Your Dealer Quoted a 22 kW Generator. The Load Math Says 14 kW and $600 of Load Modules.

The Problem

A standby generator is the most expensive appliance most homeowners will ever buy, and the person who tells you what size you need is paid more when the number is bigger. The typical whole-house installation runs $1,517 to $8,811, averaging about $5,163 according to Angi's 2026 cost data, and that average hides the real purchase: a 22 kW-class turnkey job, equipment plus automatic transfer switch plus pad plus gas work plus permits, lands around $10,000 to $15,000 once every line item is in. The equipment price steps are published. Angi's size table puts 14 to 18 kW units at $4,000 to $5,500 in materials and 20 to 24 kW units at $5,000 to $6,500. Installation labor adds another $1,500 to $5,000, and the automatic transfer switch alone runs $1,000 to $2,500 installed. Every kilowatt of upsell compounds through all of it.

Here is the structural problem. The sizing consultation is free, and it is performed by the dealer network of the company that sells the generator. Generac held over 68 percent of the US home standby market in 2025, with the top five manufacturers holding 90 percent, and its residential product sales were $2.27 billion in 2025, down 7 percent on a softer outage year. The company then guided roughly 10 percent residential growth for 2026 on the assumption that outage activity returns to baseline. The entire category runs on fear of the next storm, and the person converting that fear into a purchase order also chooses the size. Bigger units mean bigger equipment margins, bigger installation tickets, and bigger fuel consumption for the life of the machine. The homeowner has no instrument to check the answer.

The sizing itself is where the money hides. The lazy method is adding up breaker sizes, and any electrician will tell you that method massively oversizes the result. A 30-amp dryer breaker might feed a dryer that draws 22 amps; a 30-amp air conditioner circuit might serve a unit pulling 18; a 15-amp lighting circuit full of LEDs might draw three, as one master electrician put it in a widely cited sizing thread. The honest method is a load analysis: nameplate running amps for each major appliance, plus the single largest motor-starting surge, plus 20 to 25 percent headroom. Then comes the step almost no dealer volunteers. A smart load management module, a relay that watches generator output and temporarily sheds a designated large load when demand approaches capacity, costs a few hundred dollars installed. Generac's own Smart Management Modules let a smaller generator serve a larger home by cycling nonessential loads, saving thousands on the initial purchase and installation, in the manufacturer's own words.

One Generac dealer put the quiet part in writing on his own sizing guide: "I have replaced a great many 30+ kW quotes with a 22 kW unit and $600 of modules, and the customers were better served. If an installer hasn't discussed load management with you, that's a signal." Read that again. A dealer is telling you that other dealers' quotes are oversized by 8 or more kilowatts, and that $600 of modules fixes it. The modules run roughly $150 to $300 installed each, so a four-module setup adds on the order of $600 to $1,200 to the project, against a $2,000 to $4,000-plus step up in generator size. The economics are lopsided in the homeowner's favor. The information asymmetry is lopsided the other way.

Two facts sharpen the purchase. First, outage time is wildly skewed. The EIA's Electric Power Annual 2024 found US customers averaged 11 hours of interruptions in 2024, nearly double the prior decade's average, with major events accounting for about 80 percent of outage hours. Strip out the hurricanes and the routine number is about two hours a year, like clockwork. The generator is tail insurance being sold as everyday insurance. Second, penetration is still only about 6 percent in North America, per Generac's own investor materials, which estimate each point of penetration at $3 billion in sales potential. Michigan runs over 15 percent for higher-value single-family homes, per the CEO on a 2023 earnings call, while California sits under 2 percent, per the Q1 2025 call. Almost everyone who will ever buy one hasn't bought yet, and every one of them gets exactly one sizing consultation.

Market Size

TAM calculation: Global Market Insights sizes the US home standby genset market at $3.3 billion in 2025, growing to $3.6 billion in 2026 at a 7.9 percent CAGR toward $7.2 billion by 2035. Treat the house range as accurate within ±30 percent and never mix equipment-only figures with installed-project figures: the market reports measure equipment and channel revenue, while the homeowner experiences the turnkey ticket. A cross-check from the unit side: $3.3 billion divided by an $11,000 average turnkey installed cost implies roughly 300,000 standby installations a year in the US, a conservative figure since the $3.3 billion likely measures equipment revenue rather than turnkey tickets. Generac's own numbers corroborate the order of magnitude: $2.27 billion in 2025 residential product sales at 68 percent-plus share implies a $3.3 billion category almost exactly.

The buyable SAM is the referee layer, not the equipment. Sixty thousand independent sizing reviews a year at $249 ($14.9 million), capturing one in five standby buyers at the quote stage. Fifteen thousand installer referrals a year at $400 per install ($6.0 million), from the managed-sizing dealer network the reviews feed. One hundred thousand annual maintenance-contract re-bids at $49 ($4.9 million), attacking the $200-to-$500-a-year service annuity every standby owner pays. Combined SAM: roughly $26 million at maturity.

Year 3 target: 30,000 sizing reviews at $249 ($7.5 million), 7,500 referrals at $400 ($3.0 million), and 50,000 maintenance re-bids at $49 ($2.45 million), for about $13 million in Year 3 revenue.

The Product

A buyer-side generator intelligence platform that audits the size, not just the price. Existing tools answer different questions. Generac's online sizing calculator answers "which of our products." Angi answers "who will call me back." The dealer's free consultation answers "how big," asked by the person selling the kilowatts. Nobody answers "is the 22 kW quote real, what does the managed peak look like, and what will this machine cost me per hour of actual outage."

Load X-ray: Upload the dealer's quote plus phone photos of the panel directory and the nameplates on the AC condenser, water heater, well pump, and range. Parsing builds the unmanaged peak from nameplate amps and the managed peak with load modules sequenced, the two numbers the quote should have shown. Three incomparable quotes become one table: unmanaged peak, managed peak, module count, fuel burn at each.
Independent sizing review: The wedge. A licensed electrician with no dealer affiliation, paid a flat $249 by the homeowner, runs the NEC-style load calculation from the nameplate data and answers one question in writing: what size does the managed peak support, and if the dealer quoted two sizes up, what exactly is the extra capacity for. Retired master electricians are the ideal supply: they have done ten thousand load calcs and sell no equipment.
Managed-sizing installer network: The referral product. Dealers who quote the module alternative unprompted, price the managed and unmanaged options side by side, and accept flat $400-per-install referral fees with no lead auction. The pitch to dealers: pre-sized buyers with the load math already done close faster and dispute less than Angi's shared-lead lottery.
Fuel-tank sizer: The number nobody runs at purchase. A 22 kW unit burns 2.16 gallons of propane per hour at half load, 3.68 at full load, per Generac's own spec sheet. At half load that is about $6.50 an hour at $3-a-gallon propane, and a 500-gallon tank's 400 usable gallons buys roughly five to seven days of typical use. The sizer takes the homeowner's state-level major-event outage hours and returns the tank that covers the 90th-percentile outage, plus the fuel bill for it.
Gas-supply check: The most common commissioning headache is an undersized natural gas meter or regulator, which shows up as the unit stumbling under load on day one. The review flags the meter capacity against the generator's full-load draw before concrete is poured, when the fix is a utility work order instead of a re-install.
Maintenance-contract auction: The annuity is the product. Standby owners pay $200 to $500 a year for the annual service visit the warranty effectively requires, plus a $100-to-$300 starter battery every three to five years. The installer sells the contract at commissioning and auto-renews it for twenty years. Annual re-bidding at $49 breaks the grip.

Unit Economics

Metric	Value
Independent sizing review (one-time, consumer-paid)	$249
Installer referral fee (installer-paid)	$400 per install
Maintenance-contract re-bid (annual, consumer-paid)	$49
Review cost (licensed electrician, ~30 min remote)	$75
Consumer CAC (per review completed)	$60
Installer CAC	$500
Gross margin on a $249 review	46%
Startup cost (18-month runway)	$650K
Break-even	20 months

Methodology note: Consumer CAC of $60 is achievable because demand is manufactured by weather and concentrated in time. Every hurricane landfall, ice storm, and PSPS announcement sends a wave of homeowners searching "whole house generator cost" within 72 hours, and the EIA's own data shows outage hours nearly doubled the decade average in 2024. Capture is SEO on "[state] generator sizing" plus storm-season content marketing, timed to the Atlantic hurricane season and winter storm season when intent peaks. The 46 percent follows from the table: ($249 minus $75 review cost minus $60 CAC) divided by $249. Company-level margin rises only as the higher-margin referral and re-bid revenue scale. Break-even at 20 months assumes 250 installer partners by month 18 and a 25 percent review-to-referral conversion, higher than the septic analogue because the sizing review directly produces the installer's scope of work. Honest footnote: the $249 upfront payment is the behavioral bet, same as the $299 design review one trade over. Against a $13,000 purchase it is under 2 percent of the transaction, and the buyer already pays nothing for the dealer's consultation, which is exactly the problem.

Go-to-Market

Phase 1 (months 1-6): Launch the Load X-ray as a free tool gated on email, seeded in the five highest-outage states, Texas, Florida, South Carolina, Louisiana, and Michigan, where the EIA's 2024 data shows major-event hours concentrate. Distribute through SEO on "what size generator do I need [state]" queries and through storm-season content: every hurricane landfall and ice storm produces a 72-hour window of peak search intent. Every X-ray feeds the anonymized quote database, which becomes the industry's first public record of quoted-versus-managed sizing.

Phase 2 (months 7-14): Monetize with the $249 sizing review and launch the managed-sizing installer network. Recruit retired master electricians as reviewers; their credibility is the product, and the remote review takes thirty minutes. The pitch to dealers: flat $400 per install, no lead fees, no bidding, and the review pre-computes the scope so the close rate beats the shared-lead lottery. Publish the annual Sizing Gap Report, the share of reviews that downsized the quote and the average kilowatts saved. That report is the marketing.

Phase 3 (months 15-24): Open the maintenance-contract auction and the fuel-tank sizer at full depth. The installed base is the recurring pool: every standby owner re-bids a $200-to-$500 annual contract, and the platform clips $49 a year for running the auction. The fuel-tank sizer becomes the wedge in propane country, where the tank decision is made once at install and lived with for twenty years, because a platform that sizes the tank for the 90th-percentile outage earns the right to referee everything else.

Competitive Landscape

Company	What It Does	Audits the Size?	Pricing
Angi / Thumbtack	Lead generation; sells the homeowner's contact info to dealers	No: sells the lead, never reviews the load calc; the dealer who buys the lead does the sizing	Free to consumer; dealers pay per lead
Generac dealer network	Free in-home sizing consultation, equipment sale, installation, maintenance contracts	No: the consultation is the sales funnel; revenue rises with kilowatts quoted	Free consultation; ~$10K-$15K turnkey 22 kW
Generac online sizing calculator	Self-service size estimator	Partially: produces a size from appliance checkboxes, but the estimate feeds the dealer funnel and never prices the load-module alternative	Free
Costco / retail Generac	Equipment retail with installation referral	No: sells the box; sizing happens downstream with the referred installer	Equipment only
Local electricians	Will perform a load calc if hired hourly	Partially: honest ones exist, but finding one, scheduling one, and paying hourly for a pre-purchase opinion has no scaled version	$150-$300/hr
Home battery (Powerwall 3)	13.5 kWh, 11.5 kW continuous, silent, no fuel	Different answer: about $13,473 installed, the same ticket as a standby, but 13.5 kWh covers hours, not days, without solar recharging; and the 30 percent federal credit for standalone batteries expired December 31, 2025	~$13.5K installed
Portable + interlock	$500-$2,000 portable plus inlet box and interlock kit	The honest cheap answer: covers essentials for a tenth of the price, but manual start, manual fueling, no automatic transfer, and California phases out new gas portable sales at model year 2028	~$1,500-$3,000 all-in
This startup	Load X-ray, independent sizing review, managed-sizing dealer network, fuel-tank sizer, maintenance auction	Core product: revenue from the buyer and flat install fees, never from specifying the bigger machine	$249 review; $400 referral; $49/yr re-bid

No incumbent is paid by the buyer to answer the one question that matters. The dealer, the closest thing to an authority, is paid by the kilowatt. An independent sizing review, a licensed electrician paid by the homeowner to answer "what does the managed peak support," has no scaled version anywhere in the market.

Why Now

Five forces are converging. First, the outage data justifies the fear for the first time in a decade. The EIA's 2024 numbers, 11 hours per customer, nearly double the prior decade's average, with major events at 80 percent, turned "what if the power goes out" from a hypothetical into a lived experience for millions of customers across Texas, the Carolinas, and Florida. Generac is guiding mid-teens sales growth for 2026 on the expectation that outage activity normalizes upward. Demand is arriving; the sizing question arrives with it.

Second, California is closing the portable escape hatch. CARB's small off-road engine rules require zero-emission standards for new portable generators starting with model year 2028, with tighter interim standards already phasing in. About a tenth of American housing sits in the state with the lowest standby penetration in the country, under 2 percent, and the cheapest backup option is being regulated out of the retail channel. Those buyers will face the standby-versus-battery fork with no $800 portable to fall back on, which is exactly when a sizing referee earns its fee.

Third, the battery alternative just got more expensive. The 30 percent federal tax credit for standalone batteries expired on December 31, 2025, per installer analyses of the 2026 incentive landscape. A Powerwall 3 at roughly $13,473 installed now competes with a standby generator at full sticker instead of at a 30 percent discount, and 13.5 kWh still covers hours rather than days without solar. The relative economics of combustion backup improved by legislation.

Fourth, electrification is growing the peak the dealer gets to quote against. Heat pumps, induction ranges, and EV chargers all add large loads to the panel, and each one is a line the sizing consultation can point at to justify the next size up. A managed-loads design absorbs most of this growth with modules; an unmanaged quote absorbs it with kilowatts. The bigger the electrified load list, the more the referee is worth.

Fifth, the penetration runway is almost entirely ahead. Six percent nationally, under 2 percent in California, over 15 percent in Michigan's higher-value homes: the category is early enough that buying norms are still being set, and late enough that the failure modes are documented. A sizing standard established now, while 94 percent of the market hasn't bought, compounds for decades.

Original Contribution: Dollars Per Protected Outage-Hour

A calculation we could not find published anywhere: what a standby generator costs per hour of outage it actually covers. Take a $13,000 turnkey 22 kW job, the midpoint of the $10,000-to-$15,000 installed range. The EIA's routine-outage figure is about 2 hours per customer per year. Over a 20-year machine life that is 40 hours of outage. Thirteen thousand dollars divided by 40 hours is $325 per protected outage-hour in a median year.

Run it at storm-year rates and the number improves but stays striking. At 2024's 11 hours a year for 20 years, 220 hours, the cost is $59 per protected hour. The portable alternative, roughly $2,000 all-in for the unit plus inlet box and interlock, lands at $50 per hour in a median year and $9 per hour in a storm year. The standby's premium over the portable is not subtle: about 6.5 to 1 at either outage rate.

A second unpublished number is the standing cost, what the machine extracts in years with zero outages. The annual service contract runs $200 to $500; take $350. The starter battery, $100 to $300 every three to five years, amortizes to roughly $60 a year. The weekly exercise cycle, five minutes at roughly a gallon an hour, burns about 4 gallons of propane a year, call it $15. Total: about $425 a year with the power never going out, or $8,500 over the machine's life. The maintenance annuity alone approaches two-thirds of the install price, paid to keep a machine ready for 40 hours of work.

A third number is the sizing arbitrage itself. Stepping from a managed 14 kW design to an unmanaged 22 kW quote moves equipment from roughly $4,750 to roughly $5,750 at midpoints and adds on the order of $1,000 to $2,000 in installation delta on the larger pad, heavier gas work, and longer labor, against the $600 to $1,200 four-module load management setup that the managed design includes. Net first-cost delta: roughly $1,000 to $2,000. The documented upsell step is steeper: moving from 22 kW to 26 kW runs $2,000 to $4,000-plus installed, the step the dealer's own sizing guide replaces with a 22 kW unit and $600 of modules. Then the fuel delta compounds for twenty years. Generac's spec sheet puts the 22 kW at 2.16 gallons of propane per hour at half load against 1.99 for the 16 kW class, about fifty cents an hour at $3 propane, roughly $2,200 over twenty storm-heavy years at 2024 outage rates. Nobody publishes the managed-versus-unmanaged total; the dealers quote one number and call it engineering.

What follows from all three numbers: the sizing consultation is not a technical service. It is a pricing event. The dealer's free half hour selects the equipment tier, the installation scope, the fuel burn rate, and the maintenance annuity, and every one of those lines rises with the kilowatt number on the quote. The $249 review buys the only opinion in the transaction whose author profits when the number goes down.

Limitations

Several weaknesses deserve plain acknowledgment. First, remote sizing is genuinely hard. Nameplate amps wear off, panel directories lie, and motor starting current, the locked-rotor amps that decide whether the AC compressor starts, is the number most likely to be missing from a phone photo. A review built on bad nameplate data is worse than no review, because it carries the authority of arithmetic. The product needs a ruthless intake: no readable nameplate, no managed-peak number, only a range.

Second, the dollars-per-protected-hour math understates the tail on purpose, and the tail is the product. A single five-day outage is 120 hours, triple the 20-year median total, and it is the outage the buyer is actually insuring against. Price the machine against the median and every standby looks absurd; price it against the week without power and the portable looks absurd, because nobody wants to refuel a portable at 2 a.m. in a hurricane. Both framings are honest. Neither alone is the decision.

Third, the oversizing thesis is structural inference, not a measured finding. No dataset quantifies how often a dealer quotes two sizes above the managed peak. The gendealers admission supports the existence of the practice but not its frequency. Until the review business publishes its own hit rate, the share of reviews that downsize the quote, the thesis stays anecdotal.

Fourth, natural gas changes the math. On utility gas there is no tank to size, no delivery to schedule, and no $3-a-gallon propane bill; the fuel argument for the smaller machine shrinks to the burn-rate delta alone. The sizing review is worth most on propane, where every kilowatt is a fuel bill, and least on natural gas, where the gas company absorbs the logistics.

Fifth, installers may refuse to install someone else's size. The workmanship warranty conventionally covers the dealer's own design-build, and a generator that trips on overload during the first outage creates a liability argument both sides can wage. Recruiting dealers who accept independent sizing is a constraint, not just a matching problem, and the dealers most willing to accept it may be the ones with the least installation volume.

Sixth, forty percent of suburban properties need HOA approval for the installation, and some communities restrict it entirely, per industry survey data. Noise ordinances, setback rules, and the five-foot clearance from openings constrain placement before sizing even matters. The referee can right-size the machine and still lose to the architectural review board.

Strongest Counterargument

The strongest case against this startup is that the dealer's bigger number is often the right number, and the $249 review is the dangerous kind of confidence. Load management is a peak-shaving tool, not a capacity-creation tool: it manages overlap, not deficit. If the homeowner's un-sheddable essential load alone exceeds the smaller generator, no module fixes that, and a remote reviewer working from phone photos is the person most likely to miss the 4-ton heat pump with a 200-amp locked-rotor draw that the on-site dealer measured with a clamp meter.

The comfort cost is real and unpriced in the arbitrage math. Load modules shed the air conditioner. In a Gulf Coast outage in August, "the AC cycles off for 90 seconds at a time" is a comfort outcome the buyer did not picture when they imagined whole-home backup, and the dealer who quoted the 24 kW was selling the absence of that compromise. Headroom you never use is not waste if what it buys is never thinking about loads during the worst week of the year. The automatic transfer switch, ten seconds from outage to power with nobody home, is the actual product being purchased; the portable comparison that makes the standby look 6.5-times overpriced ignores that the portable requires a human being to be present, conscious, and willing to go outside in the storm.

And the future-load argument cuts against the reviewer. The 22 kW quote that looks oversized today absorbs the EV charger, the heat pump conversion, and the induction range the homeowner adds in year six. The right-sized 14 kW becomes the wrong-sized 14 kW the moment the panel changes, and the reviewer who saved the buyer $3,000 in 2026 is not the one who gets the call in 2032 when the generator trips on the new loads. Sizing for today is a bet against the electrification trend the rest of the article cites as a tailwind.

The Bottom Line

US customers lost power for 11 hours on average in 2024, nearly double the prior decade, and the home standby market is a $3.3 billion category growing toward $3.6 billion in 2026 with Generac holding 68 percent of it. The dealer's free sizing consultation converts that fear into a kilowatt number, and every line of the $10,000-to-$15,000 turnkey ticket rises with the number quoted. Smart load modules costing $600 to $1,200 installed let a 14 kW machine cover the house the dealer sized at 22 kW, a roughly $1,000-to-$2,000 purchase delta on that step and up to $4,000 on the documented 22-to-26 upsell, plus a fuel delta that compounds for twenty years. At $13,000 installed against 2 routine outage hours a year, the machine costs $325 per protected outage-hour in a median year, and the $425-a-year standing cost means the maintenance annuity approaches two-thirds of the install price before a single outage. Every incumbent either sells the lead, sells the kilowatt, or sells the battery at full sticker after the federal credit expired. Nobody is paid by the buyer to answer the one question that matters: what does the managed peak support. A $249 independent sizing review, a load X-ray, a fuel-tank sizer, and an annual auction for the service contract is the missing referee. Honest caveats stand: remote sizing from phone photos can miss the locked-rotor draw that matters, the tail outage is the real product and the median math understates it, and the bigger machine absorbs the electrified loads of year six. But the sizing consultation is not a technical service. It is a pricing event. And right now nobody is allowed to say so with a number attached.

What You Can Do

Demand the load calculation in writing: make the dealer show the unmanaged peak and the managed peak as two separate numbers, because a quote with one kilowatt number is a price, not an engineering document.
Price the module alternative on every upsized quote: ask what four load-shedding modules cost installed and which size they make sufficient, since $600 to $1,200 of modules routinely replaces a $2,000-to-$4,000 step up in generator size.
Never let anyone size from breaker sums: breaker ratings describe the wire, not the load, and sizing from them is how a 14 kW house becomes a 24 kW quote; insist on nameplate amps and the single largest motor-starting surge.
Size the propane tank to your state's outage data: at 2.16 gallons per hour at half load, a 22 kW unit empties a 500-gallon tank's usable 400 gallons in about five to seven days, so match the tank to the 90th-percentile outage in your state, not the dealer's default.
Check the gas meter before pouring the pad: confirm with the utility that the meter and regulator can feed the generator at full load, because an undersized gas supply is the most common commissioning failure and the fix is free before installation and expensive after.
Get the HOA answer first: forty percent of suburban properties need architectural approval and some communities ban standby units outright, so clear placement, setbacks, and noise rules before paying for a site survey.
Read the maintenance contract before the install contract: the $200-to-$500 annual service visit and the $100-to-$300 battery every few years are the real long-term cost, so price twenty years of standing cost alongside the turnkey quote.
Run the portable math honestly: a $2,000 portable with an interlock covers essentials at roughly a seventh of the standby's cost per outage-hour, so buy the standby for the automatic transfer and the multi-day tail, not because anyone told you the portable "isn't enough."

📰 Emergency Generator Testing Compliance — the commercial side of the same machine: NFPA 110 monthly testing, the regulation that keeps standby generators honest

📰 Grid Defection and the Home Battery Death Spiral — the battery alternative at utility scale: what happens when the backup becomes the primary

📰 Interconnection Queue Intelligence — the grid's side of the reliability story: why the power goes out and who is waiting to fix it