i need you ideas on how to wire all my Solarpanels to the EP2000.
I have the following PV arrays:
Array 1: 10 Solarpanels in series, each 37,21Voc und 13,59 A Isc, heading south
Array 2: 4 Solarpanels in series, each 43,87Voc und 16,39A isc, heading south
Array 3: 4 Solarpanels in series, each 43,87Voc und 16,39A isc, heading southeast
The EP2000 have 4 PV Inputs with 2 MPPTs.
PV 1 + PV 2 = MPPT 1 and PV 3 + PV 4 =MPPT 2.
Each PV Input can take 20A, one MPPT can handle 30A, needs atleast 160V per MPPT to start.
When only using Array 1 and Array 2, the Bluetti App team recommend to connect Array 1 to PV1 and Array 2 to PV3 to maximize performence (each Array its own MPPT).
You guys have a idea how to bring all three Arrays together?
Thanks
Erik
Assume your 700ish watt panel (43.87V/16.39A) produces 25V when the Sun is low in the horizon or conditions are extremely shaded. You would need a minimum of 7 panels (6X25=150V or NOT ENOUGH) to produce power. So I’m thinking a load balancing of 10 panels on MPPT #1 and 8 panels on MPPT #2 would be ideal.
Hello Erik, I’ll write just a few personal considerations.
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First note that the SCC accepted voltage is always a curve where voltage and current at some point intersect, at 160 V even if the SCC will start producing it will never be efficient and will never raise to maximum current, so you would need to increase the array average voltage.
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Both EP2000 SCC can work at its maximum power at around between 500 and 800 volt, in your case you can reach around 350 volt with both sets of panels and a series configuration which I think is enough to make sure Isc which is about 50% of maximum SCC input will be reached on sunny days.
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Also take note that at winter the temperature and irradiation changes, so you would always benefit of an increased VoC.
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MPPT 1:
PV1: with the 10S array you have 372.1 VoC and 13.59 Isc
PV2: empty
MPPT 2:
PV3: with the 8S array you have 350.96 VoC and 16.39 Isc
PV4: empty
This is the configuration I would use.
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By having 10 and 8 panels in series your maximum priority will be to avoid any panel to get shadowed by something during the full solar transit. This to avoid production to be severely limited by the lowest irradiated panel which will limit current flowing through the series.
I have 3 series on the EP760 of 9, 6 and 6 panels and I needed to cleanup the garden a bit to make sure they will be always fully uniformely irradiated.
Thanks @ndwr for your long answer. Im aware that 160V is only the start voltage to “just work”. The EP2000 is such a big system, that i never reach its full input potencial anyway. But thanks for the reminder!
I hear your suggestion now a few times, but indeed i could have a problem with shadows. Array 2 is located on a Garage roof, perfectly aligned for south sun and Array 3 nearly dont have any angle (laying flat) and heading like southeast. This means Array 2 take full benefit in the Midday sun while Array 3 catch the Morning sun. The more extent each other than work together.
I think about adding PV optimizers, to eliminate the different power output. But 8 optimizers arent exactly that cheap.
They will install it mid august, guess i just need to try.
I understand, so the 2 groups of 4 are aligned very differently, in that case trying a 4S on PV3 and 4S on PV4 with 175.48 VoC can be interesting to understand the actual results but I think you should seriously start thinking on how you can increase your VoC in the future to make the most out of the SCC.
Anyway you chose very interesting panels for your array 2 and 3.
Yeah, the problem is i have very limited space and my roof point to NW. Really bad for solar. I will try some setups. Really thankful for your insights!
PV Optimizers are pointless on modern panels. They were mostly beneficial to older panels that don’t have bypass diodes. You may see some marginal gain from an optimizer if you have an array or string of panels pointed in different directions. Another thought consideration is HEAT. How long will they last when mounted in a harsh environment like the top of your roof? Micro inverters are expensive but are not prone to a single point of failure, unlike PV optimizers or string inverters.
