Many older homes were built to run on a 100-amp electrical service, which was plenty to handle the electrical needs of the time. But now homes use a lot more electricity. Central air conditioning, electric stoves, heat pumps, EV chargers, and other modern appliances we rely on are now putting a huge amount of pressure on old electrical systems.
If you’re in the middle of a home renovation, planning to add more electrical equipment, or simply out of room in your electrical panel, you may be wondering if it’s finally time to upgrade from a 100-amp to a 200-amp service.
Not every house needs a 200-amp service, but for many homeowners, making the switch will give them the extra capacity they need to safely power all their current electrical products and all the new ones they’re probably going to buy in the future as well.
What Is the Difference Between 100-Amp and 200-Amp Service?
The electrical service at your home determines how much electricity can be supplied to the house at any one time. The difference between 100-amp and 200-amp service is total capacity: how much electricity your entire house can draw at the same time. A 100-amp service is limited to about 24,000 watts; 200-amp is double that.
A 100-amp service might be just fine for a smaller home with modest electrical needs. If your furnace, water heater, and range are all gas-powered, you might not need the extra oomph that a 200-amp service can give you.
When you build a new home or do a major renovation, upgrading to a 200-amp service is probably a good idea. Or if you are getting an EV charger or a heat pump or swapping all your gas appliances for electric ones, you will almost certainly need to upgrade.
Moving to a 200-amp service is not a measure of how much electricity you use in a month. Your bill doesn’t change because you upgraded. What changes is how much can run at the same time without the main breaker giving out.
Signs You May Need to Upgrade to 200-Amp Service
The size of your house doesn’t automatically mean you need a bigger electrical system. An electrician will look at the whole picture and assess your home’s electrical demands.
Even so, there are a few situations where upgrading to a 200-amp service would make sense.
You’re Getting an EV Charger
Adding an electric vehicle charger brings a lot of extra strain on your home’s power supply. The type of charger you get, your existing service, and how much other stuff is running in the house will all play a role in what your electrician thinks you need.
The type of charger you get, your existing service, and how many other products are running in the house will all affect what your electrician thinks you need.
If you intend to buy an EV, it’s a good idea to have someone look at your electrical system before you install the charger.
You’re Installing a Heat Pump or Other Electric HVAC Equipment
Heat pumps are becoming a popular option for heating and cooling homes. But converting from oil or gas heating to electric equipment can substantially change your home’s electrical requirements.
The same applies when installing central air conditioning or other large HVAC equipment.
Before you make the switch, your electrician can perform a load calculation to determine whether your existing service can handle the additional demand.
You’re Adding Major Electric Appliances
One new appliance most likely won’t require a service upgrade. However, adding several high-demand appliances most likely will.
You may need additional capacity if you’re adding or converting to equipment such as:
- An electric range or cooktop
- An electric clothes dryer
- An electric water heater
- A hot tub
- Central air conditioning
- Heat pumps
- An EV charger
The more systems in your home that rely on electricity, the more important your available electrical capacity becomes.
You’re Planning a Major Home Renovation or Addition
A kitchen remodel, basement finishing project, home expansion, or that extra little cottage can bring with it all sorts of new demands on your electrical system, such as extra lights, new appliances, AC units, and other electronic gadgets people just love to add.
If you’re already renovating, it’s a good time to think about whether your electrical service can power all your new equipment.
Upgrading now might also help you avoid the frustration of having to tear the whole electrical system open again down the line just to add one more really power-hungry appliance or system.
Your Electrical Panel Is Running Out of Space
Sometimes the issue isn’t just how much electricity you’re using, but whether your panel has enough space for new circuits.
If your upgrade plans require some new circuits, then an electrician should have a good look at how much room you’ve got in your panel for those new circuits plus your overall electrical service.
Replacing a panel and upgrading the electrical service to handle all that extra power aren’t necessarily the same project. Your electrician will do a walk-through to figure out exactly what your house needs.
You Expect Your Electrical Needs to Increase
You don’t have to wait until your existing service becomes inadequate.
Think about what you may add to your home over the next several years. An EV? Heat pumps? An induction range? A workshop? A home addition?
If you’re already doing significant electrical work, planning for future demand may make more sense than installing a system that leaves you with little room to grow.
Does a 100-Amp Service Mean Your Electrical System Is Unsafe?
No. Having 100-amp service does not mean that your home’s electrical system is unsafe or outdated.
A properly maintained 100-amp service may be perfectly adequate for a home with relatively low electrical demand.
A good 100-amp service that you have properly maintained can still be just fine for a home that doesn’t use too much electricity. That said, what matters more is whether your service, panel, and electrical setup can still power your home as it is today and as you plan to upgrade it.
However, if you have an older electrical system, there could be other issues, like an outdated panel, damaged equipment, faulty wiring, or components that don’t meet current safety standards.
What Happens During a 100-Amp to 200-Amp Service Upgrade?
Replacing an old electrical panel is not the only thing that should be considered while upgrading your electrical service.
An electrician will need to see what you have in your home already and determine what is actually needed based on the standards of your local utility and electrical inspector. This can involve replacing or upgrading the service entrance equipment, meter equipment, main electrical panel, grounding and bonding components, and related wiring.
The utility company may also need to disconnect and reconnect electrical service as part of the project.
Every home is different, which is why an electrician needs to take a good hard look at your existing setup before they can start figuring out what exactly they have to do.
Do You Really Need 200 Amps?
This is where a professional load calculation becomes important.
Rather than guessing based on your appliances, an electrician will consider your home’s size, the types of appliances you use, your heating and cooling systems, and all other electrical items drawing power.
You might be surprised to find out that your existing 100-amp service is more than enough for your needs.
But, more often than not, you’ll find out that your house is just about maxed out. And if you’re planning to add more electrical upgrades, then going to 200 amps is probably the way to go.
And then there are cases where you don’t actually need a full service upgrade. An electrician can help you figure out what other options are available to you, based on what you’ve got set up already and what you’re trying to add in.
Plan Your Electrical Service for the Home You’re Creating
Homes are going increasingly electric. Even if your 100-amp service has met your needs for decades, it can just suddenly fall short though when you start adding an EV charger, heat pump, all the electric appliances you’d like, or some major renovation work.
If you’re planning a project that will significantly increase your home’s electrical demand, have your electrical system evaluated before the work begins.
Your 100-amp service might still be up to the job, but you might soon find yourself needing to upgrade to a 200-amp electrical service. KC Electrical can take a look at what you’ve currently got, assess just what you’re planning to do with your house, and lay out the best options for you.
Planning ahead gives you an electrical system that can support the way you use your home today, with room for what you may want to add tomorrow.