Solar Panel and Inverter Log

What this sheet is for

Notice a system quietly under-performing, by keeping generation figures next to the faults, shading and cleaning that explain them.

Who it is for

Owners of a domestic solar PV system, and anyone taking one on with a property and no history for it.

How to use it

1. Fill in the panel and inverter details once, from the units themselves.
2. Read the generation and export meters on the same day each month.
3. Record the reading as it appears, and work out the difference in the next column.
4. Log every inverter fault code, cleaning, new shading and service visit as it happens.

What is on the sheet

The layout is fixed at a size that fits both A4 and US Letter, so the A4 and Letter files are visually identical and print at full size on either. Rows are set at a height that an adult can actually write a date and a few words into with a pen — most printable tables are built in a word processor and never tested with one.

Questions

Why record cleaning and shading alongside the readings?

Because a low month is only informative if you know why. A new hedge, a dirty array or a fortnight of fog explains a drop that would otherwise look like a fault — and a drop with no explanation is the one to chase.

Should I write down the meter total or the monthly figure?

Write the total exactly as the meter shows it, then calculate the difference in the next column. Totals can be checked against the meter later; a monthly figure written on its own cannot.