What actually cuts more CO₂ today in Australia?

Written By John Cadogan

Executive summary

With a $75,000 budget in NSW, buyers can choose between:

  • a Tesla Model Y Long Range AWD charged from the grid, or

  • a Toyota RAV4 Hybrid (mid-spec) plus a ~$20,000 rooftop solar system

    At 15,000 km per year, a grid-charged Model Y emits about:

    • ~1.5 tonnes CO₂ per year on today’s NSW electricity mix

    A RAV4 Hybrid driven the same distance emits about:

    • ~1.7 tonnes CO₂ per year from petrol alone

    A typical 6.6 kW Sydney rooftop solar system generates roughly:

    • ~9 MWh per year, displacing about ~6 tonnes CO₂ annually on the NSW grid

    Net result:

    • Model Y (grid-charged): ~+1.5 t CO₂/yr

    • RAV4 Hybrid + solar: ~–4 t CO₂/yr (net)

    The hybrid + solar option reduces emissions by roughly 5–6 tonnes CO₂ per year more than a grid-charged EV in NSW today

    This result reverses in countries like Norway, where electricity is ~95% renewable and EV charging is already near-zero-carbon

    If the Model Y is charged from rooftop solar, it becomes the best overall outcome — but again, the solar does most of the emissions reduction, not the drivetrain alone

    I will save you thousands on a new vehicle - conventional ICE, hybrid, PHEV or electric. There’s no face-to-face negotiation with a car salesman, just the best price my specialist car-buying team can achieve. We work for you, and there’s no obligation. More here. My team will also get you the best possible deal on home solar here.

The full enchilada

A common assumption in the EV debate is this:

Buying an electric car is the single best thing a household can do to reduce transport-related CO₂.

That assumption is sometimes true — but not universally.
In Australia, and particularly in NSW, the answer depends far more on where your electricity comes from than on whether your car has a tailpipe.

Let’s put ideology aside and run the numbers.

The scenario

Assume a buyer with a $75,000 budget, living in NSW, driving 15,000 km per year, choosing between:

Option A

  • Tesla Model Y Long Range AWD

  • Charged entirely from the NSW electricity grid

Option B

  • Toyota RAV4 Hybrid (mid-spec AWD)

  • Use the ~$20,000 purchase price difference to install a home solar PV system in Sydney

The question:

Which option leaves you in the better CO₂ position — right now — in NSW?

This model assumes a hypothetical person has $75,000 maximum to spend on cleaning up their vehicle transportation emissions. They’re going to buy $75k worth of vehicle and whatever else, and see what impact that has on CO2.

Key assumptions (totally transparent)

  • Annual driving: 15,000 km

NSW electricity grid

  • Emissions intensity: ~0.66 kg CO₂-e per kWh
    (NSW remains coal-heavy relative to the national average)

Tesla Model Y (real-world)

  • Energy use: ~15–16 kWh/100 km

  • Annual electricity: ~2,300 kWh

Toyota RAV4 Hybrid (real-world)

  • Fuel use: ~5.0 L/100 km

  • Petrol emissions: 2.31 kg CO₂ per litre

Rooftop solar (Sydney)

  • Typical system within ~$20k:

    • 6.6 kW PV

  • Annual output:

    • ~9,000–9,200 kWh

All results below are operational emissions only (fuel + electricity), excluding vehicle manufacturing.

I will save you thousands on a new vehicle - conventional ICE, hybrid, PHEV or electric. There’s no face-to-face negotiation with a car salesman, just the best price my specialist car-buying team can achieve. We work for you, and there’s no obligation. More here. My team will also get you the best possible deal on home solar here.

Option A: Tesla Model Y (charged from NSW grid)

Annual electricity use

15,000 km × 15.3 kWh / 100 km ≈ 2,300 kWh

Annual CO₂

2,300 kWh × 0.66 kg CO₂/kWh ≈ 1,520 kg CO₂

Result

≈ 1.5 tonnes CO₂ per year

This is substantially lower than a conventional petrol SUV — but it is not zero, and it depends entirely on the grid mix.

Option B: RAV4 Hybrid + ~$20k rooftop solar (Sydney)

RAV4 Hybrid tailpipe emissions

Annual fuel use

15,000 km × 5.0 L / 100 km = 750 L

Annual CO₂

750 L × 2.31 kg CO₂/L ≈ 1,730 kg CO₂

Rooftop solar avoided emissions

Annual solar generation

≈ 9,200 kWh

Avoided grid CO₂

9,200 kWh × 0.66 kg CO₂/kWh ≈ 6,070 kg CO₂

My team will get you the best possible deal on home solar here.

Net CO₂ position

+1.7 t (RAV4 Hybrid)
−6.1 t (solar)
= −4.4 t CO₂ per year (net)

Side-by-side summary (NSW, 15,000 km/year)

Annual CO₂ position

Tesla Model Y (grid-charged)~+1.5 t CO₂

RAV4 Hybrid + rooftop solar~−4.4 t CO₂ (net)

Difference:

≈ 5–6 tonnes CO₂ per year in favour of hybrid + solar

My team will get you the best possible deal on home solar here.

I will save you thousands on a new vehicle - conventional ICE, hybrid, PHEV or electric. There’s no face-to-face negotiation with a car salesman, just the best price my specialist car-buying team can achieve. We work for you, and there’s no obligation. More here. My team will also get you the best possible deal on home solar here.

Why this result surprises the ‘faithful’

  • Drivetrain choice (EV vs hybrid) shifts emissions by hundreds of kilograms per year

  • Electricity supply choice shifts emissions by multiple tonnes per year

  • In NSW, rooftop solar is a much larger CO₂ lever than the car itself

Why this flips in Norway — and similar markets

Norway is often cited as proof that EVs are the obvious choice. And in Norway, they are.

Why?

  • Norway’s grid is ~95–98% renewable (hydro-dominated)

  • Grid intensity is ~20–40 g CO₂/kWh, not hundreds

  • Charging an EV in Norway produces near-zero operational emissions

Re-run the same Model Y maths on a Norwegian grid:

2,300 kWh × ~0.03 kg CO₂/kWh ≈ 70 kg CO₂/year

That’s two orders of magnitude lower than NSW.

So the lesson isn’t that Norway is “lying” — it’s that Australia is not Norway, and importing conclusions without importing the grid is a category error.

What if the Model Y is charged from rooftop solar?

This is the crucial missing comparison in most EV debates.

If the same ~$20k solar system is used to charge the Model Y instead of the grid:

  • Model Y driving emissions → effectively near-zero

  • Remaining solar generation continues to displace grid electricity

  • Net household CO₂ position becomes even more favourable

In that case:

  • EV + solar becomes the best outcome

  • But note the key point:

    The solar is doing the heavy lifting — not the drivetrain alone

  • Many people, such as apartment-dwellers, cannot do this.

This reinforces the central message: clean electricity matters more than the powertrain in the car.

My team will get you the best possible deal on home solar here.

Important caveats (so this stays honest)

  • Solar exports are credited at average grid intensity, not marginal generation

  • Curtailment, storage losses, and timing effects are simplified

  • No lifecycle or manufacturing emissions are included

  • Real outcomes depend on:

    • self-consumption

    • charging timing

    • household electricity demand

Even with conservative discounts applied, rooftop solar dominates the CO₂ maths in NSW today.

I will save you thousands on a new vehicle - conventional ICE, hybrid, PHEV or electric. There’s no face-to-face negotiation with a car salesman, just the best price my specialist car-buying team can achieve. We work for you, and there’s no obligation. More here. My team will also get you the best possible deal on home solar here.

The uncomfortable but unavoidable conclusion

With $75,000, in NSW, today:

  • Grid-charged EV → good, but limited by the grid

  • Hybrid + rooftop solar → much larger near-term CO₂ reduction

  • EV + rooftop solar → best overall outcome, if budget allows

Or put more bluntly:

If you care about CO₂, the most important decision isn’t the car — it’s the electricity.

As the grid decarbonises, this will change.
But right now, rooftop solar remains the single most powerful household emissions lever available in Australia.

I will save you thousands on a new vehicle - conventional ICE, hybrid, PHEV or electric. There’s no face-to-face negotiation with a car salesman, just the best price my specialist car-buying team can achieve. We work for you, and there’s no obligation. More here. My team will also get you the best possible deal on home solar here.

References & data sources

John Cadogan
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