I wanted to get some feedback as far as choosing a generator or Powerwalls for back up for power outages. My housing development here in NJ tends to lose power quite often. It's not fun sitting in your house with no AC no lights no internet, TV, hot water etc especially when its 90 degrees outside and 90% humidity.
I have a 12.6K solar array and we have a 1:1 net metering so TOU is not an advantage of choosing battery back up. However, it would be nice to use the PV panels during an outage. I know on the surface, the generator makes more fiscal sense as I can get a 20Kwh Generator installed for about half the cost of 3-4 Powerwalls and the generator can run my entire household load.
But.......I find the idea of battery back up a much more elegant solution. The Powerwalls could be installed in my basement out of the weather unlike the generator. There's no noise (and man those generators are loud) or maintenance with the Powerwalls. I am pretty handy and have worked on engines, changing oil tune ups etc. But at this stage of my life, I rather not be bothered with ICE maintenance. I spoke to a friend that has a generator, while it has come in handy for him, he has had issues with it from time to time and it consumes a lot of fuel. I also spoke to others that have complained that break downs are inevitable, and generally poor customer support from generator companies. But the Powerwalls are a lot more expensive.
When trying to calculate loads I have some things in my favor when considering Powerwalls, I have a gas cooktop, gas dryer, and gas water heater and a high efficiency refrigerator. I could also load shed a few things like the electric wall oven, bar refrigerator and pool pumps.
However, I have a 5 ton Geothermal heat pump with a LRA of 118. But it does have a hard start on it. In the winter the Geo also makes heat down to 40 degrees outside and then, below 40 degrees a gas furnace kicks in, as its actually more cost efficient to run the gas furnace when its below 40 degree outside. So it would draw some juice in the winter, but I could always switch to the gas furnace during an outage to draw less on the batteries. This was set up by my Geo installer and its worked out great.
When trying to determine a back up solution I really want to include my AC as it get unbearable here in the Northeast with the humidity in the summer. Per the Tesla calculator 3 Powerwalls should do it with some load shedding. But for how many hours would they last? I was thinking of buying a 4th Powerwall if I go battery, since the ITC is still available. With 4 Powerwalls I probably should be able to power everything via the main panel with shedding a few minor things like the bar frig, pool pump and wall oven.
Would the cost savings of not having to install a critical loads panel offset some of the cost the 4th Powerwall? Doesn't the Powerwall Gateway offer a way to load shed a few items already from its panel? If so, I might be able to justify buying a fourth Powerwall.
I know the logical answer is the generator, but I am curious to know your thoughts.