My advice to you is to do a deep dive in the peak solar hours you get per day and how much that changes each month. I found this tool to be spot on: https://tsi.tyconsystems.com/html/nrel_lookup.htm. Then do a deep dive in your power consumption habits, how much it changes according to the seasons, how much of it is in the evening, etc.
The total # of kWh you consume in January (based on your power bill), divide that by 31 to get the average kWh you consume per day. Divide that by the peak solar hours you get per day in January to see how much kW in solar you need for whatever your target is. Then do it for February, then March, etc. Also do a deep dive in practical steps to take to save on power (caulk seal cracks, add insulation, etc.).
Your battery storage will depend on if you consume enough power at night to be worth getting batteries anyway. It may not be feasible. Or it may be feasible to get a large battery stack like I have. Maybe get enough battery storage for low power consumption nights, so that you're not paying a lot to try to win the battle on a few high power consumption nights. Or maybe you have high power consumption most nights, so that getting a lot of battery storage would give you a high ROI.
And if you decide to go solar, I suggest doing it like I did in two phases. Phase I was a small solar array, one inverter, and small battery stack. My inverter was one that can opt not to sell power to the grid and also one that records a lot of telemetry in 5-minute candles. After having solar for a year in Phase I, study the data to see if it's worth adding onto it in Phase II. How much solar to add in Phase II? How many batteries? How much more inverter capacity? The goal is to invest enough in each portion to take advantage of the economies of scale, but not go so far that you're fighting against the law of diminishing returns. Exactly how much will depend on your power consumption habits and the solar activity in your area. You'll be able to determine that by looking at a year's worth of data collected in Phase I.
And before you add more solar in Phase II, look at other steps to save on power. It was at this point that I replaced both my A/C and natural gas furnace with a variable speed heat pump. And I replaced my natural gas water heater with a hybrid water heater (built in heat pump). Thus, I went all-electric, with high efficient appliances. Maybe going all-electric isn't worth it to you. But it is for me where I get plenty of solar and also where our winters aren't frigid for months. This was also at the point that I decided to replace my wife's car (which needed replacing anyway) with an EV. Our driving habits and how much charging that would need was part of my math on how much to upgrade in Phase II to take advantage of economies of scale without fighting the law of diminishing returns. I settled on averaging about 80% of our power needs being met from homemade power (less than that during 4 winter months, more than that during the other 8 months).
Only after you've had solar for a year at Phase II (after the upgrades) do you look at the data again to determine if it's worth selling power to the grid. Every region has different fees they add to the bill for selling power, and different rates at different seasons for how much you make per kWh you sell. I started selling power to the grid half a year ago because that's when I had enough information to know that I'd make a little more from the grid sell than the extra fees added for the privilege of selling to the grid. And if in the future, the regulations change to make selling power not worth it, fine, my inverters have the feature to shut off the grid sell. Plus, my financial decision of whether or not to go solar isn't dependent on the grid sell to make going solar worth it. The grid sell is just gravy on top.
In other words, always be in the position where you're the one in control. If things change to where it's not in your advantage, you can part ways with the grid sell and go back to being a normal power consumer like everybody else (except you won't need as much power from the grid because your solar provides some of your needs). Also, I now have enough info on what it'd take to go completely off grid with my power if the Dims push it to that point where we have to sell our soul to get energy. Right now it's not worth it. I'm comfortable with $80/month power bills for an all-electric home and charging our EV to drive it on average 1,300 miles per month (not counting if we drive it on trips and charge it away from home).
First of all, my wife's opposition to a solar array is because she thinks they are UGLY and does not want to see it ruining the view from the north facing widows of our house. Right now it is a 1-2 acre field and woodlands beyond.
I believe I have done all I can do short of replacing ALL the windows in my 52 year old home to make it more energy efficient. I have replaced all the doors except one.
Added over a foot of bonded cellulose insulation to the attic. Caulked, foamed around outlets and switch boxes on exterior walls. Insulated the box beam in the basement.
Heat pumps really do not work here in NH unless they are in a geothermal system. It gets too cold here in the winter.
I also added a Harman Pellet stove insert to reduce my home heating oil usage.
NH does have NET metering at $.06/KHW. I have not studied it but I believe the rate is locked in by state law for some time to come. So, it can not be lowered by bureaucrats without a law passed in the state assembly and signed by the governor.
What has personally given me pause is that the cost of the panels continues to lower and the efficiency increases.
So, the ROI continues to get to be a shorter time period.
I am not planning on putting panels on my roof.
My choice would be between a large static unit or a smaller unit that tracks the sun throughout the day.
I suspect it would be less expensive to build a larger static array. Also, there are no moving parts and no maintenance other than hosing them off occasionally.
The other major issue is that NH does not get the same amount of sunny days as a place like Santa Fe, NM or other locations that get over 300 days of sun per year.
As Peter Zeihan pointed out in one of his YouTube videos, solar panels make a lot more sense in CO than they do in MI. It is more sunny in the SW US than it is around the Great Lakes. In fact the upper elevation areas of NM & CO are maybe the most efficient place to install solar panels. They work better in cold clear climates. He actually compared the mountains of Co to Germany. Apparently, in Germany it is cloudy and overcast all the time.
The other issue with the installation of solar panels is in places that get frequent large hail storms like northern TX, OK, etc. The fact is that our financial decisions really should be based on the place we live and what Mother Nature inflicts on our environment.
I’ve always appreciated your analytical approach to solar, and what living in a State that is conducive to such energy production can do.
One unanswered question in your case would be how much NOT having an EV would change the 80 twenty grid use you now have. Could you get close to zero grid use or how might the ratio change?