Paulcupine

Would be useful to know where they are... shipping them would be expensive.

I have to ask why you're heating water at 10pm... is someone bathing/showering at midnight? You have excess solar available during the day that isn't being harvested. You will be better off if you can move some of that night time water heating to the day time. The alternative is to get a bigger battery, but that isn't nearly as cost effective. EDIT: I see you're only using half your battery. There is no load shedding at the moment... why not allow the battery to cycle down to 10%?

Sheesh - how many people are taking long luxurious showers in your house? Your water bill must be face-melting. We are a household of 4 and use electric geyser for about 8 months of the year (free off PV), and gas geyser for about 4 months a year. In those four months we use about one and a half 19kg cylinders of gas. Also, the national retail price for LPG is currently R33/kg. How are you getting 19kg cylinders for R290?

Those GRID tick boxes do not mean "USE GRID", they mean "CHARGE FROM GRID IF THE SoC is below the configured value". The rows marked 100% are not going to take the battery to 100% if there isn't enough solar.

Crying in Capetonian @ R3.91/kWh, and R4.75/kWh after the first 600kWh Luckily I only bought 800kWh in the last 12 months.

Actually switching off things like game consoles and media PCs can make a significant difference overnight. I can always tell when the kids have been up late playing games. "Base" load goes from 200-300W to 500-600W. It's also interesting to see how the duty cycle on things like fridges and freezers is reduced in the winter. The 5 or 6C lower ambient temperature in the house makes quite a difference. My full height fridge and freezer use about 1.5kWh/day in summer but only around 1.1kWh/day in the winter. Of course, you lose again on water heating in the winter. Input water temperature is much lower especially around late July/August, so energy spent heating the geyser is much more.

I agree. Battery prices have come down and these are nearly "half" used. Seems like they should be going for under R10k each, all things considered.

My geyser had a 4kW element which I downgraded to 2kW. It now runs anywhere from 2 to 5 hours depending on how cold the water is to get fully hot, so interpolate for less PV available. Imho, 1kW is too little. Since I upgraded my solar I'm actually thinking of upgrading it back to 3kW.

On Paloma gas geysers you can set the water output temeperature and it regulates the flame size automatically. I feed mine with water preheated in the electric geyser with whatever PV I have available. The result is that a 19kg gas cylinder lasts us around 120 - 160 days. There is enough PV for me to bypass the gas geyser entirely for about 8 months of the year. I therefore only need to buy one 19kg gas refill per year about.

Cycling from 100% -> 10% -> 100% is totally fine. The Freedom Won warranty is reduced from 10 years to 5 years if you *regularly* discharge below 10%, as an example. On the other hand there is little point in cycling your battery lower then you have the ability to charge it with solar the next day. Also, degradation of the battery happens just as much at high cell voltages as low ones. Go and watch some of Off Grid Garage's battery testing videos on youtube. This guy makes excellent content.

Nobody?

It wasn't quite as bad in our house but the filling of a 2L kettle everytime to make one cup of coffee made me go out and buy a 1L camping kettle. It also has a smaller element, so now nobody is willing to wait for it if it is full. Problem solved, and the cleaner got the old one for free.

SUN2000G3-EU-230 were available on takealot a while back at under R7k. They are no longer listed and the other listings I can find in South Africa are all around the R10k mark. On aliexpress they are R5k. Where can one find these locally at a more reasonable price?

They're not strictly single use. These devices can typically take several (even many) small surges by becoming conductive L/N -> E, but will pop if a single significantly large surge occurs. The indicator should then go red and the unit needs to be replaced. This looks like a 3 phase setup..? I do not know if it is ok to connect on of your phases to a neutral on the SPD. AFAIK there are 3 phase SPDs for the purpose.

Type II SPDs have a varistor that becomes conductive above a certain voltage. It basically shorts the live to neutral if the voltage is exceeded. Depending on the size and duration of the surge, the device could survive many incidents if none of them are big enough to fry the SPD. However, since the SPD is not in line with the loads, if the SPD fails only your protection goes away - your power to your loads is not cut. Since you may not know that there has been an incident, you need to check the SPDs regularly. Most have some sort of indicator of whether they are still working. Type I SPDs use a gas capsule, which again can survive many small incidents but would need replacement of the gas capsule for a bigger strike. I'm reasonably sure these are inline with loads, so if the SPD fails you have no power. Needs verification however.