Charge Your EV on Solar & Off-Peak Power for Next to Nothing

An electric car is the single biggest electrical load most households will ever add. Done well, you can charge it for a fraction of the cost of petrol — sometimes for almost nothing. Done badly, you charge it at peak-rate prices and quietly hand your retailer a fortune. The difference is almost entirely about when you charge, not what you drive. This guide walks through the three cheapest ways to fill the battery and, honestly, where each one falls down.

The three cheap-charging strategies

There are really only three ways to get very low-cost kilowatt-hours into a car:

Daytime solar surplus — charge from your own rooftop generation instead of exporting it.
Off-peak grid power — use a Time-of-Use or dedicated EV tariff overnight when rates are lowest.
A free-power window — charge inside a scheduled zero-cost block if your retailer offers one.

The best answer for your home depends on your roof, your driving pattern and your tariff. Many households end up using two of these together.

Charging on your own solar

This is usually the cheapest kilowatt-hour you'll ever get, because the alternative is exporting that same solar for a feed-in tariff that is low and has trended down for years. Feed-in rates typically sit in the range of 3–10 cents per kWh, and in most states the figure is retailer-set rather than regulated (VIC, regional QLD and TAS set a regulated minimum — confirm the current rate for your state). Every kWh you pour into the car instead of exporting is worth far more to you than that feed-in credit.

A typical rooftop system generates roughly 1,400 kWh per installed kW each year, so a 6.6kW array produces a meaningful daytime surplus most of the year. The catch is timing: solar charging needs the car to be home and plugged in during daylight. If the car is at work from 8 to 6, your biggest solar window is wasted.

Smart charging helps. Many home chargers and some cars can be set to only draw power when there's surplus solar being exported, ramping up and down as clouds pass. If you're home during the day — retirees, shift workers, people who work from home — this is the gold-standard setup.

Off-peak and dedicated EV tariffs

If the car is out during the day, off-peak grid power is your friend. Time-of-Use tariffs are common across the country, with peak periods typically running around 2–8pm (later in some states). Overnight off-peak rates are usually a small fraction of the peak rate, and some retailers offer dedicated EV plans with very cheap late-night windows. Set the car (or charger) to start after the off-peak window begins and you'll charge for a fraction of the daytime grid price.

One thing to check carefully: the exact peak/off-peak times are set per plan and per state, so confirm them from your actual bill rather than assuming. Charging the car at 4pm on a Time-of-Use plan is one of the most expensive things you can do with electricity.

The Solar Sharer free-power window

A federal offer called Solar Sharer, live from 1 July 2026 via participating retailers, provides a free-power window from 11am–2pm with a daily cap of 24 kWh, on an eligible opt-in plan. Twenty-four kWh is a serious chunk of charge — enough for well over 100km of range in most EVs. If you can get the car home and plugged in over that midday window, it's genuinely close to free motoring.

The honest caveats: it requires a smart meter, you have to opt in to an eligible plan, and availability varies by retailer and state — so confirm it's actually offered where you are before counting on it. And like solar charging, it only helps if the car is home at lunchtime.

Here's the catch — cheap charging isn't free to set up

None of this is magic. A few realities worth facing before you spend money chasing cheap charging:

A dedicated EV charger costs money. If you only drive short distances, a standard power point charging slowly overnight on off-peak may be all you ever need — the faster charger may never pay for itself in savings.
Solar charging needs daytime presence. If nobody's home from 9 to 5, you can't capture the midday surplus or the free-power window, and the case for oversizing solar specifically for the car weakens.
A battery to "store solar for the car" rarely stacks up on those grounds alone. Typical battery payback runs around 8 years. Charging the car directly from the panels, or on cheap off-peak power, is usually far better value than routing solar through a battery first and losing energy to round-trip losses.

The genuinely cheap outcome often needs almost no new hardware: the right tariff, a timer, and charging when power is cheapest. Sometimes the best advice is to spend nothing extra at all.

Putting it together

If you're home during the day, prioritise solar surplus and any free-power window, and keep off-peak as backup for cloudy stretches or big trips. If the car is away all day, a cheap off-peak or dedicated EV tariff overnight is your workhorse. Either way, the single most valuable move is making sure the car never charges during the peak window — that one habit saves more than any gadget.

We don't sell chargers, panels, batteries or electricity plans — so we've no reason to talk you into any of them. We model your actual driving, roof and tariff, and sometimes the answer is that a $30 timer and the right plan beats thousands of dollars of new kit. That's the whole point of asking someone with nothing to sell.

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Figures in this guide are current at the date of publication and indicative only — rebate and certificate values change over time (federal battery certificates step down each January and July), and state schemes are amended often. Confirm the current numbers for your situation before you commit. This is general information, not personal financial advice.