Charging study for residential developments

Helping management companies, property managers and developers meet the future demands for electric vehicle charging

Electric Car Chargers UK have conducted an independent report to help residential management companies and housing developers make an informed decision when choosing the right charging points for their residents and tenants. All of our information is collated using accessible and public information.

What is the current demand for electric vehicles?

We are seeing a steep rise in new vehicle registrations, and with so many incentives for businesses and individuals to switch their vehicle to electric, or even penalties for not doing so, this rise is likely to get even steeper over coming years:

UK statistics – as of August 2020

• 330,800 plug-in electric vehicles registered
• 200 different plug-in electric vehicles available
• 10,200 electric plug-in vans registered

It is predicted that by 2023, plug-in electric vehicles will surpass combustion engine vehicles for new registrations in the UK. With Norway (as of January 2021) being the only European country to achieve this to date, it is very likely that the UK could become a forerunner for embracing this technology.

The charger or the vehicle – What should come first?

It is well documentation that whilst there are over 33,000 public chargers on UK roads (as of December 2020), this is widely considered to be inadequate. The preferred option for most electric vehicle drivers is to their vehicle at home, but this can commonly present issues such as:

• Peak power demand in the local area will not cope with the future requirements
• Properties that do not have off road parking
• Properties that do have off road parking, but it’s remote and not feasible to connect to the properties power supply

All of these are presenting problems for existing buildings that we never designed to withstand the amount of power required to support multiple charging points, and for new builds where the planned power for a development has just double to try and accommodate the future charging demands.

So what’s the answer?

Average mileage for all cars is 7,800 miles per year (or 21 miles/day)

The Department of Transport travel survey 2017

Based on an average a national average of only 21 miles per day supports the potential for electric vehicles not having a charging requirement every day and therefore it is not always the best choice to try to and provide every resident, or every parking bay with an electric charging point that might never be fully utilised..

Of the top 10 best selling electric cars sold in 2020, 80% had a charging capacity of 11kW’s or more, and an average real world range of circa 239 miles. For 11kW equipped electric cars this means around 9 hours of charging per week on a 7.4kW charger, or nearer to 5 hours per week for an 11kW AC charger or above, and about 1 hour for a 50kW DC rapid charger, per week.

Below shows a comparison of the top selling electric vehicles in 2020 based on charging their battery from 0% to 100% battery.

Bestselling Electric Cars in the UK 2020	kW	Range	Price £		Capacity AC (in hours)	Max AC (in hours)	7.4kW AC (in hours)	22kW AC (in hours)	50kW DC (in hours)
Kia e-Nero	64	230	£35,000		11	7	10	7	1
VW ID3	77	300	£35,000		11	8	12	8	1
Peugeot e-208	45	170	£25,500		11	5	7	5	1
Hyundai Kona	64	245	£35,600		11	7	10	7	1
Kia Soul	64	280	£33,750		7.2	10	10	10	1
Nissan Leaf	56	200	£33,295		6.6	10	10	10	1
Renault Zoe	52	220	£25,000		22	3	8	3	1
Tesla Model 3	72.5	270	£54,500		11	7	12	7	1
Jaguar I pace	85	225	£65,000		11	9	13	9	1
Audi E-Tron	77	250	£50,000		11	8	12	8	1

Whilst 8 of the 10 cars listed above have inverters of 11kW or greater. Pretty much all electric vehicles that are being reviewed for release in late 2021-2022 are equipped with either 11kW or 22kW inverters, including the new generation of Nissans which will carry an 11kW inverter as standard with 22kW as an upgrade option.

Almost all electric vehicles on the market today and certainly those moving forward, can withstand a DC rapid charge. These range from 35kW up to 300kW.

Utilising your power

“We predict that the majority of our local transformers will be able to accommodate one 35kwh charge every 5 days for each customer connected to it.

Western Power Distributions report on electric vehicle strategy dated March 2019

It is accepted that having a charging point on your drive, or designated parking space is the most convenient option of all. But is it the most practical when the local power supply is limited,

A designated home charger is available to an individual for 24 hours a day, and the utilisation level is only likely to ever reach around 3% over a one week period. When you compare this to a communal charger, which is available to everyone over 24 hours, it would only need to be used for 48 mins during the day to match.

In real terms a communal charger could supply an average of two charges a day, keeping around 14 x electric cars with 11kW onboard inverters (maximum charging capability) on the road, which has a more realistic 25% utilisation over a week. Alternatively, for larger developments, a 50kW rapid charging could supply and average of 6 charges a day, keeping around 40 x electric cars on the road.

Comparison of different charging solutions based on a development with 40 dwellings:

Option	Qty	Total power (kVa)	# Electric vehicles served
7.4kW	40	296	40
22kW	3	66	40
50kW	1	50	40

Conclusion

With the increase in battery size, range and charging capacity, the need to charge on a nightly basis is not always the best option and for the vast majority of users, an accessible charging provision close to their home would be perfectly sufficient for the amount of time they are actually going to be used.

Installing charging points to every parking bay on a 1:1 basis, this can present power limitation to a residential development, let alone significant costs to upgrade and install. A charging installation that adds to the overall public accessible network has to be seen as a betterment to EV adoption as a whole and should take precedence over a marginal perceived conveniences offered to a few.

In the future, car-share schemes, mobile hailing apps (Uber), alternate forms of short distance transport (electric bikes and scooters) changing in working practices (working from home (very apt now)), live work communities and the every year DoT figures show there are fewer and fewer licence registrations, as more and more twentysomethings choose not to bother to pass their driving test because there are so many more alternatives now.

So you are looking at a scenario where charging points in designated bays, albeit the most convenient, are decades away from being properly utilised but unlikely to reach full use as transport options make private car ownership less prevalent.

A communal charging solution that is extended when the charging points reach a 25% utilisation will be a more appropriate provision for the residents and a more sustainable solution for the site and the national grid.