I hope I have successfully designed a small expandable backup system for my property located in the desert. Very hot, lots of sun.
I’d like to get an opinion on what I am planning before I spend more money buying the remaining equipment that I have decided on.
I presently have 6580 watts nominal of solar panels purchased used. They are flat mounted on shipping containers.
(at least that is what I am in the process of doing).
I understand that I will lose 14% which might give me a corrected nominal of 5659 nominal.
Then I will loose more in the summer due to heat, and the panels are used and probably partially degraded.
I'm not certain what that adds up to on a 110 degree day?
I own (28 ) 235 watt panels with and open circuit voltage of 37 volts and a rated amperage of 7.84. I am making 4 series strings and then parallel those into two strings with a voltage of 296 volts @17 amps to meet the spec's of the charge controller I selected below.
Now for equipment I plan to buy very soon, it’s on sale.
(1)Schneider context xw pro 48v hybrid inverter because of the well pump.
(2) EG4 MPPT solar charge controllers 500V/100 amp for the two array strings.
(1) Schneider insight home smart box to configure the inverter with.
For batteries. I’d like to build my own.
This inverter requires 200 AH to meet the minimum standards which I am sure keeps the warranty intact? I would likely order (2) of the lower end SOK offerings because they are user repairable. If i decide to test it once It is assembled.
The other option is to further research BMS's for 48 volt packs over 100 amps. Then I may purchase 280 amp cells at Currant Connected, build some frames and roll my own.
I believe I will need at least 500 AH of batteries but for now I am interested in getting everything up and running, then adding more batteries as I can afford them and have time to build them. I am not certain if I am high or low on the battery capacity needed. Let me know what you think.
The loads that I designed the system for are as follows.
The critical loads during an extended power outage which this is designed to prevent are:
2 x 5000 btu air conditioners (500 watt run wattage) much more to start. Likely one will run continuously at night. The other will cycle intermittently as things cool off over night. It cools a very small space.
2 small chest freezers and 2 full sizer refrigerators . At least one has automatic defrosting.
Likely one of the fridges would be combined into the other during a prolonged power outage.
The chest freezers would present more of a problem.
½ hp evaporate cooler (500 watts running)
3 ceiling fans and a couple of led lights.
Presently during the day with the evaporative cooler on, 3 ceiling fans and the 2 refrigerators and 2 small freezers cycling, and a couple of lights on , the draw is between 1500 and 1900 watts. This includes one of the small ac's cycling occasionally. Typically.
At night power draw seldom drops below 750 watts, typically closer to 1000 watts. This is just looking over some energy audits done without going out of our way to conserve power.
Additionally the system must be able to run a 1 hp well pump(11 amp/240V) long enough to pump 150 gallons of water daily. Takes aprox 15-20 minutes each day. Can be done during daylight. The time of the day when it is done is flexible.
Tell me what you think? I’d rather get the bad news now than after I spend the first 10K. Hopefully no bad news.
I’d like to get an opinion on what I am planning before I spend more money buying the remaining equipment that I have decided on.
I presently have 6580 watts nominal of solar panels purchased used. They are flat mounted on shipping containers.
(at least that is what I am in the process of doing).
I understand that I will lose 14% which might give me a corrected nominal of 5659 nominal.
Then I will loose more in the summer due to heat, and the panels are used and probably partially degraded.
I'm not certain what that adds up to on a 110 degree day?
I own (28 ) 235 watt panels with and open circuit voltage of 37 volts and a rated amperage of 7.84. I am making 4 series strings and then parallel those into two strings with a voltage of 296 volts @17 amps to meet the spec's of the charge controller I selected below.
Now for equipment I plan to buy very soon, it’s on sale.
(1)Schneider context xw pro 48v hybrid inverter because of the well pump.
(2) EG4 MPPT solar charge controllers 500V/100 amp for the two array strings.
(1) Schneider insight home smart box to configure the inverter with.
For batteries. I’d like to build my own.
This inverter requires 200 AH to meet the minimum standards which I am sure keeps the warranty intact? I would likely order (2) of the lower end SOK offerings because they are user repairable. If i decide to test it once It is assembled.
The other option is to further research BMS's for 48 volt packs over 100 amps. Then I may purchase 280 amp cells at Currant Connected, build some frames and roll my own.
I believe I will need at least 500 AH of batteries but for now I am interested in getting everything up and running, then adding more batteries as I can afford them and have time to build them. I am not certain if I am high or low on the battery capacity needed. Let me know what you think.
The loads that I designed the system for are as follows.
The critical loads during an extended power outage which this is designed to prevent are:
2 x 5000 btu air conditioners (500 watt run wattage) much more to start. Likely one will run continuously at night. The other will cycle intermittently as things cool off over night. It cools a very small space.
2 small chest freezers and 2 full sizer refrigerators . At least one has automatic defrosting.
Likely one of the fridges would be combined into the other during a prolonged power outage.
The chest freezers would present more of a problem.
½ hp evaporate cooler (500 watts running)
3 ceiling fans and a couple of led lights.
Presently during the day with the evaporative cooler on, 3 ceiling fans and the 2 refrigerators and 2 small freezers cycling, and a couple of lights on , the draw is between 1500 and 1900 watts. This includes one of the small ac's cycling occasionally. Typically.
At night power draw seldom drops below 750 watts, typically closer to 1000 watts. This is just looking over some energy audits done without going out of our way to conserve power.
Additionally the system must be able to run a 1 hp well pump(11 amp/240V) long enough to pump 150 gallons of water daily. Takes aprox 15-20 minutes each day. Can be done during daylight. The time of the day when it is done is flexible.
Tell me what you think? I’d rather get the bad news now than after I spend the first 10K. Hopefully no bad news.