Trialling a pioneering green technology concept: A TfL and E-Flex partnership

E-Flex is our ambitious project to explore the benefits of Vehicle-To-Grid (V2G) technology, through direct first-hand fleet experience. As part of our introduction to the crucial partners that are helping make E-Flex a success, today we are happy to hear directly from TfL.


As the Transport Authority for London, TfL wants to know as much about the technology that can not only make a difference today, but most importantly what can make a difference tomorrow.

One of the big ambitions that I’ve been tasked with helping make a reality, on behalf of TfL, is that of the Mayor’s pledge to make London zero carbon and emission free. This will not only make life better for the millions of people who live and work in the Capital, but will help encourage the take-up of clean energy technology that will hopefully have efficiency and cost saving opportunities for fleets and individual drivers.

To help achieve this, myself and the team want to explore all the opportunities for Electric Vehicle (EV) technology and the infrastructure needed to support it.

Looking at the whole picture

When it comes to EV technology, we should avoid a piecemeal approach to its deployment. You have to look at the bigger picture, which is where TfL comes in. We understand the need for a holistic plan for the transport and energy systems that benefits from the expertise of a variety of innovators and interested stakeholders.

The infrastructure that underpins the system is crucial, which is why I’m passionate to find out more about V2G technology. Being able to potentially turn entire fleets into portable energy sources has great potential for how we manage power for our cities and EV fleets.

Potential benefits are clear in principle, but with the technology still being relatively new, the E-Flex project will let us answer several questions the industry has about the opportunity. These focus on everything from concerns around EV battery degradation to the value that can be derived from V2G-enabled charging infrastructure for fleets.

What’s the value in V2G?

This is a key question that we want to answer through this project. We know that pairing EVs with V2G technology must to generate value for individual drivers and fleets. This could be helping them reduce emissions to help achieve our ambition of a carbon free city, or by providing additional sources of revenue through being able to sell back excess energy or provide grid services.

If you consider what this technology means, we will in the future have millions of EVs plugged in to create what’s known as a virtual power plant. These EV batteries – as mobile energy storage devices, can potentially be turned up or down (charged or discharged within user-specified limits) depending on whether there’s surplus renewable generation or a spike in energy demand, which is an exciting concept. Being able to define where the absolute value lies in this is going to be crucial. As it stands, there is very little research and scarce data – and  estimates vary from a few pounds to thousands!

Another area for investigation is that of battery degradation, which we know from talking with fleet managers is something that is an important issue. Through this trial, we hope to be able to show how this can be quantified, helping to raise understanding and also make the case for EVs being an efficient and cost saving solution for the short term and especially with V2G increasing in deployment in the longer-term.

The value in collaboration

Working with the brightest minds and most innovative forward-thinking fleets and technology providers is key to creating the next generation of infrastructure. There are many questions to answer about how V2G can help make our cities cleaner and energy usage smarter, but the work being done in E-Flex will help answer these.

We would love to hear from you if you are interested in being one of the fleets involved, so please get in touch.