June 4, 20206 yr Hello Everyone, Please help me to decide on the correct PV array to inverter ratio. I will be installing a 5kW inverter with hopefully 17.5kWh battery system, now the question is how many solar panes should I install to get the best output from my inverter. I have heard that running close to the invert's max output will result in the most efficient energy output but that you also need to account for losses of about 30% of the watts produced by the panels due to environmental and other factors. I have also heard that it is not recommended to go with a ratio above 1.55 and that some warranties may be invalidated due to an incorrect ratio. Assuming that I will be using 410w panels (probably from Canadian Solar), should I go with enough panels to get a 1.48 ratio? That is 18 panels, 8 would be North facing and 10 would be East facing with a roof pitch at 30 degrees. TIA!
June 4, 20206 yr 1 hour ago, NC20 said: Please help me to decide on the correct PV array to inverter ratio. I will be installing a 5kW inverter with hopefully 17.5kWh battery system, now the question is how many solar panes should I install to get the best output from my inverter. We will need to know the inverter make as well as model number to be able to help you here, the MPPT's rating will determine the size of the array, not the size of the inverter.
June 4, 20206 yr Author 1 hour ago, Jaco de Jongh said: We will need to know the inverter make as well as model number to be able to help you here, the MPPT's rating will determine the size of the array, not the size of the inverter. My first choice is the Sunsynk 5kW hybrid inverter 48v IP65. The product code on Ellies site is FBIHSK5K48. 1FBIHSK5K48.pdf
June 4, 20206 yr 33 minutes ago, NC20 said: My first choice is the Sunsynk 5kW hybrid inverter 48v IP65. The product code on Ellies site is FBIHSK5K48. 1FBIHSK5K48.pdf 860.6 kB · 1 download According to that sheet the max pv power you can connect is 5500whp....
June 5, 20206 yr 12 hours ago, Jaco de Jongh said: We will need to know the inverter make as well as model number to be able to help you here, the MPPT's rating will determine the size of the array, not the size of the inverter. True, but the battery chemistry, the battery capacity, and the topology of the MPPT/inverter also play a role. Eg on the Victron setups, as well as the Axpert types where the MPPT is brought in on the low DC bus, you should size the PV according to the battery size as well. With that Sunsynk, I see the PV input is up to 500V, which indicates that the PV is brought into the high-voltage DC bus, so the battery capacity would not matter that much. I'm just mentioning this because he said that is the "first choice", that is, there may be others... 🙂
June 5, 20206 yr 4 hours ago, plonkster said: True, but the battery chemistry, the battery capacity, and the topology of the MPPT/inverter also play a role. Eg on the Victron setups, as well as the Axpert types where the MPPT is brought in on the low DC bus, you should size the PV according to the battery size as well. And the load during the night and the allowed charging amps and and and. There are so many variables you have to consider, but with any unit with a build in MPPT. the data sheet will tell you the max array size. With Victron of course with its external MPPT's you will have a lot more freedom, you can add enough PV to satisfy your daytime loads and then and enough Panels to charge any size back-up bank you can think of, freedom most other inverters cant offer. So my thinking was, find out what inverter it was, and then decide what to advice, with the planned 17.5 kwh battery bank, I stuck to the allowed 5500whp on the Data sheet, as the OP will need it to carry daytime loads and recharge a bank like that.
June 5, 20206 yr 21 hours ago, NC20 said: Assuming that I will be using 410w panels (probably from Canadian Solar), should I go with enough panels to get a 1.48 ratio? That is 18 panels, 8 would be North facing and 10 would be East facing with a roof pitch at 30 degrees. Layman's 2c. Don't quote me, use at own risk, do your own research, own calculations, and make own decision. As said, go by the inverter's PV input ratings.Assuming you can only fit 8 panels North-facing on the 1st MPPT, that covers 3280W of available capacity. That leaves 5500W-3280W=2220W for the East-facing panels on the 2nd MPPT. Theoretically 5.4 panels. These would never see full 90-degree incidence of light because at mid-day when the sun's rays are coming in most directly at their highest power, the panels are angled away from that light. Some articles attached so you could form an idea of how much power you may be losing through that mounting angle, but it's nothing like a 1.48 ratio. If it's say 10-15% power reduction for panels facing directly East, you could fit perhaps 6 panels, or 2460W of rated power of panels, but expect no more than 2220W to ever reach the inverter. https://www.mpptsolar.com/en/best-angle-for-solar-panels.html https://energyeducation.ca/encyclopedia/Solar_panel_orientation https://www.cedgreentech.com/article/calculating-your-optimal-azimuth-angle https://www.wholesalesolar.com/blog/solar-panel-azimuth-angle
June 5, 20206 yr 22 hours ago, Jaco de Jongh said: According to that sheet the max pv power you can connect is 5500whp.... Hi NC20, I have this inverter purchased from Ellies. Just FYI mine states maximum PV array power is 6500W and max PV volts 500V. I think their spec sheet may need updating. Battery charge and discharge at 120A. I have pasted the info sticker stuck on my inverter below.
June 7, 20206 yr Author Hi! Thank for the info! If i can ask, what has your experience been with the Sunsynk inverter? Thanks
June 8, 20206 yr Hi NC 20. Initially I did not have a great time with the inverter but this was due to a tricky wiring fault in my house that took ages to diagnose, find and resolve. If you are splitting your circuits into essentials and non-essentials with inverter taking care of essentials loads only, any common neutrals and or earth faults not on earth leakage (lighting etc) can cause havoc with the way the inverter measures power. Once that was fixed the inverter works a charm. The devices are fantastic but there is still a steep learning curve with regard to technical advice and after sales service from the suppliers and installers. Edited June 8, 20206 yr by Halcyon
June 8, 20206 yr The specs for the Ellies / sunsync inverter are very close to the Goodwe 5048. The only advantage of the Sunsync is that it can be paralleled.. What else is there pushing the Sunsync vs the Goodwe? If there are support issues and battery compatibility issues with the Sunsync, why not just go the Goodwe route? I'm only asking because I looked at the 8kW sunsync and since it was an 8kW unit I would prefer it over the Goodwe 5kW unit.
June 8, 20206 yr 53 minutes ago, FixAMess said: , why not just go the Goodwe route? No ... go blue. lol
June 8, 20206 yr I think where the 5kw Sunsynk pips the Goodwee on features is a higher backup power rating of 5000W continuous and 10 000w for 10 sec. Colour touch screen. 120A battery charge and discharge. Extra auxiliary port which can take a generator input with auto start. Same port can be AC coupled with a grid tied/micro inverter. MPPt to control wind turbine and the parallel setup. The software can control an earth bond relay from a function port, which to my knowledge a Goodwee cannot do at present? The Goodwee is Super silent as it has no fan and their app interface looks a bit better. Is the Goodwee support good? I have heard of a lot of issues as well.
June 9, 20206 yr 18 hours ago, Halcyon said: I think where the 5kw Sunsynk pips the Goodwee on features is a higher backup power rating of 5000W continuous and 10 000w for 10 sec. Colour touch screen. 120A battery charge and discharge. Extra auxiliary port which can take a generator input with auto start. Same port can be AC coupled with a grid tied/micro inverter. MPPt to control wind turbine and the parallel setup. The software can control an earth bond relay from a function port, which to my knowledge a Goodwee cannot do at present? The Goodwee is Super silent as it has no fan and their app interface looks a bit better. Is the Goodwee support good? I have heard of a lot of issues as well. On the Goodwe the max charge current is 100A but then again just how much does one need for a household system? There are no other inputs, generator etc.. The sunsync is technically a very well specced and capable system, but it lacks good a good support base..(This is from what Ive read, it may not be correct) but if i were to go off grid then i'd rather take the sunsynk because of the generator input and larger panel power rating..
July 3, 20206 yr If i do not need a battery bank. What would you recommend for a grid tied Inveter to support my PV array
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