Could you run without the grid?

Why a real year and not a typical one

Averages hide the thing that actually catches people out. Going off-grid is not undone by one bad day, because that is what a battery is for. It is undone by a bad week. Four grey days in a row in July, each one starting with less in the battery than the last. An average June never contains that week, so it would happily tell you everything is fine.

That is also why the battery carries over from day to day here instead of starting full each morning. The way the bad days bunch together is the answer, and you can see it in the calendar.

Reading what comes back

• Days you fell short. Days when the sun and the battery together could not keep up without running the battery down past the level you told us to protect.
• Power you went without. How much you would have had to find elsewhere across the whole year. ⚠️ Read it next to the number of days. Forty small days and four terrible ones can add up the same and are very different problems.
• Worst day. What the single hardest day of the year asked for. This is the one that decides what size generator you need.
• The shortfall calendar. Where in the year the bad days land. A solid block through winter means you are short of panels for the season. Scattered single days usually mean the battery is slightly too small.
• The petrol calendar. If you have told us about a generator, this shows what each day cost you in fuel. It is worth looking at right under the shortfall one, because a year can look almost perfect up top and still have a dark, thirsty fortnight in July down below. That is the fortnight you need to be home for, with fuel in the shed.
• How bad the bad days were. Lots of short bars beats one tall one on the right. Plenty of small gaps are cheap to close. One enormous gap usually is not.

Three ways to close the gap

• A generator. Usually the cheapest answer for a handful of winter days, because you are buying a few hours of running rather than gear that sits idle for eleven months. Tell us about yours and we will plan it properly.
• More panels. Best when the calendar shows a solid winter block. Short days are the problem then, and no amount of battery invents sunshine.
• A bigger battery. Best when the bad days are scattered singles, because then you are just trying to carry a good day’s extra through to the next grey one.

Change the settings above and run it again. It costs you nothing to ask twice, which is rather the point of having it.

How much to trust this

The weather is real. It is a genuine past year for where you live, not something we made up. How well we know your power use is a different matter. A standard household pattern scaled to your daily total is a rough shape; your own uploaded or measured history is far closer to your actual life. If you have real usage figures, use them. They move this answer more than anything else you can change.

The fuel figures are honest arithmetic on the numbers you gave us, but we have not yet checked them against anyone’s real fuel can. Treat the litres and dollars as a solid way to compare your options, this battery against that one, a few more panels against a generator, rather than as a budget you could bank on to the litre.

One last thing. A year is just one year, and the next one has a different winter. Run two or three from the picker before you spend real money on the answer.