Help Help Please

Re: Help Help Please

cokebbeh wrote: »

Hello All,
I am new to this and need some serious help. I posted a question earlier and many responded with invaluable advice. I decided to revise my purchase based on the prices offered. I ended up getting "4" SUN- 130 Watt Solar Panel>>> equivalence of 520Watts.

I did not buy anything else. Just empty panels. From looking inside the boxes, I could not even see wires,,, so I guess I have to purchase the wires. I plan on using this panels to run a few bulbs in Africa. Sun is available throughout the year, except for the period May - August, when we have rains.

My plan is to run 8 bulbs ( please advice me on the most efficient and low wattage bulb). I read a thread by another guy who wants to run a submersible water pump. I would also like to run a submersible water pump if possible. A stereo system, a TV and DVD. I would also like to run a basic fan and a small "Dorm Room" refrigerator and to charge my laptop.

Is this possible with 520 watts? (please see the specifics of the panels below.). What other things do I need and what do u recommend? The guys at Sun Electronics indicated that I need the following - Charge controller, batteries, combiner box, inverter dc and ac disconnect and an AC Panel Box. However, they gave me different advices as to what size of these. PLEASE, PLEASE.. with what I have - 520 watts..and the specifics below... how many batteries do i need, what kind of inverster etc. Any one can recommend good solar fan, solar tv, and solar bulbs or even solar stereo and solar submersible pump.


See below here for the specifics of my panel

SUN- 130 Watt Solar Panel

VOC 24.10V
VMP 18.80V
ISC 7.11amp
IMP 6.55amp

For a bare bones system, you need:

PV (solar panels) -> charge controller -> battery -> inverter

You also need the wire in between these things. In my little diagram, each "->" is wire. You'll need a fuse to protect the positive wire on each "->".

As for "how many batteries do I need". Well, you need enough battery(ies) to suck up (520w x (hours per day)). Let's say hours of "good" sun per day is 4 (solar panels put out almost nothing unless they are getting a good FULL sunlight.)

520w / 12v = 43 amps
43a x 4hr = 172ah (amp-hours)

The more you drain the battery, the shorter its life. Let's say you drain to 75% full (25% discharged) per day. Then you need 4 x 172ah = 688ah of battery.

If you decide to shorten the battery life and drain down to 50% every day, then you need 2 x 172 = 344ah of battery.

For a charge controller, you should get an MPPT type large enough to handle the amperage coming off the solar panels. (520w / 18v (panel voltage) = 28.8a) so you need an MPPT charge controller that can handle 30a on the input side.

For an inverter, you are running mostly electronics, so you should get a "TRUE Sine Wave" (TSW) inverter instead of a "MODIFIED Square Wave" (MSW) type inverter. You can either get one big one to run all your loads, or you can a couple of smaller ones and turn off whichever ones you aren't using.


Okay, that's the basics.


You'll have a maximum of about 520w x 4hr = 2080wh per day to spend. How you spend your 2000 watts per day is up to you.

As an example - my laptop draws 60w so if I run it 10hr per day, that's 600wh burned out of a 2000wh budget.

Figure out what you are going to run and how much it draws, and then you'll know how much it will use from your 2000 watts per day.

And don't forget that the charge controller and inverter will use some of your daily budget as well.