The saving your bill doesn't show.

01What a meter can see

Your electricity meter sits between your home and the street, and it counts two things: what flows in from the grid, and what flows out to it. That's all it can see.

When your roof makes power and your home uses it straight away, that power never passes the meter. It goes from the panels to the kettle without touching the street. As far as the meter knows, it didn't happen.

02The part with no line

This is the part of solar that surprises people. The largest saving, the electricity you made and used yourself, doesn't appear anywhere on the bill. There's no line that says 'power you didn't buy'. The usage figure is simply smaller than it used to be.

So a bill after solar can look underwhelming if you go hunting for the saving as a credit. It isn't a credit. It's an absence.

The biggest saving isn't a credit on the bill. It's an absence.

03What you will see

Three things change. Your usage, in kilowatt-hours, drops, because you're buying less. A new line appears for feed-in credits: what your retailer pays for the power you exported. And your daily supply charge stays exactly where it was, because it's the cost of being connected, not of using anything.

That last one matters. However good a system is, a home that stays on the grid keeps paying to be connected to it.

04Reading the rest

Most bills follow the same pattern once you know what to look for. Usage charges are the price for each kilowatt-hour, sometimes split into peak, shoulder and off-peak rates by time of day. The supply charge is a fixed amount per day. Feed-in credits come off the total. Somewhere, usually near a small bar chart, is your average daily use, which is the single most useful number on the page.

The billing dates matter too. A bill from July to September tells you about winter. It says little about how your home behaves in January.

05How to see the whole saving

The meter can't show you what you used from your own roof, but your system's monitoring can. It records everything the panels made. Take away what was exported and the rest is what your home used directly.

Multiply that by what you pay for a kilowatt-hour and you have the saving the bill is silent about. Add the feed-in credits and you have the whole picture.

06What we read from yours

When you share a bill with us, we read three things from it: how much you use, what you pay, and which months it covers. If it shows your use by time of day, we read that as well.

We'll tell you which season your estimate came from, because a winter bill and a summer bill describe two different homes.