48 Million Homes Need a Panel Upgrade to Go Electric. Most of Them Don't.
Peninsula Clean Energy ran the numbers on 700 all-electric single-family homes in San Mateo County, California, and found something that should embarrass the entire residential electrical industry. Ninety-nine percent of those homes never drew more than 100 amps of current in a full calendar year. Most common peak demand across the entire dataset? Twenty-nine amps.
Twenty-nine.
Less than one-third of what NEC Article 220 treats as the basement of residential service. Roughly one-seventh of the 200-amp service that Pecan Street's widely cited 2021 report argued every all-electric home requires. This gap between code-mandated capacity and actual consumption is not a rounding error or a seasonal blip. It is a chasm wide enough to park a $100 billion national infrastructure problem inside.
Pecan Street, the Austin-based research nonprofit, published "Addressing an Electrification Roadblock: Residential Electric Panel Capacity" in August 2021. One number landed like a brick: up to 48 million U.S. single-family homes need electric service panel upgrades before they can fully transition away from fossil fuels. Average upgrade cost: $2,000, for a total national barrier of $96 billion. DOE's Office of Energy Efficiency & Renewable Energy estimated in 2023 that about 21% of U.S. homes sit at 100 amps or less, with 44% having two or fewer open breaker slots available. Los Angeles alone projected $780 million to $1.8 billion to upgrade all deficient single-family panels in disadvantaged communities.
Real numbers. But they assume a home's peak electrical demand is the sum of every appliance running at full draw simultaneously, which almost never happens outside of a load calculation spreadsheet.
Spreadsheet vs. Meter
NEC Article 220 calculates residential panel capacity by adding up every connected load as if your EV charger, heat pump, induction range, clothes dryer, and water heater are all pulling maximum amps at the same moment on the same Tuesday afternoon. Add those theoretical peaks and a 2,400-square-foot all-electric home needs 200 amps easily, sometimes 320 or more if you include a Level 2 EV charger at 48 amps.
Homes do not work that way and never have. Your dryer runs for 45 minutes while nobody is cooking. Your EV charges overnight while the heat pump cycles down because everyone is asleep under blankets. Your water heater fires between showers, not during them. Temporal overlap between major loads is small, occasional, and brief.
PCE's field data confirmed what electrical engineers suspected but had never demonstrated at scale: real residential demand profiles look nothing like summed-peak calculations. Cavan Merski, senior data analyst at Pecan Street, called the results "awesome," noting that when limited funds make panel upgrades a barrier, evidence that electrification works without them is exactly what policy needs.
Enormous caveat, though. PCE's dataset covers one county on the San Francisco Peninsula, where January lows average 42°F and summer highs rarely touch 90. Scott Hinson, Pecan Street's CTO, cautioned that whether homes need electrical upgrades before going all-electric "is going to be regionally dependent." In Minneapolis, where heat pump defrost cycles trigger resistance backup heat at precisely the moment every other electrical system is working hardest, that 29-amp peak finding would be a punchline.
Enter the Algorithm
NEC 2026 changed the game by formally permitting EV Energy Management Systems under Article 625.42 to automatically throttle charger output based on real-time whole-home current draw, alongside new provisions for service-level energy management that establish a legal framework for software to do what copper used to: prevent overloads.
At the low end, that means an EVEMS device like the DCC-9 or Emporia unit, installed for $200 to $500, that monitors your panel's main feed and dynamically adjusts your EV charger's draw to stay within rated capacity. You pull into the garage, plug in, start a load of laundry, and the charger quietly drops from 48 amps to 24 until the dryer finishes. No trip, no upgrade, no electrician callback.
Jason Walls, a master electrician with IBEW Local 369 who built the ChargeRight assessment platform, put it bluntly: too many homeowners pay for panel upgrades they don't need. An NEC 220.82 load calculation, which runs about $13 through his platform, often reveals that existing capacity is adequate once you factor in actual simultaneous use rather than theoretical peak addition.
At the high end, smart electrical panels replace the entire breaker box with circuit-level monitoring, automated load shedding, and predictive energy management. SPAN's Panel MAIN 32 ($3,500 MSRP, $6,500 to $8,000 installed) includes PowerUp software that functions as a built-in energy management system, making homes "all-electric ready" by dynamically juggling loads that a traditional panel would simply trip on. Schneider Electric's Pulse panel goes further, automatically prioritizing the most sustainable energy source available and offering one-touch low-power modes. Leviton's Smart Load Center ($2,000 to $3,000 for hardware) targets new construction specifically, pairing smart breakers with an installation workflow designed for builders rather than retrofit electricians. Smart Main Panel starts at $1,650 and bundles a solar load center, battery gateway, and fault detection into a single unit.
Young market, crowded, and moving fast. Siemens offers utility-grid-integrated smart panels in the $2,500 to $3,500 range, while Basis, a New Zealand company, sells 12- to 20-circuit smart panels starting at NZ$3,299. That many entrants tells you where the industry thinks this is heading.
Builder Math
SPAN debuted two larger panels in March 2025, the MAIN 40 +MID and MLO 48, explicitly targeting production homebuilders. Pitch is straightforward: according to builder estimates SPAN has collected, expanded smart panels with load management save $3,000 to $10,000 per site by avoiding the cost of 400-amp utility service.
PulteGroup bought it. Kirk Hammerstein, National Director of Procurement at the country's third-largest homebuilder, called SPAN's expanded panel family "the key to providing more homeowners with visibility, control, and savings on their utility bills." Pulte is already a partner, deploying smart panels across communities where the alternative would be speccing 400-amp service to support EV chargers and heat pumps at full theoretical draw.
Run the arithmetic at national scale. About 1.4 million housing starts are projected for 2026. Pecan Street estimated that more than half of new homes being built have panels too small for full electrification, which, if extrapolated to current starts, means approximately 700,000 homes per year leave the factory floor with an embedded future problem. Speccing a smart panel at construction adds a premium of roughly $1,500 to $3,000 over a standard breaker box. At scale, that is $2.1 billion to $4.2 billion per year to make every new home electrification-ready through software rather than copper.
Compare that to the alternative: a homeowner who wants to add an EV charger five years later discovers their 100-amp panel is maxed, calls an electrician, and pays $1,300 to $5,000 for a 200-amp upgrade (This Old House and Angi both put the national average around $2,150), plus potentially $5,050 to $12,000 for a full service upgrade if the utility feed needs upsizing. In Denver, Uni Colorado quotes $5,050 to $7,350 for a full 200A upgrade including Xcel coordination, permits, and inspection. Two to four weeks of project time. Pre-wiring for a Level 2 EV charger during construction, by contrast, costs $300 to $1,500 per the National Association of Home Builders, and as little as $300 if the main panel is already in the garage.
$1,500–$3,000 at construction
vs. $4,000–$17,000 as a retrofit
For every dollar a builder saves by speccing a traditional panel, the homeowner eventually spends three to ten.
Strongest Case Against
Smart panels are consumer electronics bolted onto safety-critical infrastructure, and construction has earned its skepticism about anything that requires firmware to keep the lights on.
Longevity is the real question. A traditional breaker panel has no moving parts, no software, and no company whose continued solvency determines whether your house works. It sits in the basement for 40 years and does exactly one thing. A smart panel is a connected device that depends on cloud services for advanced features, receives over-the-air updates, and carries all the risks of any IoT product bolted into a load-bearing wall. SPAN has raised over $100 million in venture funding, but the solar industry is littered with defunct companies whose inverters now display error codes nobody can clear. What happens to a smart panel when the manufacturer goes under? Nobody knows yet. Five years is not forty.
Climate is the other gap in the pitch. PCE's 29-amp finding comes from a region where heating load is minimal and air conditioning is a luxury rather than survival infrastructure. An MIT-led field study published on arXiv examined whole-home current-limiting control in fully electrified homes and found that heat pump defrost cycles with resistance backup heat are a dominant driver of electricity demand peaks. In cold climates, brief but intense demand spikes that occur when a heat pump switches to resistance heating at 5°F are precisely the peaks that smart panels would need to manage. Whether a $200 EVEMS or a $3,500 smart panel can reliably handle those peaks without tripping safety systems or leaving occupants cold during a polar vortex remains unanswered by any large-scale field study.
Contractor skill gap is a practical barrier too. Most residential electricians have installed zero smart panels. Troubleshooting is different from traditional breaker diagnostics. Misinstallation of a device that actively manages load creates failure modes that a passive panel simply does not have.
What This Means for the Person Writing the Check
If you are building a home in 2026 and your electrical plan does not include at least a conversation about load management, your builder is speccing infrastructure for a world that NEC 2026 already moved past.
Decision tree is shorter than the product catalog suggests: if the only goal is adding an EV charger to an existing home without upgrading the panel, an EVEMS device at $200 to $500 is dramatically cheaper and mechanically simpler than anything else on this list, and running a load calculation first often reveals that existing capacity is adequate once you factor in actual simultaneous use rather than theoretical peak addition.
For new construction, the premium for a smart panel is small relative to total project cost and negligible relative to the retrofit cost the next owner will face, so at minimum, specify pre-wiring for a Level 2 EV charger ($300 to $1,500), a heat pump water heater circuit, and an induction range circuit even if the current plan calls for gas. Wiring is cheap at rough-in and expensive after drywall.
For production builders making spec decisions across hundreds or thousands of units, the PulteGroup playbook is worth studying: partner with a smart panel vendor, eliminate 400-amp service from the standard package, and market load management as a feature rather than a compromise, because the savings per site are real and buyers get homes that can absorb an EV, a heat pump, and a battery without a phone call to the utility.
What We Did Not Prove
This analysis relies on PCE's field data from a single temperate county and SPAN's builder-sourced cost savings estimates. No independent third-party study has yet validated smart panel cost savings across a statistically significant sample of production builder sites. Pecan Street's 48 million figure, while widely cited, is a 2021 estimate extrapolated from 263 Austin homes and has not been updated with post-pandemic housing stock data. NEC 2026 provisions for EVEMS and service-level energy management are adopted jurisdiction by jurisdiction, and many areas still operate under the 2020 or 2023 code. Smart panels have been on the market for fewer than five years in most product lines. No long-term reliability data comparable to traditional panel lifespan studies exists. Cold-climate performance under real demand conditions remains the single largest gap in the evidence base.
That 29-amp finding is real. But it is a finding about San Mateo County. Treat it as a provocation, not a national benchmark.