The proportion of grid electricity generated by renewables such as wind and solar energy fluctuates depending on how hard the wind is blowing or how strong the sun is shining. This can lead to a huge variation in the grid power available, which can be a problem for power companies. But, if householders and businesses can be flexible about when they charge their EVs, then they can help to balance the grid and support renewable power generation.
How EVs can help balance the grid
To understand how important smart EV charging can be in helping even out peaks and troughs in the electrical grid it is useful to understand how electricity generation is changing.
Until recently most power stations relied on coal and gas to power generators. Now countries’ electrical grids are increasingly powered by renewables. According to Denmark’s national grid, Energinet, in 2019 half the country’s electricity was generated by renewables, while in Germany the figure was only slightly lower at 46%.
While fossil fuel generating capacity could be turned on and off relatively easily to match variations in electrical requirement, matching demand with a renewable-powered grid is far more difficult; the wind cannot be made to blow harder or the sun to shine brighter to match desired levels. With grids increasingly powered by renewables, electrical demand has to follow supply.
An intelligent EV charging point, which can communicate with the grid, can help balance demand with supply. A smart EV charger will enable an EV to be charged when weather conditions allow and there is a surfeit of low carbon, low cost power available. Similarly, because a smart EV charger can adapt charging speed and time, it can also help minimise demand on the grid when renewable-generated power is low.
The flexibility of controlled EV charging
According to the International Energy Agency’s 2019 Global EV Outlook report, controlled EV charging is well suited to contribute to increased flexibility in power systems by managing charging patterns to coincide with low demand periods.
In addition to helping balance the grid the IEA say that installing an EV charger will also enable an EV to be linked to the electric infrastructure. Most people think installing an EV charger is about enabling electricity to flow from the grid to the car. However, Vehicle to Grid (V2G) technology enables electricity to flow from the grid to the car and from the car to the grid, which will allow users and utilities to benefit from the EV’s battery for purposes other than powering the vehicle.
There are several trials currently underway looking at the effectiveness of combining battery storage from multiple EVs to create what is effectively one giant battery, to deliver V2G benefits on a large scale. Many major car manufacturers, including Jaguar Land Rover, Nissan, Volkswagen and Fiat Chrysler, are involved with V2G research projects and large V2G trials. If successful, these could make electricity grids around the globe more resilient by supplying EV battery power when grid demand is at its peak and by providing a ready source of electricity if there is a power outage.
The EV as a mobile electricity storage device
Since most vehicles spend up to 90% of their time parked, installation of an EV charger will enable users to effectively turn their electric vehicle into a mobile electricity storage device. It is a development which could also see customers receiving money, or free energy, in exchange for allowing their EV to be used to provide the grid balancing service.
V2G technology is one of the emerging benefits of installing a smart EV charger. It is only by connecting to the grid that homes or businesses can be flexible about when they charge their EV, maintaining a balanced grid and encouraging the growth of renewables for electricity generation.