Seen as a major way to reduce greenhouse gas emissions, electric vehicles (EVs) are critical to the UK meeting Government’s plans to reduce carbon emissions by 77% by 2035 compared to 1990 levels. Sam Illsley, Head of Public Sector at Mer, Statkraft’s EV charging business, examines the role of intelligent technology to address the key challenges our infrastructure will face.
The transition to EVs is gathering pace and is advancing changes – legislative, commercial and societal – across all areas of the country. The proportion of EVs being sold is on the increase. In 2022, battery electric vehicles (BEV) accounted for 16.6% of all new car sales, and plug-in hybrid EVs (PHEVs) 6.3%.
Private EV car owners and drivers have a number of options for charging their vehicles from home, workplace and public charge points. As businesses, local authorities and emergency services transition their fleets to electric vehicles, back-to-base or depot charging is an additional option.
Regardless of whether it’s public or fleet charging, every EV charge point operator (CPO) faces the challenge of ensuring their power demand is met by the available supply. This is driving CPOs to look for innovative ways to address the challenge. Building intelligence into the charge point technology is playing a key role, which will develop further as the infrastructure evolves to meet new challenges.
City councils and local authorities are key partners in this shift in transportation because of their ability to build for the future and shape the way this much-needed infrastructure will be delivered across both urban and rural areas.
Rapid EV charging
Generally, most rapid charging facilities are located out-of-town to capture the on-route charging market. The business case for charging at these facilities is well established, with the infrastructure being upgraded and expanded to meet current and anticipated EV adoption.
As you move further into urban areas, the provision of rapid charging is reduced. Here, charging locations typically comprise one or two chargers.
It is more common to see AC fast charging in the city centre. This is due to the long-held view that we use fast charging as our primary charging method and rapid as our on-route facilitator. While we accept that this is the case for those with access to off-street parking, the same can’t be said for vehicles that park overnight on the street. However, if we consider rapid charging in the urban environment, the faster top up speeds that an ultra-rapid charger provides offers flexibility and convenience for those who can’t charge elsewhere.
Focusing demand at a single location will assist in developing a sustainable business model for local authorities or owners of public land. This does, inevitably put pressure on the local grid and sub-stations to match demand with supply.
Shifts to address barriers
Both technology and behavioural shifts have already helped to address some of the major barriers to adoption.
While ‘range anxiety’ was commonplace a few years ago, today’s EVs now have bigger, more efficient engines and greater battery capacity to extend their range.
As vehicles can travel further between charges, the energy requirement for recharging will be greater. The average length of time to recharge on 50kW will increase, and in turn will decrease throughput and convenience. DC charging speeds have increased to address this, and modern chargers can provide charging speeds up to 350kW. To put it in context, a 50kW rapid charger adds around 80-100 miles of range in half an hour, whereas with a 150kW charger, the same could be done in 10 minutes.
On a more human level, people are adjusting their behaviours as EVs and EV charging becomes normalised. Someone who drives 20 miles a day realises that they don’t need to charge for a 300-mile journey. Because electricity is everywhere, drivers no longer have to travel to refuel as they would with a petrol or diesel car. They recharge on the go. Wherever EVs are stationary is a good place to install a charger.
So, there’s a case for both bigger, faster chargers and greater availability. All of this puts a strain on the local grid network.
Scaling up electric vehicle charging infrastructure
Adding more chargers to public charging sites is increasingly commonplace. Where you might once have seen a couple of charge points in a car park, for example, you are now more likely to see a bank of ten or twelve. This of course makes it more attractive for EV owners and more lucrative for the site owner, be they a local authority, retail unit or car park provider.
When EVs charge, they can pull on a full charge for as long as possible. For a few vehicles charging at the same time, this can cause problems. Five, ten or twenty charge points running simultaneously consumes a lot of energy.
Traditionally, the way to get more power to the site was to pay the district network operator (DNO) to upgrade the local infrastructure. An expensive enough undertaking even if the DNO has capacity. A DNO upgrade may not deliver a return on investment for decades and can also take a long time to complete – 18 months or more.
The answer lies in load balancing. This enables more charge points to be located on site at a lower cost than a DNO upgrade, providing the flexibility for expansion.
Load balancing and smart charging
Load balancing is all about fairly distributing the available power to multiple vehicles. Smart chargers can be programmed to take care of this automatically.
To give a basic example, a single vehicle on a 22kW fast charger with two sockets will draw the full 22kW (if the vehicle is capable). When a second vehicle connects to the other socket, each vehicle gets 11kW. Smart chargers like Mer’s have this capability embedded in the hardware. Building this out to a bank of smart charging points enables them to be connected to create a smart charging network. The network understands how much power is available in total, and the chargers communicate with each other to automatically ramp up and down the charge they provide to the vehicles to remain under the limit.
If a site reaches a point where all sockets are in use and there is insufficient power to charge all the vehicles at once, the smart chargers start alternating. Unit one stops while units two and three continue to charge. Then unit two stops and units one and three charge.
Dynamic load balancing
In a workplace environment, where the available energy is used to power lighting, data centres, lifts or manufacturing plant, the EV charging infrastructure needs to take into account the dynamic load.
Where this happens, it pays to nominate one charge point as the master unit and connect it to the building management system (BMS) or energy management system (EMS). The charge point network will be able to get real time updates about the power parameters in which it must operate, and the network can then ramp up or down based on the live data from the BMS.
Where there is access to energy storage or renewable energy generation, dynamic load balancing can integrate with those sources. By linking the network to an EMS or BMS, charge points can be instructed to draw energy from the battery or renewable sources.
Intelligence in EV charging infrastructure is all about using technology to create a more holistic approach to energy generation, usage and management.