Your forecast, number by number

Press Calculate and the Forecast section fills with numbers. Each one answers a plain question. Here is what each is asking, and how we work it out, so you can check us.

Your predicted bill: what you will earn or pay, and what you save

The big number is your bill for the days you chose, on your plan, with the battery doing what the Action plan says. Negative is money coming to you.

The line underneath is what the same days would cost with no solar at all, and the difference is your saving. Those two are worked out on the same weather and the same usage, so they reconcile.
If the number surprises you, check the Retail plan row first. Most surprises are a plan with a different feed-in rate than you thought.
On a single day we lead with the saving instead, because a one-day bill is small and the saving is the point.

Forecast Solar: what your roof makes, in kWh

Everything your panels are predicted to produce over the period, before any of it is used, stored or sold.

The CO2 figure beside it is what your usage would have emitted on grid power, minus what you did emit, plus a credit for what you sent to the grid. It uses the real carbon intensity of your part of the grid, hour by hour.
A cloudy week and a sunny week can differ by two to one. The band on the chart is the honest version of this number.
With your inverter connected, "Measured so far" is what it has actually made over the days that have already happened. Compare it with the forecast for the same hours, not the whole period; the rest is still to come.

Self sufficiency: how much of your usage your own system covered

The share of everything the house used that came from your roof or your battery rather than the grid.

Worked out as your usage minus what you imported, divided by your usage. 100% means you bought nothing.
The kWh beside it is the usage itself, so you can see what the percentage is a share of.
A high number is not always the cheapest outcome. On a plan with a good evening feed-in, selling the battery and buying back overnight can beat self sufficiency. That is what Optimise for decides.

Power exported: what you sold to the grid, and what it earned

Every kWh that left your house for the grid, priced at your plan's feed-in rate for the time it went.

The dollar figure is the revenue, before the supply charge and the imports on the bill headline.
A feed-in rate that changes by time of day, or a tiered one with a daily cap, is priced the way the plan files it.
Off-grid layouts show Generator run time here instead. There is nowhere for the power to go.

Power from grid: what you bought, and what it cost

Every kWh that came in from the grid, priced at your plan's rate for the time it came.

The Action plan may buy on purpose: topping the battery up overnight when the rate is low so it can cover the evening peak. That shows here as an import and pays for itself in the bill.
Off-grid layouts show Power not covered here instead.

Battery charge: where the battery finished, and how that compares with the start

How full the battery is at the end of the period, and the change since the beginning.

A plan that ends the week lower than it started has sold some of the battery. That is fine when the price was right; the bill headline already counts it.
A single day starts from the starting battery charge in your layout; a week starts from the same and carries the battery forward day to day.

Battery cycles: how hard the plan works the battery

How many full charge-and-discharge cycles the plan used over the period. One cycle is a full charge plus a full discharge.

We add up every step of charging and discharging, allowing for the round-trip losses, and divide by the battery size. Charging to half and back twice is one cycle, the same as once to full and back.
Fewer cycles means less wear. A plan that cycles hard for a small saving is one to weigh up; the number is here so you can.

Generator run time: how long it ran, and the fuel it burned

Off-grid only. The hours the plan needed the generator to keep the lights on, and roughly how much fuel that is.

We say roughly because fuel use depends on the load on the generator, and we cost it at a pump price that may not be yours.
Zero is the good outcome, and the headline says so in words rather than showing $0.00.

Power not covered: what the house wanted and could not get

Off-grid only. The usage your solar, battery and generator together could not meet.

Anything above zero means a brown-out somewhere in the period. Shift the load, run the generator longer, or look at the year view for how often it happens.
The same series appears on the usage chart under the same name.

The calendar year: the same numbers, over twelve months

The Calendar year tab runs the whole year day by day and shows the same tiles as totals, plus the average solar per day.

Average over 5 years smooths out one odd year. A single year shows you what that year actually did.
The year view runs the same full-year engine the plan ranking uses, so the two are reading the same maths.

Closes this tab and returns to the calculator.