GridSync – Electrical Design & EV Charging Experts in California
GridSync – Electrical Design & EV Charging Experts in California
The Short Answer: The size of your electrical service (200 amps) has almost nothing to do with your generator size. What matters is your actual load—the appliances you plan to run during an outage. Most homes need a generator in the 14-18kW range, not the 22kW salespeople often push.
You’ve got 200 amp electrical service, and you’re shopping for a backup generator. Some salesperson just told you that “200 amps needs a 22kW generator” like it’s some kind of universal law. But here’s the thing: that’s complete nonsense.
Let me be blunt because apparently, a lot of generator salespeople won’t be. The size of your electrical service has almost nothing to do with what size generator you actually need. What matters is your actual load – what you’re planning to run when the power goes out.
A real generator professional will do a proper load calculation. For a detailed look at what a 200-amp upgrade entails and why it’s so common, see our guide on 200-amp panel upgrades in California.
Here’s what’s really going on: virtually all new construction gets 200 amp service these days. It’s standard. Your tiny cabin? 200 amps. Your massive McMansion? Also 200 amps. Does that mean they need the same generator? Of course not.
A real generator professional will do something called a load calculation. They’ll look at what appliances you have, what you actually plan to run during an outage, and size the generator accordingly. Anyone who skips this step and just points to your service panel is either lazy or doesn’t know what they’re doing.
One homeowner put it perfectly: “If a sales guy can’t do a basic load calculation, he shouldn’t be selling generators.” Run from anyone who can’t show you the actual math behind their recommendation. This is the same type of calculation required for a full service upgrade.
Let’s break down what generator sizes actually mean in terms of amperage, because this helps you understand what you’re buying:
These are maximum running amps, not accounting for surge when things like motors start up. Notice something? Even a 14kW generator only provides 58 amps. That’s nowhere near 200 amps, yet plenty of homes with 200 amp service run just fine on these smaller units.
Here’s the approach that actually works: make a list of everything you want to power during an outage. Be realistic about it.
Your essentials probably include:
Your “nice to haves” might be:
The thing is, you’re probably not going to run everything simultaneously. One cabin owner calculated their total possible load at 16kW with literally everything running at once – and then realized they’d never actually do that. They’re not going to run the dishwasher, do laundry, cook a full meal, AND blast the heat pump all at the same time during a power outage.
Your heating and cooling system is usually your biggest concern. Modern inverter-driven heat pumps have changed the game here.
Traditional AC units have high starting loads – they need a big surge of power to get the compressor going. But inverter systems? They start at low power and ramp up gradually. Starting load equals running load, which makes sizing much easier.
One homeowner thought their 2-ton inverter heat pump would need 60-70 amps to start. Turned out it only needed 10 amps to run, with no startup surge. That’s the difference between needing an 18kW generator and maybe getting away with a 14kW.
If you’ve got an older traditional AC system, you might want to look into a soft start device. These reduce that initial power spike and can let you run your AC on a smaller generator.
GridSync provides professional load calculations and whole-house generator installation. Our C-10 licensed team ensures your generator is perfectly sized for your actual needs, not your service panel’s theoretical maximum. We’ll help you navigate fuel choices, transfer switches, and load management to get the most reliable and cost-effective backup power solution.
A 1,000 sq ft cabin with a 2-ton heat pump, induction range, tankless water heater, and LED lighting. Owner chose 18kW after math showed it had headroom to spare.
A home with a 3-ton AC, hybrid water heater, servers, gaming PCs, and TVs runs on an 11kW inverter generator with a soft start on the AC. They can’t run the dryer and AC simultaneously, but that’s a minor inconvenience during an outage.
Some homeowners get by with just 6.5kW. This shows the massive variance in actual needs based on lifestyle and expectations. For a broader look at generator options, see our whole-house generator guide.
Here’s something interesting that might surprise you: bigger isn’t always less efficient.
When you’re comparing similar generator models, sometimes the larger unit actually uses less fuel at the same load. For instance, Generac’s 14kW and 18kW models use the same engine, but the 18kW sometimes uses slightly less propane while producing more power.
And all of Generac’s 20kW through 26kW units use the same engine platform. The 26kW is actually the most fuel efficient of the bunch in some comparisons.
The takeaway? Don’t automatically assume a smaller generator saves you fuel money. Do the research on the specific models you’re considering. For a detailed look at fuel types, see our guide on choosing the right generator and installer.
If you really want to run a lot of stuff on a smaller generator, look into Smart Management Modules (SMMs) from companies like Generac or Champion. These devices let you prioritize your loads and automatically shed the less important ones if you’re approaching the generator’s capacity.
With these systems, you could install a 14kW or 18kW generator and prevent overloading by having the system automatically turn off, say, the electric dryer if the AC kicks on and you’re cooking dinner. You still get to run everything, just not quite all at once.
Forget the “200 amps = 22kW” nonsense. Here’s what you actually need to do:
And remember: the goal isn’t to replicate normal life during an outage. The goal is to stay comfortable and safe until power returns. You probably don’t need to run absolutely everything you own simultaneously.
Get the size that matches your actual needs, not your theoretical maximum service capacity. Your wallet and your propane tank will thank you.
Bringing hands-on experience in electrical installation and system design, specializing in residential and light-commercial projects. The team focuses on delivering safe, code-compliant solutions for electrical panel upgrades, backup power systems, and modern electrical infrastructure.
GridSync provides expert load calculations and professional generator installation. We’ll help you cut through the sales hype and get the right-sized system for your actual needs. Serving San Francisco, Menlo Park, Palo Alto, Mountain View, Los Altos, and the entire Peninsula.
Request a Consultation View Our Services
Bringing hands-on experience in electrical installation and system design, specializing in residential and light-commercial projects. The team focuses on delivering safe, code-compliant solutions for electrical panel upgrades, backup power systems, and modern electrical infrastructure.
With deep experience navigating complex permitting and inspection requirements particularly in highly regulated regions like California Team GridSync.pro emphasizes accurate load calculations, long-term reliability, and safety-first execution. They work closely with homeowners, contractors, and property managers to ensure every installation meets current electrical codes and performs reliably in real-world conditions.
Through their writing, Team GridSync.pro breaks down technical electrical topics into clear, practical guidance, helping readers make informed decisions about electrical upgrades, system planning, and compliance requirements.
