There are two main classes of generators (gensets) for home use: standby and portable. If you already know their differences, just scroll down to see our picks; otherwise please read on.
Standby units are hardwired to the house electrical system via a transfer switch and permanently connected to an external fuel source (such as LPG or natural gas). They can provide continuous power in case of emergency for as long as there is the fuel flow. You would just need to periodically turn them off for oil changes. A portable generator is normally used for short-term powering selected AC loads. It connects via extension cords or via a special cable plugged to inlet wired to a manual transfer switch. This type is generally cheaper than stationary, but most models get the fuel from an on-board tank and therefore need frequent refueling. Some more expensive multi-fuel portables can also be connected to an external fuel source for extended runtime (see portable models review and ratings). Street prices for residential gensets range from about $100 per kW to as much as $1000/kW. Here are my picks of the popular models at discount prices in various power categories.

1000 watt peak (800 W run). 4.5 liters (1.2 gallon) tank, 120 volt AC and 12VDC at 15 A with cables, low weight 44lb; manual recoil start.

Briggs & Stratton 030469: 7.5 kW peak, 6 kW run, 7 gallon tank. 12-hr runtime at half load. Manual start; non-CARB compliant.

DuroStar DS4000S 4000W peak/ 3300W rated. 120 V outlets, 8 hours run time at half load; EPA compliant; OHV engine. Low noise level of 69dB. Also see CARB compliant Champion 46533.

Cheap 60A transfer switch for a portable generator <15 kW for entire service. For transferring individual lines see Generac 6376 30A, which contains 6-10 circuits and dual wattmeters to balance the loads.

Generac's Guardian automatic system 06551: 22kW propane/ 19.5kW gas. Includes 200A auto transfer switch with 16 circuit panel. Works from standard household natural gas pressure.

Generac PowerPact 6998: 7,500 watt propane and 6 kW natural gas. This is one of the lowest cost standby genset with included 50A transfer switch. Noise level 67dB.

Sportsman GEN4000LP propane genset: 4 kW start/ 3.250 kW run. Provides 120VAC and additional 12 VDC 10 amp outlet. Runs 10 hr at half load on one 20lb BBQ tank.

Guardian Ultrasource® gasoline 5735: 17.5kW run/ 26.25kW surge. 16-gal tank, electric start, battery is included. Runs a 5-ton central air conditioner. This is probably the highest power portable.


A small single-family house typically needs 3 to 5 kW to power essential items. Among cheap mid-size portable generators, Champion, Duro Star and Champion lines feature one of the lowest costs on the market. Some of their models are CARB and EPA complaint and meet California and federal emission regulations. However, in general most portable models on the market are still non-CARB compliant. So, thanks to California politicians, their residents have very limited choice of emergency devices. Eastern Tools and Equipment who used to sell popular low-cost ETQ series, recently went bankrupt.
Northern Tool + Equipment used to offer tri-fuel model NorthStar 8000TFG that worked on gasoline, propane (LPG), and natural gas. It could be very handy during power outages when gasoline was not available- you could switch fuel easily. Unfortunately, this model is no longer available. There are still bi-fuel devices for sale though. However all multi-fuel portables are too expensive- you can buy two different gensets (say, one gasoline and one propane) for the price of one multi-fuel. If you prefer a permanent connection to supply only the most important devices, consider Generac CorePower 5837 which in 2012 was awarded "best buy" by a consumer magazine.

The homes with up to 4-5 ton central air conditioner would normally need a 15-17kW system (see our sizing guide). In this power range, you can probably get Generac GUARDIAN® models for less dollars per kW than other top brands. I understand you can order installation of your GUARDIAN® or Generac system from local Generac dealer regardless of where you bought it, in other words even if you did not buy from them. Note that while standby models are normally listed by their continuous power, portable models are usually advertised by their peak (starting) power.

For review and ratings of other top-ranking models, see our detailed comparison charts and review of portable and fixed home generators. If you got a stationary model and looking for a licensed electrician and/or a setup quote, complete this no-obligation form.

NOTES. The "best prices" shown above are automatically provided by and relate to what you can buy from their site from various sellers. These numbers do not include taxes and shipping, although Amazon usually offers free shipping on the gensets they carry. Being a discount retailer, it offers prices that in most cases are below the respective manufacturer's list or MSRP. I am not implying of course that other retailers are necessarily selling at MSRP, but Amazon prices often may be indeed the lowest ones you can find anywhere online at authorized dealers. You should always do your own research though.

The characteristics and features (including ability to run a specific size of an air conditioner) are based on manufacturer's specifications or seller's description available at the time we compiled this review. All data here are provided AS IS. While efforts have been made to provide the most current and accurate data - we are not responsible for any errors. For official specifications and warranty info, you may contact the respective product manufacturers. Although the models mentioned here have generally positive user ratings at Amazon, no attempt was made to analyze their actual reliability and the customer service. We suggest you to do your own independent research before you buy any model to be sure it will fit your application. This review is provided for information purposes and reflects only the opinion of the author. The sole responsibility when selecting a generator rests with the buyer- see complete Disclaimer linked below.