Vish999

Hi Vish999
Is the bill only for electricity, or is it the whole bill?
There is a way to check your electricity usage. You would need to install a CT (current transformer) on the live wire of the 60A isolation switch in your DB or a Meter fitted in your DB.
Many devices come with a CT, and that can be connected to the web. With this, you can monitor your electricity usage. compared to your bill. Just remember, the bill might not cover the entire month from the 1st to the end.
If you leave the element off for most of the day and at night, it can take up to 3 hours to heat a geyser in Winter to 65 degrees in the morning.
The cost would be about 3KW X 3HR X 30 Days X R4/Unit = R1080.00 a month, including VAT, only for the geyser element if you only heat for 3 hours a day.
It will cost you about R80.00 a month if you boil your kettle (5 minutes) 4 times a day. 0.083 X 4 X 30 X 2KW X R4/unit
If you have an electric oven and use it, it will also contribute to the electricity usage.
The 12VDC 60W solar pump. If on for 8 hours a day. 8 X .06Kw X 30 days X R4/unit=R57.60 a month.

Awesome solution (SONOFF Devices are my goto-home automation solutions), bit pricey though in SA.
I have recently purchased my 1st spm main and spm4relay
Will be redoing my whole main DB with more spm4relay modules, goal is to have every main circuit running through the relays for fine grained control and of course the power measurement functionality
Bonus tasmota compatible So can fully integrate into my custom nodered data flows and thingsboard portal

The problem with measuring the whole DB means the results does not help much as you need to measure the loads that would be powered from the inverter. Having said that you can isolate/switch off the loads that won't be on the inverter and thus measure at one point the power used by the items you listed.
Also a problem as you cannot get their reading over a 24hr cycle unless you take each one item's reading and record how many hours you would like to use it per LS cycle. TV for most households is the LS period. My house it is zero as we stream on phone or laptop.
The easy way is recording each items use on a spreadsheet and the hours of use to be able to tally up.

Hi, Sonoff SPM and SPM4RELAY can be installed in DB they have 4 x 20  amp channels that can monitor power. Ewelink app which is the default Sonoff app now has a power dashboard so you can track usage. Its not as simple as a clamp type solution but it gives you the ability to switch of loads during loadsheading. Generally you need a additional board because they are big device's. They work well and have overload protection. If you dont need the ability to switch off loads the clamp type solution is much easier for monitoring only.

Rent/Borrow/Buy a Kill-a-watt meter to get an exact consumption figure for all of those,that way you can get an educated recommendation for batteries

You can also get a Sonoff Pow2 or pow3. This measure as per the pic displayed on my cell via the APP. Although it records the use in 24hrs per the bars one can also use the USE value and deduct the initial reading from the one after say 1 HOUR to get the consumption. It stores for 100 days and can be downloaded as CSV. It can then double up as a multi function timer. I built mine in a box next to a 3 pin socket.
 

Lithium for best value over time if you have the capital to buy initially
 
There are Smart-breakers that can go into your DB to get an overview yes

Yes the CBI Astute does the same as Sonoff but can measure 60A vs the 10A or 15A of the Sonoff.
There are other brands as well being called Smart switch/circuit breaker/isolator.