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How to make a safe and scalable EV Ready Plan using EVEMS

This article was originally published in E2Q magazine, a publication of the Corporation des Maîtres Électriciens du Québec (CMEQ). To read the original publication in French, click here (page 38).

Several configurations can be used to prepare infrastructure to be ready for electric vehicles but only one type of technology can be used to control and monitor charging equipment: electric vehicle energy management systems (EVEMS).

In 2022, the Regie du batiment du Quebec (RBQ) published an interpretation of Chapter V – Electricity of the Quebec Construction Code in which the definitions of EVEMS (electric vehicle energy management systems), EVSE (electric vehicle supply equipment), charge controllers (power management devices on the feeder), and load miser (devices that do branch circuit switching) were defined.1 2

These types of technologies can each have a unique impact on the viability of a EV charging project and can be used to design an EV ready plan. In this article we will suggest how, and how adding EVEMS is an essential component in electric vehicle planning for reasons of safety and reduced grid impact.

What is the importance of an EVEMS?

The Quebec RBQ update specifying the safety required by code for an EV ready plan was a significant release for two reasons. In it the components an electrician or EV Ready Plan engineer could identify as being a part of a well-designed EV ready plan were conclusively defined, and clarifications about load calculations for the purposes of safety and protection of the panel feeder and everything upstream of it were stated.

The RBQ defined the electrical components of an electric vehicle charging project as the following (also presented in a chart below):3

Electric Vehicle Supply Equipment (EVSE), otherwise known as charging stations, supply the charge between a dedicated circuit and a vehicle;
a charge controller (also known as a single-tier EVEMS) reads the total energy load of a panel and operates an EVSE accordingly so as not to over power the threshold
a load miser uses an existing circuit and load to alternate between two appliances (such as an oven and an EVSE);
a multi-tier EVEMS, manages the distribution of the available power for a group of EVSE, while monitoring feeder branches, and wiring and connections upstream to the transformer and service entrance, accounting for energy at the building level.

Figure 1: A diagram of a charge controller or single-tier EVEMS installation using the DCC by RVE. The figure shows that the DCC is placed between the metering centre and the electrical panel to act as the power source and control charge to EVSE.

And in so defining the above, the RBQ rightly orients planning toward a holistic approach where more than electric vehicle supply equipment needs to be considered for effective charging that protects both site infrastructure and what is upstream of that, at the grid level.

Additionally, and perhaps the most important section of the RBQ interpretation in terms of safety, the update reads “when [the] EVSE is connected to the dwelling’s panel or feeder, with or without a charge controller, it is mandatory to include the EVSE’s rated load in the load calculation according to Articles 8-200 and 8-202 anywhere upstream of the dwelling’s panel feeder to avoid any risk of overloading the rest of the distribution upstream of the dwelling’s panel feeder (e.g. meter column transformers if present, main entrance)” (art. 86-300, p. 135).4

This suggests that all EVSE will contribute a load, even when in a fail safe mode, and that charge controllers (single-tier EVEMS) need to reduce this load to a calculation of 0 A on the feeder (art. 86-300).

Also implied is that charge controllers, while the optimal solution for management of the feeder, when installed alone for a scalable (e.g. multiple EVSE) EV charging installation, are insufficient for reducing the total load calculated when accounting for distribution upstream of the housing panel feeder, this being calculations of the meter column, transformers, and main entrance, and must be calculated at varying percentages (art. 8-202 3) a)).

When an EVEMS strategy is implemented however, the distribution upstream of the housing panel feeder can be calculated at 0 A because monitoring will take place at all levels of power in a building. Therefore, an EVEMS strategy is a necessary component to executing the most scalable and safe EV charger installation that also respects and limits any negative impact on building and grid infrastructure.

Advantages of an EVEMS

Pictured is a multi-level EVEMS diagram and its associated EVEMS technology from a pilot project in Laval, demonstrating the effectiveness of integrating an EVEMS into the electrical infrastructure to monitor and manage EVSE. Without the installation of an EVEMS in this multi-unit building, the main electrical input would have had to be “enlarged” by 546 kW (equivalent to 71 x 7.7 kW terminals).

A cost of over $500,000 without an EVEMS, according to an estimate by a local master electrician specializing in charging station installations, estimates such as these quickly become a deterrent to those interested in EV Readiness for condos and apartment buildings. By contrast, installing an EVEMS system can have a starting cost of $20,000, representing a potential savings of $480,000 on material and labour.

Figure 2: A diagram of a multi-tier EVEMS installation that uses the HUB by RVE, demonstrating the potential to monitor electricity consumption at multiple points.

Figure 3: A multi-tier EVEMS (a demonstration model of the HUB by RVE) installed for a pilot project in a multi-family home in Laval.

Besides an enormous savings on cost and a reduced footprint, the advantages of EVEMS include:

Its ability to monitor as many EVSE as required
Its ability to control electrical current precisely and safely
Its ability to adapt to Peak Demand Management (PDM) and peak demand programs by utilities
Its ability to lend to savings in electricity costs
Its advanced, multi-level load-shedding intelligence
Its future-proof status, making it immune to changes and decommissioning of EVSE technology over time.


TechnologyUse CaseConnectivityNeed
Multi-Tier EVEMSIntegrated within the infrastructure of multi-unit buildings and commercial propertiesYesTo monitor and manage a set of EVSE at multiple points (e.g. the feeder, transformer, and service entrance) so as to not exceed the capacity of a dwelling.
EVSEAll propertiesYes, if a wifi connection is possible and all EVSE can be connected to each otherTo supply energy to an electric vehicle.
Smart Metering Panel for Electrical VehiclesIntegrated within the infrastructure of multi-unit buildings and commercial propertiesYesTo monitor the consumption of several EVSE and intelligently manage energy use and kWh billing.
Single-Tier EVEMS (Charge Controller)Integrated within the infrastructure of multi-unit buildings and single-family homesYes, when paired with a multi-tier EVEMSTo manage and share energy between an appliance (e.g. an EVSE) and a feeder panel.
Load MiserIntegrated within the infrastructure of single-family homesNoTo manage and share a branch circuit between two appliances (e.g. an EVSE and a oven).

Are there other possible solutions for code-compliant energy capacity reporting?

Currently in Quebec, there is a measure for making an EV Ready strategy without access to an all-encompassing EVEMS (SGEVE) solution: energy capacity studies. An energy capacity study is a method to capture an accurate picture of energy use at the level of a transformer or a service entrance and is acquired by equipment and data collected over time by a hired master electrician or by obtaining data directly from an electricity distributor.5 For the latter, Hydro Quebec provides this data on an exceptional basis and only through authorized consultants.6

But make no mistake, a wholescale EV strategy will be a needed step for the planning of electrical infrastructure that is to supply the charge to electric vehicles in a building. Hydro Quebec is invested in grid-level energy efficiency by way of programs such as Hilo or dynamic pricing, allowing for the decreased demand on Hydro Quebec’s distribution and transmission networks, and the end consumer’s cost for electricity. EVEMS is a technology that has the potential to integrate with these programs and offer dynamic pricing, while making sure that capacity is safely available and appropriately managed, and that usage is recorded so that changes are possible without drastic costs and interruptions; it is a future-proof technology.

And what are the incentives?

Quebec has a unique and proactive commitment in the Canadian landscape; it will be the first province to require EV readiness in all newly constructed MURBs with more than 5 units, as suggested in the Strategie quebecoise sur la recharge de véhicules électrique: “Starting in 2024, regulations will be introduced to require the installation of charging infrastructure in new multi-unit buildings with five or more units.”7 Existing buildings or retrofits will need to adapt too. In total, Quebec anticipates that 35% of MURBs will be adapted for electric vehicles, or 600,000 spaces both existing and planned by 2030.

And a $108 million commitment will ensure that these new requirements are possible. Of the $514 million and more dedicated to charging infrastructure throughout the province, a large portion is set aside specifically for multi-unit residential buildings.This will include funding for energy management systems and professional service fees for the design of charging solutions and the preparation of plans and specifications. A strategic and needed approach given that nearly 90% of electric vehicle drivers are charging at home.

To conclude and quote directly from the Strategie Quebecoise sur la recharge de vehicules electrique: “Most of Quebec’s multi-dwelling buildings were built before the advent of electric vehicles. The vast majority of the electrical infrastructure in these buildings (electrical inlets, electrical panels, wiring, etc.) were not designed to handle the high loads required to operate several charging stations simultaneously”.8 EVEMS (SGEVE) has a place in both new builds, where it could serve to protect infrastructure no matter the scale of EVSE (ARVE), and in existing buildings, where it could replace needing to delay an EV charging installation for as long as it takes to conduct an energy capacity study. RVE, an energy management system company based in Quebec has the products, resources and knowledge to tackle this exact challenge.


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RVE’s EVEMS are ready for all electric vehicle charging needs

At RVE, we offer a range of single and multi-tier EVEMS that are developped to enable charging and electrical infrastructure protection for all types of homes, making sure that no matter where you live, you can get an EV without worrying about charging it.

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