LehloPI

Good Afternoon All I apologise in advance for the long essay but I find that I'm in need of unbiased information- both to use in my research work and to decide on a solar installation for my home. We are currently wired for 3-phase and are direct customers with Eskom. We are looking for a hybrid solar solution that has us generating as much of our own power as possible. The main stumbling block at the moment is how best to deal with the 3 phase wiring. A number of solar installers have done an inspection of our DB configuration and I am getting conflicting opinions. Opinion A- Install a 3-phase hybrid inverter (This would be the 12KW Deye although I am interested in the 10KW Goodwe as an alternative as we are not a big household). Opinion B- Install a single phase hybrid inverter per phase at leisure until all three phases are connected to a solar inverter. Solar installer pushing Option A discourages Option B by saying that the inverters are not meant to operate in parallel like this (this is my first point of skepticism because the Deye/Sunsynk specifications state they support parallel operation and I have seen multiple three phase solar installations in SA which have been done with an inverter per phase) and that they would be more prone to blowing as the voltage/current rises would be unbalanced between the inverters and because of the lower tolerances built into the single phase inverters. Solar installer pushing Option A also states that the minimum voltage running in a 3-phase house is around 380V with a higher amperage while single phase inverters max out at around 18A and 230-240V. Also presented by solar installer is that with an inverter per phase, one cannot run appliances such as microwave, kettle, geyser, stove etc. because of the higher kw/h usage (this is my second point of skepticism because if the house was single phase and installed with a single phase inverter, these appliances have been slated to be able to run no problem bar the stove as it has a heating element). Also, each inverter would need its own independent battery backup, solar panels etc. so it's like installing three separate solar installations Solar installer pushing Option B discourages Option A by saying that by installing the single 3-phase inverter, there is no redundancy/backup built into the system. If that inverter blows, then the whole solar system is down (and the inverter is very difficult to get repaired/replaced even with a warranty) whereas if one inverter on the parallel install blows, then the other two inverters are able to continue providing solar supply while the dead one is either repaired or replaced. This also then gives us more options for inverters whereas the 3-phase hybrid inverter market in SA has very few options. It also allows the solar install to grow as budget becomes available or as we see our needs change. There is also the problem of the 3-phase Deye/Sunsynk inverters running hot and noisy- which then requires them to have a fair degree of ventilation to assist that fan in maintaining the cooling of the inverter. This option however will require the DB board to be rewired and split according (but a rewiring may need to happen anyway for other unrelated reasons). I have a little bit of background in electrical engineering as part of my profession so I see the points that both installers are making but I don't have sufficient knowledge on (a) power engineering and (b) solar specifications to be able to say confidently one way or the other which opinion is the most correct and the one we should go with even with the research I've done and continue to do. So I come to the court of public option to ask people who may have real world experience- what were your experiences with Option A or B, the pros and cons, and what you would recommend as the best way forward. This information will also inform the direction of some of the research work I am conducting. Thank you so much for your assistance in advanced