1. Separate circuits in a new DB
2. install a bypass/change over switch( less hassle when things go wrong)
3. Lithium & inverter combination - choose carefully. Not all inverters can communicate with the lithium BMS(battery management system) Goodwe 4.6kw is set up for a few different brands of lithium batteries. I recommend it highly. Not lots to tinker with. You can use the app....very simple.
Off grid inverters are generally better off with gel batteries. Lithium batteries shut off with no output...dramas. some inverters depend on DC from batteries to do switching. No DC No power ...even if grid is available. You then have to reset batteries physically.
There are third party devices who take care of the comm side, but in my experience rather stick to direct comm devices. These third party devices don’t ‘wake’ the lithium up like direct comm inverters do.
4. Start with 9 x 330watt panels and at least a 150ah battery (lithium) or 200ah gel. 2.9kw panels will give enough to recharge lithium by 11am and run base load with spare capacity for outages. You have to add batteries later in order to store energy for later use in order to get better savings.
Gel recharge time is longer( different charge rate) . Lithium makes more sense in the long run though. It trumps gel in most every category (energy density, DOD, cycles, round trip efficiency, cycle life....etc.)
There are new products like Alpha ess smile5, which are modular and has its own batteries....no comm issues . You set DOD and forget about it. Watch this space....Alpha will have a huge market share soon. Check them out.
Schneider has a similar product as well.
TBB products are good. Direct rivals for Victron and Axperts. TBB is transformer based (toroidal) so efficiency is around 96% or so they claim.
Kodak do inverters now (Solis and Axpert knockoffs)...better software though.
Solis is good...not too many installed.
5. Get a seasoned installer. I’ve come across too many botched installations....you’ll end up spending double if you go with a ‘fly by night’ installer. Someone with electrical background and a PV green card can definitely add value rather than cost you.
6. You need a COC for the electrical. Thus far the regulations for PV is not cast in stone, but I was promised by the SANS guys that we can expect some form of COC for PV by March 2020.
NB! There is a lot to consider when doing a design. I haven’t even scratched the surface....
