09/09/2026
The fact that lithium-ion batteries are roughly 50 times less energy-dense than traditional jet fuel. creates a brutal physics problem often called "Battery Gravity".
While an electric car can simply carry a heavier battery pack to gain range, a plane is governed by the lift-to-weight ratio.
For a long-haul flight like Melbourne to London, the weight of the batteries required would currently be so heavy the plane couldn't actually leave the ground.
If you are looking at your ethical investment portfolio and wondering why aviation isn't "going green" as fast as passenger cars, this is the reason.
Fuel burns off during a flight, making the plane lighter and more efficient as it goes. A battery stays exactly the same weight from takeoff to landing.
What this means for sustainable investing:
1. Short-haul is the first frontier: Expect to see small regional electric flights (under 90 minutes) become viable this decade.
2. Long-haul needs a different hero: We are likely looking at Sustainable Aviation Fuel (SAF) or green hydrogen rather than batteries for international travel.
3. Beware of over-hyped tech: If a startup promises a long-distance electric 747 next year, the physics simply don't support it yet.
Understanding these technical limits helps you spot which companies are actually leading the transition and which are just using "sustainable" as a marketing label.
Do you think we should prioritise carbon taxes on long-haul flights until the tech catches up, or focus entirely on developing new fuels?
If you want to look under the hood of your own portfolio to see what’s actually being funded, you can download our free Guide to Ethical Investing here: https://www.vivafp.com.au/get-the-guide