Solar + battery vs solar-only examples
Compare 5–30 kWh illustrative battery scenarios. Pages separate solar self-consumption value from tariff shifting and expose the assumptions.
A battery does not create extra solar generation
The battery-capacity range above is designed to show how storage can change the timing of solar use. The panels generate the same amount with or without the battery; storage can increase the share used in the home by moving surplus daytime electricity into later periods. The financial value therefore depends on the difference between avoided import cost and the export income that is given up.
Larger batteries are not automatically better. Once most useful surplus has already been captured, extra capacity may spend many days under-used. Winter generation can also be too low to fill a large battery from solar alone, while summer demand may be too low to empty it fully.
Compare solar-only first
Start with the economics of the solar array without storage, then add the battery as an incremental decision. Enter realistic export rates, import prices, usable capacity, efficiency and installed battery cost. This makes the additional value of storage visible instead of blending the solar and battery returns together.