Solar Generation and Export Log

Who this is for

Know what your panels are worth to you. Record the generation and export meter readings, and the log works out what was generated, sent to the grid and used at home, valued at your export rate and your import unit rate.

Homes with solar panels that want to see the return in their own figures, and anyone checking export payments against what the meter says.

What this helps you track

• Generated and exported kWh between readings
• How much of the generation was used at home
• The export payment and the value of imports avoided, at your rates
• Totals and the share of generation you used yourself

How to use it

1. Enter the system size, your export rate per kWh and your import unit rate from your contracts and bills.
2. Read the generation meter and the export meter on the same day, daily or weekly, and write both readings on one line.
3. Generated, exported and self-used kWh and both values are worked out in the browser and the workbook.
4. Add a weather note so a poor week has an explanation when you look back.
5. Compare the export total with your export statement each quarter, and start a new sheet when either rate changes.

Formats

• Printable PDF (A4 and US Letter)
• Fillable PDF with form fields
• Fill in online, saved in your browser
• Excel / Google Sheets workbook

The printable is laid out inside a box that fits both A4 and US Letter, so the two files are identical and neither one is scaled. The fillable PDF has real form fields. The workbook uses plain formulas only — SUM, IF, COUNTIF and the like — so it opens in Excel, LibreOffice and Google Sheets without anything breaking, and every calculated cell is grey so you can see which figures it worked out.

How to print

Download the A4 or US Letter file to match the paper in your printer, open it in a PDF reader and print at 100% — not "fit to page", which shrinks the writing space. Both files leave a 14 mm margin, which clears the unprintable edge on home printers. To print the online version with your entries in it, use the Print this sheet button, which prints only the sheet and none of the page around it. More on printing.

Questions

How is self-use worked out?

Generation minus export: whatever the panels made that did not leave through the export meter. With a home battery some of that was stored for later, so it is still energy you used rather than bought.

I have no export meter. Can I still use it?

Yes, but leave the export columns blank and self-use will equal generation, which will overstate it. If your export is estimated or deemed, enter the figure from your export statement instead.

Where do the rates come from?

From your export agreement and your import tariff. No rates are supplied, because they vary by supplier and contract. Enter them in whole currency units per kWh.

Why is the first line blank?

The first reading is the starting point. Generation and export are measured from the line above, so figures begin on the second line.