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Adding a battery

I already have solar and I am wondering whether storage is worth adding.

7 steps, 2 written so far. Covers Batteries, Payback, Tariffs and export.

  1. Not written yet

    Retrofitting has different economics to buying together.

  2. What the solar ROI calculator actually models

    A battery is only worth what it stops you importing.

    25 July 2026 · 6 min read

  3. Not written yet

    Usable capacity, not the number on the box.

  4. Not written yet

    Size to the evening load, and see where bigger stops paying.

  5. Not written yet

    The tariff can matter more than the battery.

  6. Not written yet

    What you are buying is cycles, and they run out.

  7. What the solar ROI calculator actually models

    Budget the second battery before buying the first.

    25 July 2026 · 6 min read

Every step here ends at the same place. You can also skip to the calculator and work backwards from the answer.