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Fleetworld: Future-proofing EV charging

Many facilities and places of work have grid limitations, i.e. a limit to how much electricity that can be used by the site.


Picture the scene: A works yard has 60 electric vehicles, and 20 charging points. A rota is organised around shifts to make the charging work across the fleet. A road traffic accident affects traffic. A goods van needs unscheduled rapid charging but there isn’t sufficient energy capacity. Vehicles back up and the fleet has to be moved around, the schedule gets more and more out of sync. Staff time is wasted, productivity drops, customers are disappointed.

This is a feasible scenario.

Many facilities and places of work have grid limitations, i.e. a limit to how much electricity that can be used by the site (the import capacity). This means only a certain number of chargers are able to provide power to charge EVs at any one time.

Active management can only so do much, after which the only option is to address the site’s energy infrastructure. An extra 100 kilowatts of connection could cost £1,000 or £100,000 depending on the site and the constraints in the area. One electric vehicle charger will require anywhere from 15kW to 350kW depending on how quickly you want to charge your EVs.

How many facilities know their grid capacity and how many EV chargers can this accommodate?

The Welsh Local Authorities, with the Centre of Excellence for Low Carbon and Fuel Cell Technologies (CENEX) explored this issue at an event on 23 March, helping to ensure good decisions are made when electrifying their depots.

A key part of this is exploring the role of a battery energy storage system (BESS) in helping to manage electricity supply.

It’s a common misconception that battery energy storage has to be combined with sun or wind power. While a BESS is the ideal companion to independent, onsite energy, a stand-alone system can provide the grid flexibility a constrained site needs.

How do you go about conducting a holistic review of your site’s energy requirements to see if you are at risk of grid constraint, and if a BESS could be a benefit?

These are our suggested first five steps:

  1. Identify the current maximum capacity of your electricity supply – your energy supplier should be able to tell you this
  2. Pinpoint your highest point of current energy consumption
  3. Calculate current and future fleet size and its EV charging requirements
  4. Check and allow for any other energy-use coming on stream, such as additional IT equipment, HVAC units, heat pumps or machinery
  5. Combine all estimated consumption in 5 and 10 years time and cross reference this against absolute grid capacity.

If the gap between your energy supply and maximum consumption is narrow – around 50kW – active management will be essential to keep you within your energy limit, but in reality this is not a 100% secure option, as the opening scenario showed.

This is where a battery energy storage system will ‘plug the gap’. The BESS can be charged up when electricity is plentiful on the site (evenings and weekends or low electricity usage times) and used to supply electricity when the site or the area is affected by constraint. The BESS will help to smooth out the usage across the day and provide additional capacity for the EV chargers.

Cabling work will be inevitable when you instal EV chargers, so it also makes sense to ‘do it once and do it well’ by installing a BESS at the same time. The BESS is an asset in its own right, so it has short- and long-term value.

It is this holistic, long-term view that the Welsh Authorities are exploring. Along with an exploration of grid constraints, each site must be reviewed for its suitability to take a battery storage system.

Connected Energy’s battery energy storage systems are supplied in ISO 20ft shipping containers which are purposely built to hold racks of batteries, inverters, power control equipment and all the ancillary parts needed to operate them.

A summary site check list includes:

  • Vehicular access – the container is ‘plug and play’ and brought in on an articulated lorry. Could such a vehicle reach your site?
  • Location – a flat secure location is needed for the container, safe from flood risk.
  • Maintenance – the majority of the maintenance checks can be done remotely but annual onsite maintenance and access will be required.
  • If the check list suggests your site could accommodate a BESS, the added benefits will be a welcome bonus.

Awareness of energy security and the need for renewable energy has skyrocketed in recent months, along with the price of fuel. Onsite energy creation can provide an independent, clean source of fuel, with solar arrays becoming both more affordable and more adaptable.

With onsite energy creation, battery storage is an obvious companion, which is why it has been described as ‘the true bridge to a clean-energy future,’ making it possible to store energy from wind and solar PV.

Of particular interest to fleet managers, BESS made from second life vehicle batteries, like those supplied by Connected Energy, also drive the circular economy and make a significant additional impact on carbon reduction.

The International Council on Clean Transportation has calculated that reusing an EV battery in a second life application extends the battery lifetime by 72% which therefore reduces the vehicles’ carbon footprint by 42% per kilometre.

While the long-term benefits of a BESS are now well documented, if an immediate fix is required to provide grid flexibility, to use an advertising phrase which some readers may remember, a BESS could be ‘your flexible friend.’

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