Generators, Backup Power And Outage Planning

Backup power is usually discussed in terms of the generator. The harder questions are what it needs to run, how it connects to the house, and what keeps it working between outages.

Deciding what has to stay on

Loads divide into those with consequences and those with inconvenience. Heating controls, a sump pump, refrigeration, medical equipment and well pumps fall in the first group.

Electric heat, central air conditioning and electric ranges draw far more than the rest, and including them changes the size of every part of the system.

Motors also draw a surge on starting well above their running load. Sizing that ignores starting current produces a generator that stalls when the well pump engages.

Portable and standby systems

A portable unit is moved outdoors, started manually and connected to selected circuits. It is the lower-cost approach and requires someone present to operate it.

A standby generator is installed permanently, connected to a fuel supply and starts automatically when it detects an outage. Installation involves electrical and often gas work.

Battery storage systems occupy a middle position, running silently for a defined period and recharging from the grid or from solar, with capacity as the limiting factor.

Connection is the safety question

Power fed into house wiring can travel back through the service and out onto utility lines, which endangers line workers. This is why the connection method is regulated.

A transfer switch or interlock physically prevents the generator and the utility supply from being connected at the same time. Installation is permitted electrical work.

Improvised connections through an outlet are prohibited and dangerous. Extension cords running from a portable unit to individual appliances are the alternative where no transfer switch exists.

Fuel and running conditions

Gasoline degrades in storage and is difficult to obtain during an extended regional outage, since fuel stations depend on power themselves.

Natural gas removes the storage problem where a service line exists, while propane requires a tank sized for the expected runtime. Each involves different installation requirements.

Engines running for days need oil checks and, on some units, service intervals shorter than an outage. Portable units also require rest periods rather than continuous operation.

Placement and upkeep

Exhaust contains carbon monoxide, so units run outdoors well away from windows, doors and vents, never in a garage even with the door open. Working alarms indoors are part of the system.

Standby units exercise themselves periodically, and both types need fuel management, battery checks and periodic testing under load rather than at idle.

Electrical codes, permit requirements, noise ordinances and utility interconnection rules differ by jurisdiction and change over time. A licensed electrician and the local building department are the right sources before installing anything.