What Is a Service Panel, and Why Does Amperage Matter?

A service panel is the metal box, usually gray, that takes power from the utility line and splits it into circuits for your home. Amperage is how much electricity that panel can safely handle at once. Most older North Idaho homes run on 100-amp panels. Most new construction and remodels call for 200 amps. If your panel can't keep up with what you're plugging in, you'll know it, and it's worth fixing before it becomes a real problem.

What the panel actually does

Every wire in your house eventually leads back to the panel. It's the switching station between the utility meter and your outlets, lights, furnace, and appliances. Inside, you'll see a main breaker at the top and a row of smaller breakers below it, each one protecting a specific circuit. If something overloads a circuit, the breaker trips and cuts power before wires overheat. That's the panel doing its job.

Why amperage matters

Amperage is the ceiling on how much your home can draw at one time. A 100-amp panel was fine for a house with a furnace, a stove, and a few lights. It's not enough once you add central air, an electric range, a hot tub, a well pump, an EV charger, and a couple of space heaters in winter. Every one of those draws current, and once you're close to the panel's limit, breakers start tripping to protect the wiring.

Common signs your panel is undersized:

• Breakers trip when you run the microwave and a space heater at the same time

• Lights flicker or dim when the fridge or well pump kicks on

• Your panel is rated 100 amps and you're adding a generator, EV charger, or major appliance

• The panel is old enough that breakers no longer match modern safety standards

None of these mean your house is unsafe today. But they mean the panel is working at its edge, and that edge gets closer every time you add a new appliance or circuit.

How much power do you actually need

A 100-amp panel can run a modest home without electric heat or major add-ons. A 150-amp panel gives some breathing room. A 200-amp panel is the standard now for a reason. It covers central air, an electric range, a dryer, a well pump, and leaves room for an EV charger or a generator hookup later. If you're building new or doing a major remodel, 200 amps is worth the extra cost up front rather than upgrading again in five years.

What a panel upgrade costs

In our area, a straightforward panel upgrade runs in the low thousands of dollars. The exact number depends on a few things:

• Service size: going from 100 to 200 amps costs more than a simple panel swap at the same amperage

• Meter location: if the meter and panel need to move or the utility has to reset the service, that adds time and cost

• Utility coordination: your power company has to disconnect and reconnect service, and their schedule affects the timeline

• Wall conditions: open framing is cheaper to work in than finished walls that need to be cut and patched

• Distance from panel to service entrance: longer runs mean more wire and more labor

• Permit and inspection: every panel upgrade in Bonner and Kootenai counties needs a permit and a final inspection, and that's a real cost, not paperwork for its own sake

Many older homes in this area were built with panels that made sense decades ago but don't match how we use power now. We cover the specific patterns we see locally in why North Idaho's older homes often need a panel upgrade, if you want more detail on what to look for in your own house.

What triggers most upgrades

Few homeowners upgrade a panel just because. It's usually one of these:

• Adding a whole-home generator, which needs its own transfer switch or interlock wired into the panel

• Installing an EV charger, which draws more continuous current than almost anything else in the house

• Adding a major appliance like a hot tub, well pump, or second heat source

• Finishing a basement or building an addition that adds new circuits

If a generator is part of your plan, the interlock or transfer switch itself runs anywhere from several hundred to a couple thousand dollars depending on the setup, separate from any panel work needed to support it. We walk through the seasonal side of that in winter storm prep and getting your generator ready.

The honest tradeoff

You can wait until a breaker trips one too many times, or you can plan the upgrade around something you're already doing, like a remodel or a generator install. Waiting doesn't save money. It just means you're making the decision during a stressful moment instead of a calm one. If you're not sure whether your panel can handle what you want to add, that's a fair question to ask before you buy the appliance, not after.

Sageland Electric has been doing this work in Bonner and Kootenai counties for over 21 years, and we can look at your panel, tell you honestly whether it needs attention, and give you a real number before any work starts. You can see examples of past panel and service work in our project gallery, or reach out through our contact page to get a straightforward assessment of your setup.