From DNOs to drivers, are we ready for the EV revolution?

Dunstan Power, Director, Versinetic

The appetite for electric vehicles (EVs) shows no indication of easing with 260,000 battery electric vehicles on Britain’s by the end of May 2021 – 535,000 if we take into account plug-in hybrids. This – coupled with the £1.3bn pot in green transport funding to support the installation of public EV charging stations and the 2030 ban on new petrol and diesel-fuelled cars – has accelerated the switch to EVs.

With EVs on the rise and an increased emphasis on clean energy, Dunstan Power examines whether the National Grid, and, indeed, we as drivers are ready for the EV-revolution.

Is the National Grid up to the task?

Our environment-consciousness, together with the uptake of cleaner, renewable fuel has resulted in a decrease in our energy usage compared to twenty years ago. Distribution Network Operators are confident that energy supply will meet the additional demands on the Grid, concluding that even an overnight switch to electric vehicles now would only require a 10% increase in electricity.

If enough capacity exists in the National Grid to tackle a switch to EVs – in terms of load fluctuation – let’s turn our attention to electricity supply at street level.

7,200 kilometres (4,470 miles) of overhead line, 1,400 kilometres (870 miles) of underground cable and 330 substations [1] make up National Grid infrastructure. In addition, there are 400,000 UK-based substations in total, each of them servicing around 1,500 customers.

Power is supplied to homes and businesses through a step-down process at substations to ensure usable levels for consumers. Although the National Grid states there will be sufficient capacity to service pan-UK uptake of EVs, if everyone were to charge their EV using a standard 7kW EV during peak times, there is the danger of electricity overload.

Most EV owners will, naturally, require a charging station on their driveway. However, whether or not domestic wiring can take on EV-charging in conjunction with running other household appliances is still to be determined – with configurations ranging between TT, TNS and TNCS regulations. 

Are our energy consumption habits EV-ready?

We’ve taken a look at the energy capacity, distribution level and domestic wiring to determine how ready we are for the EV-revolution. Now let’s examine our habits as consumers of energy and drivers.

If our current habits are anything to go by, energy use for EVs is at its highest between the hours of 6pm and 8pm at the end of a typical working day, when vehicles are recharged -much in the same way one recharges a phone at the end of the day.

This may vary organically due to the rise of working from home in the past 18 months during the pandemic – however, change will take time. The make, model and size of a car battery determines how often it will deplete. The range is currently between 140-300 miles.

Regardless of the fact that most drivers do not come close to these distances in a day and so should not need to recharge their vehicle daily. However, psychologically, the phenomenon of range anxiety should be factored in – namely the concern that an EV’s battery will run flat en route without the amenity of a nearby charging facility.

Allaying range anxiety would mean more accessible charging points both in workplaces as well as places where petrol pumps are primarily located such as in supermarkets and service stations.

Here, energy companies could also play a role in changing post-work charging habits through increased tariffs at peak times to relieve the pressure on the National Grid. In any case, controlled charging deployed through software or a regulatory process is a contentious issue. 

Smart charging – a step toward balancing future energy demand?

Smart or intelligent chargers that are both flexible with inbuilt smart technology are a key to resolving the increased energy demands engendered by EVs. This sentiment is echoed by the government’s Energy Taskforce which recommends that EV chargers need to be “smart” by design. 

Smart chargers are remote-control chargers that allow a cloud-based back office third-party to stipulate when a charger can be used, the pumps are amount of energy used, while also allowing customers to charge their vehicles during off-peak times, thereby minimising charging costs. Simply put, a smart charger will replenish an EV battery when required but will also pause during high tariff times when pressure on the grid is at its peak.

Firstly, there’s load balancing of cars, where the electric charger distributes power across multiple vehicles. Even in a local context, such as having two EVs per household, a smart charger could load balance between them.

The benefit of smart charging is that it not only sets and controls the charging management across charging stations for efficiency, but it does so without overload or an increase in power supply costs.

It ensures an electric vehicle household or business fleet is ready for each day’s use – just as if conventional petrol- and diesel-powered vehicles were used.

As well as allowing for the charging of multiple EVs within a household, load balancing facilitates workplace EV charging and powers electric vehicle fleets, with pilot schemes demonstrating that load balancing results in reduced costs for cabling and substation upgrades.

Another critical benefit is that load balancing lessens the need to upgrade power infrastructure, though optimising charging by assessing the available charging capacity. This in turn adjusts charging rates and times.

A user can minimise their electricity bill by charging their car when tariffs are low and not charging when they’re high. Thus, a third-party operator – e.g., DNO – could constrain a network of chargers’ charging rates, in order to prevent grid overload.

V2G – Vehicle-to-Grid

In a Vehicle-to-Building/Vehicle-to-Grid (V2B/V2G) setup, electric vehicle batteries can be used as a short-term energy source for the building’s energy load, which can lead to the reduction of energy costs during peak periods.

With V2B, drivers can use the EV battery to store energy at no extra cost, which can then be used to power homes or offices at night during peak energy rate hours.

V2G sees excess electricity sold back to the grid, as you would with a net-metered solar panel system. V2G has the added macro advantage of a grid load balancing effect and is being piloted in the UK by Octopus Energy, with its Powerloop project. V2G can also be used as an emergency backup to run a house in case of grid failure. Frustratingly, however, most cars, charge points and building infrastructure do not currently support this operation.

Adaptable, intelligent charging solution

To resolve the challenges that mass EV adoption will bring, we need to consider viable smart charging solutions that take into consideration load limits of power substations and building infrastructure.

Smart charging technologies must be easy to use if they are to be successful in wide adoption. With that in mind, we co-developed ViGiL (VehIcle-to-Grid Intelligent controL), the UK’s first end-to-end, fully integrated Vehicle-to-Grid system.

ViGiL was a proof of concept and is an off-vehicle communication and control platform especially designed for different types of V2G/V2B charging points. It manages energy dispatch between EVs and buildings, while ensuring that the voltage/thermal distribution limits are never exceeded.

EVs are growing in popularity and as consumers become more comfortable with them, we will see multi-EV households UK-wide and, in the case of businesses, multi-fleet EVs.

Smart charging technologies need to grow in tandem with the end-users needs – if only to avoid constantly replacing smart chargers, which is neither cost-effective nor environmentally friendly.

Working with smart charger manufacturers, we have found that there is no one size fits all, hence the need for modular components or smart chargers that can be adapted to different business needs.

For example, our local controller module LINKRAY, sits passively between the charge station management system and charge points, allowing load balancing of groups of chargers based on local site meter readings, even when their cloud management system is offline.

If the country-wide adoption of electric vehicles is to become a reality over the next decade, the concerns and habits of EV drivers really do need to be taken into greater consideration.

Perhaps most importantly, accessible, intelligent and easy-to-use smart charging technologies that are compatible with all EVs are paramount. They need to bridge both the shortcomings of the grid and domestic infrastructure moving forward.