Electrifying vehicles – how grids will cope
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- Feb 6, 2020 12:35 pm GMTFeb 3, 2020 6:26 pm GMT
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This item is part of the Special Issue - 2020-01 - Predictions & Trends, click here for more
Electric vehicle (EV) numbers are on the rise as consumers start to ditch petrol and diesel in a bid to do their bit to tackle climate change. As car manufacturers ramp up production of electric vehicles to keep up with a growing demand and businesses look to electrify their fleets and install charging points, electricity grids will be under increasing pressure to cope with the impending surge in demand for power.
The local distribution, national transmission and generation infrastructure of the electricity system will all be impacted as EVs become more mainstream – unless the charging process can be effectively managed, EVs have the potential to put enormous strain on the grid. Peak charging times, the time of day that electricity demand already peaks – around 6pm – would be further impacted by people returning from work and plugging in their car.
Consequently, what we’re likely to see in 2020 is significant progress in the EV charging arena, with capabilities such as smart charging and Vehicle to Grid (V2G) being introduced to alleviate the pressure.
Emerging technologies, such as smart charging, will enable EVs to determine the best time to charge and in turn, alleviate potential issues caused by charging during peak times. Once plugged in, the EV or charger will examine parameters relating to the demand on the grid, then decide on the most optimal time to charge. In time, such systems are likely to become even more flexible – responding to price signals and local demand, enabling a EV owner to benefit from charging at a much reduced cost in return for being flexible or pay a premium if the charge is required immediately with no interruption.
Giving back to the grid
Grid operators are heavily reliant on providers of so-called balancing services that can absorb power when generation outstrips demand, or supply power when demand is higher than generation. Such services are required to smooth fluctuations in output from renewable generation and demand for balancing services is set to increase as more renewables are added to reduce carbon emissions from electricity generation.
This is where Vehicle to Grid (V2G) comes in, which will allow EV owners to absorb electricity when supply is plentiful and give it back to the grid when demand is high. Plug-in EVs, including battery electric vehicles (BEVs), and plug-in hybrids (PHEVs) will all have the ability to export electricity to the utility provider in time. Utility providers could then effectively draw electricity from V2G connected cars, with EV owners benefitting from financial incentives, being either directly compensated or given preferential energy rates for charging. Early UK trials have promised participants savings of up to £570 a year.
Although we’re yet to see widescale deployment of V2G, several trials have been taking place to test its efficacy, which could hold the answer to alleviating demand on the grid as more renewable and unpredictable generation comes online and EV adoption increases.
Questions remain, however, over the operational challenges of such dynamic systems. EVs don’t always charge in the same location, so who benefits? The EV owner, the owner of the charging point or the electricity supplier?
Before fully dynamic smart charging and V2G are introduced into the mainstream, back-end systems will need to be in place that can analyse multiple parameters necessary for effective V2G operation and appropriately assign financial benefits. Real-time information, such as electricity prices, grid frequency, predicted generation availability, weather data and EV owner preferences will all need to factor.
EV owners will also want to feel in control of the whole process, knowing they are benefiting financially from allowing access to a small part of their EV’s battery, but also knowing the vehicle is available for them to use when required. In all likelihood V2G preferences will be set within a smartphone app that will allow a user to define the range their car has at any given time, how much battery capacity they are willing to allow access to and a schedule of when the vehicle will be in use.
An app-driven system will allow them to choose preferred charging times and range, and the system will operate to ensure the vehicle charges sufficiently at the lowest cost by charging and discharging as required. The software will then determine how and when the car charges in order to minimise the cost to charge and how and when the battery can be accessed for demand response services, whilst providing the user with data regarding cost and benefit. The ability to override the software and simply ‘charge now as quickly as possible’ will also be key in ensuring V2G adoption.
Stand-alone battery storage
Whilst EV adoption rates sill remain low in the overall scheme of new vehicle sales and V2G remains at the trial stage, we will likely see continued investment in standalone, behind-the-meter battery storage – essentially a battery system that exists solely to provide grid balancing services in return for a revenue stream.
However, as EV adoption rates increase and V2G becomes a standard feature, the market for behind-the-meter storage may decline along with the revenues associated with providing these services. When purchasing an EV, the battery is a necessary part of the machine, it just so happens that it is also capable of providing balancing services – the latter being a side benefit rather the sole reason for investment.
Whilst a single EV will not be able to absorb or supply the same quantity of power as a standalone battery, in time the number of EVs available to provide V2G balancing services will result in access to only a small proportion of the battery of each, collectively equating to enormous reserves. When this point is reached, the requirement for standalone battery storage may disappear altogether.
There’s no doubt that increased adoption of EVs could put a major strain on the electricity grid, however, as we shift electricity generation away from fossil-fuels to intermittent renewables, EVs could also effectively solve the problem they create and will be key in supporting a stable, greener, grid in the future.