AC vs DC Charging: Improving Public EV Infrastructure
As the UK races towards its net-zero goals, the electric vehicle (EV) revolution is in full swing.
With EV charging points increasing by a staggering 38% in the 12 months since July 20231, the question of how to optimise public charging infrastructure has never been more pressing.
At the heart of this challenge lies a crucial decision: rapid charging or AC charging? This choice isn’t just a technical consideration; it’s a strategic one that will shape the future of our roads and cities.
Our industry survey “Charging on the Go” 2 revealed that 44.7% of EV users spend between 30 minutes to 1 hour at public charging stations, while 28.8% require 1 to 2 hours.

These figures underscore the urgent need for a well-balanced charging infrastructure that caters to diverse user needs and driving patterns.
Here, we examine how this balance can be struck, ensuring that the UK’s public EV infrastructure is not just fit for purpose, but future-proof.
Whether you’re a charge point installer, operator, or a decision-maker in the transport sector, understanding these dynamics is key for acerating along the electrified road ahead.
Understanding AC vs DC Charging
When it comes to public EV infrastructure, two main charging types dominate the landscape: rapid charging and AC charging.
Each has its own set of characteristics, advantages, and applications, making them crucial components of a comprehensive charging network.
Definitions and Technical Differences
AC Charging uses alternating current directly from the grid. It’s the most common type of charging and is what you’ll typically find in homes and many public locations. AC chargers require the vehicle’s onboard charger to convert AC to DC for battery charging.
DC Charging or Rapid Charging, on the other hand, uses direct current (DC) and bypasses the vehicle’s onboard converter. This allows for much faster charging speeds as the conversion from AC to DC happens within the charging station itself.

The key technical difference lies in how the electricity is delivered to the vehicle. AC chargers provide alternating current, which the car then converts, while DC rapid chargers deliver direct current straight to the battery.
Charging Speeds and Power Outputs
AC charging speeds vary depending on the power output of the charger and the capacity of the vehicle’s onboard charger:
- Slow AC: Up to 3.6kW
- Fast AC: 7kW and above
DC charging, being significantly faster, is categorised by higher power outputs:
- Rapid DC: 50kW to 100kW
- Ultra-rapid DC: 100kW to 350kW
To put this into perspective, a 7kW AC charger might add about 25-30 miles of range per hour of charging, while a 50kW rapid charger could add up to 100 miles in just 30 minutes.

It’s worth noting that the actual charging speed can vary based on factors such as the vehicle’s battery capacity, state of charge, and ambient temperature.
AC and DC charging speeds comparison table
Charger Type | Power Output | Charging Time (for 10-80% battery capacity) | Range Added per Hour |
---|---|---|---|
Slow AC | <3.6 kW | ≈11 hours | ≈12-15 miles |
Fast AC | >7kW | 3-10 hours | ≈25-88 miles |
Rapid DC | 50 kW | ≈ 50 minutes | ≈175-200 miles |
Ultra-Rapid DC | 150+ kW | ≈16 minutes | ≈500 miles |
Estimates only: actual charging times and range added can vary depending on factors such as the specific vehicle model, battery size, and current state of charge
The choice between AC and rapid charging for public infrastructure depends on various factors, including location, expected dwell time, and power availability.
While rapid chargers offer the advantage of speed, they’re also more expensive to install and operate. AC chargers, though slower, are more cost-effective and suitable for locations where vehicles are parked for longer periods.
As the EV market continues to grow, balancing the deployment of these charging types will be crucial in creating an efficient and user-friendly public charging network.
Advantages and Limitations of DC Charging
Rapid charging, also known as DC charging or fast charging, has become a game-changer in the EV world.
As we push towards widespread EV adoption, it’s crucial to understand both the benefits and drawbacks of this technology. Let’s look at charging times, battery life and infrastructure requirements.
Fast Charging Times
The most obvious advantage of rapid charging is its speed. While a typical 7kW AC charger might add about 25-30 miles of range per hour, a 50kW rapid charger can add up to 100 miles in just 30 minutes.
This dramatic reduction in charging time is a significant step towards making EVs as convenient as traditional combustion vehicles for long journeys. For example, Tesla’s Supercharger network, which can deliver up to 250kW, can add up to 200 miles of range in just 15 minutes for compatible vehicles.
This kind of charging speed can significantly reduce range anxiety and make long-distance EV travel more feasible.
Impact on Battery Life
While rapid DC charging is undoubtedly convenient, its impact on battery life is a topic of ongoing research and debate.
Theoretically, frequent use of rapid charging could accelerate battery degradation due to the higher temperatures and currents involved.
However, recent real-world data has thrown up some surprising results. A study by Recurrent2a, which analysed data from 13,000 Teslas, found no statistically significant difference in range degradation between cars that rapid charged more than 70% of the time and those that rapid charged less than 30% of the time.
This suggests that modern EV batteries and their management systems may be more resilient to rapid charging than previously thought.
That said, it’s worth noting that this study primarily looked at relatively new vehicles, with 57% from 2021 or later. The long-term effects of frequent rapid charging over a decade or more are still unknown.
Infrastructure Requirements
The infrastructure needed for rapid charging is perhaps its most significant limitation. Rapid chargers require substantial power delivery capabilities, which can strain local electrical grids.
A typical 50kW rapid charger needs about as much power as a small supermarket.
This high power requirement means that installing rapid chargers is expensive and often requires significant upgrades to local power infrastructure. For example, National Grid estimates that a single 350kW charger could cost up to £1 million to install in areas where the electricity network needs to be reinforced.

Besides, the high-power demand of rapid chargers can lead to load balancing issues for the grid, especially if multiple vehicles are charging simultaneously.
The upshot of charging large numbers of vehicles on rapid-chargers, limited by the grid supply, is that charging rates will end up being throttled down to AC charging speeds, but with DC charger infrastructure costs.
This challenge is driving innovation in smart charging systems and energy storage solutions to help manage peak loads. Despite these challenges, the UK is making significant strides in expanding its rapid charging network, crucial for supporting long-distance EV travel and boosting consumer confidence in EVs.
Benefits and Challenges of AC Charging
AC charging, while slower than its rapid DC counterpart, offers several advantages that make it a crucial component of the public EV charging infrastructure.
However, it also comes with its own set of challenges. Let’s explore these in detail.
Lower Installation and Operational Costs
One of the primary benefits of AC charging is its cost-effectiveness.
AC chargers are significantly cheaper to install and operate compared to rapid DC chargers. According to ElectrAssure, AC EV charger installation can start from £3,500-5,000+ per install, which is 5 to 20 times less than DC chargers per charging point.3
This lower cost makes AC charging an attractive option for businesses and local authorities looking to provide EV charging facilities without substantial capital investment.
The operational costs of AC chargers are also lower. They require less maintenance (because they are less complex) and consume less energy (because they have no energy loss from inverters, nor storage), which translates to reduced electricity bills for the operator.
They are also much smaller; taking up as little as 0.01m3 compared with at around 2m3 for rapid DC chargers. These advantages allow for wider deployment, potentially increasing the overall availability of charging points.
Longer Charging Times
The most significant challenge of AC charging is the longer time required to charge an EV. While a 50kW rapid DC charger can add up to 100 miles of range in just 30 minutes, a 7kW AC charger might only add about 25-30 miles of range per hour.3a
This slower charging speed can be a drawback for drivers on long journeys or those needing a quick top-up.

It suggests that users who charge for longer periods are making a deliberate choice, where it is not an inconvenience; such as destination charging while engaged in another activity.

Suitability for Different Scenarios
AC charging is particularly well-suited for certain scenarios, which highlights its importance in a comprehensive charging network:
- Workplace Charging: AC chargers are ideal for workplace parking, where vehicles are typically parked for several hours. Employees can plug in their EVs upon arrival and have a fully charged battery by the end of the workday.
- Overnight Charging: For hotels, B&Bs, and residential areas without off-street parking, AC chargers provide an excellent solution for overnight charging.
- Destination Charging: Shopping centres, restaurants, and leisure facilities can benefit from AC chargers, allowing customers to top up their EVs while they shop, dine, or enjoy activities.
- Fleet Charging: For businesses with electric fleets that return to a depot overnight, AC chargers can provide a cost-effective charging solution.
Real-world examples demonstrate the effectiveness of AC charging in these scenarios. For instance, Dundee City Council in Scotland has successfully implemented a mix of AC and rapid chargers.
Their strategy includes AC chargers in long-stay car parks and rapid chargers in more transient locations, effectively balancing cost and convenience.
Although AC charging may not offer the speed of rapid DC charging, its lower costs and suitability for various scenarios make it an essential part of a well-rounded public charging infrastructure.
The key lies in strategically deploying AC chargers where vehicles are likely to be parked for longer periods or where minor topping-up is required, complementing the rapid chargers used for long journeys.
Balancing AC vs DC Charging in Public Infrastructure
The key to a successful public EV charging network lies in striking the right balance between DC charging vs and AC charging options. This balance is crucial for meeting diverse user needs, optimising infrastructure investment, and managing grid capacity effectively.
Strategic Placement Considerations
When deploying public charging infrastructure, location is paramount.
Rapid chargers are best suited for high-traffic areas and along major travel routes, where drivers are more pressured for time.
For example, optimising long-distance travel. AC chargers, on the other hand, are ideal for destinations where vehicles are parked for longer periods, such as shopping centres, workplaces, and residential areas.
The city of Amsterdam provides an excellent case study, with over 1,000 public AC charging points installed in residential areas, catering to those without off-street parking.
Nevertheless, some AC chargers are also essential for highway travel for EVs that don’t have DC charging, or require minor charging.
User Preferences and Behaviour Patterns
The same data also suggests that a mix of rapid and AC charging options is necessary to cater to different charging needs.
A study by Transport & Environment found that 90% of EV charging happens at home or work, with only 10% occurring at public charging stations. However, this 10% is crucial for enabling long-distance travel and providing charging options for those without home charging facilities.
User Preferences and Behaviour Patterns
Balancing rapid DC charging and AC charging is also essential for managing grid capacity.
Rapid chargers, while convenient, place significant demands on the local grid. For instance, a single 350kW ultra-rapid charger requires as much power as 500 homes.
To address this, innovative solutions are being implemented:
- Smart Charging: Technologies that adjust charging rates based on grid capacity and demand. For example, UK Power Networks’ Active Network Management system has enabled the installation of over 500 rapid chargers in London without the need for costly grid upgrades.
- Energy Storage: Battery storage systems can help balance the load on the grid. The Electric Forecourt in Essex, operated by Gridserve, uses a 6 MWh battery to support its 350kW chargers, reducing strain on the local grid.
- Renewable Integration: Combining EV charging with renewable energy sources can reduce grid strain. The IONITY network, for instance, aims to power all its charging stations with 100% renewable energy.
- Load Balancing: Distributing power intelligently between multiple charging points. Our Versinetic report highlights the importance of this, noting that “Evidence-based, proportionate en-route charging” is crucial for efficient infrastructure deployment.3c
Successful deployment of public EV charging infrastructure requires a carefully considered balance between rapid DC and AC charging options. This balance must take into account strategic placement, user behaviour, and grid management considerations.
Key Trends Shaping The Future of Public EV Charging

Advances in Charging Technology
The push for faster charging times is driving significant innovations in charging technology.
Ultra-rapid chargers, capable of delivering up to 350kW, are becoming more prevalent. For instance, IONITY has deployed over 400 high-power charging stations across Europe, with chargers capable of delivering up to 350kW.3d
These chargers can add up to 200 miles of range in just 15 minutes for compatible vehicles. Another exciting development is the emergence of solid-state batteries, which promise higher energy density, faster charging times, and improved safety compared to current lithium-ion batteries.
A large number of companies are close to viable Solid-State battery designs including: QuantumScape (low-volume production now), Adden Energy, ION storage systems, Panasonic, CATL, Factorial (+LG Chem), Thailand New Energy, to be eagerly incorporated into EVs by BYD, Mercedes, Toyota (from 2027-2028), VW, NIO, Nissan and Tesla.
Meanwhile, with a 133kWh battery and 1000km range, the Zhangjiang Hi-Tech Zhiji L6 Max Lightyear was the first solid-state battery EV to appear in limited numbers in summer 2024.
Peak Charging Needs
Intuitively it’s perceived that charging needs are proportional to the size of EV batteries, and so as EV batteries (on average) grow, they’ll need proportionally more charging.
However, this is not the case, because ultimate charging requirements depend upon distance travelled, not battery capacity in the same sense that fuel requirements primarily depend upon distance travelled not the size of the tank.
Because we know how much travelling is done by car today, this essentially sets a bound on the amount of charging infrastructure needed in the future. For example, between 2022 and for charging EV cars; the largest single segment of UK transport.
Ultimately this too defines our maximum charging needs from both AC and rapid charging.
Integration with Renewable Energy Sources
In the Netherlands, Fastned has been pioneering the integration of renewable energy with EV charging. Their stations are powered by 100% renewable energy, primarily from solar and wind sources. They’ve installed solar canopies at many of their charging locations, directly generating clean energy on-site. In 2022, Fastned reported that their network of fast-charging stations produced over 1.3 million kWh of solar energy.4

Another innovative example comes from Sweden, where a pilot project in Visby on the island of Gotland has combined wind power, battery storage, and EV charging. This project, led by Vattenfall, uses a 32 kW wind turbine and a 1,000 kWh battery to power EV chargers, showcasing how local renewable generation can support EV charging infrastructure even in more remote locations.5.
These examples demonstrate the diverse approaches being taken to integrate renewable energy with EV charging, highlighting the potential for creating a more sustainable and resilient charging network.
Smart Charging and Load Balancing Solutions
As the number of EVs on the road increases, smart charging and load balancing solutions are becoming crucial for managing grid capacity and ensuring efficient use of available power.
Versinetic’s LinkRay6 is a prime example of an innovative load balancing solution. This local load balancer allows for easy management of site power and transactions, enabling charging station operators to optimise power distribution across multiple charging points.
By dynamically adjusting charging rates based on available power and user demand, LinkRay helps maximise the utilisation of existing infrastructure while avoiding costly grid upgrades.
Other smart charging solutions are also emerging. For instance, Octopus Energy’s Intelligent Octopus tariff uses AI to automatically charge EVs during off-peak hours when renewable energy is most abundant and cheapest. This not only saves money for consumers but also helps balance grid load.
The UK government is also pushing for smart charging capabilities. Since July 2022, all new home and workplace EV chargers have been required to have smart functionality, allowing them to respond to signals from the electricity system to avoid overloading the grid.
The future of public EV charging is set to be faster, smarter, and more sustainable. As these technologies continue to evolve and become more widespread, they will play a crucial role in accelerating the transition to electric vehicles and supporting a more resilient and sustainable energy system.
Conclusion: Creating a Robust and User-Friendly Public Charging Network
As we’ve explored, the future of public EV charging lies in striking the right balance between rapid and AC charging options. This balance is crucial for meeting diverse user needs, optimising infrastructure investment, and managing grid capacity effectively.
The UK’s EV charging landscape is fast-moving, with a 38% increase in charging points in the 12 months since July 2023. This growth brings both opportunities and challenges.
On one hand, it’s making EV ownership more viable for a broader range of people. On the other hand, it’s putting pressure on our electrical infrastructure and highlighting the need for smart, efficient charging solutions.
As we move forward, several key factors will shape the development of public EV charging:
- Strategic placement of both rapid and AC chargers to meet varied user needs
- Advances in charging technology, including ultra-rapid chargers and solid-state batteries
- Integration of renewable energy sources to create a more sustainable charging network
- Implementation of smart charging and load balancing solutions to optimise grid usage
The last point is particularly important. With more EVs hitting the roads every day, we’re facing a real challenge in managing power distribution. Even though we know our ultimate charging needs are very feasible, it’s not just about having enough chargers; it’s about using the power we have smartly.
That’s exactly why we developed LinkRay at Versinetic. It’s our answer to efficient power management, designed to make the most of every watt available at charging sites.
LinkRay allows charging station operators to optimise power distribution across multiple charging points, ensuring efficient use of available power and avoiding costly grid upgrades. This kind of smart technology will be essential in creating a public charging network that’s not only widespread but also efficient and reliable.
If you’re involved in the planning, installation, or operation of public EV charging infrastructure, it’s crucial to consider how smart charging and load balancing solutions can enhance your offering. Versinetic’s expertise in EV charger design and our LinkRay module could be the key to future-proofing your charging infrastructure.
To learn more about how Versinetic can support your EV charging projects with smart design and efficient power management, book in a call with our engineering consultants. Let’s work together to build a public charging network that’s ready for the electric future.
UK public EV infrastructure and payment systems report available now
Further Reading
- https://www.gov.uk/government/statistics/electric-vehicle-charging-device-statistics-july-2023/electric-vehicle-charging-device-statistics-july-2023
- 2a: https://www.recurrentauto.com/research/impacts-of-fast-charging
- 3a., 3b., 3c., 3d., https://www.versinetic.com/news-blog/charging-on-the-go-public-ev-charging-whitepaper/
- https://www.electrassure.co.uk/commercial-ev-charging-costs/
- https://www.electromaps.com/en/blog/integration-renewable-energy-ev-charging
- https://cleantechnica.com/2023/11/05/study-reveals-effects-of-fast-charging-on-electric-car-battery-health/
- https://www.versinetic.com/hardware/linkray-charge-station-load-balancing-controller/
- https://www.recurrentauto.com/research/impacts-of-fast-charging
- https://www.gridx.ai/success-stories/fastned-fast-efficient-ev-charging
- https://evmagazine.com/top10/top-10-charging-networks-in-the-uk
- https://shaktifoundation.in/centrestage/integration-of-renewable-energy-with-ev-charging-station-organised-by-germi/
- https://wepoweryourcar.com/commercial-ev-charger-installation-costs-uk-a-guide/