One of the quieter problems with Australia’s rapid renewable energy rollout is that, at times, we’re generating too much clean power. Wind and solar farms increasingly produce electricity when the grid can’t absorb it, and without enough storage, that surplus energy is simply thrown away. It’s an uncomfortable irony for a country investing billions in clean generation.
This issue isn’t uniquely Australian. In the UK, wind farms were forced to curtail 4.3 terawatt hours of electricity in 2023 — about five per cent of their annual output. That wasted energy could have powered around 1.5 million homes for a year and cost consumers hundreds of millions in unnecessary charges. Similar constraints are now emerging across Europe, North America and Australia as renewable capacity outpaces grid upgrades .
What’s becoming clear is that the solution isn’t just more poles and wires. It may already be sitting in our driveways.
When electric vehicles stop being passengers and start pulling their weight
A trial currently underway on the Isle of Wight points to a very different way of thinking about energy storage. Instead of treating electric vehicles purely as electricity consumers, the project is testing “bidirectional charging” — technology that allows EVs to both take power from the grid and send it back when needed.
The logic is compelling. By 2040, around 36 million electric cars and vans are expected on UK roads. Even today’s models can store enough electricity to run an average household for seven to ten days. Collectively, future EV batteries could offer around 2.5 terawatt hours of storage — enough to soak up surplus solar at midday or excess wind power overnight.
Most of the time — roughly 95 per cent — cars are parked. Bidirectional charging simply makes use of that idle capacity.
Why drivers would bother (hint: it’s not charity)
This isn’t about asking EV owners to save the planet out of goodwill alone. There’s a strong financial incentive.
Drivers could charge their vehicles when electricity is cheapest, store that energy, and then use it during peak pricing periods to power their homes. A recent study from the University of Michigan found that vehicle-to-home charging could save drivers up to US$5,600 over the life of their vehicle — potentially cutting charging costs by as much as 90 per cent .
Energy companies also stand to gain. One estimate suggests European power systems could save up to €4 billion through vehicle-to-grid and smart charging schemes, largely by reducing the need for expensive infrastructure upgrades.
The technology works — but it’s not simple
Most EVs and chargers today only move electricity in one direction. Bidirectional systems are more complex, requiring conversion from the direct current stored in batteries to the alternating current used by homes and the grid.
Only a handful of EV models currently support this capability, and widespread adoption will require:
- Factory-installed bidirectional hardware in vehicles
- Affordable smart chargers
- Clear regulatory standards
- Strong consumer protections around battery warranties, privacy and fair payment
Without these, the technology risks stalling at the pilot stage.
Why the Isle of Wight makes sense as a test case
The Isle of Wight trial, part of the Europe-wide DriVe2X program, is testing four bidirectional chargers across hotels and a visitor boat mooring. The island hosts more than two million tourists each year, creating big seasonal swings in electricity demand.
Many visitors arrive with EVs, which could temporarily store and redistribute energy during peak periods. Participants in the trial can set departure times and minimum battery levels, ensuring they’re never caught short — a practical response to one of the biggest concerns around the technology.
Crucially, the project is being shaped with local input through Future Isle of Wight, a community-owned organisation focused on ensuring residents benefit rather than being sidelined .
From pilot projects to everyday life
There are now more than 100 vehicle-to-grid trials worldwide, including airport car parks in Portugal and smart homes in Budapest. But most remain small and experimental.
Still, the direction of travel is clear. The UK government has suggested that by 2050, EVs could supply more than 40 gigawatts of flexible power — roughly the equivalent output of 40 large nuclear reactors during peak demand.
For that future to work, the technology has to be invisible to daily life. Drivers need to wake up with a charged car, understand what’s happening without needing an engineering degree, and see clear savings — all without worrying about battery degradation or data privacy.
The Isle of Wight trial won’t solve the global energy storage problem on its own, but it does offer a glimpse of something important: a future where electric vehicles are no longer just transport, but a critical part of a smarter, more resilient energy system .
This article has been adapted with care, respect, and love from: The Conversation - Two-way electric vehicle charging at scale could stop renewable energy being wasted – here’s how it works
