Companies talking about the interaction between battery electric vehicles and the electricity grid often talk about V1G and V2G interactions. What do these bits of jargon mean, and what are the implications for fleet operators?
Both refer to more complex interactions than simply connecting the battery vehicle to its charging point and starting to fill the battery. The two options were both on the agenda in a recent discussion on ‘Grid-Integrated Electric Buses and Trucks’ organised by Smart Energy Europe (SmartEn).
V1G is generally referred to as ‘smart charging’. In its simplest form this is now routine for many electric car drivers who have their own charging points and are on an appropriate tariff. They plug in any time, but the vehicle does not charge until a period when wholesale electricity is generally much cheaper and suppliers pass on some of the saving to consumers. V1G can be smarter than this. If suppliers predict that there will be surplus power for a short period they can offer it cheap for an hour or two. Even smarter, charging can be interrupted for a short period from as little as a few minutes, which in aggregate allows the grid to ‘ride through’ a period of instability. As discussed previously in FCZ, smart charger users benefit financially from being flexible in these ways.
V2G is shorthand for ‘vehicle to grid’ and is sometimes referred to as ‘bi-directional charging’. This would allow battery vehicle owners to export energy to the grid and it presents a new opportunity, but also new challenges. It’s not just about reversing the flow, although that has implications on a system that was built on the assumption of one-way traffic between local network and user. In addition, there are very tight controls on how power is fed into the grid and how it interacts second by second. That has made V2G slow to arrive, but now commercial use appears to be closer.
Speakers at the meeting noted that the standards needed to underpin V2G equipment are being finalised by the European Commission’s Sustainable Transport Forum, and an action plan is expected within the next few weeks. The meeting also heard from Benjamin Kroupa, senior advisor at grid operator TenneT (which serves the Netherlands and parts of Germany). He highlighted the SPIRIT-E programme to demonstrate the uses of V2G, saying the programme was moving on to the long haul sector (above 500km/day).
Kai Tullius, policy officer at DG MOVE in the European Commission, talked about the potential value available from electric trucks.
Tullius said heavy duty vehicles like trucks have advantages over domestic EVs when providing flexibility. First is their size: accessing the energy stored in an HDV fleet of, say, 100 vehicles would require access to at least ten times that many domestic vehicles. But equally important is management. Each domestic EV would have to be qualified, contracted and paid separately, resulting in a far higher admin cost than dealing with one or two freight companies. What is more, HDVs work to a strict schedule and being sure what vehicle will be where, and when, is a big advantage when bidding into the flexibility services market. Tullius said meeting EU targets would see 400,000 to 600,000 electric lorries in the bloc by 2030 (to be exact these are ‘zero emission’ lorries, but the EC expects these will be mostly electric, as other options are not so advanced).
Tennet’s Kroupa said V1G markets “are already showing a lot of value”. With the rules for V2G still being settled, he said, for fleet operators “we need to make sure we are not violating their trust” around their strict schedules so they can “tap into energy markets in the right way”.
Quentin Maitre, chief strategy and development officer at EDF’s DREEV subsidiary, a joint venture set up to explore V2G options, agreed that “the cost of electricity is completely key for logistics companies. They are used to buying the cheapest fuel”. He argues that flexibility is a way to cut the ‘fuel cost’ (ie electricity price) for battery vehicles. He showed DREEV figures claiming the average cost of electricity would be 42% lower if lorries participated in V1G services. But there is a catch. If the service requires the battery to discharge, or stop charging, it requires either more time to recover the charge or an oversized grid connection to recharge more quickly. To achieve Maitre’s 42% saving required double the charger capacity (150kW rather than 75kW in his example).
Tullius said there was market interest from charging providers because “it can be quite lucrative”. But the ‘pull factor’ on the demand side is more difficult. He said providing flexibility could help address one obstacle - the total cost of ownership – but he also highlighted that the problem with installing chargers of any size across Europe is grid access.
In this case, what applies in the EU also applies in the UK: with grid access at a premium and users needing to upsize to gain flexibility benefits, potential e-truck users are caught in a vicious circle.
