May 21, 20197 yr On 2016/01/15 at 7:15 AM, Chris Hobson said: to de-rate them by 1.25 and round to nearest size whereas you calculation is higher (1.56). Hi Chris you have answered your own question as to why the factor is 1.56 and not 1.25. Like TTT says it's all in the maths. Standard calculation for a breaker is 1.25, if that is then 'derated' for a solar application by 1.25 the calculation is 1.25*1.25 = ?? The reason that we 'derate' the calculation is that unlike in a normal situation with utility power where the amps with a given power draw can be fairly accurately determined (factor of 1.25) in a solar situation the figures can be a lot more unpredictable. The Isc of a particular panel is measured at STC conditions. Especially here in SA it is not uncommon to have conditions better than STC( standard test conditions) I have seen a 330w rated panel for instance comfortably running at 345w for instance. Hence the industry recommendation of the 1.56 factor for highly variable solar applications.
May 21, 20197 yr 1 hour ago, BDL said: ... for instance comfortably running at 345w for instance ... Ditto. Like my 2.1kw Canadian Kumax array. Have seen on the MPPT like in excess of 2700 watts generated on a good special day. 😜
March 25, 20206 yr Hey it is easy these days. You can do any solar related calculation in seconds with solar calculators. These calculators are available online and help you figure out the cost of solar, the optimum solar system size, the savings from solar and financing/loans related calculations in just seconds.
July 9, 20206 yr @nikki.adra yes but that calculator is localized to India. This here is The South African Solar Investment Calculator
January 29, 20233 yr I’ve got three 320 watt panels. Why do I get the same wattage output from all three in parallel as just two in series?
January 29, 20233 yr 13 minutes ago, Hendrik Viljoen said: I’ve got three 320 watt panels. Why do I get the same wattage output from all three in parallel as just two in series? Thats unusual on face value. But it could very well have something to do with the optimum voltage and current regions that your charge controller operates on. What controller are you using and what is its pv input voltage and max current specifications.? EDIT: and of course what are the voltage and current specs of those panels? Edited January 29, 20233 yr by BritishRacingGreen
January 29, 20233 yr Wild random guess: Axpert MKS 3kVA with a 600W MPPT input? But seriously, as above, please confirm inverter and panel specs. And also confirm the load you're trying to run, because regardless of the amount of panels, the inverter will just produce as much power as is needed and can be used in that moment.
January 29, 20233 yr 58 minutes ago, GreenFields said: Wild random guess: Axpert MKS 3kVA with a 600W MPPT input? But seriously, as above, please confirm inverter and panel specs. And also confirm the load you're trying to run, because regardless of the amount of panels, the inverter will just produce as much power as is needed and can be used in that moment. Inverter MPPT 1600W input 60A charge maximum MPPT Voc 150V. More detail in this topic. Full inverter specs. Very weird to get about the same with the 2 and 3 panel connections. Edited January 29, 20233 yr by Scorp007
January 29, 20233 yr 28 minutes ago, Scorp007 said: Inverter MPPT 1600W input 60A charge maximum MPPT Voc 150V. Charging what type of battery? 2x100Ah AGM in series? Again, random guess.
January 29, 20233 yr 17 minutes ago, GreenFields said: Charging what type of battery? 2x100Ah AGM in series? Again, random guess. I don't think Hendrik mentioned it. Based on the spec sheet a 3kW Sunmagic is only made in 24V. If PV is only used for charging AGM then it could be that the batteries can't accept more charge. If there was a say 500+W load connected and the maximum PV charge is set at say 30A+ then the 3 in series should provide more power provided batteries are well discharged. The devil is in the detail I would guess. Edited January 29, 20233 yr by Scorp007
March 30, 20233 yr So just a quick and maybe stupid question… All things being equal, if you’ve got 8 x 550w panels would that not equate to 4400w which is 4.4kw?
March 30, 20233 yr 2 hours ago, Raiden2912 said: So just a quick and maybe stupid question… All things being equal, if you’ve got 8 x 550w panels would that not equate to 4400w which is 4.4kw? Yes that is correct. Now the but..... We tend to only get 75-80% of it in Gauteng.
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