Grid congestion is a growing challenge. As cities advocate for electrified transport, electric vehicles (EVs) appear to exacerbate the issue. However, they hold the key to a sustainable solution. EVs can balance the grid through Vehicle-to-Everything (V2X) technology. This allows the stored energy in EV batteries to flow back to the grid or buildings when needed. Smart charging and bidirectional energy transfer offer a greener, more efficient grid management. This will reduce the investment needed in more cables and provide a more reliable grid and power supply.
Tackling grid congestion in an electrified era
The relentless rise of urbanisation and economic growth brings with it a sharply increasing demand for energy. This demand, coupled with the imperative shift towards renewable energy, places unprecedented strain on our electrical grids. Germany, for example, has experienced significant grid congestion due to the slow expansion of the grid and the long distances over which electricity must be transported, causing bottlenecks. The grid is only stable with balanced power input and output, overloads pose a tangible threat of blackouts and system damage.
Indeed, the complexity of managing a grid with a high penetration of renewable energy sources (RES) is evident. These sources, while crucial for a sustainable future, add a layer of unpredictability to energy supply, contributing to grid congestion. With a surge in the adoption of electric vehicles (EVs), concerns mount over the grid’s capacity to cope. Yet, paradoxically, EVs, with their large-capacity batteries, are a potential ally in the battle against grid congestion.
Electric vehicles as part of the problem
The electrification of transport, while instrumental in reducing greenhouse gas emissions, initially seems to intensify grid congestion. Charging numerous EVs, especially during peak hours, adds a significant load to the electrical grid, exacerbating existing congestion issues. A study published in the Journal of Energy Storage highlights the challenges posed by the rapid integration of photovoltaic systems and EVs in low-voltage grids, which can lead to grid congestion[4]. This integration necessitates costly grid reinforcements or, alternatively, the development and application of smart charging algorithms to alleviate the strain on the grid.
Concerns are not unfounded. The introduction of shared electric vehicles in car-sharing schemes, for instance, requires a delicate balance between providing sufficient charging infrastructure and managing the load on the local grid. The concept of using shared EVs for smart charging, which has been shown to have the potential to mitigate grid congestion at relatively low car-sharing adoption rates, highlights the complexities of integrating EVs into the grid without exacerbating congestion.
Electric vehicles as part of the solution
However, the potential of EVs to support the grid is gaining recognition. Vehicle-to-Grid (V2G) technology can transform EVs into mobile energy storage units that not only draw power from the grid but can also supply it back when needed. V2G is not the only technology in which vehicles deliver power. The all encompassing term is Vehicle-to-Everything (V2X) which also includes Vehicle-to-Building (V2B), and Vehicle-to-Home (V2H), each designating different destinations for the electricity stored in EV batteries.
The V2G concept envisages an ecosystem where EVs contribute to grid stability by providing power during peak demand, thus avoiding the need to increase generation and transportation capacity. This facility is not merely theoretical. In Utrecht, the Netherlands, the car-sharing provider MyWheels, in collaboration with We Drive Solar, is piloting the use of shared EVs as ‘neighbourhood batteries’ capable of discharging power back to the grid. This innovative approach could alleviate grid congestion, particularly at times of high demand.
Smart charging and bidirectional energy flow
Smart charging is an integral part of how EVs can eliviate grid congestion, carefully orchestrating the charging of EVs to ensure a safe and reliable power supply without overloading the grid. This smart charging system uses communication and intelligence to balance grid demand and can be facilitated by smart charging control systems.
The ElaadNL project in the Netherlands is pioneering the standardisation of V2G technology, aiming to develop protocols for grid operators to use car batteries for extra flexibility. By harmonising the technology and protocols across the network, V2G can offer a consistent and scalable solution to support grid stability using locally produced sustainable energy.
Implementing V2X technologies
The practical implementation of V2G requires enabled vehicles, bidirectional chargers, and a communications link between the charger and the vehicle using V2G-compliant protocols. Moreover, for V2G to be a viable option, the EVs must be connected to the grid through charging stations that are compatible with bidirectional energy flow. This infrastructure is now slowly being rolled out in urban areas.
A simpler solution is specifically reducing charging power for EVs. GridShield, an initiative from the Dutch Topsector Energy, proposes an autonomous, decentralized intervention in the low-voltage network as a safeguard against congestion. This approach involves instructing charging stations to reduce consumption when required, an autonomous and decentralized control from the substation, ensuring compliance with data protection regulations. It provides a robust safety net capable of responding swiftly to emergencies without the vulnerabilities associated with centralized systems or mutual coordination that might be susceptible to communication disruptions or security breaches.
Economic implications
The economic implications of V2X technologies are multifaceted. Redispatch, a method to prevent grid congestion by adjusting the output of power stations, and feed-in management, which involves disconnecting renewable energy sources temporarily, cost consumers in Germany a combined total of ???878 million in 2016. These costs, added to the grid charge, highlight the financial burden of managing grid congestion using current methods.
V2G technologies could offer a cost-saving alternative by utilising the existing battery storage of EVs to manage grid loads. Research indicates that regulated discharging can extend battery life, and EV owners may engage in providing power to the grid during peak times and using off-peak power for charging. This suggests a shift in the economic model of energy distribution, potentially resulting in consumer savings and a more efficient use of energy resources.
Challenges and opportunities
Despite the promising potential of V2X, several challenges remain. The availability of suitable vehicles and charging stations is currently limited, and the impact of discharging on battery life is a subject of ongoing research. Regulatory adjustments are also necessary to allow for the kind of autonomous decentralized intervention proposed by GridShield. Moreover, private individuals and companies must introduce and use these concepts. This can be done with financial insentives or they could be implemented as contractual requirements to allow for the necessary capacity reductions.
Nevertheless, the opportunities are significant. The utilisation of EVs as home batteries can help alleviate grid congestion
