Below is a brief summary of a number of options to source power for EV charging. This is not intended to provide a complete list, but rather provide ideas that a strata can work through and develop their own solution.
Keep in mind that a building strategy will often involve more than one charging option depending on the individual apartment, car bays, proximity to infrastructure etc.
Power Sourced from Apartment or Resident's Meter
Options where charging costs are included in the resident's normal electricity bill
The introduction of Level 2 charging units having embedded load management, which utilise overall power sensing, now provides more opportunities to safely access the Lot Owners metered supply. A charging unit with built-in load monitoring enables EV charging only at times when the apartment has spare capacity. This ensures the apartment cannot exceed power design limits. Smart chargers having Bluetooth management and RS485 communications are particularly suitable for basement garages where there may be no WiFi and also a considerable distance between the power/current sensor, monitoring the total metered supply, and the location of the charging unit in the garage.
Examples applicable for installation of a single charging unit:
Power sourced where the Lot Owners meter is located in the basement and both an EV supply cable and a communications cable can be run between the sensor measuring the output of the meter and the EV charging unit. The sensor may be located in the meter room or at some more convenient intermediate location between the output of the meter and initial point of power usage. The take off for the EV supply cable must be downstream of the sensor.
Power sourced from the dwelling switchboard (House, Townhouse or Apartment) with a separate supply cable and communications cable from the switchboard for a Level 2 charging unit. If you are in a townhouse or single dwelling, then charging via an existing or additional power point may be possible. Advice from an electrician should be sought to determine the capacity of the circuit which may only be suitable for a Level 1 charging unit.
Sourcing power where the Lot Owners air conditioning compressor is located in the basement and cabling can be run to the charging unit. This requires the current sensor to measure the total demand in the A/C circuit and signal the charging unit to direct any surplus to vehicle charging. If the A/C is not operating then all power up to a predetermined limit can be directed to the charger. The original design capacity of the A/C circuit may limit the power available for a Level 2 charging unit.
Power Sourced from Common Property Power
where the costs are billed by a 3rd party
Multiple Chargers Controlled by a Load Managed System
Load managements systems monitoring the total building supply enables multiple chargers to be installed without a negative impact on the general electricity supply by maintaining the overall load with the design parameters for the supply.
Load managed features and key points
System is supplied and maintained by a provider.
Each user will have an account with the provider.
Requires an ongoing subscription which is typically charged to users of the system.
Electrical power to the system is sourced from the building's common power.
Users will pay the provider for power consumed by charging sessions (normally via a credit card attached to the individual's account). The owner’s corporation will set the price of electricity charged to the owners, typically enough to cover power and administrative costs, if any. The provider will periodically reimburse the owners corporation for power consumed ensuring the owners corporation is not out of pocket for ongoing power consumption.
Key components of a load managed charging system
The "smarts" of a load managed system is usually a small box mounted inside the power distribution room.
This device will...
monitor the building's overall power consumption with CT clamps
communicate with individual chargers in the building, dynamically adjusting the power consumption of each charger as required
report usage data to a cloud portal for centralised account and user management
A discrete wall or pole mounted EV charger.
This device will...
optionally provide user authentication
communicate with the smart hub to dynamically adjust charge rate (power consumption) as required
report usage to the smart hub