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Published date 28 July, 2025

Engaging DNOs for your EV fleet transition

Insights

Transitioning to an electric vehicle (EV) fleet is a major step toward reducing emissions and future-proofing your business. But it’ll also have a big impact on your electricity demands.

Industry forecasts suggest that by 2030, electric vehicles could increase U.S. electricity demand by as much as 185 terawatt-hours—roughly 2.5% to 4.5% of the nation’s total usage.

So, to accommodate this demand and reliably power your charging infrastructure, you’ll need to engage with a key player: your local Distribution Network Operator (DNO).

DNOs are responsible for delivering electricity from the national grid to homes and businesses. If your depot or site needs additional capacity to support EV charging, the DNO is who makes that happen.

Engaging early with your DNO helps avoid delays, ensures accurate planning, and gives your project the best chance of success.

 

Understanding the role of DNOs

DNOs operate and maintain the electricity distribution infrastructure in specific regions.
They don’t generate electricity or supply it commercially, but own the cables, substations, and equipment that power your buildings.

When you install EV charging stations, especially multiple units for a fleet, you’re increasing the load on the network.

If the site’s existing capacity isn’t enough, you’ll need approval, infrastructure upgrades, or new connections from the DNO.

There are six (seven if you count NI Electricity for UK) principal DNOs in the U.K. and an increasing number of licensed independent DNOs (iDNO) and similar utilities in the U.S. Each one governs how businesses can install EV chargers at scale while protecting grid integrity.

For any commercial EV charging setup, working with your DNO is not optional, it’s essential.

 

Planning your EV fleet charging

Before contacting a DNO, it’s crucial to understand what your fleet needs.

Several factors influence the size and type of connection you’ll require:

  • Number of vehicles in your fleet today, and how this might change over time
  • Types of chargers you plan to install
  • Charging schedules (overnight, staggered, or rapid turnover)
  • Current site power capacity and availability of existing infrastructure

If your charging needs exceed your site’s current capacity, you’ll require a network upgrade. That’s when DNO power supply discussions begin.

The more accurate your estimates, the easier it is for the DNO to plan and support you. This step also helps avoid unnecessary costs and future limitations.

 

The DNO engagement process: steps and best practices

Engaging with your DNO follows a clear set of steps. We’d always recommend starting this as early as possible, and ideally during the design and feasibility phase of your EV transition plan.

Step 1: Initial inquiry

Submit a request for information through the DNO’s website or portal.  Most now offer pre-application advice sessions, called DNO surgeries. These are usually short sessions that allow you to discuss project feasibility and possibly rough cost estimates. The more information about your scheme you can provide up front, the more useful this session will be.

Step 2: Formal Application

Complete a DNO application form to provide key information, including your business name, site address and site ownership boundary map, , number, makes and models of charge points, electrical schematic drawings for the charge point installations and anticipated timelines. The applications will also be slightly different depending on whether you are asking for an increase in load for an existing connection or for a brand-new connection in a new location.

Step 3: Receive a quotation

The DNO will assess your site, determine available capacity, and issue a quote if upgrades or a new connection are needed, or a zero quote if no works are needed. Either of these will form a connection agreement which must be signed before connection of the equipment can take place. This may take around 6-8 weeks, and sometimes around 8-12 weeks for more complex applications.

Step 4: Accept and schedule works

A quote involving works will be split into Contestable and non-Contestable works. Contestable works are those you can carry out yourself using a qualified third party, while non-contestable are works that must be carried out by the DNO. Once you agree the arrangement and accept the quote, the DNO will arrange for works to begin. Lead times can vary based on network constraints, complexity and availability of equipment.

To streamline the process:

  • Use a trusted installer familiar with DNO notification rules and DNO authorisation requirements
  • Align planning applications with your DNO timeline
  • Be proactive in following up and providing technical details

In addition, you can work with partners like Hitachi ZeroCarbon to support your DNO engagements, ensure it aligns with your EV fleet transition plan, and ensure new connections or capacity upgrades are what’s best for your business.

 

Overcoming grid and capacity challenges

Not all sites have enough spare capacity for large-scale EV charging installations.

Common issues include:

  • Network constraints in densely populated or industrial areas
  • Reinforcement needs, such as new substations or cabling
  • Long lead times for delivery of physical infrastructure

To solve these, your DNO may propose:

  • Smart charging solutions to stagger energy demand
  • Load management systems to avoid exceeding limits
  • Alternative connection points, such as linking to a nearby substation

Working closely with your DNO ensures you’re aware of potential constraints and gives you time to adapt your project accordingly.

 

The value of data and digital tools

Many DNOs now offer interactive digital maps that show available capacity in specific areas. These tools help businesses plan locations, scope infrastructure, and avoid grid bottlenecks.

For example, UK Power Networks offers a heat map for EV charging capacity. In the U.S., utilities like PG&E and Con Edison provide similar network planning resources.

These tools can guide decisions about:

  • Where to locate depots or charging hubs
  • Whether to apply for full upgrades or use managed load strategies
  • How to future-proof installations based on network growth plans

 

Building a collaborative relationship

Engaging with your DNO early in the EV transition journey saves time, reduces costs, and keeps your project on track. A collaborative, transparent relationship with your DNO ensures your infrastructure is safe, compliant, and scalable.

As EV fleets grow, so does the need for proactive planning. To support this journey, Hitachi ZeroCarbon offers EV fleet management solutions designed to align charging infrastructure with operational goals.

For businesses starting small or scaling fast, we offer EV fleet charging solutions to help you plan, install, and manage infrastructure with long-term efficiency in mind.

 

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