Thanks for the video.
I think a lot depends on what the goal is. I have a genset which is great. However, I don’t like running the genset for an extended period of time to get my batteries fully charged. For me, solar works well. I use my Genset to take care of the Bulk and some of the absorb charging. My charger will charge at a max of 130amps. Once the batteries are brought up to the proper voltage then the amount of amps needed to hold at that voltage drops over time. At some point, it is kind of silly to be running a diesel genset to deliver a relatively low amount of amps to the batteries. That is where the solar is nice. It can finish off the absorb phase and float so the batteries get back to 100%.
That is a lot different than trying to rely on solar to replace all of the power requirements. While it would be possible here in the Northwest, it would be tough to rely on solar entirely during the dark months. I don’t know how much a diesel generator costs, but I think long term getting power from diesel fuel would be a lot cheaper than from a methanol fuel cell.
The other difference is that the Efoy puts out DC current rather than AC. So if you have AC loads that you want to power you would lose 10-20% converting that DC power to AC.
If I was starting from scratch, I would consider a fuel cell. It would be much more efficient for final charging of a house bank than a genset. However, a single panel solar system such as I installed, still is a very efficient way to do the final charging of my battery bank.