By Gene and Katie Hamilton

A standby generator is designed to keep the appliances and systems of a house working when there’s a power outage. When power goes, the lights go out, the food in refrigerator and freezer begins to spoil, and there’s no way to charge electronic devices. You can’t even access your car if it’s parked in a garage with an electric garage door opener.

A standby generator is located outside and wired directly to the house through a transfer switch. Loss of power starts the generator and connects it to the house wiring. The most economical units to purchase and run are in the 20 kilowatt (kW) range and fueled with natural gas or propane. This size will power specific circuits you choose like the refrigerator, heating unit and lights, but will not be a substitute for the power company.

A professional will install a 20 kW Generac Synergy unit with a variable speed motor for $7,700. This includes wiring the transfer switch and hooking up a propane or natural gas line. You can purchase the generator and transfer switch for $5,400 and save $2,300 or 29 percent.

While the cost difference is significant, don’t be tempted by the potential savings. In most areas you are required to get a building permit, which usually comes with some sort of inspection. Most of the work requires a licensed electrician and a plumber to hook up the gas line. To honor the warranty, most manufacturers require a trained tech do the initial startup and checkout. Most of these costs are included in the professional installation. Leave this project to the pro.

For more information go to www.generac.com.

Improvement and Repair Cost Updated 2018

The cost and time data is generated by averaging labor and material data from annually updated cost books used by contractors and refined by the authors' experience remodeling 13 houses. They are authors of 20 home improvement books and Do It Yourself or Not, a weekly column syndicated by Tribune Content Agency. The national cost can be adjusted by ZIP Code.