That's interesting. I've used the built in relay on a charge controller to turn on a relay for a dump load before. Midnite solar has 2 12 volt relays built in either to power a fan or a dry relay. You can' set it to go off on voltage up, voltage down, of battery or array... Very useful. Outbacks have a relay as well charge controllers and some inverters.
Codding it would be nice especially to add function to more basic units.
There is certainly room for automating a lot of the load shedding off grid users have traditionally used to balance loads to production. Of course load shedding only becomes necessary when the storage element has been undersized. It's a choice of course but I would have recommended at least a doubling or even a trippling of the battery bank for that array size. You would have a good reserve and your battery longevity would increase far more then 3 times which would decrease the necessity of the automation. I am really interested in the link and plan on diving deeper some time.
You didn't tell me he was so big. Unlike this tiny ad:
Building a Better World in your Backyard by Paul Wheaton and Shawn Klassen-Koop