frivan

Most definitely you can do it. Will you get a CoC (electric and gas) for it, not sure. Will it blow up, probably only if you go from 0 to 75 degrees inlet water quickly.
I don't have the manual, but check if there are high inlet temperature trips. Otherwise you must devise an electric cut-out for the gas heater if the electric geyser temperature is too high.

I like it. Was wondering if a couple of 50mm holes through the wall will work for the external box... But screw it, dig up the floor!

I will give you the short version:
The more warm water you use, the more energy you use. The warmer the water in the geyser, the more losses you add to your system. Controlling time is a poor way of controlling hot water temperature and quantity in the geyser. Geyserwise and some smart thermostats measure water temperature inside the geyser.
In your situation, you should consider what you can hide from the landlord. I suggest installing an Elon thermostat:
ELON SMART WATER THERMOSTAT https://leroymerlin.co.za/elon-smart-water-thermostat-81504247?sfdr_ptcid=32806_617_759128507&sfdr_hash=7335bbd6c20f0137a8f17f884afc1515&gad_source=1&gad_campaignid=17335597113&gclid=CjwKCAjw0o3SBhBVEiwAh28-jSaEDa18r5LEgEY0IkANeWI_WTyUOj0ZvL4DGkbWcgE9jZvnfXWOXhoCy1UQAvD_BwE

Add two more panels on the eastern side of the smaller roofs, try vertical panels, drill holes in the trees and pour in diesel... Lots of options.

My solar system has an IRR around 23%. I added a second battery which has an IRR of about 18%. However, winter in Cape Town is not the period when the equipment performs.
Any IRR above inflation is good but the higher the IRR, the more pain for Eskom. A solar panel can theoretically give 200% IRR.
This father's day, spoil someone you love with the gift that keeps giving: a PV panel.

If you add a changeover switch (and disconnect the Solis), why isn't it a long term solution?

A cheap system could set their 0% where others call it 20%. But then you would see poor energy per weight figures.
Sungrow is a reputable player in the grid scale environment, I would buy their equipment.

Once you invest in solar, you want to maximise use of the solar system under normal conditions: use it for the geyser, cooking, etc. I like induction plates because they are very responsive.
When the grid is out, you want to minimise draining batteries and then gas heating comes in handy. I use a Cadac cylinder if needed. I doubt if gas heating beats electrical heating on a price basis.

Once you invest in solar, you want to maximise use of the solar system under normal conditions: use it for the geyser, cooking, etc. I like induction plates because they are very responsive.
When the grid is out, you want to minimise draining batteries and then gas heating comes in handy. I use a Cadac cylinder if needed. I doubt if gas heating beats electrical heating on a price basis.

I am using the R3 to switch the old 20A relay.
The Geyserwise main unit would probably be installed at the geyser. But running a small wire for the display is not so bad. Financially the Geyserwise and Geyserwala is not better than my solution, specifically because I had some of the components already.

I would use the generator just to charge the battery. You could get a dedicated charger, a chargeverter or rectify the generator output onto a MPPT (unconventional). All of these would probably work better with a traditional alternator.

Why can't you utilise the Eskom supply to operate a relay/NEB?

Well, at least it's not completely wasted - I'm sharing it with her daughter 😁😂🤣

I have had about R36k savings in two years. October last year I added a second 5kWh battery. This saved me about R300 per month in the summer months. Looks like the sun is running out now in April. Below is last year's generation.

The issue is that Eskom is supposed to be only one of the generators and distributors in the country. And while they are against home solar, municipalities don't care. Municipalities are supposed to manage their electrical networks and collect revenue but most are like Stoffel the badger.

In fact, I even do it with indoor lamps if I am too lazy to replace the wholeder:

Run the inverter off-grid and disconnected from the grid-earth until the grid neutral to grid earth voltage is basically zero.

Agreed, just sad that we can't do the right things first. So, people who can will go off-grid, others will suffer and eventually the distributors will come to off-grid customers and beg them to be connected.

Good information in the reply above. I would like to point out that the distance between positive and negative wires can act like an antenna for nearby strikes. The biggest risk area would be under your PV panels. If your positive and negative cables aren't running together in this area, ask how big your antenna is.

Good information in the reply above. I would like to point out that the distance between positive and negative wires can act like an antenna for nearby strikes. The biggest risk area would be under your PV panels. If your positive and negative cables aren't running together in this area, ask how big your antenna is.

I don't know the Deye menu system, but probably not. If that is the export limit of your solar, that is all the inverter is rated to transfer from DC to AC. The DC to DC charging of the battery should allow you to use more of the solar than the 5kW limit.

No, you need to run identical inverters in parallel.
Buying a hybrid inverter and not using with a battery is a waste of money. If you couple both inverters to the batteries, you will have double the losses/own consumption.

A Solis grid tie inverter on the Aux port with frequency control is better than a standalone MPPT.

No, you need to run identical inverters in parallel.
Buying a hybrid inverter and not using with a battery is a waste of money. If you couple both inverters to the batteries, you will have double the losses/own consumption.

Make up a long jumper lead (bridge 4 panels) and test various 4S configurations.