Dave
Former Reddit lurker
I got myself free API access to openweathermap.org and added it to Home Assistant. You can create some nice dashboard items from the data from it.
The simple answer would be just to click “instances” at the bottom of any lemmy page to view the list of other instances the one you’re on is federated with. Most instances have both a linked list and blocked list on that page.
I wonder if it can be cheaper and better at scale than iron-air batteries. Those seem inexpensive to make, and can carry a large enough capacity if you put a whole lot of them in parallel with each other, and have a long lifetime. They’re just really heavy for their amount of energy density and fairly low current per cell, but that shouldn’t be a problem when building enough to be grid-scale.