by Dr Bjorn Sturmberg, Dr Kathryn Lucas-Healey and Laura Jones, Battery Storage and Grid Integration Program, Australian National University

Vehicle-to-Grid technology presents a huge opportunity by making the batteries in electric vehicles available for grid services, but who will this benefit and who will drive uptake of the technology?

The energy sector is working hard to be more customer-centric, see for example the article Customers at the centre of the energy sector in the February 2022 issue of Utility magazine.

We are very supportive of this shift, but wish to raise the provocation that some innovations, such as Vehicle-to-Grid (V2G), offer primarily “grid wide” or public benefits.

Where this is the case, we believe it should be acknowledged. This enables a shift in focus from making private financial value propositions to disinterested customers to realising system wide benefits that flow to all customers. This is particularly important where value can be realised with minimal impact to customers.

In many cases, including that of electric vehicles (EVs) and V2G, this means reasserting the grid as a common resource and establishing systems that lead customers to act as good grid citizens by default.

This may be achieved using standards, incentives or connection conditions that make participation as seamless and low-impact as possible, rather than relying solely on market mechanisms where customers opt in on the promise of financial returns.

This discussion is analogous to appliance standards. Standards set a base level of performance all appliances must meet. Customers can of course still opt for higher again through purchasing decisions.

This provocation is informed by our experiences in REVS, Australia’s first fleet-scale trial of V2G technology. REVS brought together seven electricity and transport sector organisations (ActewAGL, the ACT Government, ANU, Nissan, SG Fleet, JET Charge and evoenergy) and as a result has provided practical insight across all facets of V2G.

REVS received funding support from ARENA. Further details can be found on the ARENA website here.


Bi-directional charging technology enables vehicles to discharge as well as charge their batteries. This requires bi-directional EVs and chargers.

The technology goes by many names depending on how it’s used: “Vehicle-to-grid” when used for grid services, “Vehicle-to-home” (V2H) or alternatively, “Vehicle-to-building” when used behind the meter of a home or building, or “Vehicle-to-load” (V2L) when used as a standalone power supply.

From the customer’s point of view there is a categoric difference between V2G and other use cases. V2H and V2L directly speak to customers’ needs: energy independence, resilience, and cost reduction. V2G in contrast solves grid challenges – things customers often don’t understand or care about.

This is akin to the difference between using stationary batteries for private purposes and enrolling them into a Virtual Power Plant (VPP) to serve grid or market needs – and indeed many of our conjectures can be translated from V2G to VPPs.

For the grid

To grid managers, the risks posed by mass EV uptake and the value proposition of V2G are as clear as they are sizable. Early analysis from the RACE for 2030 project suggests that unmanaged charging of EVs could double local peak demand by 2030, bringing with it a new wave of costly network upgrades.

The batteries in electric vehicles, on the other hand, present an enormous pool of fast, flexible energy storage distributed across the grid, just waiting to resolve peak demand issues and contribute to system security.

If all of Australia’s 19 million vehicles (including buses and trucks) were to be electrified, their batteries would be five times the capacity of the planned Snowy 2.0 scheme. This storage capacity would benefit all energy users by providing reserves that help manage unexpected disturbances as well as long periods of low wind and solar generation.

While V2G presents clear benefits to the grid, the same cannot necessarily be said for customers. From the perspective of EV owners, V2G presents a potential risk to the longevity of their asset and its availability when needed for mobility, while the primary benefits accrue to energy users collectively.

This risk is, in practice, minimal. Many V2G use cases – such as the grid stability use case we’re developing in REVS – deliver most of their value by the batteries being on call, and only require very short use of the battery (a 7.2 kW maximum power rating of an average home charger is tiny compared to the vehicle’s engine) on rare occasions.

In other cases, the V2G behaviour can be tightly controlled to keep batteries within their optimal range for mobility and battery health. This notwithstanding, the challenge remains to develop approaches that correctly calibrate EV owners’ perception of the risks and persuade them to participate – through mandated and/or market means.

By the grid?

If V2G is primarily “for the grid” then it follows that it should be made to work “by the grid”. Currently, grid standards and processes are barriers to V2G, rather than aids.

The Australian grid connection standard (AS4777), Australian Energy Market Operator’s (AEMO) specifications, and Clean Energy Council (CEC) classifications are misaligned with one another and with international norms. And distribution network connection agreements impose further restrictions.

Resolving these barriers (detailed in our REVS reports for ARENA) is a crucial first step, which is squarely the responsibility of grid actors.

Once these are resolved we must have an inclusive discussion to decide which aspects of V2G are best left as customer choices and which should be an expectation of good grid citizens and perhaps be made a requirement of grid connection. The former may be well served by tariff and VPPs offerings. The latter is better suited to standards and incentives.

A good example of an incentive is the UK’s Electric Vehicle Homecharge Scheme. Under this scheme chargers are only eligible for subsidies if they respond to energy system needs (through dynamic “smart” charging, not V2G). Australia meanwhile almost had an EV demand response standard in 2019 as part of the Greenhouse and Energy Minimum Standards (GEMS) Act. Whilst this stalled (as it was deemed outside of the act’s powers) there is no reason why an appropriate process cannot be established in the future.

The road ahead

Looking ahead, V2G is on the horizon as an attractive (arguably essential) feature of a clean and coupled transportenergy system. There is however still a long road to travel, and fortunately there are still many open choices. One non-negotiable is that V2G will only be realised through alignment of the energy sector, the transport sector, and society.

Our experience to date suggests that V2G may stand to be of greatest attraction “for the grid” and that there is much to be done “by the grid” to accelerate this innovation becoming a seamless part of the EV experience.

©2024 Utility Magazine. All rights reserved


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