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Factors affecting the time and cost of an installation include:

  • Whether you can use an existing electrical connection.
  • Whether you need to increase the capacity at the local secondary substation.
  • Whether you need a new substation to be constructed to support the site.
  • Whether a primary substation needs to be reinforced.
  • Whether you are installing a private wire connection to off-site generation, for example, Oxford’s energy superhub.

The DNO will advise you of the options available based on an assessment of the existing electrical network and the type of infrastructure you are planning to install.

The table below provides an overview of the new energy supply generally needed to support different types of chargepoint.

Chargepoint device type and power output per outletEnergy supply capacity required per chargepoint
Fast 3.7kW AC (dual outlet)Single phase AC supply, 32A
Fast 7kW AC (dual outlet)Single phase AC supply, 63A
Fast 11kW AC (dual outlet)Three phase AC supply, 32A per phase
Fast 22kW AC (dual outlet)Three phase AC supply, 63A per phase
Rapid 25kW DC (single outlet)Three phase AC supply; 63A per phase
Rapid 50kW DC (single outlet)Three phase AC supply; 80A per phase
Ultra-rapid 150kW DC (single outlet)Three phase AC supply; 250A per phase

Engagement with the DNO can also aid in understanding what future capacity may be available at a particular site and whether a later expansion in the number of chargepoints is commercially viable or reasonably practicable in design terms. Completing this type of assessment at this stage will complement future planning and strategy. The DNO may agree to reserve additional capacity for the site. This can be incorporated into their future plans, and will help them coordinate other electrical works in the area.

As the number of chargepoints in Scotland grows, it is likely that more creative solutions will be needed to power them. There are however various projects underway to increase the resilience of the network, particularly in rural and island locations where power supply is often constrained. The AppleCoRRE project, based in the village of Applecross in the northwest Highlands, is one example, highlighted later in this section.

This challenge is certainly not unique to rural areas. Town centre locations in more urban areas often suffer from distribution network constraints, with electric vehicle charging demand adding to this.

Steps in the installation process

Arranging a network connection can be a lengthy and time-consuming process. The DNO engagement timeline will vary depending on the size of an installation. Typically, the process contains the following steps:

  • Initial contact with the DNO requesting a quotation
  • Agreement process
  • Arranging the DNO’s role in any civil work
  • Arranging wayleaves
  • Procuring and installing meters
  • Testing and commissioning of the chargepoints

There are additional steps to complete post-installation. These include arranging bay marking and registering the chargepoints. The registration process involves listing the chargepoints with ChargePlace Scotland or the procured CPO’s back-office network and arranging to be added to online platforms such as the national chargepoint registry, Plugshare and ZapMap.

The image below (containing a table and timelines chart) shows the typical installation process for a single 50kW rapid chargepoint. This resource was provided by HITRANS as a learning tool from the FASTER project. Further information on the FASTER project can be found here.

The chart shows the typical time taken for each step in the process. As you can see, initial engagement with the DNO, and the actions required from the DNO, account for a significant portion of the total project time. Project management efficiencies can however be found as some elements can progress simultaneously.

There are some potential bottlenecks in the process; a key one being meter installation. This stage involves the installation of the equipment needed to measure the amount of power being delivered to the charging vehicles. Early engagement with the DNO can help you plan the optimal time for meter installation to avoid delays.

While this is indicative for a local authority or public body installation, turnkey projects under a partnership arrangement with a CPO may see a different model/timescale.

A supplementary table of potential risks and impacts associated with the DNO stages of the installation process is provided below.

Risks and dependencies of installation steps relating to the DNO process

Indicative timescale
DNO quote request2-13 weeksUnacceptable, requires requote; No supply capacity possibleFurther 2-13 weeks; Project cancelledAll
DNO order acceptance and process4-14 weeksWayleaves issues; Supply chain issuesIndeterminate timescale; Delayed energisationEnergisation, Metering, Commissioning
Site preparation0.5 weeksObjections if planning requiredDelay of project startAll
Civil works0.5-3 weeksWeather; Obstructions undergroundDelay, redesignEnergisation, Metering, Commissioning
DNO works (Low Voltage)6-9 weeksFault works; Road opening notice/ road crossingDelay, indeterminateEnergisation, Metering, Commissioning
DNO works (High Voltage)6-30 weeksAs Low Voltage plus outage restrictionsDelay, typically <1 weekEnergisation, Metering, Commissioning