Will Our Power Stations Be Able To Cope With More And More Electric Cars?
It’s a good question and we set out to answer it here.
Electrical power is ubiquitous and as much a staple of modern life as water and food. But while there may be variations in daily use, what would happen to the energy grid if everybody suddenly switched to electric vehicles.
National grids are responsible for a country’s energy generation, typically via a mix of coal, gas or nuclear power stations as well as an increasing amount of renewables. They’re also responsible for the physical energy transmission, linking power stations to consumers via a system of cables, transformers and substations, so that before the electricity gets to our homes, the voltage has been reduced to a safe level.
Balancing both energy demand and supply is known as system frequency, and the flatter we can make a demand curve, the more efficient the electricity supply can be and the cheaper that energy becomes. It’s safe to say that electric cars will drive up electricity demand, but it’s the shape of that demand profile that will really dictate how much, or how little, the grid will need to adapt in order to cope.
In short, this is an issue of power, not energy. If everybody plugged in their cars at the same time everybody is also making their dinner, having a shower or turning on the lights, then the grid will experience a power-demand peak. Grids have been developed to support these peaks and prevent power blackouts, but extending these peaks is an expensive business, because it requires more energy generation, which means building another power station.
Instead, making the grid smarter, via modeling, forecasting and even large-scale battery storage can help soften those short-term demand spikes, which is known as ‘peak shaving’. In effect, the grid is making better use of the energy it already creates. Time of use tariffs, designed to encourage people to charge their cars when demand is low, can also be used to support peak shaving and prevent localized restraints.
The cost and installation of renewables used to be a huge stumbling block, but today, wind and solar are frequently the cheapest source of energy creation, helping our total energy mix become much cleaner.
But due to the nature of the sun shining and the wind blowing, this energy creation is also highly volatile, which is why battery storage should be used, both to capture excess energy on those sunny or windy days, but also to help defer those bigger grid connections.
The latest rapid charging hubs are now often installed with battery storage, so they can trickle charge energy from the grid in, but discharge from the batteries at a higher output. It means the existing grid connection doesn’t require upgrading because it’s unaffected by those local surges in demand.
Almost all EVs now feature apps that allow owners to schedule charging for later, so letting both car and grid talk to each other also helps to balance demand in real-time.
Another technology being researched by carmakers, and already used in limited markets, is vehicle to grid (V2G). It lets owners transfer the energy that’s in their car’s battery – back to the network during times of peak demand, which generates a nice income and helps to balance the grid.
So a combination of load balancing, smart charging and battery storage will mean the growth in global energy demand will be controlled despite an impending surge of EV sales. It should also provide grid engineers with the breathing space to prioritize analytical tools and network reinforcements where they are most needed.
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