EV charging needs a rethink

Jon Hiscock, chief executive of power systems technology company Fundamentals, highlights the need for more real-world data on charging behaviour to ensure network infrastructure can accommodate “unprecedented” surges in demand from electric vehicles.

National Grid predicts that 11 million plug-in electric vehicles (EVs) will be on UK roads by 2030. That’s up from around 500,000 today. With increasing petrol prices and government pledges to further incentivise clean transport, the rate of EV adoption is only set to accelerate. In turn, distribution network operators and distribution system operators will now be required to upgrade infrastructure to accommodate the surge in demand. The challenge is to ensure that local grids are robust enough to handle unprecedented changes in patterns of demand. Crucially, they need to avoid the network being overwhelmed by unexpected load spikes, leading to voltage drops, grey-outs and blackouts.

A key part of the solution to this problem is to look firstly at the demand side of the equation – what EV owners need and how they behave – rather than regarding it as a network supply issue. And it isn’t just about how they handle more vehicles. It’s also how we can facilitate faster, public charging stations.

EVs need smarter substations

Before distributors start aligning investment to reinforce their grids, we need a lot more real-world information on how EV owners charge their vehicles. Where, when, and how large are the surges in demand going to be?

The good news is that the technology exists to collect and analyse EV charging behaviours directly at the local substation level, using simple bolt-on data collection units and artificial intelligence. It’s what’s required to turn the previously dumb substations into smart stations to deal with the adoption of EVs.

The technology gathers information by detecting and measuring waveforms that are unique to EV charging. These measurements are linked to a satellite-based GPS system, which identifies precisely where charging is taking place. The data is then fed into an artificial intelligence algorithm which can learn and improve accuracy as more data is collected over time. Patterns of real-world charging behaviour then develop over days, weeks, and months.

This enables distribution grid operators to spot changes in demand from EV charging in real time, so they can react to balance loads quickly. Plus, they can plan for expected peaks in demand at specific times of the day and week, based on known patterns of driver behaviour.

Charging on the cheap

When we understand when, where, and how drivers charge their EVs in the real world, we can do two things. We can make smarter investments in grid infrastructure, based on accurate load predictions. We can also take action to change EV driver behaviour in ways that will benefit them, as well as helping to avoid grid-stressing peaks and balance demand.

The key to changing EV charging behaviour is providing incentives to consumers to make it a no-brainer to charge EVs when electricity is cheap and plentiful. This puts the grid under minimum stress. Practically, it means that instead of millions of drivers automatically activating their home chargers when they get back from work – when demand is already peaking with cooking, showers and (increasingly) heat pumps – we need to shift to charging into the night, when demand is low.

Smarter tariffs protect grids

The incentives to shift demand must be simple and provide tangible financial rewards for consumers. Mass uptake will not happen if people are forced to fiddle with apps and timers. They need a choice of deals that automatically charge their cars while they sleep, as well as a satisfying figure on their electricity bills, which highlights how much they’re saving.

Smart tariffs, specifically for EV owners, are already on offer from several electricity suppliers, ranging from set hours during the night when power is cheap, to even smarter time-of-use pricing, where charging is switched on and off remotely by the retailer to give customers the best deals. At the next level, thousands (or millions) of EV owners can be rewarded for making their car batteries part of a dynamic energy storage system, with power uploaded or downloaded automatically, to balance demand.

Energy retailers and grid operators must work together to make these smart tariffs even more widely available and appealing. Retailers will benefit from attracting customers. Grid operators can iron out peaks of demand, balance loads and avoid unnecessary reinforcement. EV owners will also get better value for money. Everyone wins.

Local charging for all

What we can see from the Norwegian market (where plug-in EVs already account for 85% of new car sales) suggests that most owners prefer to charge at home or at work and only use fast, but expensive, public chargers as an occasional backup.

However, not everyone in the UK has off-street parking where they can mount a wall charger. Many live in flats and terraced houses and are therefore forced to park on streets or local car parks. The answer must be a radical change to where chargers are located, and thereby the type of chargers available too.

It must become possible to develop standardised, relatively low-powered EV chargers that can be deployed in high quantities in virtually every street and car park – as is the case in some Chinese cities – with domestic-level pricing and contactless payment, together with many more free chargers in places like supermarkets.

Owners should eventually get used to charging their EVs as they charge their smart phones – little and often – in place of the old fossil fuel mindset of expecting a 400+ mile range per fuel stop, with a refill every week or two. Although this will only happen when EV chargers are almost as ubiquitous and user-friendly as phone chargers.

Speed isn’t everything

We still need lots more super-fast public chargers (Norwegian local governments are mandated by law to provide at least two every 15 miles or less). And, with EVs now being marketed with 350kWh charging capabilities, they will require significant investment in electricity distribution infrastructure.

Though they are not the only answer. Focus needs to shift to the local level, to make EV charging accessible and affordable for all, while avoiding the cost and disruption of unnecessary grid reinforcement.

The UK government has pledged to incentivise the switch to EVs – with some money but little detail. What we need now is urgent collaboration between Whitehall, Ofgem and every sector of the electricity industry to come up with a comprehensive strategy to match EV charging needs with grid capabilities at the lowest possible cost.