Electrical panel upgrade: when you need one, 100A vs. 200A and the PG&E wait

For Silicon Valley homes · Updated October 2026 · Sources below

You need a bigger panel only when your current load plus the new appliances would be more than your service can safely carry. Many older homes have 100-amp service and many newer ones have 200 amps. An electrician can run a load calculation first - sometimes a smart panel, a circuit-sharing device or PG&E's PanelBoost program avoids a full upgrade.

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The short version

Older homes often have 100-amp panels; many newer homes have 200 amps
A load calculation tells you whether you really need an upgrade
A panel or service upgrade needs an electrical permit and a city inspection
PG&E's review of a new load request can take up to 30 days
Alternatives: smart panels, circuit sharing, lower-power appliances or PG&E PanelBoost

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What it costs

Panel upgrade prices vary too much in the Bay Area for a fair range - especially when PG&E service work is needed. A pro will quote it after seeing your panel.

Signs you may need more capacity

You're planning an EV charger, heat pump, heat pump water heater or induction range
Your panel is 100 amps (or smaller) and you're going all-electric
There are no open breaker spaces left
Breakers trip when several big appliances run at once

What to do first

Ask an electrician for a load calculation. The U.S. Department of Energy guide shows two ways: one uses your past 12 months of peak use from your bill, the other adds up the home's loads.
If the numbers are close, ask about alternatives: a smart panel or smart breakers, a circuit-sharing or circuit-pausing device, or 120-volt and lower-power appliances.
If you do need more service, have the electrician file the request with PG&E early - the utility's review and any work on its side set the schedule.

In Silicon Valley

PG&E PanelBoost: a compact smart panel extension next to the meter that lets you add heat pumps, EV chargers and other big appliances without a full upgrade. It's for single-family homeowners with 150-amp or smaller service; PG&E pays for the equipment and you pay the electrician. Check PG&E's page for current availability.
PG&E's process for new load: up to 30 days for the load assessment, then design and any utility work if needed. After the new panel passes city inspection, PG&E typically reconnects power within one day.
California's Powering Up Californians Act (SB 410 and AB 50) led the CPUC to set target times for utilities. For a main-panel upgrade the target is an average of 30 days and a maximum of 45 days.
PG&E says a full panel upgrade usually costs far more when your service comes in underground, because trenching is often needed.
Some local utilities offer panel rebates, often only alongside a qualifying electric appliance. Palo Alto Utilities' panel add-on, for example, needs a core appliance rebate and caps the new panel at 200 amps. See the Rebate Finder for your city.

Questions homeowners ask

How do I know if I need a panel upgrade?

Only a load calculation can tell you. The Department of Energy's guide says that if your existing load plus the new loads stays under the panel's rating, you don't need to upgrade, and it recommends keeping the load under 80 percent of your service capacity. An electrician can run the numbers in one visit.

Is 100 amps enough for a house?

Many older homes run fine on 100 amps, but adding an EV charger, a heat pump and an induction range at once can push it past its limit. Smart panels, circuit-sharing devices and lower-power appliances can sometimes let you stay at 100 amps. Ask for a load calculation before you assume you need 200 amps.

How long does a panel upgrade take with PG&E?

The schedule usually depends on PG&E. PG&E says its load assessment takes up to 30 days, and if the lines or transformer need work, design and construction come next. Once the city inspector signs off, PG&E typically restores power within a day.

Do I need a permit to upgrade my electrical panel?

Yes. A panel or service upgrade needs an electrical permit, and the city has to inspect it before PG&E reconnects your power. Your electrician normally pulls the permit.

What is PG&E PanelBoost?

It's a PG&E program that adds a small smart panel extension at the meter so you can add big electric appliances without a full panel upgrade. It's for single-family homes with 150-amp or smaller service, and PG&E pays for the equipment while you pay the electrician. It isn't a fit for old or unsafe panels or very large projects like an ADU.

How much does a panel upgrade cost?

It varies too much in the Bay Area for a fair single number. The biggest swing is whether PG&E has to upgrade the service to your home - underground service that needs trenching costs much more. An electrician can quote it after seeing your panel and meter.

Do you need a permit?

Yes - a panel or service upgrade needs an electrical permit.

General guidance based on California's building code - your city can have stricter rules, and zoning, historic and HOA rules can apply too. Check with your city's building department before you start.

Check the rule for your city

Rebates: Electrical panel & circuits

San José Clean Energy EcoHome Rebates
Silicon Valley Clean Energy Home Rebates
Silicon Valley Power Residential Rebates
City of Palo Alto Utilities Rebate Hub
Switch Is On incentive finder

Rebate programs change often and money runs out. Amounts are from each program's page as of Oct 2026 - always confirm on the program page, and check whether you must apply before you buy or install.

See the rebates for your ZIP

Questions to ask the pro

Can you do a load calculation before we decide on an upgrade?
Could a smart panel, circuit-sharing device or PanelBoost avoid the upgrade?
Will PG&E need to do work on its side, and who files that request?
Is the permit and inspection included in the price?
Does my project qualify for a panel rebate from my utility?

Before you sign, check the contractor's license at cslb.ca.gov. How to hire a contractor in California

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