Three Hours Of Free Power: What It's Actually Worth On The Sunshine Coast

Since 1 July 2026 every electricity retailer has to offer at least one plan with three hours of free power a day. In South East Queensland the window is 11am to 2pm and the free allowance is at least 24 kWh. It is real, it is not a gimmick, and for the right household it is the biggest change to home energy economics since the original feed-in tariffs. It is also not free money for everybody. For some houses, switching to one of these plans leaves them worse off. Here is the arithmetic, including the part the advertising leaves out.

What Solar Sharer actually is

The rule applies across New South Wales, South Australia and South East Queensland. Our window is 11am to 2pm; South Australia runs midday to 3pm. The 24 kWh daily allowance is a mandated minimum, not a ceiling, and some retailers have gone further — there are plans offering up to 50 kWh and a four-hour window. Ergon has extended the same idea to regional Queensland under Tariff 12F. The detail varies by retailer, so the plan you are offered matters as much as the concept.

It is worth understanding why this exists, because it tells you how durable it is. Queensland makes so much rooftop solar in the middle of the day that wholesale prices routinely fall to zero or below. Nobody is being generous. Retailers would rather you soak up that midday glut than have them pay to push it somewhere else. That is a reasonable trade, and it is the same logic that will eventually decide whether the free window stays at three hours or moves.

You have to opt in, and you need a smart meter

Nothing happens automatically. You have to ring your retailer, or switch to one offering it, and opt in. You also need a smart meter. Most homes that had solar installed after about 2017 already have one. Older houses may need a meter exchange, which the retailer usually does at no charge, though it can take a few weeks and it has to happen before the plan starts.

Before you ring anyone, write down three numbers off your current bill: the daily supply charge in cents, your general usage rate per kilowatt-hour, and your feed-in tariff. You cannot tell whether a free-window plan is better without them, and the retailer will not do that comparison for you.

The catch nobody leads with: the daily supply charge

These plans carry a higher fixed daily charge, and that is the part the ads skip. Customers have reported Origin moving from 80.4 cents to 186.1 cents a day on switching — about $387 a year before you use a single kilowatt-hour. That is your cost of entry, and it is the same whether the plan saves you $200 or $2,000. It is the single reason these plans suit some houses and not others, and any honest comparison has to start by subtracting it.

With no battery, the only way to use the free window is to be running something in it. A typical home draws three to six kilowatt-hours in a three-hour midday block, which is roughly $1.30 a day, or about $485 a year — against a $387 supply increase. That is a thin margin for the trouble. If you already have solar covering your midday load, you gain almost nothing, because your panels were doing that job for free already. The free window is not really a plan for people without storage or shiftable load.

What it's worth with no battery

A battery can take that free power and hold it until the evening peak, and that is the whole game. Until July, a battery could only store what your roof spilled, which meant a modest array with a big bill could never fill one. We modelled a 6 kW array on a $600 monthly bill: a 15.3 kWh battery paid back in about 35 years on a standard plan and 8.4 years on a free-window plan. Same house, same battery, same price. The plan is doing the work, not the hardware.

Why a battery changes the picture completely

Twenty-four kilowatt-hours in, at about 90 per cent round-trip efficiency, is roughly 21.6 kilowatt-hours delivered — about five battery modules. Past that, the free window cannot fill your battery, and the extra capacity only earns its keep if your roof has surplus to top it up. So on a free-window plan a bigger battery is not automatically better. If someone quotes you past that point, they should be able to show you where the extra energy is coming from.

The 24 kWh cap is a sizing limit, not a target

If your solar already fills your battery every day, the free window has nothing left to add and you still pay the higher supply charge. We modelled a 10 kW array with a 20.4 kWh battery: 7.4 years to pay back on a standard plan, 9.3 years on a free-window plan. Switching made it worse. It is the same story for a good array with no battery — on a $400 monthly bill, annual savings dropped from about $2,264 to $1,923. Anyone telling you the free window is good for everybody has not done the sums.

When switching will cost you money

The allowance covers your household load first, because using a kilowatt-hour directly beats storing it — there is no round-trip loss. Electric hot water is eight to ten kilowatt-hours a day. A pool pump is four to six. An electric car is around ten. Put those on timers inside the window and you are running twelve kilowatt-hours a day at zero cost, worth roughly $1,459 a year, before a battery does anything at all. That is electrical work — timers, contactors, occasionally a dedicated circuit — not a phone call to your retailer.

Load shifting is where most of the money is

No solar, electric hot water or a pool, a $500 to $700 bill: solar and a battery together, with the plan and the timers, is the strongest case on the board and pays back in about three years. An existing 6 to 6.6 kW array: a battery only stacks up if you also switch plans, and without that we would tell you not to bother. An existing 10 kW array or larger: a battery pays either way, so check whether the plan actually helps before you move. Gas hot water, no pool, nobody home during the day: the supply charge will probably eat the benefit.

What we'd actually recommend, by household

Our solar and battery calculator has a free-window mode. Put in your bill, your array size, the battery you are considering and how much load you could genuinely move into the middle of the day, and it will give you a payback — including telling you when switching would leave you worse off. It deducts the higher supply charge automatically rather than quietly leaving it out. It is the same tool we use sitting at your kitchen table.

How to check your own numbers

One last thing worth knowing. During an actual blackout there is no free window, because there is no grid. Your battery runs the house on what it has already stored and whatever the roof can make that day. That is not a reason to skip the plan. It is a reason not to let anybody talk you out of panels on the grounds that power is free at lunchtime.