I live off the grid using solar panels and most of the information I got was from these sources.
Check out the Homesteading Today forum at https://www.homesteadingtoday.com. They have an alternative energy board there and a good share of the members are living with different forms of power.
Another is https://www.backwoodssolar.com. They will send you a free catalog if you are going off the grid as they do not do grid tied systems. It you buy from them, you can call them anytime with questions and they will walk you through your problems.
Also at Backwoods Home Magazine they have some very good articles on alternative energy systems written by Jeffrey Yago and that is at https://www.backwoodshome.com/energy.html#ajy.
Even Mother Earth Magazine has some really good alternative energy articles. The best writers are the ones who live with it…….not just talk about it.
katlupe