solar power system

The best way to learn about renewable energy and solar power is to get hands on and build your own system.
Here is a small solar photovoltaic (electricity producing) solar power system which includes charge regulation, monitoring and fused outputs all within a laser cut enclosure. Its designed to be a entry level solar power system to recharge small devices such as mobile phones, mp3 players and power small sound systems.
This has been designed to be put apart with very little soldering, using mainly connector block and crimp terminals.

Step 1: Parts required

First get everything ready....
Parts required:

• 10Wp Solar PV panel (cost £20-30)
  • Such as this:
  • http://www.ebay.co.uk/itm/10-W-Monocrystalline-Solar-Panel-10-Watts-12V-PV-with-Diode-/200731609496?pt=UK_Gadgets&hash=item2ebc894998
  • Check eBay
• Cable (£2-5)
  • 0.75mm² or 1mm² diameter (enough to take 2 to 5A).
  • In red and black if possible.
  • I used 3 different types - twin core for the solar panel, thick tri-rated for the battery cable and thinner cable for internal wiring, after the fuse.
• Battery (cost £? depends upon size of battery. I got some used but OK UPS batteries for free)
  • Rechargable lead-acid
  • I used a sealed gel lead acid battery taken from a UPS system.
  • Capacity (Ah) of the battery is dependant upon the load and solar resource
• Charge regulator (£6)
  • This stops the battery being over charged by the solar module.
  • 2A rated 12V DC.
  • I used this Chinese one: http://www.ebay.co.uk/itm/Solar-Power-Panel-Charge-Battery-Controller-Regulator-/380359116665?pt=LH_DefaultDomain_0&hash=item588f2b8779
  • Here is a UK-made unit: http://www.256.co.uk/?cat=3
• 12V voltage monitor / Voltmeter (£3)
  • To easily measure 12V DC
  • Such as this: http://www.ebay.co.uk/itm/DIGITAL-LED-VOLT-METER-RED-BLUE-GREEN-DC-4-5V-30V-No-Power-Needed-Panel-12V-/251094347641?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&var=&hash=item3a7663af79
  • You could also use a small cheap multimeter.
• Small push button switch (£0.50)
  • This is for the voltmeter so that it is not left on, which would drain the battery.
• 12V 'cigar' lighter socket (£4)
  • This is a standard 12V DC socket
  • Lots of loads are available that will fit this style socket
• 5A resettable fuse (£2)
  • This protects the everything from the high currents the battery can supply.
  • Rated for 12V DC
• Terminal connector block (£0.50)
• 2A rated plug and socket (£2)
  • This is for the solar PV panel connection
• Insulated crimp spade connectors (£0.20)
• M3 20mm long machine screws and nuts x approx 20 (£1)
  • Both countersunk and pan head can be used
• Laser cuttable 3mm birch plywood A4 sheet (£3 + £2 for laser cutter time)
  • This is for the enclosure
  • You could also use any enclosure you have to hand, but I like the wood aesthetic.

(Total cost around £50-£70)

Tools required:

• Cable cutters
• Screwdriver
• Laser cutter - if making your own enclosure (try visiting your local hackspace)
• Soldering Iron + solder
• Terminal crimpers
• Screwdriver(s)
• Small pliers

Right - get eveything together and lets begin....

Comments

[JoshuaZimmerman]

I must say, I love your box design. It adds such a wonderful flare to the entire project. Kudos good sir.

[amgibson]

Hi there,
This is a great design, well done!!! I was wonderinf if you could add the diagram of the box as a pdf?
Thanks

[chunkyhampton]

Thanks for your comment. I've just added the box design as a pdf. It just fits onto one side of A4.
Regards,
Matt

[GJ_Token]

Thank you for the PV design sheet...
I've been after something like this to figure out what would be needed to power a wireless router "off grid"

I'm sure I could mount both the router, battery and regulating electronics in a weatherproof container for mounting on a pole or sorts..

Thank you for both this 'ible, and the worksheet alone..
Both have helped me towards figuring out my project...

[foreverdisturbed]

Nice project and love the logo.

[msemtd]

Like! I look forward to building one of these small-scale systems at Nottingham Hackspace this weekend.

[Schmidty16]

very cool man i love it might make it some day isint it a medium sized small one small is in an altods tin mabe could u sore all of that in a brief case

[chunkyhampton]

That is one thing I love about solar PV - it is incredibly scaleable. You can get tiny solar panels to power a calculator, right up to multi-mega watt arrays, all with the same technology.
I mainly work with domestic grid-connected PV systems in the range of 1000Wp to 4000Wp, hence this 10Wp system is a 'micro' system to me, but might not be to everyone.
Like you say - it would fit in a briefcase. but not in a mint tin. The solar PV module is around 400mm x 300mm. Its a glass panel, so a bit heavy - you can get ones with palstic substrate, but they are 3-5 times the price.....
Cheers,

Matt

[ChickenGrylls]

I think you could get all that in a brief case yes. ChunkyHampton only has normal sized hands so looking at the scale of the first picture. Not sure about getting the electronics in an Altoids tin though.

[keegancdr]

do you think you could post a total project cost on here?

[chunkyhampton]

Good point - please find approximate costs for things added to the parts list. Total cost of parts is between £50 to £70 UK pounds plus the cost of the lead acid battery. If you can reuse any items then obviously that would mean a lower cost. I was given some 7Ah lead acid batteries to use for old UPS. New batteries are quite expensive.
Hope that helps,
Regards,

Matt

[XTL]

There is no wiring diagram - brown lead on solar controller is not labeled on their label. what's it connected to ?

[chunkyhampton]

Hi,
There is a wiring diagram attached as a .pdf on step 6, please scroll down that step to find the diagram. I will try and do a .png to make it easier to view. This should have all the wires drawn.
As you say the brown wire on the controller is not labelled - this has no conenction (and is labelled on the wiring diagram as N/C). This is a relatively cheap charge regulator and did not come with extensive documentation (ie it came with none) - I have just wired it to a spare connector on the connector block to keep it neat and out of the way.
Hope that helps. You can use any charge regulator you like, mayb one with better documentation.
Regards,

Matt

[rikkiesix]

Pretty nice project
Nicely explained
Great job man
I added the pdf to my computer so i can build this too
Greetings from Belgium
Erik