BETT - Battery Electric Truck Trial

Lessons Learnt: Charging Infrastructure

Cenex has interviewed BETT fleets and BETT charging infrastructure providers to understand best practice when planning, installing, and operating electric vehicle chargepoints. The learnings cover aspects from grid upgrades to load management, including charging hardware and other considerations. Experience from previous Cenex projects and publications has also been applied.

Key Points

  • It is important to assess early on if your site has enough spare power capacity to charge your vehicles, as you may require a grid upgrade.

  • Planning for the future and undertaking a single large site upgrade may be worthwhile in the long run. You may only be electrifying a small number of vehicles on day 1, but what does your charging infrastructure for your 2030 fleet need to look like?

  • Load management, and on-site generation and storage can help avoid/defer a grid upgrade.

  • If you do need a grid upgrade, contact your DNO as soon as possible.

  • From April 2023, any upgrades required further up the network (i.e. not linked to your sole use assets) will be removed altogether (with limited exceptions), potentially reducing the total cost of new and upgraded DNO connections.

  • Site inspection in the planning phases needs to involve all stakeholders.

  • The standard cable length of 3.9 metres on DC units did not work for most locations, so alternative lengths had to be sought.

Grid Upgrades

Do I need one?

A major constraint to consider when deploying multiple EVs in any depot is how much spare electrical capacity you have and when it is available. Spare capacity means the peak power available on-site minus all existing loads that need to be supplied prior to any charging infrastructure installation. Charging multiple EVs, even on lower powered chargepoints can quickly use up the power you have available on site. Early in any charging infrastructure project you should assess how much capacity you have available, when it is available, and you should also get in touch with your Distribution Network Operator (DNO) to find out early on if you are able to increase your capacity. They will also be able to give you a cost estimate for the work. However, please note that each site is different and may have different grid upgrade requirements or different DNOs.

Some sites will not be able to support chargers with more than a certain power without a grid upgrade. This is especially important in the case of electric trucks, which may require high charging powers if they need to be topped up during, for example, a lunch break or a change of shift. This is also known as ‘opportunity charging’. However, once the current and future demand of EVs charging on the site has been understood, if the unmanaged demand is greater than the supply, solutions to reduce the demand should be considered before going down the grid upgrade road straightaway.

One of these solutions can be load management, which is the process of controlling when charging happens and the power delivered by the chargepoints to avoid exceeding local power constraints. Load management can reduce spikes in power demand by smoothing the charging over time, which can reduce the peak power required by the site. Depending on the level of load management (how intelligent the system is) the price can vary.

For an introduction to load management and the effect it will have on site energy demand please refer to these Cenex documents: Introduction to Load Management and Site Assessment Methodology. These documents also brief you on another option to avoid/defer a grid upgrade: on-site storage and generation. An energy storage system, typically a battery energy storage system (BESS) located on-site, is charged when demand is low and/or supply is high and then discharged when demand is high and/or supply is low. On-site generation can provide you with further independence from the grid via small-scale wind or solar photovoltaics (PV), connected as part of the site’s energy system behind the meter.

If you need a grid upgrade…

After assessing the power demand, if there is still greater demand than supply, an electricity connection upgrade will likely be required. This upgrade will need to be completed by your DNO and therefore, you will need to get in touch with them about your upgrade request. The DNO will then quote you for the works, which are split into contestable and non-contestable. The non-contestable works must be completed by the DNO, however, the contestable works can be completed by a third party. Examples of non-contestable works are site evaluation and network access enablement. Examples of contestable works are ground works. Costs and timescales can vary depending on the DNO and kVA rating power of the required connection. For more detail on costs and timelines see the Site Assessment Methodology document from Cenex.

For any EV charging project, it is recommended that the relevant DNO is engaged as soon as possible. There can be substantial lead times on DNO upgrades, depending on the size of the upgrade, therefore it is important to begin this process early in the planning stages of the charging infrastructure installations. The site in the BETT project that is in the process of a power upgrade is being supported in the interim through the deployment of mobile chargers. These are a potential contingency where significant delays are experienced in the initiation and completion of the DNO works. 

Upcoming changes in costs

It is important to note an upcoming change in the scope of costs regarding grid upgrades: the Access and Forward Looking charges Significant Code Review starting in April 2023. The overall connection charge will be reduced, and the charge for wider distribution network reinforcement (above the voltage level of connection) is removed, with limited exceptions. Going forwards, if a site needs a connection, they will have to pay for any 'sole use' assets (i.e. equipment that no one else on the network will use), but any upgrades required further up the network will be removed (with limited exceptions) and recovered via Distribution Use of System (DUoS) charges. There is an upper limit to this, which is meant to dissuade the most expensive applications, whereby any upgrade costs in excess of £1,720/kVA would have to be paid for by the applicant. All this means that a depot would still be charged to upgrade its supply for all the sole use assets, but they would be insulated from potentially crippling costs incurred by reinforcements to the wider network (e.g. transformers and lines down the street). These changes will apply only to applications received from 1st April 2023. More information can be found here.

Installation planning

In the early phases of any charging infrastructure project, site inspections need to be thorough and involve all stakeholders: site managers, fleet managers, drivers, health & safety officers, electrical engineers, groundwork contractors, etc. In many cases, the person doing the initial site surveys may not appreciate important factors to consider:

  • Charger location

  • Site operational requirements

  • H&S requirements

  • How will the vehicles be parked

  • Site one-way systems

 Another important consideration when performing chargepoint installations is the need to power down the site as this can take significant planning, especially for sites that operate for 24 hours. For example, in temperature-controlled sites, generators will be required to keep goods refrigerated. However, in sites with less critical infrastructure, powering down may be easier.

Feedback from this and past Cenex projects suggests that it makes sense to plan for the future and do one big upgrade if an upgrade is necessary. Ground works can be a substantial portion of the cost of chargepoint installations. Therefore, limiting the number of times major works must be done should save money in the long run. If more power is required from the grid for current chargepoints, you should consider installing cabling and infrastructure that is suitable for your future power demand. This passive provision will ensure a smooth transition to EVs in the future.

Charging hardware

Planning charging infrastructure well in advance is absolutely key. Charging hardware lead time can be longer than expected, especially due to the current shortage of some electrical components. It is also useful to have replacement components in stock to minimise infrastructure downtime. Moreover, some other parts of the process can take some time:

  • Load management study (more information in this Cenex document)

  • Procurement: there may not be enough experience at a site to assess suppliers

  • Charger delivery and installation, including adaptation of charger power ratings to site specifications (if required)

  • Training (different vehicles will be operationally different when using charger)

This project experienced some teething issues around sufficient charging cable length considerations. If we do not consider all factors such as location of parking bays, chargepoint location regarding H&S, or vehicle movements around the site, we may encounter problems. In this particular project for example, the standard cable length of 3.9 metres on DC units did not work for most locations, so alternative lengths had to be sought.

Additional information

You can find more information on other EV charging infrastructure topics such as connector types, AC or DC requirements, vehicle-charger compatibility, etc. on this Cenex document.