International Transport Forum brief suggests Smart Grid and EV technologies could be mutually beneficial; V2X potential
A new policy brief published by the Organisation for Economic Co-operation and Development’s (OECD) International Transport Forum (ITF) notes that existing electricity systems will need to be reconfigured to support the widespread adoption of electric mobility and suggests that Smart Grid technologies and EVs and EVs could be mutually beneficial. EVs could both benefit from and help to drive forward investment in Smart Grids.
EVs could grow to account for a substantial share of total electricity consumption and peak load, increasing peak demand by over 20% in some long term scenarios, according to the brief. The greater the increase in consumption, the larger the potential benefits from Smart Grid technologies that improve the ability of the electric utility to follow load, and schedule EV charging outside of peak hours.
The ITF brief defines a Smart Grid as an electricity network that uses digital monitoring technologies to efficiently deliver electricity wherever and whenever it is needed.
The ITF is an intergovernmental organization with 52 member countries and acts as a strategic think tank for transport policy and organizes an annual summit of ministers. The policy brief is based on a longer discussion paper prepared for the ITF by Trevor Morgan of Menecon Consulting in the UK. Among the top-level findings of the paper are:
Smart Grid technologies make it possible for electric vehicles to proliferate without overloading the electric supply industry and at the same time electric vehicles are driving investment in Smart Grid technologies;
Electric vehicles may be useful for matching intermittent solar and wind power supplies to demand, soaking up excess off-peak power supply and feeding power back into the grid when needed;
Electric cars may be attractive to some home-owners for their capacity to produce some back-up supply in case of power-cuts; and
Governments need to change the regulation of electricity prices to encourage the uptake of Smart Grid technologies and the use of cars for supplying power to the grid.
Smart Grid technologies enable not only the automatic shifting of EV charging to off-peak periods (smart charging), the paper notes, but also can, in the longer term, enable EVs to be used as distributed storage devices for the grid or for home.
In the longer term, there may be some potential for Smart Grid technologies to enable EVs to be used as distributed storage devices. EVs could feed electricity stored in their batteries back into the system (Vehicle-to-Grid, or V2G) or directly into the home or office (Vehicle-to-Home, or V2H). Vehicles are parked an average of 95% of the time, providing ample opportunity for their batteries to be used for V2G supply. An EV owner with no immediate need for his vehicle may be willing to feed power into the grid, if the price the grid company pays for this power is high enough.—Policy brief
The demand management and load following potential of Smart Grids needs to be exploited to compensate for the intermittency of renewable power supplies, the policy brief notes. Smart Grids also permit the storage potential of EV batteries to be used to smooth this variable renewable electricity output.
However, while vehicle-to-grid electricity supply is technically possible, potential barriers to adoption include:
Unpredictability: The availability of V2G capacity during peak demand periods is uncertain.
Battery efficiency: Technology is not yet available to design batteries efficient enough to be commercially viable under the frequent charge/discharge regime required for intensive V2G use.
Cost of managing fragmented V2G supply: While the Smart Grid technology already exists to manage V2G supply, it has not been demonstrated yet on a large scale. The sheer number of EV connection points that would need to be managed makes it prohibitively expensive at present.
In light of these factors, the potential for V2G in practice is likely to prove to be small relative to G2V unless charging times can be reduced significantly and battery storage capacity increased markedly.—Policy brief
On the other hand, V2H systems are currently leading the development of smart charging systems, with interest in plug-in hybrids as part of experiments with “positive energy buildings” that generate power on-site.
Much of the technology needed to integrate EVs into a Smart Grid is still under development, the paper notes, and will need to be demonstrated on a large scale for testing in real world operating conditions.
Adapting the regulatory framework for electricity supply will be essential to making G2V and V2G technically and commercially viable, according to the paper. Tariff structures will need to provide incentives for electricity companies to invest in Smart Grid technologies and also need to encourage G2V charging to be carried out in off-peak hours and incentivize V2G feed-in at peak times.
Too, tariffs will need to be sufficiently attractive for vehicle owners to make their batteries available to the grid operator; dynamic pricing will have to be made available to individual consumers as well as industry, with prices varying in real time and the introduction of peak time rebates for V2G.
Governments will have to change the regulation of electricity tariffs to permit and encourage necessary innovation in pricing.—Policy brief
July 2012 Policy Brief: Smart Grids and Electric Vehicles: Made for each other?
April 2012 discussion paper Nº 2012-02: Smart Grids and Electric Vehicles: Made for each other?