HUGE SOLAR PROJECT IN AFRICA

[Zicas888]

Hi Everyone, I'm trying to figure out the calculation on this massive project in a 3rd world country that doesn't have power in the small villages.
If anyone can confirm the calculation that would be so appreciated.

110 houses, 2 amps each at 220volts using, 550 watts solar panels and 55kw inverter at 80% efficiency for 10 hours of power.
Using 45 batteries at 48volts 280 ah per battery and 184 solar panels total. How long to recharge the batteries using 6 hours of sunlight from the array of panels?

Ahhh...a mouthful... and a brain fry...PUN intended. lol

 

[wpns]

None of that makes sense.

I can tell you that 184 panels at 550 watts at (SWAG) 5 peak hours will make ABOUT 1/2 MWHR per day. That’s not too far off your APPROXIMATELY 0.6 MWHR battery pack so there’s a certain symmetry there, if no margin for cloudy days.

But a 2-amp (480W) service makes nearly no sense, and you are talking a huge capex for something I’m not convinced you have a good handle on. This is a DIY forum, you need to understand the systems and variables and be able to ask cogent questions and understand the answers.

Try explaining the problem again carefully

 

[Zicas888]

None of that makes sense.

I can tell you that 184 panels at 550 watts at (SWAG) 5 peak hours will make ABOUT 1/2 MWHR per day. That’s not too far off your APPROXIMATELY 0.6 MWHR battery pack so there’s a certain symmetry there, if no margin for cloudy days.

But a 2-amp (480W) service makes nearly no sense, and you are talking a huge capex for something I’m not convinced you have a good handle on. This is a DIY forum, you need to understand the systems and variables and be able to ask cogent questions and understand the answers.

Try explaining the problem again carefully

I appreciate your candidness, thank you for that. 2 amps seems incredibly nominal, but for a country that has no power, its a start for cell phone charging, reading lamp and a bit of television enjoyment. Things we typically take for granted. They will use an extension cord to access power from a distribution community box. Solar panels to inverter and batteries to distribution box. That's where the project stops.

 

[Zicas888]

They are currently using generators with that equation, minus the consistency of power. Each house gets 2 amps unstable for 2 or 3 days, until the generator runs out of diesel. We are bring a more stable source of power for 7 days at the same amps per house. Backing it with lithium batteries, per micro system. No grid involved...but the batteries acting as one. 6 hours of sunshine to charge battery...trying to figure out the amount of time needed to charge batteries along with providing power to about 100 houses.

 

[wpns]

They are currently using generators with that equation, minus the consistency of power. Each house gets 2 amps unstable for 2 or 3 days, until the generator runs out of diesel. We are bring a more stable source of power for 7 days at the same amps per house. Backing it with lithium batteries, per micro system. No grid involved...but the batteries acting as one. 6 hours of sunshine to charge battery...trying to figure out the amount of time needed to charge batteries along with providing power to about 100 houses.

Well, yes, 2-amp extension cords to 110 houses could be considered to be a thing, but maybe you could upgrade your distribution network at the same time you are spending (SWAG) $250-500K on the system? Not just safety, but overload management might important. You know Feature Creep means someone will get a microwave or a hair dryer or something, and then their neighbor will... I tried to support a WISP that was severely bandwidth constrained back in the dawn of time, and I'd constantly get "Yes, I know you don't support streaming video, but I was just trying to watch the online basketball game". #TragedyOfTheCommons

Note that your batteries will NOT charge in 6 hours, even with no loads. They will charge in (*) 6 PEAK SOLAR HOURS, please grok the term and find the insolation for your area, along with average length of cloudy days, though if you keep the generator you could use it as a supplemental battery charger.

(*) All approximate numbers, as that's all there is to work with here. Didn't bother to try to figure round-trip efficiencies, or anything else, as the above is to a first approximation. See Fermi Numbers at https://en.wikipedia.org/wiki/Fermi_problem

 

[Zicas888]

Well, yes, 2-amp extension cords to 110 houses could be considered to be a thing, but maybe you could upgrade your distribution network at the same time you are spending (SWAG) $250-500K on the system? Not just safety, but overload management might important. You know Feature Creep means someone will get a microwave or a hair dryer or something, and then their neighbor will... I tried to support a WISP that was severely bandwidth constrained back in the dawn of time, and I'd constantly get "Yes, I know you don't support streaming video, but I was just trying to watch the online basketball game". #TragedyOfTheCommons

Note that your batteries will NOT charge in 6 hours, even with no loads. They will charge in (*) 6 PEAK SOLAR HOURS, please grok the term and find the insolation for your area, along with average length of cloudy days, though if you keep the generator you could use it as a supplemental battery charger.

(*) All approximate numbers, as that's all there is to work with here. Didn't bother to try to figure round-trip efficiencies, or anything else, as the above is to a first approximation. See Fermi Numbers at https://en.wikipedia.org/wiki/Fermi_prob

Thank you. We're hoping with the BMS system we'll fine tune usuage as the project progresses. Currently, the appliances available are merely electronic devices, 1' cube freezes are the highest draw...but consistency will yield demands, eventually. 10am to 4pm is our window of optimal charging, though costly, we're contemplating a separate grid for the batteries....do you think that's necessary? Or can the solar provide day amps and charge the batteries for night usuage? They also have a rainy season with minimal overcast.