Electrifying a home usually happens one project at a time: first the EV, then the heat pump (or the other way around). Each is the biggest electrical load most houses have ever had - and together they are the reason "do I need a panel upgrade?" became a mainstream question. Usually the answer is no, if you plan.
The loads, honestly
| Load | Typical draw | When |
|---|---|---|
| Level 2 EV charger | 7.7-11.5 kW (32-48A) | Overnight, 3-9 hours |
| Air-source heat pump (heating) | 2-5 kW running, brief 10-15A compressor starts | Coldest hours - often also overnight |
| Heat pump water heater | 0.5-1.5 kW | Schedulable any time |
| Induction range | 3-7 kW in bursts | Evenings |
| Everything else (lights, fridge, electronics) | 0.3-1.5 kW baseline | Always |
The 100A question (US) and its equivalents
Older US homes often have 100-amp service (24 kW theoretical). Add the loads above naively and you exceed it; plan the timing and you rarely do. A realistic worst-case winter evening: heat pump 4 kW + water heater 1 kW + cooking 4 kW + baseline 1 kW = 10 kW (42A). Add an EV charging at 7.7 kW and you are at ~74A - inside 100A service, though tighter than electricians like. The same logic applies to UK 60A cut-outs (upgrade often free via the DNO) and Australian single-phase 63A services: tight but workable with management.
Three ways to avoid a panel upgrade
- Load management devices. A load-shedding device or a charger with built-in load management (Emporia, Wallbox, Hypervolt and others) watches total house draw and throttles the EV charger when the heat pump or range runs hard. Cost: $100-300 built in, versus $2,000-5,000 for a service upgrade. This is the single highest-value trick in home electrification.
- Scheduling. Heat pumps run hardest in the coldest pre-dawn hours; charging can be set for the early night or shoulder hours. On a cold-climate night the two can genuinely conflict, which is why scheduling alone is the second-best option behind hardware management.
- Right-sizing the charger. A 32A (7.7 kW) charger already refills any realistic daily driving overnight - dropping from 48A to 32A frees 4 kW of headroom and often dodges the upgrade entirely. Speed you never use is capacity you pay for twice.
When you do need the upgrade
- All-electric home in a cold climate (heat pump + EV + induction + electric dryer + hot tub class loads).
- Adding a second EV charger on the same service.
- Fuse-based panels or known-undersized service where any added load is unsafe.
- Home battery with backup ambitions, or future solar + battery + two EVs - if the 10-year plan includes all of it, upgrading the service once now beats two retrofits.
The order of operations
- 1. Get a load calculation before any project quote. NEC 220.83 (US) or your electrician's local equivalent tells you the real spare capacity; it is a 30-minute job that decides everything downstream.
- 2. Install with management from day one. A charger and heat pump that can talk (or a panel monitor watching both) future-proofs every later addition.
- 3. Check incentives for the panel itself. The US 25C credit covers 30% of panel upgrade costs (up to $600) when it enables electrification equipment, and several utilities add make-ready rebates - see our state tracker.
What to read next
- Where a home battery fits the picture
- Install costs including panel work
- Charger install options at 32A vs 48A
Sources: NEC load calculation methods, Pecan Street residential load research, DNO guidance (UK), installer surveys. Checked November 2026.