Our electricity usage increased significantly when we realized that predictable temperatures result in better infant/toddler naps, so the "post-installation" numbers below are for more kWh than the "pre-installation" ones. We were also forced to switch from a "tiered" rate plan to a time-of-use (TOU) one when we applied for net energy metering, which also makes it a little harder to calculate the benefit. But the offset roughly averages out to ~$200/month. I'm unable to access my old bills because I moved to a new house, thus the imprecise numbers.
Your personal benefit is a function of your weather and latitude. High temps reduce efficiency, as do, more obviously, cloud cover and shading. With TOU plans, your benefit will also depend on your usage habits and schedule.
In my case, the benefit was mainly psychological. I never wanted to use AC before, but I started to use it liberally after I turned on my solar system. My wife and child were grateful!
I did roughly the same thing as the parent poster, but I bought used hardware and got my total installation under $1/Wp. I pay the minimum grid connection charge now. About $12/mo, down from about $150/mo before I got an EV.
Your personal benefit is a function of your weather and latitude. High temps reduce efficiency, as do, more obviously, cloud cover and shading. With TOU plans, your benefit will also depend on your usage habits and schedule.
In my case, the benefit was mainly psychological. I never wanted to use AC before, but I started to use it liberally after I turned on my solar system. My wife and child were grateful!
Pre-installation
* June 2019: $160.92
* January 2020: $252.59
Post-installation
* June 2020: $-4.11
* January 2021: $115.27