SM ART GRIDS
THE V2G REVOLUTION:
HOW ELECTRIC VEHICLES CAN HELP STABILISE THE GRID In the past, increased uptake of electric vehicles has been considered a potential challenge to electricity grids, mostly due to the energy required to charge them and the likelihood of charging occurring during peak demand times. Yet this doesn’t need to be the case. With the advent of smart charging and vehicle-togrid (V2G) technologies, the charging and storage capabilities of electric vehicles could make them valuable assets to electricity networks, helping enhance grid stability within Australia and worldwide.
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he uptake of electric vehicles (EVs) is on the rise around the world, with consumers drawn to benefits including reduced emissions (especially when charged with renewable energy), increased efficiency, and lower running costs compared to internal combustion engine vehicles (ICVs or ICEVS). While electric vehicle adoption within Australia has been slower than in other developed countries, modelling by the Bureau of Infrastructure, Transport and Regional Economies suggests that demand will expand rapidly over coming years, with EVs making up around 50 per cent of new vehicle purchases by 2035. However, a higher number of EVs needing to be charged could potentially create demand management problems for electricity networks, depending how the charging load is distributed. If many EVs are charged at the same time, during peak demand periods, electricity demand could exceed the current capacity of the network, necessitating expensive infrastructure investment to increase generation and supply, and increasing electricity prices. Many EV owners currently charge their vehicles in the early evening when they get home from work, which is also usually when general demand peaks. Depending on the weather and season, the period of greatest demand often also occurs when one of the largest intermittent renewable energy sources, solar PV, is not generating. Research suggests that, as things currently stand, Australian networks can only support 5–10 per cent EV penetration in a scenario
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of uncontrolled charging before encountering demand management issues that threaten grid stability. Thankfully, technological innovation is offering solutions to this issue, potentially transforming rapidly expanding EV uptake from a gridstability threat to a grid-stability asset.
EV CHARGING GETS SMART Smart charging, otherwise known as V1G or unidirectional V2G, enables charging to occur during optimum periods when the demand on the grid is low and renewable generation is strongest, instead of beginning the moment a vehicle’s owner plugs it into the grid. The electric car or other vehicle is plugged into a smart charger, which communicates in real-time with a centralised platform connected to the grid, other smart EV chargers, and other smart devices and infrastructure. Using data about how much energy the vehicle needs and current loads on the grid, the charging operator controls the time and rate of charging through artificial intelligence. As a result, charging is optimised to ensure all vehicles connected to the platform get the charge they require, without overtaxing the grid. As an added benefit, the smart chargers can respond to wholesale electricity prices, saving EV owners money by charging vehicles when costs are lower. By shifting and balancing the charging load, smart charging can play a pivotal role in avoiding the problems associated with uncontrolled EV charging. It can also help absorb excess renewable energy that may
UTILITY • AUGUST 2021
otherwise affect grid stability, such as that generated during sunny periods in areas of high rooftop-solar penetration, allowing it to be stored in the vehicles’ batteries. According to recent research, the current Australian grid could support 60-70 per cent EV penetration if charging is intelligently controlled (up from the previously mentioned 5-10 per cent uncontrolled) and electricity costs would reduce by 4-6 per cent (instead of increasing 6.6 per cent under uncontrolled charging). Using smart charging alone, power flow remains unidirectional, from the grid to the EV. Thus, the vehicle represents a load on the grid, albeit an intelligently managed one. The next technological step enables bidirectional power flow, where energy stored in EV batteries can be discharged back into the grid under certain circumstances.
V2G TECHNOLOGY: THE NEXT FRONTIER In comparison to smart charging, vehicle-to-grid (V2G) technology operates via the same principles of real-time communication between EVs and a centralised artificially intelligent electricity network platform. The key difference is that it also incorporates the capability for bidirectional energy flow. In other words, electricity can also flow from the car battery to the grid, essentially allowing EVs to act as mobile energy storage assets that can support the grid if required. When connected to the grid, the EV operates just like a residential battery system. (There are even suggestions that EVs could largely replace
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