The Question We Get Every Week
We get asked this question every week. You buy a vehicle. You want a Level 2 EV charger installation in Calgary
at your home. Then someone says, “Wait, you only have 100 amp service.” Now you’re wondering if you need to upgrade your panel.
The honest answer is that sometimes you do. Sometimes you do not. It really depends on your house.
Let us walk through it the way we explain it to our customers.
Why 100 Amp Service Used to Work (and Why It’s Tight Now)
Years ago, 100 amp service was completely normal. It handled your lights, appliances, a dryer, and a range. Fast forward to 2026 and most homes now have air conditioning, electric ranges and dryers, basement developments, hot tubs, home offices, and now electric vehicle chargers.
How Much Power a Level 2 Charger Pulls
A Level 2 electric vehicle charger usually draws 32 to 48 amps. Because electric vehicle charging is considered a continuous load, it counts heavier in your load calculation. That is where 100 amp panels start running out of room.
Calgary Permits and Inspections: What Inspectors Focus On
When we install an electric vehicle charger in Calgary, a permit is required. That means it will be inspected. Inspectors are very focused on total service demand, accurate load calculations, proper breaker sizing, and whether your panel can safely handle the added load. If you have 100 amp service, expect the question: “Has a load calculation been done?” Because if your service is already near its limit, they will not approve the installation without a solution.
Load Calculations: The Part You Can’t Guess
A load calculation is not a guess. It is not “it should be fine.” It is a breakdown of your square footage, heating type, appliances, existing electrical loads, continuous loads like electric vehicle charging, and total service capacity. Sometimes the numbers work. Sometimes they are too close for comfort. This is where most homeowners are surprised.
Two Options When Your 100 Amp Panel Is Maxed Out
If your 100 amp panel is maxed out, you have two options.
Option 1: Upgrade to 200 Amp Service
Option 1 is to upgrade to 200 amp service. This gives you room for electric vehicle charging, future upgrades, heat pumps, air conditioning, and basement suites. It involves a new panel, utility coordination, possible service changes, and a higher upfront cost. For some homes it makes sense long-term.
Option 2: Install a Load Management Device
Option 2 is to install a load management device. This is becoming very common in Calgary. A load shedding device monitors your home’s power use. If your house starts pulling too much power, it temporarily pauses the electric vehicle charger. When demand drops, it turns the charger back on automatically. You do not notice it. Your car still charges overnight. In 100 amp homes, this allows us to install an electric vehicle charger without upgrading to 200 amp service. Inspectors are very familiar with these now.
When 100 Amp Service Is More Likely to Be Fine
You are more likely to be okay if you have gas heat, gas hot water, no central air conditioning, no hot tub, and no large electric heating loads. In those situations, we often find there is room. We do not assume. We calculate.
Do You Need a Permit for an EV Charger in Calgary?
Do you need a permit for an electric vehicle charger in Calgary? Yes. It requires a permit and an inspection, and you should expect a load calculation to be part of the process. Skipping the permit is not worth it. It can create problems with resale, insurance, and safety.
Bottom Line
The bottom line is that a 100 amp panel can sometimes handle an electric vehicle charger. Not always. The only way to know is to look at the panel, run the numbers, and decide whether you need load management or a service upgrade. We are seeing electrification every year in Calgary. Planning your service capacity properly now saves you from changes later. If you are thinking about installing an electric vehicle charger, it is always better to assess your panel before booking the installation.