Amperes (Amps, A)
Also known as: AmpsAAmperageCurrent
An ampere — usually just called an "amp" — is the unit of electrical current. Current is the rate at which electrons flow through a wire. The more amps a circuit can carry safely, the more simultaneous load it can support.
Two practical numbers to know in your home: your panel's amperage rating (how much current your whole house can draw at once) and each circuit's amperage rating (how much current any single circuit can carry). Both are determined by the size of the wires and the breakers in the system. A 200A panel can pull up to 200 amps total across all its circuits combined; each individual 20A circuit can pull up to 20 amps before its breaker trips.
When we talk about a "200A panel upgrade," we're talking about increasing your panel's total amperage capacity — so it can handle more simultaneous loads like an EV charger plus a heat pump plus solar plus your existing house. Most older Santa Cruz homes have 100A or 125A service; modern electrification typically requires the 200A upgrade.
Ampacity is what governs how much electrification a home can absorb. Before installing an EV charger, a heat pump, or a battery system, the first calculation is whether your existing service supports the new load. We do this calculation on every job.
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