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 EV’s.
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:
Identify the current maximum capacity of your electricity supply – your energy supplier should be able to tell you this
- Pinpoint your highest point of current energy consumption
- Calculate current and future fleet size and its EV charging requirements
- Check and allow for any other energy-use coming on stream, such as additional IT equipment, HVAC units, heat pumps or machinery
- 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.
