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Electric vehicle charging infrastructure: The impact on new development


Installing an electric vehicle charger in every dwelling will not necessarily reduce the number of vehicles on our roads, according to Jason Horner

By 2025, it is estimated that between 8 per cent and 16 per cent of all vehicles on the road will be electric. By 2040, all new private cars sold must be electric or ultra-low emission (e.g. hydrogen).

Last month Green Alliance and a group of MPs urged the government to ban new petrol and diesel vehicles by 2032 rather than 2040.

Local planning authorities are rightly beginning to insist that new residential schemes are developed with electric vehicle (EV) charging infrastructure; commonly new policy includes ‘active’ EV charging infrastructure, which is installed immediately, and ‘passive’ infrastructure, which requires physical conduits to support future charging points, and the reservation of electrical capacity. In some cases, emerging planning policy includes a requirement for 100 per cent of dwellings to include passive infrastructure and this means reserving electrical capacity now for a charging point on every dwelling.

‘Trickle-chargers’ can charge most electric and hybrid cars from empty to full overnight but as more EVs start to use bigger batteries (Tesla is now using a 100kWh battery) a more powerful ‘fast-charger’ may be required. As an example, Surrey County Council 2018 Parking Guidance states that a 7.4kW ‘fast-charger’ should be included on every dwelling.

"Local planning authorities are rightly beginning to insist that new residential schemes are developed with electric vehicle (EV) charging infrastructure"

The problem is that a standard gas-heated home requires circa 2.5kW per dwelling; the addition of a 7.4kW EV charging connection increases the electrical demand on a single dwelling by 400 per cent.

If we added-up all the electrical fittings in our homes our home would require circa 15kW. However the electricity network operators sensibly apply ‘diversity’ because in every home not everything is switched on simultaneously and across a community of homes this reduces the peak demand further. Considering this we would expect the same approach to EV charging infrastructure. However, despite early evidence that suggests that many EV users charge their car less than twice a week the electricity network operators must err on the side of caution and are applying very low levels of diversity. This is frustrating as electricity providers are transitioning to more flexible networks; and emerging technology will likely mean new homes will contain smart meters and benefit from ‘Time of Use’ energy tariffs.

When a planner conditions a ‘passive’ EV charging point, a developer must secure a very large quantum of additional power that could be unused for 20 years or more. With current utility regulations it is possible to purchase oversized infrastructure, however not possible to reserve the electricity capacity within this infrastructure for more than three years. There are also huge cost implications, potentially adding millions to a new housing project and forcing developers to rethink its viability.

What can we do?

Planning authorities need to understand the unintended consequences of their requirements and work more closely with stakeholders (particularly electricity network operators) to develop a more pragmatic policy: Increasing electricity distribution cables sizes in our new highways and making additional land available for future substations would provide better value than ‘reserving capacity’.

Cleaner cars and healthier streets are certainly a worthwhile aspiration but installing an EV charger in every dwelling will not necessarily reduce the number of vehicles on our roads and could impact the housing development we so desperately need.

Jason Horner is the head of infrastructure services at design consultancy Hilson Moran

Image credit | iStock


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