Do You Need a 200 Amp Panel Before Solar or a Home Battery?
A lot of Ontario homes still run on 100 amp service. Here is when a panel upgrade makes sense before solar or a home battery, when it does not, and how the ESA permit and utility steps fit in.
TRU Off Grid · November 5, 2026
The Short Answer
Not always. Many solar and battery systems install on a 100 amp service without any trouble. A 200 amp panel upgrade makes sense when the house is already near its limit, when the panel is full or worn out, or when you are adding big loads like an EV charger, a heat pump or an electric range at the same time.
The only way to know for sure is to look at your panel and your loads. That is part of every site visit we do.
Signs You Might Need an Upgrade
Your panel has no open spaces and is full of tandem breakers. The main breaker trips, or lights dim when the dryer or air conditioner starts. You are planning an EV charger, a heat pump or other large loads. The panel is an old brand that is known for problems, or shows rust, heat marks or loose parts. Your home insurance company has asked about the panel.
If any of these sound familiar, it is worth upgrading before the solar or battery goes in. Doing both in one project usually means one permit process and one shutdown instead of two.
When You Do Not Need One
A home battery that backs up a set of critical circuits does not usually need a bigger service. The battery and its smart panel sit beside your main panel and only take the circuits you choose.
Solar that sends power back to the grid has its own rules about how much the panel can safely take. Our electrician checks the panel rating and the main breaker before we design the system, and sometimes a different connection method avoids a full upgrade.
How the Upgrade Works
A panel and service upgrade is done by a licensed electrician under an ESA permit. Your utility, such as Milton Hydro or Hydro One, has to disconnect and reconnect the service, so we book that with them. Depending on the house, the meter base and the service wires may also need to be replaced.
On the day, the power is off for part of the day while the new panel goes in and every circuit is moved over and labelled. After the work, ESA inspects it before the utility reconnects. We handle the permit, the utility booking and the inspection.
Plan It With the Solar or Battery
If you are thinking about solar, a battery or an EV charger in the next few years, plan the panel at the same time. We can quote the upgrade and the system together so the design fits and the work happens in the right order.
TRU Electrical Services is the electrical side of TRU Off Grid, with a Master Electrician License issued by the ESA. See what we do on our electrical services page, learn about solar installation, or book a site visit.
