XRC700's post is spot on, if you buy a cheap generator you will be putting your high end electronic at risk due to the wide "dirty" sine wave they put out. The older Genercraps were notorious for this and those gensets were used on many products that didn't bear the Generac name. Case in point, I have a 6500 watt Husqvarna generator with a Honda engine and it is a classic case of false marketing, the Honda motor is the GC series and meant to compete with the more cheaply built Briggs motors while the genset is actually a Generac. I bought it because it was reasonably priced and fit my needs while I built my home. I never however use it to power my high end stereo or electronics! By the way you should also never use a generator's auto idle when running power tools as the low amperage when engaging the tool start up will definitely do harm to your tools.
If you are thinking of installing an automatic whole house generator don't do so without first getting a quote for a solar array with backup. The solar backup will cost more initially but pay you back many, many times over as the years pile up and eventually all of your clean power will be coming to you for free.
Here is a link for an excellent short video on the
SolarEdge StorEdge back up system. We've installed many of these for happy clients but they do only provide backup for about 5,000 watts of essential loads (refrigeration, circulators, water pump, internet and maybe a few outlets). Most folks can get by comfortably during an outage on just this lower priced solution but maybe you want it all. There is a newer
EnergyHub version of this system now becoming available and that is capable of backing up the
whole house (200 amp main electrical panel), plus it also has an input for an auxiliary generator. Why would you need the generator? Suppose you had a bunch of guests up for the holiday week and there was a major ice storm and then constant flurries as the cold front followed through (yup... typical NH winter weather). Because the solar modules would be covered by the snow flurries it wouldn't take all that long before the batteries might be drained and if you only had solar as a backup you'd be sunk. But if you had a small roll around generator (I too favor the Honda inverter models) all you would need to do is fire it up long enough to re-charge the batteries and you could continue to party on like full time rock stars with the stereo crankin' and everyone safely online. 99% of the time however the solar modules would do all of the re-charging, so a generator isn't really necessary. We have two recently installed off-grid systems on Gansy Island capable of generator input, but at this point neither has a generator ...yet. One of them will have a mini-split installed soon and come fall I think that they may finally need install the
Kohler 12RES propane generator that matches their projected loads perfectly. Even then the generator will only run long enough to meet the loads and recharge the batteries, so 98+% of the time all will be quiet and fully lit.