Can Your Electrical Panel Handle Modern Load Demands?

November 5th, 2025

With more San Diego homeowners switching to EVs, installing heat pumps, and adding solar systems, many are finding that their old 100-amp electrical panels simply can’t keep up. So you might be wondering: is a 200-amp upgrade enough, or do you need a full 400-amp service?

This guide explains how load demand is professionally calculated, what tools are available locally, and how to choose the right capacity for your home’s safety, performance, and long-term value.

1. What Is Electrical Load Demand — and Why It Matters.

Electrical load demand (or load calculation) determines how much electricity your property requires. We use this to ensure your main panel can safely power all your appliances, lighting, and equipment at once without overloading or overheating.

If your panel’s capacity is too low, an upgrade is necessary before adding high-demand equipment, in other words, if your panel is undersized, you risk:

Frequent breaker trips.
Overheating and fire hazards.
Wasted investment — installing new equipment only to upgrade later anyway.

As licensed electricians, we follow the National Electrical Code when calculating electrical load demand.

2. The Biggest Energy Consumers in the Home

While lighting and electronics use minimal amperage, these common upgrades often drive panel upgrades:

Appliance / Equipment	Typical Load (Watts/Amps)	Impact on Demand
Level 2 EV Charger	Up to 48A	Most common cause of panel upgrades
Central Heat Pump (HVAC)	High (5-ton units draw heavily)	Essential for modern comfort
Electric Range / Stove	Up to 8,000W	Requires dedicated circuit
Electric Dryer	Up to 5,000W	Steady draw needing its own breaker

3. Choosing the Right Amperage in San Diego

100A Panel

Once standard for San Diego homes, a 100A panel can still work if managed smartly. However, this setup limits future expansion and full electrification.

200A Panel

Ideal for most modern homes, a 200A panel provides headroom for EV chargers, solar systems, and heat pumps. It’s the minimum recommended capacity for complete home electrification.

400A Service

A significant upgrade suited for:

Large homes with multiple heavy systems (pools, spas, workshops)
Main houses plus ADUs connected to the same service
Multi-EV households or other high-power users

Pro Tip: SDG&E Energy Management Tool

San Diego Gas & Electric offers an online dashboard to analyze your energy usage by hour, day, or month. Reviewing these insights helps identify when your power demand peaks and whether your panel is keeping up.

Conclusion: Choosing the Right Amperage

For minimal upgrades → 100A may suffice with load-management devices.
For EVs, solar, or home electrification → 200A is the smart long-term choice.
For multi-unit or high-demand properties → 400A delivers maximum flexibility.

Ready to Power Up Your San Diego Home?

Don’t guess your amperage — get a professional load assessment from GR Pro Electric.
Our licensed team will calculate your exact power needs, handle SDG&E coordination, and manage all city permits.

Get a quote