Despite all the scaremongering, EVs will not overload the electricity grid. It will cope and manage to juggle simultaneously the increased burden from distributed energy resources, heat pumps and the electrification of industry. Even so, Europe’s power grids do face an almighty challenge from the imminent rollout of 130 million EVs. If EV drivers are to charge wherever and whenever they choose, the existing grid infrastructure must be expanded, reinforced and digitized.
Electricity demand from EV charging is expected to grow by 11% per year, adding 200TWh by the end of this decade. By then, EVs will account for around 5% of total electricity demand in Europe.16 Any destabilizing impact will come not from demand growth but from thousands, or even millions, of EVs attempting to charge simultaneously – an “unmanaged charging” scenario. The more vehicles that connect to conventional electrical networks, the greater the risk to the adequacy, security and quality of power supply. This can lead to voltage drops, voltage fluctuations and power losses.17 DSOs need to stop that from happening.
Studies show that once EV penetration reaches 50%, network voltage deviations go beyond the standard level.18 For that reason, a “fit and forget” approach to charger connections risks exacerbating congestion in already heavily loaded grids. It will be further accentuated where peak load periods – for example, the end of the working day – coincide with peak EV charging periods.19
Analysis of the six most common charging use cases – residential (rural and urban), workplace, fleet hub, overnight stay hub and highway corridor – finds that peak load will increase by 21% to 90%, and transformer utilization will rise by 19% to 80% in 2035. In particular, EY analysts predict an 86% increase in peak load in multi-unit dwellings and a 90% increase on highway corridors where rapid and high-powered chargers draw large amounts of electricity from the grid. Transformers, in most cases, will have to operate above their rated capacity.
Managed charging is a game changer. It allows DSOs to transform the liability that comes from millions of EVs, charging at will, into an asset. Aided by real-time operational systems and advanced applications, managed charging will control the available capacity, time and duration of charging and mitigate the risk of overloading the grid. Charging can then take place when the electricity network has sufficient or surplus capacity, or when there is reduced demand (overnight, for instance) or when electricity is cheaper. Across different charging segments, managed charging indicates savings of 7% to 21% of peak load. And that is a win-win for the grid and for the customer.
Managed charging solutions can be supplier-managed, via a data connection, to channel energy in one direction, from the grid to the vehicle. In time, as vehicle-to-grid (V2G) technologies mature, EVs will become energy storage units on wheels. They will discharge power from the EV battery to the grid, or to a building, to level out energy production and consumption, reducing the need for additional generation or network reinforcement.
Other solutions are also being piloted. Solar distributed generation and storage co-location, for instance, may be deployed at highway corridor service stations where grid supply is insufficient for fast and superfast charging. Smart wires, to actively balance power flows on transmission lines, and wireless charging are novel concepts that are also being explored. Each of these demand-side solutions creates synergies between the grid and the EV. And though they will not resolve every scenario, they will help to mitigate the impact of large clusters of EVs charging simultaneously. They should:
- Reduce the need for massive grid investment
- Shift a centrally operated power system to a decentralized paradigm, populated by autonomous smart participants
- Allow EV drivers, operating as part of a decentralized and regulated model, to provide balancing capacity to the power system and to be properly remunerated for it
As these solutions mature, digitizing the grid to monitor and validate performance against assumptions will be critical for understanding, anticipating and optimizing customer behaviors, grid impacts and network needs, both now and long into the future.
DSOs will play a pivotal role in eMobility expansion. They are responsible for planning grid development and managing distribution operations and new connections for chargers. But they also have a social obligation to deliver the best environmental outcomes, at the lowest possible cost, by investing in the right locations, at the right time, while avoiding the risk of stranded assets. Their oversight of local networks allows them to identify areas of congestion, to assess the impact from EV charging on electricity demand, and to anticipate future grid investment needs. And, as Europe shifts to smart grids and local flexibility markets, DSOs will be equipped to integrate maturing solutions to shave peak consumption, reduce congestion, and improve power quality and reliability.
As the momentum for EVs gathers pace, planning the power system for electrification is a massive undertaking. To succeed, DSOs need:
- A better understanding of what is happening and where, by improving visibility over low- and medium-voltage networks
- The right skill sets, capabilities and investments to support a fully automated and harmonized customer experience to promote EV take-up
- An ability to track real-time behaviors from the vehicle to the grid and back again, to help manage an increasingly stressed distribution network
The extension of DSOs’ skill sets, and better execution of their responsibilities, will enhance customer centricity. It will help to bring about more innovative solutions, resulting in a better EV experience for drivers.