SoCal Dave
Member
As far as load calculations its true that many houses use less power per device, however I'd be surprised if overall the house trend isnt to heavier power useage overall. As electric cars get more popular homes will need more not less capacity. A dozen LED lights vs incandecent barely registers on your main panel load. Its things like an EV charging, air and water heating and cooling, and pumping water that make the biggest demand on a main panel.
EV charging is new, but most homes don't have an EV vehicle.
A new AC is 20-40% more efficient than one from 20+ years ago.Add the better insulation and air sealing practices and the AC becomes even more efficient. Variable speed pool pumps can use 1/10th the power. Energy Star appliances are significantly more efficient than older appliances. Refrigerators from 20 years ago would use 3-4 times the power of modern one.
For a larger house like mine, incandescent lighting could be pretty significant with down lights and exterior lights adding up especially over the many hours they are used. I'd estimate my lighting, if I had incandescent, would be 5-10kWh per day in the winter. Though admittedly I probably wouldn't be letting as many incandescent lights run for as long as I let the LED counterparts go.
If I was building a new house would I go small on the main panel? Absolutely not, I would go with a 225A or 400A as the cost difference is pretty minor compared to a lower rated panel. However, I would definitely push back on a service upgrade if I already had a 200A panel for an existing house.