EV energy management system in Mahogany: an EV charger without a service upgrade
August 2026 · Residential · EV charging · Mahogany, Calgary SE
Koop Electrical installed an EV energy management system (EVEMS) at a home in Mahogany, southeast Calgary, in August 2026, so the owners could add a Level 2 EV charger in the garage without upgrading their 100 amp electrical service. The system cost $1,500 installed, against $5,000 or more for a full service upgrade. The car charges every night; the panel never goes over its rating.
At a glance
Client: A homeowner in Mahogany, Calgary SE
Job type: EV energy management system (EVEMS) [plus a garage sub-panel and Level 2 EV charger
Date: August 2026
Scope: EVEMS controller mounted beside the main panel; current transformer sensors on the main service conductors; feed to a new sub-panel in the garage; Level 2 charger on the garage wall; controller set to the service rating; City of Calgary electrical permit and inspection
Cost: $1,500 for the energy management system $500 for the sub-panel and $800 for the charger
Service: 100 amp — unchanged
The problem
A Level 2 charger draws up to 48 amps, close to half of a 100 amp service. On paper, once you add the charger to the furnace, the range, the dryer and the rest, the house is over its limit, and the City will not pass a charger that puts it there. The usual answer is a service upgrade at $5,000 to $10,000 and a day without power. The owners did not want to spend that to charge a car.
How an energy management system works
The EVEMS watches what the whole house is drawing through sensors on the main service. When the house gets near the limit of the service, say the oven, the dryer and the furnace all running at once, it pauses or throttles the charger for a few minutes, then lets it resume. The car still fills overnight, because those peaks last minutes and a charge takes hours. Because the system guarantees the panel can never be overloaded, the Canadian Electrical Code lets it count in the load calculation, which is what allows the charger to go in on a service that would otherwise be full.
What we did
Mounted the EVEMS controller beside the main panel in the basement and fitted the current sensors on the main service.
Ran a feed from the main panel to a new sub-panel in the garage.
Installed the Level 2 charger on the garage wall — brand: Tesla
Set the controller to the service rating and the charger's draw, tested it under load, and had the work inspected under a City of Calgary permit.
The result
A charger in the garage on the existing service, and the money for the upgrade still in the bank. The owner: "Koop Electrical installed a management system for us, saving a huge cost of having to upgrade our service. Professional and clean service, great to work with."
Energy management system or service upgrade?
One big new load on a 100 amp service, an EV charger, a hot tub or air conditioning: an energy management system, $1,500 to $2,000 with Koop Electrical. Two or three new loads, or a suite: the service has to grow, $5,000 and up. We will tell you which one you need on the first visit, before you buy the charger.
EV charger installation in Calgary
Koop Electrical installs Level 2 EV chargers for Calgary homes and businesses, typically for around $1,500, and energy management systems for $1,500 to $2,000. Most home installs take about half a day. Estimates are free: call 403-702-6053 or use the contact form.
Related projects: Ford Lightning charger in Chaparral · 200 amp service upgrade in Dover · What is a load management system? (FAQ)
This job is one of our load management systems in Calgary and EV charger installation in Calgary. See every service with pricing on our Services page →
