A practical path from “we need backup power” to a quote you can actually compare—starting with real equipment and installed-cost ranges.
Equipment price is only the opening number. Installation can materially change the total, so compare like-for-like quotes that spell out transfer equipment, fuel work, permits, placement, and startup.
The installed spread is the useful shopping number. Ask exactly which transfer switch, electrical work, fuel connection, pad, permits, and startup are included.
Higher researched ranges do not settle the decision. Local installer coverage, quoted scope, fuel choice, and service access still need to be checked in your market.
Start with the two questions buyers can answer cleanly: what does the equipment cost, and what does the installed system cost? Treat brand preference as a tiebreaker after local service and quote scope.
The lower researched price range in this comparison. The comparison point is the Guardian 22kW package — generator plus 200-amp whole-house transfer switch. Check the current equipment price on Amazon before you collect installed quotes.
The higher researched price range in this comparison. Kohler sells through dealers and online marketplaces — check the current 20kW equipment price on Amazon, and expect the installed quote to come from a local dealer.
Decide locally. A model is only as useful as the installer who can size, permit, commission, and service it. Ask each bidder to show the load calculation and define every line item.
Move from outage priorities to comparable written quotes. The goal is not a bigger generator—it is a correctly scoped system with clear ownership after installation.
Separate must-run circuits from nice-to-have loads before talking about model size.
Document whether natural gas, propane, or an unresolved fuel question belongs in the quote.
Ask every bidder to break out equipment, transfer gear, site work, fuel work, permits, and startup.
Check who services the unit locally, what the warranty requires, and what ongoing maintenance looks like.
Choose what matters, then copy or download a clean one-page prompt to send to installers. This does not size the generator; it makes the first conversation sharper.
For owners who would rather buy their own gear than pay an installer's labor. A professionally installed 20–22 kW system runs $10,000–$16,000; the same job done DIY typically runs about $7,300–$11,500 in parts, materials, permits, and startup. This is every phase of the project — site prep through first startup — with what each item is, what it costs, and where to get it. Prices are typical 2026 U.S. ranges; confirm current prices before you buy.
| Item | What it is / why you need it | Typical price | Where to get it |
|---|---|---|---|
| A — The generator and core equipment | |||
| Standby generator package | 22 kW air-cooled generator with a 200-amp automatic transfer switch bundled in the box (Generac Guardian–type package; the Kohler 20 kW package is the comparable alternative). The bundle is the best value — the switch alone costs hundreds more bought separately. | $6,000–$7,500 | Home Depot, Lowe's, Electric Generators Direct, Norwall Power Systems, local dealers |
| Automatic transfer switch (if not bundled) | 200-amp service-rated switch. Senses an outage, starts the generator, and moves the house onto generator power — and keeps generator power from ever back-feeding the grid. | $500–$1,200 | Home Depot, Lowe's, Amazon, Electric Generators Direct |
| Starting battery | Group 26R automotive battery. Most standby generators ship without one, and the unit will not start without it. | $100–$200 | AutoZone, O'Reilly Auto Parts, Walmart, Home Depot |
| Load-management modules | Optional. Smart modules that briefly pause big loads (AC, dryer, range) so a smaller generator can carry a whole home without stalling. | $250–$400 each | Amazon, Home Depot, generator dealers |
| Cold-weather kit | Optional in cold climates. Battery warmer and oil warmer so the unit starts reliably below freezing. | $150–$300 | Amazon, Electric Generators Direct, dealers |
| B — Site prep and the pad | |||
| Precast generator pad | Composite or concrete pad sized for the unit (about 3 ft × 5 ft). The generator must sit level, off the ground, and clear of settling and splash-back. One precast pad replaces the whole pour-it-yourself list below. | $150–$400 | Electric Generators Direct, Amazon, Home Depot |
| — or pour your own: concrete | Roughly 8–12 bags of 80 lb concrete mix for a 4-inch pad, if you pour instead of buying precast. | $60–$90 | Home Depot, Lowe's |
| Gravel base | Crushed stone under the pad for drainage and a stable, level bed — about half a cubic yard. | $30–$60 | Home Depot, Lowe's, landscape supply yards |
| Rebar or wire mesh, form lumber, anchor bolts | Reinforcement for a poured pad, 2×4s to frame it, and anchors to bolt the unit down. | $40–$80 | Home Depot, Lowe's |
| Landscape fabric and edging | Keeps the area around the unit clear of weeds and mud; most codes want a clear, maintained space around the generator. | $25–$75 | Home Depot, Lowe's, Walmart |
| C — Electrical materials | |||
| Feeder wire and conduit run | The heavy cable (aluminum SER or copper conductors in conduit) that carries generator power to the transfer switch and panel. The single biggest variable on this list — cost is set by the distance between the generator and your panel. | $300–$900 | Home Depot, Lowe's, electrical supply houses |
| Conduit, fittings, and disconnect | PVC or metal conduit, elbows, LB fittings, straps, weatherproof entries, and the outdoor disconnect where required. | $50–$150 | Home Depot, Lowe's, Grainger |
| Breakers | The generator breaker in the transfer switch/panel and any replacement breakers the layout requires. | $40–$120 | Home Depot, Lowe's, Amazon |
| Control wire | Shielded multi-conductor cable that carries the start/stop and status signals between the generator and the transfer switch. | $30–$80 | Amazon, Home Depot, electrical supply houses |
| Whole-house surge protector | Type 2 surge protective device at the panel. Recommended with any standby install, and required by newer electrical codes in many areas. | $100–$300 | Home Depot, Lowe's, Amazon |
| Grounding materials | Ground rod, clamp, and copper grounding conductor sized to the install. | $40–$100 | Home Depot, Lowe's |
| Electrical consumables | Sealant for wall penetrations, anti-oxidant compound, lugs, tape, wire nuts, labels and placards. | $30–$75 | Home Depot, Lowe's |
| D — Fuel materials | |||
| Natural gas line materials | Black iron pipe and fittings — or CSST flexible gas line — sized for the generator's fuel demand and the length of the run from the meter. | $150–$600 | Home Depot, Lowe's, SupplyHouse.com, Grainger |
| Shutoff valve, sediment trap, flex connector | The service shutoff, the drip leg that catches debris before the engine, and the flexible stainless connector at the unit (a flex connector is included in some packages — check the box first). | $60–$150 | Home Depot, Lowe's, SupplyHouse.com |
| Thread sealant and leak-test supplies | Gas-rated pipe dope or PTFE tape, plus leak-detector solution or a pressure gauge to prove the line before startup. | $35–$85 | Home Depot, Lowe's, Amazon |
| Propane path (instead of natural gas) | Tank purchase, 120–250 gallon, if there is no natural gas at the property. Leasing from a propane supplier can cut the upfront cost. | $700–$2,500 | Local propane suppliers |
| Propane regulator and line | Two-stage regulator, pigtail, and the buried poly or copper line from tank to generator. | $175–$600 | Local propane suppliers, SupplyHouse.com |
| E — Tools, first service, and paperwork | |||
| Tool rentals | Hammer drill, concrete mixer, and trencher or auger as your site requires — rented by the day. | $100–$300 | Home Depot and Lowe's tool rental counters |
| First-service kit | Engine oil for the first fill plus the oil, oil filter, air filter, and spark plugs for the break-in service — the unit is not warranted on good intentions. | $50–$100 | Amazon, Home Depot, dealers |
| Permits and inspections | Electrical and gas/mechanical permits and the final inspection. Non-negotiable almost everywhere — it protects your insurance coverage and your resale. | $100–$500 | Your city or county permit office |
| Load calculation | The sizing math that proves the generator matches your house. Free from many dealers with a quote, or a modest fee from an electrician — do this before buying anything. | $0–$250 | Generator dealers, licensed electricians |
| Startup and commissioning | Documented first startup by an authorized dealer. Activates the full factory warranty on most models — the cheapest line on this page and the most expensive one to skip. | $150–$400 | Authorized Generac or Kohler dealers |
These are the commercial-intent questions shoppers use before they are ready to choose a model or installer.
A tight quote now is cheaper than ambiguity later.
No. Use the complete installed scope as the comparison point. The researched ranges differ by thousands of dollars between equipment-only and installed totals.
Not by itself. Ask the installer for a documented load calculation tied to the circuits and equipment you want backed up.
Generator, transfer equipment, electrical work, fuel connection, site preparation, permits, commissioning, warranty terms, and ongoing service.
No. The figures are a dated research snapshot from September 30, 2026. Confirm current price, availability, program terms, and local installation cost before deciding.
The model cards above link to Amazon with our Associates tag, so this guide can earn a commission on qualifying purchases at no extra cost to you. As an Amazon Associate, Northwest Power Group earns from qualifying purchases. More merchant programs are on the way; installed quotes still come from local dealers.