Quick Answer
A whole-home standby generator is a permanently installed unit that powers an estate automatically during an outage, switching over within seconds through an automatic transfer switch. For larger Ross and Kentfield homes — with wells, pools, multiple HVAC zones, and EV charging — sizing is the whole game, and it comes from a load assessment, not a catalog. A licensed electrician sizes the unit, coordinates fuel and permitting, and installs the transfer switch. We size to your home, not to the biggest unit on the shelf.
Key Takeaways
- A whole-home standby generator is permanently installed and starts automatically during an outage, restoring power within seconds through an automatic transfer switch.
- Estate homes in Ross and Kentfield often carry loads a smaller house never sees — well pumps, pools, multiple HVAC zones, and EV charging — which makes correct sizing essential.
- Sizing comes from a real load assessment of how the home actually uses power, not from picking the largest unit in a catalog or a rule of thumb.
- Public Safety Power Shutoffs during North Bay fire season are a planned, sometimes multi-day loss of power — exactly the scenario a standby system is built for.
- A proper install is permitted, fuel-coordinated, and inspected, with the transfer switch wired so the changeover is seamless and safe for utility crews.
A whole-home standby generator is a permanently installed generator, wired into your home’s electrical system, that detects an outage and restores power automatically — usually within seconds — without anyone lifting a finger. Unlike a portable unit you roll out and plug in, a standby system lives outside the home on its own pad, runs on natural gas or propane, and hands power back and forth with the utility through an automatic transfer switch. For a larger home, that hands-off reliability is the entire point: the power simply stays on.
What is a whole-home standby generator?
The device that makes this seamless is the automatic transfer switch, or ATS. It senses when utility power drops, safely disconnects the home from the grid, starts the generator, and switches the house onto generator power — then reverses the whole sequence when the grid returns. That grid disconnection isn’t just convenience; it protects utility crews working on the line from dangerous backfeed. On an estate, the ATS is often sized to carry the whole home rather than a handful of essential circuits.
A standby generator is a permanently installed backup unit wired to the home that starts automatically during an outage and runs on natural gas or propane.
Why estate homes change the sizing math
This matters in Ross and Kentfield specifically. These are larger homes on wooded, sometimes creek-adjacent lots in central Marin, and many sit in areas exposed to Public Safety Power Shutoffs during fire season. A home here may run a well pump, a pool, multiple heating and cooling zones, a wine cellar, and EV charging — a load profile that rewards a properly sized whole-home system. When we assess an estate, we start with how the home actually uses power, because that’s what determines the generator, not the other way around.
An automatic transfer switch (ATS) safely disconnects the home from the grid and switches it onto generator power during an outage, then back again when utility power returns — protecting line crews from backfeed.
How does a whole-home generator work during an outage?
During an outage, a whole-home standby generator detects the loss of utility power, starts its engine, and — through the automatic transfer switch — brings the home back online within seconds, then runs until grid power returns. You may notice a brief blink; often you notice nothing at all. The generator runs on a fuel supply sized to sustain it, and the transfer switch manages the entire handoff so no one has to be home or awake for it to work. That autonomy is what separates a standby system from a portable one.
On a larger home, load management can make a well-sized generator do more. Smart controls can stagger big loads — for instance, sequencing HVAC compressors or pausing EV charging — so the generator carries the whole home comfortably without being oversized for the rare moment everything runs at once. This is where estate sizing becomes an engineering exercise rather than a purchase. For homeowners comparing options, our guide to whole-home versus essential-loads backup lays out the trade-offs.
Why PSPS season is the real design case
In Marin, a standby generator is designed around Public Safety Power Shutoffs as much as ordinary outages. According to the California Public Utilities Commission, utilities may proactively de-energize lines during high fire-risk conditions to prevent ignitions — and these PSPS events can last from hours to multiple days. For an estate with a well, refrigeration, medical equipment, or a home office, a multi-day outage isn’t an inconvenience; it’s a genuine disruption. A whole-home standby system is built precisely for that planned, extended loss of power.
On an estate, backup power isn't about a few lights. It's about the well, the wine cellar, and the home simply carrying on.— Towery Electric
Whole-home or essential-loads — what's right for an estate?
For most Ross and Kentfield estates, a whole-home system makes sense because the loads that matter — wells, refrigeration, HVAC zones, security — are spread across the house rather than concentrated in a few circuits. An essential-loads system, which backs up only selected circuits, can be the right call for a smaller home or a tighter budget, but it asks you to decide in advance what you’re willing to lose. The table below compares the approaches so the choice matches how your home lives, not just its size.
The decision also touches fuel and runtime. A natural-gas standby unit draws from the utility gas supply for effectively unlimited runtime, while propane relies on an on-site tank sized for the expected outage length — a real consideration for the multi-day PSPS scenario. For homeowners weighing that, our guide to sizing a standby generator walks through matching capacity to the household.
| Approach | What it powers | Best fit |
|---|---|---|
| Whole-home standby | The entire home, automatically | Larger estates with loads spread across the house |
| Essential-loads standby | Selected critical circuits only | Smaller homes or a defined budget; you choose the circuits |
| Natural-gas fuel | Utility gas — effectively unlimited runtime | Homes with reliable gas service and long-outage concern |
| Propane fuel | On-site tank — runtime tied to tank size | Properties without gas service; size the tank to the outage |
| Load management | Full home, staggered smartly | Estates that want whole-home coverage without oversizing |
How does a standby generator installation work?
A standby generator installation is a permitted, coordinated project a licensed electrician manages from load assessment through inspection, typically involving a concrete or composite pad, fuel connection, and the transfer switch. It’s more than dropping a unit in the side yard — it involves electrical, fuel, permitting, and often a gas fitter or landscape coordination on an estate. Because it interfaces with the panel, the work pairs naturally with any service review; our guide to automatic transfer switches explains the piece that makes it seamless.
- Load assessment. We measure how your home actually uses power — wells, HVAC, pool, EV, kitchen — to size the generator to the home, not a catalog.
- Placement & permitting. We site the unit for clearances, noise, and aesthetics, then pull the electrical and any required mechanical permits.
- Fuel & pad. The generator is set on its pad and connected to natural gas or a propane tank sized for the expected outage.
- Transfer switch. The automatic transfer switch is installed and wired so the changeover is seamless and safe for utility crews.
- Inspection & commissioning. The system is inspected, then tested under load and set to self-exercise so it’s ready before the next PSPS.
When it’s done, the estate has power that manages itself — starting within seconds of an outage and standing down when the grid returns. What you should expect from a good electrician is a genuine load assessment, a unit sized to your home rather than upsold, and a system commissioned and set to test itself so it’s ready when you need it.
Wondering what it takes to keep a larger home running through a PSPS?
Request Your EstimateWhich estates most need a whole-home generator?
The estates that most need whole-home backup are those with well water, extensive refrigeration, multiple HVAC zones, home offices, medical equipment, or anyone who simply can’t tolerate a multi-day outage. In Ross and Kentfield, well-dependent properties are a clear case — no power means no water. Homes with wine cellars, aquariums, or sensitive electronics have continuity needs a portable unit can’t reliably meet. And for households where someone works from home, a PSPS shouldn’t mean losing a workday.
When resilience is part of the home's value
For many estate owners, reliable backup power is part of what the home is worth — a house that stays warm, lit, secure, and connected through a multi-day shutoff simply lives better. It also protects the property itself: sump pumps that keep running, refrigeration that doesn’t spoil, and security systems that stay armed. On a wooded central-Marin lot exposed to fire-season shutoffs, that resilience isn’t a luxury add-on so much as a match for how these homes are actually used through a North Bay autumn.
What are the common mistakes with estate generators?
The most common mistake on an estate is sizing the generator by guesswork — buying too small and browning out under real load, or oversizing and paying for capacity that never runs. Both come from skipping the load assessment. Another is treating the transfer switch as an afterthought; an improperly installed switch can backfeed the grid, which the U.S. Consumer Product Safety Commission warns is a serious hazard to utility workers, as covered in general CPSC generator safety guidance. Skipping permits or maintenance rounds out the list.
How to avoid them
Avoid these pitfalls by insisting on a real load assessment, a properly sized and permitted transfer switch installed by a licensed electrician, and a maintenance plan that keeps the unit ready. A standby generator that never gets serviced can fail exactly when it’s needed. Our guide to standby generator maintenance covers what keeps a system dependable year over year — because on an estate, a generator that doesn’t start is worse than none at all.
Key Terms
- Standby generator
- A permanently installed backup generator that starts automatically during an outage and runs on natural gas or propane.
- Automatic transfer switch (ATS)
- The device that safely switches a home between grid and generator power, protecting utility crews from backfeed.
- Load assessment
- A measurement of how a home actually uses power, used to size a generator to the household rather than to a catalog number.
- PSPS (Public Safety Power Shutoff)
- A utility-initiated, proactive de-energization of lines during high fire-risk conditions, which can last from hours to several days.
About the Author
Founder of Healthcare Marketing Group and author of The Ultimate Guide to Digital Marketing. Previously led a digital marketing company with 8,000+ clients. Writes on local-service SEO and E-E-A-T content strategy.
Reviewed By
Alex founded Towery Electric in Novato in 2014 and has installed whole-home standby systems on larger properties across central and southern Marin. Reviewed this article for technical accuracy on Sep 23, 2026, 2026.
“On an estate, the temptation is always to sell the biggest generator. I’d rather run the load assessment and put in exactly the right size — a unit that carries the home cleanly and doesn’t cost more to own than it needs to.”
— Alex Towery, Licensed Electrical Contractor
How We Ensure Accuracy
Sources
- California Public Utilities Commission. “Public Safety Power Shutoffs (PSPS).” cpuc.ca.gov
- U.S. Consumer Product Safety Commission. “Portable Generator Safety.” cpsc.gov
- National Fire Protection Association. “NFPA 70 — National Electrical Code.” nfpa.org
- California Contractors State License Board. “License Detail — Towery Electric, Inc. (#989290).” cslb.ca.gov
- Pacific Gas & Electric. “Public Safety Power Shutoff Preparedness.” pge.com
Frequently Asked Questions
What size generator does an estate home need?
There’s no standard size — it comes from a load assessment of how your home actually uses power. Estate homes often run well pumps, pools, multiple HVAC zones, and EV charging, which push the requirement higher than a typical house. But bigger isn’t automatically better; an oversized unit costs more to own and run. A licensed electrician measures your real loads and sizes the generator to the home, sometimes using load management so it carries everything without being oversized.
How fast does a standby generator restore power?
A whole-home standby system typically restores power within seconds of an outage. The automatic transfer switch senses the loss of utility power, starts the generator, and switches the home over — usually a blink, sometimes unnoticeable. That’s the key advantage over a portable unit, which someone has to roll out, fuel, and connect manually. For an estate with a well or refrigeration, that automatic, near-instant handoff is what keeps the home functioning during a PSPS.
Will a standby generator run through a multi-day PSPS?
Yes, when it’s fueled for it. A natural-gas unit draws from the utility gas supply for effectively unlimited runtime, while a propane unit runs as long as its tank lasts — so the tank is sized to the expected outage. Public Safety Power Shutoffs can last from hours to several days, which is exactly the scenario a standby system is designed around. Your electrician sizes the fuel supply to match the outages your area actually sees.
Does a generator installation need a permit?
Yes. Installing a standby generator in California requires an electrical permit and inspection, and often a mechanical or gas permit for the fuel connection. The permit confirms the transfer switch is wired correctly so it can’t backfeed the grid — a genuine safety matter for utility crews. A licensed C-10 contractor handles the permitting and coordinates the fuel connection. Skipping permits creates problems at resale and can void manufacturer or insurance coverage.
How much maintenance does a standby generator need?
Standby generators need regular service to be dependable — typically periodic inspections, oil and filter changes, and a self-exercise cycle that runs the unit briefly on a schedule. A generator that sits unserviced can fail exactly when a PSPS hits, which defeats the purpose. Most systems are set to test themselves automatically and flag issues. On an estate, a maintenance plan is worth having so the system is genuinely ready before fire season, not just installed.
Editor’s Summary
For Ross and Kentfield estates, a whole-home standby generator keeps water, heat, refrigeration, and security running through a Public Safety Power Shutoff — automatically, within seconds, via an automatic transfer switch. The work is in the sizing: a real load assessment of how the home uses power, not the biggest unit in a catalog. Done right, it’s permitted, fuel-coordinated, inspected, and set to test itself, so an estate simply carries on through a multi-day North Bay outage.