Here in wildfire and drought stricken California, we have experienced somewhat frequent power outages over the last few years. I have considered many times various solutions for backup power and settled on a $3,000 option.
The majority of outages are a result of weak trees or weak branches falling on power lines. These are local power lines, not large distribution wires and so far have not caused any wildfires. PG&E (despite all of its many flaws) in the last few years has locally done an ‘okay’ job at keeping the wires clear of trees. But even the smallest collision of tree and power line can disrupt power for a few hours to a fair number of people. Because of these more frequent disruptions, I investigated a backup power solution.
Since the solar panels are now 16 years old, I had no luck finding a contractor who would legally upgrade the panels. Technology has changed a lot and no one wanted to mix the two technologies. I did get one quote for a battery backup and it ended up running over $25,000 with installation and wiring. Because the house already has solar panels, no rebates are available for the power walls without being combined with solar. And solar rebates are not available for homeowners who already have solar panels.
Another option I decided to explore was a backup generator. I loathed to do so but I saw an add that they start at $4,000. Unfortunately, the real quote was in the same ballpark as a battery backup, and the company has stopped running this misleading ad.
Spending $25,000 for a few power outages seemed excessive. Instead the choice was to spend about $3,000 on the following items:
A Jackery 1000 Portable power station that could be used for modem/router power during outages and other small electronics. The cheaper older uninterruptible power supply (UPS) only lasts for about six hours. The Jackery also is useful for road trips and camping for recharging a laptop and boiling hot water for coffee instead of using a gas stove.
The second purchase was two battery backup garage door openers on the important doors. New homes built in California today are required to have a battery backup on the garage door opener. The law was passed after some people died in wildfires and couldn’t manually open their door. Although the manual process is not inherently difficult, the doors are gigantic and require frequent adjusting in order to be able to lift in manual mode and open the door completely. The hack when the adjustment is off is to lift the door onto a ladder that can support the weight while driving out the Tesla. Works for a car but not a larger height vehicle. The $1800 spent was worth the money in the case of a power outage or a potential wildfire evacuation.
The refrigerator and freezer will keep cold enough for food for a considerable amount of time, and the worst case is to go to an open grocery store and buy some ice for a few old fashioned coolers.
Although these solutions do not address the entire house power needs, they work fine. I know full battery backup is quite popular now, but just seemed like a lot of money for a minor problem.
TESLA OWNER 
You could have been writing our experience with finding a ‘suitable’ backup power source. I also installed a new garage door opener with battery back up a few years ago. Has been envied by our neighbors during power losses.. Solar was installed 7 years ago. Had the same discussions with folks to install PowerWall – misleading ads that were always too expensive. Purchased a 2000W solar generator and installed a 4 circuit manual transfer switch. Only use two circuits at a time when power fails, usually our kitchen circuit and the office – for internet and Wifi. Think we made a wise choice with minimal expenditure and a multi-use power supply.
Interesting solution with the manual transfer switch. I hadn’t heard of this solution before. I’m interested in that perhaps just for the refrigerator, so that would be a one circuit. Part of my challenge is that this is a large house with multiple panels, but that could be a cool thing to add with another small battery. Do you have any pointers somewhere on best practice?
Hi, We also live on the SF Peninsula and have contracted to have 3 Powerwalls installed. We already have a 10 kWh PV array. There are still significant rebates available through the SGIP program. Try Swell Energy – they buy Powerwalls from Tesla, do the drawings and get the local permits, apply for the rebates, and then subcontract with local electricians for the installation.
I had not heard of the SGIP program before. Thanks! Still not sure if it is worth the trouble to install a power wall however. I like the other commentors suggestion on just putting in a manual transfer switch for the refrigerator.