Vermont winters put real strain on the grid. Ice storms and heavy snow regularly knock out power for hours or days, and homes here often depend on electric well pumps, heat pumps, and freezers full of food. A standby generator solves that — but only if it's sized correctly. Too small and it can't carry your loads; too large and you've overspent.
This guide walks through how generators are sized, the common kW ranges and what they actually run, and the specific things about Vermont homes that change the calculation. When you're ready, a licensed electrician should do a proper load analysis before you buy.
Two approaches: whole-home vs. essential circuits
Essential-circuit (managed) systems power a chosen set of circuits — typically heat, well pump, refrigerator, and some lighting and outlets. They use a smaller generator and a transfer switch (often with load management) and are the most cost-effective choice for many homes.
Whole-home systems run everything automatically, including larger loads, usually with a load-management module that sheds non-essential circuits during peak demand. They cost more but require no thinking during an outage.
Common generator sizes and what they run
10–14 kW — Essential circuits for a small-to-mid-size home: heat/boiler controls, well pump, refrigerator, lights, and outlets. A common, economical choice.
16–20 kW — Most of a typical Vermont home, including some larger loads, often with load management for the biggest draws.
22–26 kW — Whole-home coverage for larger homes or those with electric heat, central AC, or multiple high-draw appliances.
26 kW and up — Large or all-electric homes, properties with shops or barns, or homes adding EV charging on top of everything else.
What drives your size the most
Well pump — Pumps draw a large surge when they start. Almost every rural Vermont home has one, and it heavily influences sizing.
Heating system — A propane or oil boiler needs only modest power for controls and circulators; electric heat or heat pumps need far more.
Electric range, dryer, and water heater — Each is a significant 240V load.
Central AC or multiple mini-splits — Add meaningful demand if you want them running during an outage.
EV charging — A Level 2 charger is a large continuous load; if you want to charge during outages, it changes the math considerably.
Fuel: propane vs. natural gas in Vermont
Most of Vermont — including the Upper Valley — has little or no natural gas service, so the large majority of standby generators here run on propane. Sizing interacts with your tank and line: bigger generators burn more fuel per hour, which affects tank size and runtime. We coordinate the electrical side and work with your propane supplier on the fuel connection and line sizing.