Solar Panels

[NM]

Your battery cost may not be 20c/kWh. It may be higher for smaller batteries. Could be 30c/kWh before adding charging costs.

Suggest get a quote.
Are you single phase?

Quote is coming. Single phase with a maximum inverter size of 5kW per phase (set by the energy distributor). With battery, can have up to 10kW total inverter, but 5kW maximum to the grid.

I am seriously considering a DC-coupled battery that can take DC directly from panels (replacing existing inverter) and adding around 5 or 6 kW additional panels, which should overcome my limited current excess generation issue on some days. Current panels (6.6kW) are all north facing, but any new panels will likely be on 2 MPPTs facing east-west, which will primarily extend the generation time, starting earlier and ending later, with a moderate increase in peak generation.

My main goal is not to find the cheapest installation cost. I will pay more for dealing with a known entity that I trust rather than try to find the cheapest battery cost. The software control capability for scheduling and directing the energy within my system and ability to connect to my home automation system is very important and is a capability for which I am happy to pay extra. Without a good control capability, I will not be able to achieve the primary desired outcome of zero grid consumption during peak tariff periods.

 

[NM]

Past quotes - particularly when you factor installation - made the numbers marginal at best, so I had previously said no for now. However, with 30% off thanks to albo looks like it will bring it under breakeven (depending on how much prices inflate when the subsidy comes on line) and the WA state govt credit could seemingly push it into genuinely money saving territory.

I am not planning on receiving the full 30% rebate off battery prices that were quoted before the rebate was announced. I expect that both the battery manufactures and the installation companies will adjust their pricing to ensure they get some of the rebate benefits, especially as demand will have suddenly increased significantly so they will be looking to similarly increase their margins (supply-demand model).

 

[Quickstatus]

16450

Less charging/discharging inverter losses of 10%
Also assume that the charge/discharge cycle is 90%. Ie discharge to no lower to 10% state of charge. Some say no lower than 20% state of charge.

Then factor in battery degradation. I use 15% in the 10th year and assume degradation is a straight line. So average degradation (in other words battery capacity that is not available ) is 15/2 = 7.5%

So 16450 x 0.9 x 0.9 x 0.925 =12,325 usable and warranted kWh.

Divide by 3650 = 3.37 kWh/day rather than 4.5

 

[DC3]

... I will pay more for dealing with a known entity that I trust …

A great point that many over-look.