What is the difference between a 100 AMP electric panel and a 200 AMP electric panel?
The physical difference between your average 100-amp panel and 200-amp panel is that your 200-amp panel will have more space available typically, which means you can fit more breakers into the panel and the panel will be able to supply more circuits.
Houses built in the ’40s and ’50s will typically have smaller services, 60 Amp is not uncommon. In the ’60s and ’70s, 100 Amp was common. And since the ’80s, 200 Amp is standard.
The amperage is the rated power it can handle. Modern houses are generally built with 200-amp panels, and a lot of the newer ones are going 300-350 amps as more and more electronic devices and fancy and high-demand kitchen devices and increased lighting are used in homes. Both are just as safe – the 200 AMP one will just have many more breaker slots, allowing way more circuits, and providing more room for expansion in the future, especially for power-hungry things like shop tools. Each uses only as much electricity as is used in the circuits – the panel itself does not consume any electricity, so no long-term impact there. It is just a circuit connection box where the individual circuits are connected, with circuit protectors (breakers) in line before it connects to the main line to your electric usage meter.
Why upgrade from 100-amp to 200-amp?
Having the larger panel, especially if 200-amp capacity all the way from the meter, can be a selling point (or rather, lack of a negative point) to a potential buyer with lots of electronics or who is into shop power tools. It would also facilitate conversion to electric heat/water heating if someone wanted to do that.
Other thoughts to consider is that you may want to get a hot tub or possibly a pool. If you are a major do it yourself guy and have a lot of tools. A welder, saws, drill press, etc. all use a good amount of power. Not to mention a heater in the winter.
You never know when an electric car might be in your future. In these case of electric cars, companies have realized not everyone has a 200A service and have made load monitoring devices to disconnect the charger if things like a stove and dryer are running. But, for everything else you may need to upgrade your electrical after the fact which is way more expensive than doing it up front. Finally, it seems clear that although electrical devices are getting more efficient, there are way, way more devices in our lives today which shows no sign of that slowing down.