Interesting! I've been following this through cleantechnica, electrek & other sites.
It's transforming a complex heat/fluid/mechanical system issue into a computer network and security issue. Usually the home network internet access market is very concentrated so a failure there could make the VPP unavailable. Solvable by putting control servers in various places and having each box connecting to multiple redundant control servers hosted with diversity and redundancy in mind.
Also ISM low bandwidth IoT radio technology like LoRa and sigfox might help redundancy too.
Might become important is VPP grows beyond handling rare grid events.
It's transforming a complex heat/fluid/mechanical system issue into a computer network and security issue. Usually the home network internet access market is very concentrated so a failure there could make the VPP unavailable. Solvable by putting control servers in various places and having each box connecting to multiple redundant control servers hosted with diversity and redundancy in mind.
Also ISM low bandwidth IoT radio technology like LoRa and sigfox might help redundancy too.
Might become important is VPP grows beyond handling rare grid events.