Instructables

Portable Solar Power Supply

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Hello there. You've probably found this Instructable to gather ideas about making a portable solar power supply yourself. I've always been interested in electronics with this project being my latest idea to come wandering out of my head, why not make a portable box on wheels, that I can plug basically anything into, thats powered by the sun? So therefore I thought I'd share this Instructable with the rest of the world.

 
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Step 1: Start thinking...

Picture of Start thinking...
The first thing to do is to think of what you will be wanting to power via the sun, the whole house would be nice, but that's a tad too expensive and not very portable. Our family go away camping many times during the year so I knew what I had in mind. Some 12 volt energy efficient lightbulbs, a 15 inch LCD TV with a free-to-air digital receiver, some sort of radio/CD player would be nice too, a way to charge our mobile phones/sat navs and being able to inflate our air-beds, one which is 12 volts DC and one which is 240V AC.

With all of that in mind I started looking at prices of components on websites such as Ebay and Maplin as price is a very important factor in designing a solar system. Our LCD and receiver draw 2.2 Amps DC on 12 volt, energy efficient lighting draws just under 1 Amp for a 12 watt bulb whilst the phone/GPS chargers draw very little power. Using the TV for say, 3 hours a day max would equal 6.6Ah consumed, lighting used for 4-5 hours a night would consume roughly 4Ah while all the charging of portable devices would be around 2Ah while pumps for air-beds wouldnt run for long so maybe only consuming around 1Ah, totalling 13.6Ah. Deep Cycle batteries shouldn't be discharged below 50% of their rated capacity, the smaller the discharge cycle, the longer the battery will last, therefore a battery of 30Ah would suffice. The UK receives on average 6 hours of sunlight during summer, which is the time of year we go camping and replacing 13.6Ah into a battery would take a 50W solar panel roughly 5 hours to recharge.

(Watts = Voltage x Amps)
(Average solar panel voltage at max power = 17 Volts)
(50 watts/17 volts = 2.94 Amps)

It's easier to draw power from a battery than to replace, requiring usually 10% more power to recharge than what was consumed, therefore:
(14Ah / 2.94 Amps = 4.76 hours of direct sunlight)
In a real world situation this will never happen due to too many different factors such as;
Solar panel shading,
Overcast conditions,
Battery temperature,
Size of wiring,
Other losses.

Therefore it's safer to use a larger battery bank, where power can be used up repeatedly if weather conditions the day after aren't suitable for efficient solar charging to completely recharge the battery.
This looks awsome, however if you could have made it a slight bit smaller or added something like this. Perhaps you wouldent even need the Tv Screen at all
you could connect:

mini itx motherboard.
500gb sata hard drive.
2 gig ram.
duel core 1.6ghz processor.

i think if you did them improvements it would be a 1 of a kind thing that could possibly be one of the best ever built!

http://cgi.ebay.co.uk/12-VGA-TFT-Touch-Screen-Monitor-Car-PC-GPS-B12-/370269880656?pt=UK_Computing_ComputerComponents_Monitors&hash=item5635ce0150
a TFT touch screen from a car to be used in a house right........ why the hell would you want to look at a small screen in your home?
He used a car radio as there 12 volts and often have good tuners in them and maybe had it laying about....
Lastly this is an Assumption on my part but i going to run with it, because this guy made this for his home and wanted it portable i would think this guy is in a rented place like most people now days, so therefore it is portable, i also live in Rented property and installing a Solar system for rented property is a nightmare in some cases would not be worth your time in other cases you would not be allowed in nearly all cases you only stay at rented property for about 4 to 10 years if lucky thus this guy made a portable solar unit that looks great.
This is like the best solar party power station ! Well done on building this!
co19733 years ago
Excellent guide! Your attention to detail and well-thought out design is very inspiring. I especially appreciate the time you took to detail your calculations! Most of the time, authors fail to provide that info, if they even did the calculations themselves, at all!

Keep up the good work!
cooper733 years ago
An amazing guide - thank you for sharing your knowledge, and hey thanks for you advice on youtube - all the best,

Coooooperman :)
gmoon3 years ago
When I first looked at the photos, I thought "wow, huge box for only one battery; what's up with that?".

But then I realized this is a solar-powered portable entertainment center. Not bad at all (but maybe the title is a bit off).

this is so awesome!!!

Good project and a professional finish, and Geek Sexy, i assume like my self you live in a Rented property due to the fact you using this at home, you have inspired me.
I currently working on some idea's to make a portable power system for the house it would be on wheels, but i plan to make it grid tie with some way to just plug in the meter box.
miamibeach1 year ago
Good work. I love to utilize natural resources like sun, wind, water to generate power.
woa this is crazy!
mrbobmaster2 years ago
One problem why have a tv on camping?? it's for the fun of camping. I mean I am twelve and I think that that is sad :(
ya but if you live in a area with regular power outages it would be nice. and the radio is nice if you are having a party
Forgot to include this last time. oops. It is a great write-up though.
You could also build your own solar panels for cheaper.