Smart Panels
Published February 10, 2026
Smart electric panels are smarter than just being smart!
There is a ton of confusion and possibly misinformation surrounding what sort of panels and service requirements builders are going to face as we move toward an ever-electrified future. More often than not, we are seeing assumptions being made about how everyone is going to end up in 400A panels. Nothing could be further from the truth.
EnergyLogic recently attended the Colorado Building Science Symposium put on by BuildTank (which did a very nice job, and you should consider attending). One of the leaders in the smart panel world, Span, presented on what they see in the real world in terms of actual loads in homes. The data is based on thousands of installs and some stress tests that they’ve done.
The data clearly shows that homes simply don’t use anything like the peak amps that we have traditionally thought (without any real reason for thinking so).
High current events are rare:
- 86% of All-Electric SPAN Homes w/ 100a service have never experienced a throttling event
- 98% of All-Electric SPAN Homes w/ 200a service have never experienced a throttling event
- In PG&E territory, the 98th percentile of peak concurrent load is 88A
High current events are short in duration:
- For All-Electric SPAN Homes that experience a high current event, they avg. ~5 events per year
- For All-Electric SPAN Homes that experience a high current event, they avg. ~6 mins per event
When smart panels do detect that they are reaching load limits, they go into what is called “curtailment”. That means that the panel starts using a preset prioritization scheme to shut power off to certain circuits. The most typical would be that in homes with EV chargers, they turn the EV charging circuit off until the situation has resolved. In stress tests, the SPAN team and builder partners in real homes have been unable to force curtailment. This is in all electric homes with EV charging, heat pumps, heat pump water heating, induction ranges, etc. Bottom line, they almost can’t make it happen. That tells us a lot about what is really going on, safety margins, and what that means for load center design; i.e., they can be considerably smaller than we might think.
It’s important to note that the National Electric Code supports this approach (using EMS/PCS) in a very clear way, so the AHJs and Inspectors should have no issues with builders using this to avoid building over 200a. This has been true since the 2014 NEC.
While SPAN is certainly a leader in the development and deployment of smart load centers, they aren’t the only option. Different suppliers take different approaches, so there are multiple pathways that you can explore.
We see smart panels as another tool for builders to use in the early stages of developing new communities, when they can consider dropping gas lines and reducing the overall electric service required. These moves add up to real dollars without sacrificing performance. In fact, in most ways, overall system performance will be better, homeowners will have and perceive more control, along with far greater features and future proofing.
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