Calculations

Yesterday I met with Mr. Kamalu to calculate some numbers to give to Revolusun to get materials.  My hope was that when I walked into Mr. Kamalu's classroom that he would tell me some magical formula to get all the answers and we could get our prototype up!... Unfortunately there was no magical formula.  We calculated that we would need something like a 12V battery 105 AH @ 20 Hr. rate.  It would probably take 44.3 AH for the battery to run for 19 hours (5 hours of sunlight during day).

While writing this blog post I received an email from Alan! So this is the plan:
They have a Sharp 240W module with 37.4 volts and 7.98A.  The panels produce 37.4 volts but the pump needs 12 volts to operate.  We will use a Peak Power Point tracker in order to lover the voltage down to 12 volts for the pump to function but it also raises the amps to charge the battery. Without this device you would lose 25.4 volts of solar power. This combo of the Sharp Module and Peak Power Point Tracker will produce 15A/hr for an average of 5 sunlight hours= 75A.  The current pump will not work so they will provide a 12V pump that runs for 24 hours and consumes 43.2 A.  So if the combination of the module and tracker= 75 A and the pump will take 43.2 A then there will be 32A to charge the battery.  This will provide enough energy for 2-3 days of stormy weather a month.

In order to provide supply for these 2-3 days, we will need 129.6 AH. They will provide a 225 AH @ 20 hr Deep Cucle 12V battery bank.  There is extra AH so that the battery doesn't discharge completely and ruin the battery.

Alan said they will be delivering everything on Monday in the afternoon!! So exciting!!! Thats the plan so hopefully it will work out!

Peak Power Point Tracker
planetarypower.com.au