Solar system intallation info needed

joefanfan said:

Hi, Please anyone who can help. I have bought 4×300 watts solar panels to install in haiti on top my house. What specific other items do i need to install this solar system ? Your idea will be greatly appriciated since i have yo do it myself.

BB Thanks for this great post I copied this guideline as my target I do have a few questions

The charge controller I bought is the pcmx60 as the name implied 60 amps charging max, going by your disign suggestion
647 bank would need a larger cc unit , what is your thought?

the panels the cc can only handle 3200 watts @ 48 volts 1600@ 24 any input 

the inverter I was going with the magnum 4024 unit a little larger then you propose what do you think?

also as  far as the batteries

I generally like to suggest a system that is capable of providing around 3.3 kWH (3,300 Watt*Hours) per day. That not only gives you plenty of power for most energy efficient 120/240 VAC refrigerators, it has enough power left over for running a small well pump, clothes washer, LED lighting, TV/Laptop computer.

Doing a rule of thumb design... 1-3 days of energy storage, with 2 days being a pretty good optimum point, 50% maximum discharge (for longer battery life). That gives us a nominal 24 volt battery bank of:

• 3,300 WH per day * 1/0.85 AC inverter eff * 2 days storage * 1/0.50 max discharge * 1/24 volt battery bank = 647 Amp*Hour @ 24 volt flooded cell lead acid battery bank

Then there is enough solar to charge the battery bank. 5% to 13% rate of charge:

• 647 AH * 29.0 volts charging * 1/0.77 solar panel+charge controller deratings * 0.05 rate of charge = 1,218 Watt array minimum (weekend/seasonal usage)
• 647 AH * 29.0 volts charging * 1/0.77 solar panel+charge controller deratings * 0.10 rate of charge = 2,437 Watt array nominal (full time off grid)
  
• 647 AH * 29.0 volts charging * 1/0.77 solar panel+charge controller deratings * 0.13 rate of charge = 3,168 Watt array "cost effective" maximum

And then there is sizing the array for your load and hours of sun per day (by season):
http://www.solarelectricityhandbook.com/solar-irradiance.html

Port-au-Prince
Average Solar Insolation figures

Measured in kWh/m2/day onto a solar panel set at a 72° angle from vertical:
(For best year-round performance)

Jan	Feb	Mar	Apr	May	Jun
5.58	5.73	5.69	5.69	5.63	6.26
Jul	Aug	Sep	Oct	Nov	Dec
6.26	5.77	5.44	5.22	5.13	5.29

Assuming you want to minimize your generator time (noise and fuel costs), your worst case "typical" month of November would give you an array of:

• 3,300 WH per day * 1/0.52 off grid system eff * 1/5.13 hours of sun per day in November = 1,237 Watt array minimum "break even" November

Now--If you are going to live there full time and don't want to watch your energy usage and clouds every day, I would suggest 10% minimum solar array of 2,437 Watts. That would give you:

• 2,437 Watt array * 0.52 off grid system eff * 5.13 hours of sun (Noveha 1,200 Watt minimum array (could work pretty nicely), or an array that could be "oversized" for your system (you have lots of sun) of 2,437 Watts--Your choice.
  

If you have few times with days of cloudy weather, the smaller array may work out OK for you (you can try the smaller array and add to it down the road, if needed). The large array would be very nice and would provide a lot of "extra energy" for fans, well pump, etc. during sunny weather.

The minimum AC inverter for running a full sized frost free refrigerator is around 1,200 to 1,500 Watts. A typical inverter for a 647 AH @ 24 volt battery bank could easily be 2,400 Watts to ~3,300 Watts maximum (maximum capability of that flooded cell battery bank).

The number supplied are a rule of thumb design with no real knowledge of your loads, exact location (if I guessed wrong), and your over all needs (minimum power, want to provide more power for other appliances), how much you want to spend for the system, or how much you know about solar and managing the system.

The above is just a starting point, which can give you a very nice system (conservative design). Use 6 volt @ ~200 AH "golf cart" batteries (4x in series, 3x parallel strings for 12 batteries total). If you can get/justify larger capacity batteries, the above "golf cart" battery bank is about the maximum I would suggest building use GC batteries (vs larger/better quality batteries).

-Bill