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

Charging an electric car at home is where the running-cost savings live — but only if you charge at the right time. Pull power off the grid at a 2–8pm peak rate and you can pay several times more than you would at midday on your own solar or overnight on an off-peak plan. This guide walks through the three ways to charge cheaply, the numbers that actually matter, and the honest cases where one option beats another.

The three cheap ways to charge

Broadly, there are three low-cost windows for filling up a car battery at home:

Daytime solar (self-consumption). Instead of exporting your rooftop generation for a small feed-in tariff, you use it to charge the car. Every kWh you self-consume is a kWh you didn't buy from the grid.
Off-peak / overnight tariffs. Many Time-of-Use plans have a cheap overnight rate. You schedule the car to charge in the small hours when grid demand — and the price — is low.
Free or ultra-cheap midday windows. The federal Solar Sharer offer, live from 1 July 2026 via participating retailers, provides a free-power window of 11am–2pm with a daily cap of 24 kWh, on an eligible plan with a smart meter. Availability varies by retailer and state — you'll need to confirm it applies to you.

The solar case: why self-consumption beats exporting

Here's the key insight. Feed-in tariffs are low and falling — the typical range is just 3–10 c/kWh (some states like VIC, regional QLD and TAS set a regulated minimum; most retailers set their own). Meanwhile the grid electricity you'd otherwise buy costs far more per kWh.

So if you export a kWh of solar for, say, a few cents and later buy a kWh back to charge the car at the peak rate, you lose money on the round trip. Charge the car directly from that midday solar instead and you effectively "pay" yourself the export rate you gave up — a fraction of the retail price.

Rough sizing check. A typical Australian system yields about 1,400 kWh per kW of panels per year. A 6.6kW system therefore generates roughly 9,000 kWh a year. An average EV driven ~13,000 km might need somewhere around 2,500–3,000 kWh a year — a meaningful slice of a mid-sized system, but only if the car is home and plugged in during daylight hours.

Here's the catch: solar only works if the car is home at midday

This is the beat most sales pitches skip. Solar charging is brilliant for retirees, shift workers, work-from-home households and second cars that sit in the driveway all day. It's far less useful if the car leaves at 7am and returns at 6pm — because at 6pm your panels are winding down and the grid is at its peak rate.

If that's your pattern, you have two honest choices:

Charge overnight on an off-peak tariff. No solar needed. You just need a plan with a genuinely cheap overnight rate and a car (or charger) that can schedule itself. For a commuter who's never home in daylight, this is often the cheapest and simplest answer — full stop.
Add a battery to "time-shift" solar into the evening. Store midday sun, use it to charge the car at night. This works, but a battery is a large spend and adds its own payback question (typically around 8 years). Don't buy a battery just to charge a car if a cheap overnight tariff would do the same job for nothing.

Working the numbers on your own bill

The only figures that matter are on your actual electricity bill. Before deciding anything, find these:

What to find	Why it matters
Your peak c/kWh rate	The price of charging at the wrong time — usually ~2–8pm
Your off-peak c/kWh rate	The overnight price — often a fraction of peak
Your feed-in tariff	What you give up by self-consuming instead of exporting
Your car's kWh per 100 km	Converts your driving into an annual kWh figure

With those four numbers you can compare: daytime solar charging costs roughly your forgone feed-in tariff per kWh; overnight charging costs your off-peak rate; peak charging costs your peak rate. The gap between them, multiplied by your annual charging kWh, is your real prize — and it tells you whether a schedule change alone captures most of the saving.

Smart chargers, timers and the free-power window

You don't necessarily need an expensive smart charger. Many EVs let you set a charging schedule from the car itself, so a standard outlet plus overnight scheduling can capture off-peak rates for very little. A dedicated smart charger adds features like "solar-only" charging (it modulates to soak up surplus generation) and can be worth it for a home-all-day solar household — but it's an added cost you should weigh, not assume.

If you can access Solar Sharer's free 11am–2pm window and the car is home, that's up to 24 kWh a day at no charge — potentially covering a big chunk of a commuter's weekly driving on weekends and days off. Confirm your retailer offers it and that you have the required smart meter.

Before you spend on hardware: the cheapest win is almost always a tariff and scheduling change, not new equipment. Test whether simply moving your charging to off-peak or midday captures most of the saving before you buy a battery or a premium charger.

We sell no chargers, no panels and no batteries — so we've got no reason to talk you into any of them. Sometimes the right answer is a free scheduling tweak on your existing setup; sometimes it's solar; and sometimes, honestly, it's just a better tariff. We'll run your numbers and tell you which — even when the answer is "buy nothing."

Want to know what actually pays for your place?

Get an independent, engineered read on your whole bill — solar, battery, tariff and the rebates you're really entitled to — for a small fixed fee. No system to sell, no sales call.

Start your audit — $100

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.