5 ms·

I have it running in a testing setup for about 2 weeks now. 8 modules flat on the lawn (Maysun glass/glass 410Wp), the battery connected and tied to the grid wi

I have it running in a testing setup for about 2 weeks now. 8 modules flat on the lawn (Maysun glass/glass 410Wp), the battery connected and tied to the grid with export power limited to 0 because my meter is ancient enough to spin in reverse (which is illegal to do here). Which setpoints do you mean? I'm not familiar with all the terms, especially when they vary by manufacturer. If you mean the power limit the Deye should put on the DC bar (i.e. put into the battery), that works reasonably well. If it's at 100% it will still charge a few Watts, but nothing severe. The other meaning I could come up is the target power to draw from the grid when export is disabled (as in my case, for now), or when it is feeding energy from the battery into the house when I draw more than the PV array delivers. That's 20W by default, but can be user configured. This fluctuates somewhat strongly, but overall works out correct. I believe the reason isn't the software, but the poorly routed measurement cables: It uses measuring transfomers and the cables in my setup go tightly and parallel to the power line that connects the inverter to the grid. The electrician said that's not an issue, but I guess he usually measures 50A+, in that case the noise is negligble. Around the 0A point the noise has a much bigger impact. But that's easily fixed. Eventually I'll use that option to prevent the battery from discharging when the car is charging over night (e.g. when I charge with 1200W, I plan to set the target to that value). I'm not sure if I can configure other setpoints, e.g. the MPPT target voltage (which would be a nice trick to get shadow managment). I can define some other things like "from $x a.m. to $y p.m., keep the battery at $z%, grid charging is [not] allowed, powering on the external generator is [not] allowed". For testing the battery balancing (it has an additional Neey active balancer) I used that. And yeah, it can trigger an external 3phase generator to power up (not sure if the 1ph can do that). As far as I could find, all options are exposed via RS485. I adjusted the sunsynk HA addon to work with the newer 3 phase inverters (sunsynk = deye rebrand; changes are already merged upstream). Only thing that I'm missing is the current limit set by the BMS, as well as other BMS data sent to the inverter (I did not search the published register map for that, yet). What I can already say: All in all the technical side is pretty nice; as said in a sibling comment, I could theoretically push out 12kW AC on a single phase if my local load is severly inbalanced. And the MPPTs are pretty flexible in how much power they can accept (as long as the sum is less than 15.6kW at all times). What's horrible is the UI side. Some phrases are highly unclear, and requires knowledge of what the option actually does. E.g. "signal island mode" means "in case of grid failure, tie neutral to PE on the UPS output". In German installations that's always necessary, else RCDs will be much less effective. They would benefit greatly if they had a team of knowledgable translators. Having to ask their support to do an update is also a joke; especially since they don't publish release notes. Also, the update power cycles the inverter, which causes the UPS output to lose power. My 14.3kWh LFP battery has a 200A Seplos BMS. The inverter and the battery talk via CAN. In the BMS the power limit is set to x Amps. But the inverter shows a limit of (x/2) Amps. Now my battery should eventually operate a 140A continuous, but I'm not feeling to well about setting the limit to 280A and one sunny day having the two systems decide to get along and actually push 240A (the Deye's limit) over the connection+BMS sized for "only" 200A. The solution is to get another BMS, but back when we formed the respective group orders, people didn't yet know of this incompatibility. Plus we were focused on Seplos because the Victron users felt it was imporant to get a BMS that would not disconnect the negative bus. Still, for someone looking at a small plant with just a few panels and a small battery, it's a great value preposition. Especially when paired with a different battery/BMS. With the 8 modules behind the house (shadowed in the morning and the late evening) I had 105kWh PV and 120kWh grid power over the last two weeks. That's 1k€ for the modules, 1.3k€ for the smaller 1phase 3.6kW inverter, 1.2k€ for the 3kWh Pylontech US3000C, plus some cables and AC fuses for 200€, plus a DC fuse+SPD box (<100€ if DIY) = 3.8k€ for basic stuff. What's missing is panel mounting (800€?) and, depending on local laws, an electrician to sign off on everything.

jacquesm 3y ago
Dead thread comment: I just scored a 17 KW Solax inverter on the local ebay equivalent for $500, 4 strings, 2 MPPT, super happy :)
jacquesm 4y ago
12KW on a single phase is really not what you want to do though, that works out to 50A which is likely more than your distribution panel is wired for, usually they are good up to 40A and 50A for a couple of seconds but more than that and you are inviting blowing up the utility side fuses. You will also need pretty beefy cable to be able to run that kind of current, 6 mm^2 ~30A, 10 mm^2 ~40 and 16 mm^2 ~55. Unless you want to run your cable really hot, which I would not recommend. Also, you will have to beef up the wiring in your distribution panel, the utility side fuse (which normally is 3x25 or 3x35, rarely 3x50 though it is possible but will require fatter bus bars and special breakers as well). Much better to divide the power over your phases. That way you can run 12KW on 3x2.5 mm^2. The setpoints I am struggling with are the difference between for instance the voltage at the inverter versus the voltage at the distribution panel, when pushing a mere 5KW into the grid from the upstairs inverter that raises the voltage enough that the inverter will trip. This is not due to the usual suspects (faulty wiring, loose contacts) but simply because of the length of the feedline to the attic and the fact that it is 2.5 mm square tri phase cabling, which has a 4V voltage drop over that length and there is absolutely no way to compensate for that. Highly frustrating. Other interesting set points would be to be able to de-rate the inverter and to be able to get it to shut down faster once the sun has gone under. That's really good value for the money what you've got there. My setup is a bit more expensive than yours but it also makes a lot more power (as it should :) ), I've spent a lot of time on getting it all set up properly for the summer. The biggest problem remaining (and that I won't be able to fix) is that I can't angle the panels on the low roof properly because that would upset my neighbors so they are at a very shallow angle, just enough to the get the water to run off them but even then at the edge of the panels in the 'down' direction there is a little area of about 5 cm where water pools long enough for algae to grow. So I will have to clean these quite frequently. Maybe I'll figure out a way to deal with that but so far nothing that really worked well. A steeper angle would require a higher starting point or a lower ending point, neither of which are feasible. The real pay-off is in March/April and September/October when we will save substantially on gas by heating using an air/air heatpump with a COP of about 3 to 3.5 at the temperatures at that time of the year. That should put a sizeable dent in the energy costs.

jacquesm 3y ago

Dead thread comment: I just scored a 17 KW Solax inverter on the local ebay equivalent for $500, 4 strings, 2 MPPT, super happy :)

jacquesm 4y ago

12KW on a single phase is really not what you want to do though, that works out to 50A which is likely more than your distribution panel is wired for, usually they are good up to 40A and 50A for a couple of seconds but more than that and you are inviting blowing up the utility side fuses. You will also need pretty beefy cable to be able to run that kind of current, 6 mm^2 ~30A, 10 mm^2 ~40 and 16 mm^2 ~55. Unless you want to run your cable really hot, which I would not recommend. Also, you will have to beef up the wiring in your distribution panel, the utility side fuse (which normally is 3x25 or 3x35, rarely 3x50 though it is possible but will require fatter bus bars and special breakers as well). Much better to divide the power over your phases. That way you can run 12KW on 3x2.5 mm^2. The setpoints I am struggling with are the difference between for instance the voltage at the inverter versus the voltage at the distribution panel, when pushing a mere 5KW into the grid from the upstairs inverter that raises the voltage enough that the inverter will trip. This is not due to the usual suspects (faulty wiring, loose contacts) but simply because of the length of the feedline to the attic and the fact that it is 2.5 mm square tri phase cabling, which has a 4V voltage drop over that length and there is absolutely no way to compensate for that. Highly frustrating. Other interesting set points would be to be able to de-rate the inverter and to be able to get it to shut down faster once the sun has gone under. That's really good value for the money what you've got there. My setup is a bit more expensive than yours but it also makes a lot more power (as it should :) ), I've spent a lot of time on getting it all set up properly for the summer. The biggest problem remaining (and that I won't be able to fix) is that I can't angle the panels on the low roof properly because that would upset my neighbors so they are at a very shallow angle, just enough to the get the water to run off them but even then at the edge of the panels in the 'down' direction there is a little area of about 5 cm where water pools long enough for algae to grow. So I will have to clean these quite frequently. Maybe I'll figure out a way to deal with that but so far nothing that really worked well. A steeper angle would require a higher starting point or a lower ending point, neither of which are feasible. The real pay-off is in March/April and September/October when we will save substantially on gas by heating using an air/air heatpump with a COP of about 3 to 3.5 at the temperatures at that time of the year. That should put a sizeable dent in the energy costs.