Indeed it is good to learn: ipv6.he.net/certification is a free course everybody should take the first 2-3 levels of.
The login credentials you create for that website will allow you to login to their sister site tunnelbroker.net and claim a /48 delegation for your DDNS tunnel, also free, to promote the changeover to v6 from v4, especially for people with dynamic WAN IPS from their ISP and no IPv6.
Ok, what to do with the heat of the batteries? Some sort of heat exchanger would need inclusion on this storage system to not waste the heat byproduct. Replacing gas/electric water heaters would be one option if enough heat is generated to do so, or it could supplement existing systems as preheating energy. Same for HVAC, depending on the season/location.