PJJ

Now that is Savage! I'll see myself to the punitentiary

You should! You could also even cover the potential role we solar + storage folks can play in helping with grid services

Sorry if it wasn't clear in my post, but that is exactly what I tried to illustrate, its not the capacity of a single home that is the problem, its this added load that potentially thousands of inverters could all add to the grid following a loadshedding event, on top of the already big strain the system would face from just geysers/fridges etc all kicking in as well.

Well you could but you won't, because your demand would be whatever it was before. (predating your install) In the install that I mentioned earlier where the AC Input limit works so great, that house never had a event where the main breaker tripped due to drawing too much power. But after the install, maxing the 70A charger of the 5kVA Multi you will see that your grid power draw now goes up by a additional 3.7KW+- because of the AC Charger. Now multiply that by potentially thousands of homes and you will see that you might have a peak demand problem right after a loadshedding event.

I don't think people realize how much 3.5KW is, its plenty, I ran all my house lights, networking equipment, TV, 1 PC and fridge on a 800VA Multi for 2 months with no issues. Of course I made sure the killers (Microwave / Kettle / Hairdryers) where kept away, but I guess one man's non-critical load is another man's critical

Its also VERY useful in preventing you from accidentally tripping your mains supply in a house with big loads and charging batteries after a grid outage. We have one farm house with 2x Big geysers elements multiple aircons, swimming pool pump etc, and watching the Multi throttle its AC charger to ensure it keeps within the AC input Limits (Or even take power from the DC bus with power assist) is a thing of beauty!

Its only on the AC Input side, as stated above, once you are islanded the sky is the limit.

It definitely is. As the saying goes: Everyday I know more and more about less and less. Edit: I just realized now, I only mentioned the Mandelbrot set, the video covered : the logistic with its connections to fluid convection and neuron firing, definitely worth a watch.

THE SIMULATION IS REAL Veritasium did a excellent video recently about the Mandelbrot set, and it blew my mind.

I guess you could also ad a 4) Keeping capacity spare in case of a unplanned unit trip, preventing entire grid collapse.

I see a similar problem already with water. If like me, you happen to live in a high laying area, pumps are also used to keep your taps at pressure, of course our municipality is so bad at maintaining this pump that for the past 3 years (I have only lived here for 3 years) its steadily gotten worse we now only have water for around 6 hours a day, and some days not at all. (Our record last year over December was 8 days!) So everyone in my neighborhood does have a 5000L holding tank to carry us through. (See our tanks as batteries and the Municipal pumps as the grid) Instead of the municipal pump coming on and only getting everyone's homes back to pressure, we are all putting massive strain on it by refilling our tanks (I mean we are not going to go without water), so when it is actually working it is being pushed to 100% capacity for hours, and so the vicious cycle repeats.

That is why I said: They are the only true Hybrid inverters in the Voltronic range. I think I just chopped my sentences badly there, I wanted to point out, that even tough the Voltronic models all have MPPT's as well, all wrapped into one package, it does not make them Hybrid inverters. (Excluding the King and Infinisolar models)

Grid tie inverters do AC-Coupling, so they need a sinewave to couple to, thus no mains no generation or backup (They can however be used downstream from a inverter that can provide it with a sinewave to couple to, they do this with frequency shifting) Well not necessarily, Off grid could also mean, no AC Input, since its "Off grid" meaning no AC power close by. E.g (Victron Phoenix inverters, they could be seen as "Off grid" inverters) Here is where I think the misunderstanding comes in, a Hybrid inverter isn't necessarily a all-in-one solution, its a inverter, that has the ability to blend power from a DC bus with AC to supply a load, the fact that a Goodwe unit happens to ship with a MPPT doesn't make it a Hybrid, Voltronic units (Baring the King and Infinisolar models) all ship with MPPT units built in, but they can't be seen as Hybrids because they can either supply power from Only the DC bus or Only grid power, they have no ability to blend power.

Yup, Peukert, inverter and battery losses are often not taken into account, and also very often omitted is inverter self consumption, which can also be quite a load on some models.

Ryan if I where you I would buy a single US3000 now. In terms of price it would be the same as the 48V 200Ah Lead acid bank (It might even be cheaper when you consider the added components like Balancers and a BMV) Drop the Aircon for now, keep powering your other loads, where a single US3000 would be more than sufficient. Save up and when you buy your second module you can add the aircon back into the mix. If you do 50% DOD cycles I can't think of many LA banks that would give you more than 700-1000 cycles with that usage. Seeing as a loadshedding event could = 1 cycle (Not a guarantee of course single load shedding could happen while you don't have high loads actually taking it down to 50%) If we go with the conservative estimate of 700 cycles at 50% DOD, if we had daily stage 1 load shedding, your bank would need to be retired after only 2 years. Sure daily loadshedding for 2 years on end might not seem likely now, but its entirely a possibility.

If you tally up the other losses: 2.1KW AC = 2.3KW On the DC bus (92% inverter efficiency) and 2.7KW from the battery (At 85% battery efficiency) So that's 5.4kWh Also discharging at that steep a rate (4 hour rate essentially) will mean his batteries won't be 200Ah, more like 150Ah-180Ah. Unless of course they are rated at 200Ah at a 4 hour rate, but most of the batteries I have looked at are rated over 10 hours, and the real cheats give 100 hour discharge ratings.

Ahh yes, those one movie wonders, like Ghostbusters

I ruined my wife's day once when I informed her that Celine Dion: All By Myself Is actually from Eric Carmen.

Yes, at R6/kWh it really would be a very easy decision. I would actually not mind a TOU tariff, it would send the right market signals to end users that electricity is scare at certain periods of the day and abundant in others, this would allow for a much better use of resources I think.

I think the only area where solar really is financially viable as a cost saving measure is big grid tie systems with no backup. But for Storage + PV I know my back of the envelope math puts its around R2.8 per kWh over the lifetime of the plant. So should you ever have to pay a constant price over R2.8 kWh then its financially viable from day one. (Financing costs dependent of course) But I think most of us on here don't even lie to ourselves, the financial savings are a bonus, the real reward is in the security of supply that we have.

It depends on your plan. Mine starts at a mere 90c for the first 50kWh, then picks up to R1.38 per kWh then on the R2.2 we go, and should you be so unlucky as to hit the high tier usage bracket, hello R2.8 per kWh

Where do you live Danie?

I have no problem with a installer adding a little extra margin on the hardware cost, prices can change overnight, there are shipping costs, admin costs etc. But there is a line. Adding 40-50% markup on hardware while charging a massive installation fee I think goes over that line. Not all installers are guilty of course, many charge fair prices and do great work. But as with every corner in life, there are guys looking to make a quick buck.

Yup.

I also don't really have a barometer as to how much a UPS only install would cost, but probably not a lot, from a additional hardware point: You would need battery fuses and a disconnect the size would depend on which inverter you go with, lets be safe and add R800 for that. The Pylon Cable pack is R350, So that should be your battery cable sorted. Then there would be additional AC components needed which I also don't know at what cost. No advantage really, in fact its actually a bit gutted in the sense that it doesn't have a CAN interface, so you just run it till the BMS turns it off. The only reason why I suggested it is because its the only 24V Pylon available, it also has around 400Wh more nominal energy than the US2000