Residential energy storage
Home storage is bought once and lived with for a decade. The decisions that matter are made at specification stage — sizing, depth of discharge, installation location — and they are hard to change afterwards.
Size from the evening load, not the array
The most common residential specification error is sizing the battery to the solar array. A 6 kW array on a clear day produces far more than a household can store, and the surplus is exported at whatever the tariff allows.
Size from what you want to cover after sunset. Then check that the array can recharge it. That order matters: a battery sized to the array is usually either never fully charged or never fully discharged, and both waste the investment.
Depth of discharge is the warranty question
Cycle life is specified at a defined depth of discharge. A battery cycled daily to 90 % of its capacity and one cycled to 50 % will not last the same number of cycles, and the datasheet usually gives the figure for the gentler case.
In practice: a somewhat larger battery cycled shallowly often costs less over ten years than a smaller one cycled deeply, even though the purchase price is higher.
What we need to configure a system
The daily consumption and its profile; the inverter make and model; whether backup of specific circuits is required; the intended installation location and its temperature range; and the local grid requirements if grid services are being claimed.
With those we can propose a capacity, an inverter interface and an installation position, and be honest about whether the economics work in your tariff structure.