Standby Generator or Portable? How Marin and Sonoma County Homeowners Should Think About Backup Power

Standby Generator or Portable? How Marin and Sonoma County Homeowners Should Think About Backup Power

Quick Answer: A standby generator is a permanently installed, natural gas or propane-fueled backup power system that detects an outage and starts automatically within seconds, restoring power to some or all of your home without any action on your part. A portable generator is a gasoline-powered unit that must be manually set up, started, and connected to appliances or a transfer switch during an outage. Standby generators cost more upfront but provide seamless, whole-home coverage with no manual intervention. Portable generators cost less but require fuel storage, manual operation, and carry significant safety risks if used incorrectly. Ongaro & Sons is a licensed C-10 electrical contractor based in Petaluma, CA, serving Marin, Sonoma, and Napa counties since 1932.

In October 2019, PG&E cut power to roughly 730,000 California customers across 34 counties in one of the largest Public Safety Power Shutoff events in state history. Sonoma County was among the hardest hit, with some residents without power for five days. Marin County was also affected, particularly in the hills above Mill Valley, Fairfax, and in northern Marin near Novato, where PSPS events have disrupted power in hillside communities during high-wind fire weather. It wasn’t a storm. It was a planned outage, designed to reduce wildfire ignition risk, and it gave a lot of North Bay homeowners their first real understanding of what multi-day power loss actually costs: spoiled food, medical equipment concerns, no heat, no well pump, no way to charge an EV, and the realization that a small camping generator and a 5-gallon gas can is not a serious backup power plan.

Since 2019, PSPS events have become a recurring feature of fire season across the North Bay. Both Sonoma and Marin county residents in the affected zones deal with this reality. The question isn’t whether the power will go out during a future high-wind event. It’s whether your home will be ready when it does.

That conversation starts with choosing between a standby generator and a portable one.

What Is a Standby Generator?

A standby generator is a permanently installed backup power system connected directly to your home’s electrical system through an automatic transfer switch. It runs on a continuous fuel supply, either natural gas from the utility line or propane from an on-site tank, and requires no manual intervention to operate.

When utility power fails, the automatic transfer switch detects the outage within seconds and signals the generator to start. The generator reaches operating speed and the transfer switch reconnects your home’s electrical loads to the generator power, all within 10 to 30 seconds. When utility power is restored, the process reverses automatically: the transfer switch reconnects to the grid and the generator shuts down. You don’t have to be home. You don’t have to do anything. The system handles it.

Standby generators are sized by kilowatt output. Residential units range from 7 kW (covering essential circuits only) to 24 kW and above (capable of powering a whole home including air conditioning and major appliances simultaneously). Whole-home standby generators from manufacturers like Generac, Kohler, and Cummins are designed for indefinite runtime as long as fuel is available, which for natural gas connections means no practical limit during an outage.

A standby generator must be installed by a licensed electrical contractor, requires a permit, and must be placed according to local setback and clearance requirements. It’s a permanent addition to the property, similar in that respect to an HVAC system or a solar array. Generac is the leading residential standby generator brand in the United States, and factory certification matters: a certified Generac installer has completed manufacturer training on installation, commissioning, and service across the full product line.

What Is a Portable Generator?

A portable generator is a gasoline-powered unit that produces electricity on demand. It has no permanent connection to your home and requires manual operation every time you use it.

During an outage, the process looks like this: retrieve the generator from storage, move it to an outdoor location at least 20 feet from any door, window, or vent, add fuel if the tank isn’t full, start the engine (pull-start or electric start depending on the model), run extension cords to individual appliances or connect to a manual transfer switch if one is installed, and monitor the fuel level throughout the outage to refuel as needed.

Portable generators range from small recreational units producing 2,000 to 3,500 watts (enough for a few lights, a refrigerator, and phone charging) to large construction-grade units producing 7,500 to 12,000 watts (enough for essential home circuits). They require gasoline or in some cases dual-fuel operation with propane, and they produce exhaust that must be kept entirely outside the home.

The appeal of portable generators is primarily cost: quality portable units are significantly less expensive than installed standby generators. For homeowners who experience infrequent, short outages and are comfortable with the manual process, portables serve a legitimate purpose.

The limitations become apparent during extended outages, when you’re not home, or when the outage occurs at 3 a.m. in a wind event.

How Do They Compare on Power Output?

The power comparison depends almost entirely on what you need to keep running during an outage.

Portable generators: A typical residential portable producing 7,500 to 10,000 watts can power a refrigerator, lights, phone and laptop charging, a window AC unit, and perhaps a sump pump or well pump. It cannot power a central air conditioning system (which draws 3,000 to 5,000 watts or more at startup), a heat pump, an electric range, or multiple large appliances simultaneously. You’re in survival mode, not normal operation.

Standby generators: A 13 kW to 20 kW standby generator can power a typical North Bay home including central air conditioning, the refrigerator, lights, outlets, a well pump, garage doors, and electronics simultaneously. A whole-home standby generator at 20 kW or above can power virtually everything in the home without load management. You’re in normal operation.

For households where an outage means genuine hardship, including those with medical equipment that requires power, electric-dependent heating or cooling, or a well pump as the only water source, the power output gap between portable and standby is the deciding factor.

How Do They Compare on Fuel?

Fuel is where the practical difference between the two options becomes most tangible during a real emergency.

Portable generators run on gasoline (or dual-fuel with propane). During a PSPS event or major outage, gas stations in affected areas run out of fuel quickly. In the 2019 Sonoma County PSPS, lines stretched for blocks at gas stations that still had power. Storing large quantities of gasoline at home is a fire hazard and a code compliance issue in many jurisdictions. Gasoline also has a shelf life of roughly three to six months before it degrades and causes carburetor problems. A generator that hasn’t been run in a year and has old gas in the tank may not start when you need it.

Standby generators run on natural gas or propane. Natural gas supply is typically unaffected by power outages because the gas distribution system operates independently of the electrical grid. A standby generator connected to the natural gas line has, for practical purposes, unlimited fuel during an outage. Propane-fueled standby generators require an on-site tank that needs periodic refilling, but a properly sized tank provides days to weeks of runtime depending on load.

The fuel comparison alone resolves the choice for most North Bay homeowners dealing with PSPS events: a portable generator that requires gasoline sourced from a gas station during a regional outage is a system that can fail when you most need it. A standby generator on natural gas is not subject to that constraint.

What Is the Safety Difference Between Standby and Portable Generators?

Carbon monoxide poisoning from portable generators kills dozens of Americans every year and sends thousands more to the emergency room. It is consistently among the top causes of non-fire carbon monoxide deaths in the United States, and the frequency spikes every time a major weather event or power emergency drives generator use.

The Centers for Disease Control and the Consumer Product Safety Commission are explicit: portable generators must be operated outdoors, at least 20 feet from any window, door, or vent, with exhaust directed away from the home. Carbon monoxide is colorless and odorless. By the time occupants notice symptoms, including headache, dizziness, and confusion, exposure may already be at dangerous levels.

Every year, people run portable generators in garages with the door open, on covered porches, or near open windows and end up in the hospital or worse. This is not a risk reserved for careless people. It’s a risk that’s easy to underestimate during a stressful outage situation at 2 a.m.

Standby generators are installed outdoors on a permanent pad with proper exhaust management as part of the installation. They do not present a carbon monoxide risk to home occupants under normal operation. This safety difference is not a minor footnote. For households with children, elderly residents, or anyone with respiratory conditions, it should be weighted heavily in the decision.

What Does Standby Generator Installation Involve?

Installing a whole-home standby generator is a multi-trade project involving electrical work, potentially gas plumbing, and sometimes concrete or ground preparation. The components:

The generator unit and pad. The generator is mounted on a concrete pad outside the home, positioned according to local setback requirements from windows, doors, property lines, and gas meters. Most jurisdictions require the generator to be at least 5 feet from openings in the building and at least 18 inches from the wall surface. The pad must be level and properly sized for the unit.

Automatic transfer switch. This is the brain of the system. The transfer switch monitors utility power and controls the transition between utility and generator power. It’s installed at or near the main electrical panel and requires a licensed electrician to install. Whole-home transfer switches replace the main panel or connect to it directly; partial-load transfer switches manage a selected subset of circuits.

Electrical connection. The generator connects to the transfer switch with appropriately sized conductors. If the project includes an electrical panel upgrade, the panel and transfer switch work is coordinated as a single project.

Fuel connection. For natural gas, a licensed plumber runs a gas line from the home’s gas supply to the generator location. The line must be appropriately sized for the generator’s BTU demand. For propane, an on-site tank is installed and connected by the propane supplier.

Permit and inspection. A permit is required. Electrical and gas work are both subject to inspection by the local building department before the system is activated.

Commissioning and load test. The contractor programs the automatic transfer switch, sets the exercise schedule (most standby generators run a brief weekly self-test to verify operation), and runs the system under load to confirm it performs correctly.

The full installation typically takes one to two days once permits and equipment are in hand.

What Size Standby Generator Does a Whole Home Need?

Generator sizing depends on the loads you want to support during an outage.

Essential circuits only (7 kW to 12 kW): A partial-home standby generator powers the refrigerator, select lighting, outlets, and critical equipment while leaving high-draw appliances like air conditioning offline. This is appropriate for homeowners whose primary concern is food preservation, communication, and basic function, rather than whole-home normal operation.

Whole-home with standard loads (14 kW to 18 kW): Covers the full home including central HVAC (up to approximately 3 to 4 tons of cooling), refrigerator, lighting, outlets, well pump, and electronics simultaneously. Appropriate for most North Bay single-family homes with gas cooking (the range doesn’t need generator power).

Whole-home with large loads or all-electric homes (20 kW to 26 kW+): Required for homes with all-electric HVAC (heat pumps), electric ranges, multiple large appliances operating simultaneously, or larger square footage. As homes throughout the North Bay electrify and remove gas appliances, generator sizing requirements increase accordingly.

An electrical load calculation, based on your home’s actual circuits and expected operation during an outage, is the proper sizing method. Oversizing a generator adds unnecessary cost; undersizing one results in overload tripping when you try to run the system under real conditions.

Standby vs. Portable Generator vs. Solar Plus Battery: At a Glance

Here is how the three approaches compare across the factors that matter most in a Sonoma or Marin County PSPS scenario.

The runtime and automation rows are where the comparison resolves for most homeowners dealing with multi-day PSPS outages.

What Does Backup Power Cost: A Realistic Comparison

Portable generator (purchase only): Quality residential units vary in price based on wattage output. A manual transfer switch for cleaner connection to circuits adds to the total installed cost.

Standby generator (installed): Cost depends on kilowatt output, fuel type, transfer switch configuration, gas line run length, and local permitting costs. Whole-home systems with automatic transfer switches represent a larger investment than partial-load configurations.

The standby generator costs more. It also starts itself, runs indefinitely on natural gas, requires no manual operation, carries no carbon monoxide risk, and is there whether or not you’re home when the outage happens. The portable costs less and requires you to be present, have fuel, and operate it correctly every time you need it.

For homeowners who have experienced a multi-day PSPS event, the calculus usually resolves clearly after the second one.

When Does a Portable Generator Still Make Sense?

Portable generators are the right choice in certain situations:

• Budget is the primary constraint and whole-home protection isn’t required
• The home is a rental property or a seasonal residence where a permanent installation isn’t practical
• Outages in the area are infrequent and typically short, making the standby investment difficult to justify
• The homeowner is comfortable with manual operation and has a reliable fuel storage plan
• A portable is needed as a temporary solution while a standby installation is planned

For these situations, a quality dual-fuel portable generator (gasoline and propane), paired with a manual transfer switch installed by a licensed electrician, is meaningfully safer and more practical than running extension cords. Never operate a portable generator indoors or in an attached garage under any circumstances.

When Is a Standby Generator the Right Choice?

A standby generator is the right investment when:

• Multi-day PSPS events are a realistic concern for your property or neighborhood
• The household includes anyone dependent on powered medical equipment
• Your home relies on a well pump for water supply
• You are frequently away from home and cannot manually operate a portable during an outage
• You want whole-home protection including air conditioning and HVAC
• You’ve already experienced a difficult outage with a portable and want a real solution
• You are planning a home electrification project that increases your electrical load and your dependence on a continuous power supply

What About Solar Plus Battery Storage?

Battery storage systems paired with solar, such as Tesla Powerwall, Enphase IQ Battery, and Franklin WH units, provide backup power without a generator, operating silently and without fuel. During a grid outage, they discharge stored solar energy to power the home.

The limitation is capacity. A single Powerwall unit stores 13.5 kWh of energy. A typical North Bay home uses 20 to 40 kWh per day. Without solar recharging during the outage, a single battery unit lasts less than a day under normal loads. With solar recharging, a battery system can sustain essential loads indefinitely during daylight hours, making it a viable whole-home solution for many PSPS events, which typically occur during clear, high-pressure weather when solar production is high.

For homes with existing solar installations, a battery system is a strong alternative to a standby generator for PSPS resilience, with the tradeoff that it doesn’t provide the multi-day, high-load coverage that a standby generator on natural gas can deliver.

Some homeowners choose both: a battery system for frequent short outages and a standby generator as the ultimate backstop for extended events. For households in high-risk fire zones, this combination provides the most complete protection.

Frequently Asked Questions

What is a standby generator? A standby generator is a permanently installed backup power system connected to your home’s electrical panel through an automatic transfer switch. It runs on natural gas or propane, detects a power outage within seconds, and starts automatically to restore power to part or all of your home without any manual intervention. It shuts off automatically when utility power is restored.

How long can a standby generator run? A standby generator connected to natural gas can run indefinitely as long as gas supply is available. Natural gas supply is typically unaffected by power outages because it operates on its own distribution infrastructure. A propane-fueled standby generator runs until the tank is depleted, which for an appropriately sized tank can be several days to weeks depending on load.

What is the difference between a standby generator and a portable generator? A standby generator is permanently installed, starts automatically, runs on natural gas or propane, and can power a whole home. A portable generator must be manually set up and started, runs on gasoline, and is limited in power output. Standby generators cost more but provide seamless protection with no manual operation. Portable generators are less expensive but require fuel storage, manual operation, and must be kept entirely outdoors due to carbon monoxide risk.

How much does a standby generator cost installed? In Sonoma and Marin counties, standby generator installation cost depends on the system size, fuel type, transfer switch configuration, gas line run, and permitting. Get a written estimate that breaks out the generator unit, automatic transfer switch, gas line connection, pad, permit, and labor separately. Larger units and more complex installations cost more.

Do I need a permit to install a standby generator? Yes. Standby generator installation requires an electrical permit and in most cases a gas permit as well. The work must be performed by licensed contractors, and the installation is inspected by the local building department before the system is activated.

Can a standby generator power an entire house? Yes, with appropriate sizing. A 20 kW standby generator can power a typical North Bay home including central air conditioning, refrigerator, lighting, outlets, and electronics simultaneously. All-electric homes with heat pumps and no gas appliances require larger units due to higher electrical load.

Is a portable generator safe to run in a garage? No. Portable generators must never be operated in an attached garage, even with the door open. Carbon monoxide from a generator running in or near an enclosed space can reach lethal concentrations indoors within minutes. The generator must be positioned at least 20 feet from any window, door, or vent, with exhaust directed away from the home.

What size standby generator do I need for my home? Sizing depends on the loads you want to support. A 13 kW to 17 kW unit handles most North Bay single-family homes with gas HVAC. Homes with electric HVAC or large square footage typically need 20 kW or more. A load calculation based on your actual circuits is the correct sizing method. Your electrician or generator installer should perform this calculation before specifying equipment.

What is a PSPS event and how does it affect generator decisions? A Public Safety Power Shutoff (PSPS) is a planned outage implemented by PG&E during high fire risk weather conditions, specifically low humidity, high temperatures, and strong winds. PSPS events can affect large portions of Sonoma and Marin counties and last from one to five days. In Marin, hillside communities in the WUI zones above Mill Valley and Fairfax and northern Marin near Novato have been among the affected areas. Portable generators are an inadequate solution for multi-day PSPS events due to fuel supply constraints during regional emergencies. Standby generators on natural gas are specifically well-suited to PSPS resilience.

Install a Standby Generator in Sonoma or Marin County

Ongaro & Sons is a certified Generac installer and licensed C-10 electrical contractor based in Petaluma, CA, serving Marin, Sonoma, and Napa counties since 1932. We hold Diamond Certified® status and a BBB A+ rating. We install and service whole-home standby generators throughout the region, handling the electrical, gas coordination, permitting, and commissioning as a complete project.

If you’ve been through a PSPS event and are done relying on a portable, schedule a consultation to discuss which system is right for your home and what the installation involves.