EDF launched a trial on 12 September 2024 into how bi-directional charging technology can be optimised to let customers with solar panels use the spare capacity in their electric vehicle batteries to power their homes and earn extra cash1. The trial uses bi-directional chargers from Indra Renewables to integrate a customer's EV battery with their existing solar panels1.
Trialists will use EDF's existing Smart Export Guarantee (SEG) tariff to sell surplus power from their car batteries to the grid at the best times, which EDF says could earn drivers an average of £650 a year compared with a smart charging baseline, based on research carried out by EDF1. Customers will also be able to use cheaper electricity stored in their electric vehicle to power their home1. EDF says the trial has just begun and ends in February 2025, with data collected throughout giving customers insight into their charging behaviour1.
Loughborough University and the University of Sheffield will carry out qualitative and quantitative studies with the customers, which EDF says will provide insight into the export tariff's feasibility for optimising EV charging so that it aligns with low carbon generation at the lowest cost to the customer1.
The trial is one of five created and developed as part of a wider project by EDF's Research and Development and Customer teams, and forms part of the Department for Energy Security and Net Zero's Alternative Energy Markets Innovation Programme. It is backed by £1.3m of funding from the Net Zero Innovation Portfolio1.
"Our mission at EDF is to help Britain to achieve net zero, and we will only succeed by empowering our customers and giving them the flexibility to manage their energy at home, saving them cash and carbon."
EDF states that the trial follows the launch of its EVolve tariff, which it describes as one of the cheapest EV tariffs on the market for drivers with any EV or charger, saving customers £200 a year and promising they will never pay more than the Ofgem price cap1. No further detail on the number of trial participants, the specific charger model, or the terms of participation has been reported1.
Why it matters for households
Bi-directional charging reverses the usual direction of flow: instead of electricity only going into the car, the car battery can discharge back into the home or the grid. For a household with solar panels, that turns an EV into a form of storage, holding daytime generation or cheap off-peak power for use later, and allowing exports when prices are favourable. This is the difference between bidirectional charging and smart charging, the latter shifting when a car charges but not discharging it.
The £650 figure is an average annual earning estimate from EDF's own research, not a guarantee, and it is measured against a smart charging baseline rather than against no managed charging at all. The trial's outcome depends on the SEG tariff rates available and on how often the car is plugged in and available. Households without solar panels, or without a compatible charger, are outside the scope of what has been announced. The wider question of whether an EV battery can substitute for a dedicated home battery is covered in EV charging and household energy independence, and the interaction with generation is set out in charging an EV from solar panels.
What happens next
The trial ends in February 2025, with EDF collecting data throughout1. Loughborough University and the University of Sheffield will conduct studies with participating customers1. No date has been reported for publication of the trial's findings, and no decision on a commercial offer beyond the trial has been announced1.
Sources1 cited
- Solar PV customers to earn cash and power home in new trial, edfenergy.com