Solar Power With Generator Backup For a given level of power output, generators are usually the least expensive option for backup power production. In the vast majority of residences we evaluate, generators provide the most reliable and cost effective source of extended backup power. The simplest solution is to install a relatively inexpensive generator in conjunction with a manual transfer switch. The transfer switch directs the source of power for critical loads from the utility (which is presumably down) to the generator - without backfeeding the electric grid. During a power outage the transfer switch is operated and the generator is started, thereby providing power to the critical loads in the house. Total costs for this type of installation are typically in the $3,000 to $7,000 range, with manual start gasoline generators at the lower end and autostart propane/NG generators at the higher end.    More durable diesel powered generators, such as a 10,000 watt autostart unit, can be purchased for about $10,000. This generator has higher quality power output and a much longer, maintenance reduced life. Since they don't require complicated carburetion, propane generators are also good solutions for remote backup systems. With these higher price range generators one can install an automatic transfer switch and auto-start capabilities so that the generator automatically begins to supply your electrical loads in the event of a power outage. Note that, with most generator systems it will take several minutes for the generator to come online and provide adequate power.