Yup. There's also a lot of room at the utility scale for improved designs of the old Edison batteries. Nickel-Iron chemistries are heavy and initially expensive

Yup. There's also a lot of room at the utility scale for improved designs of the old Edison batteries. Nickel-Iron chemistries are heavy and initially expensive, but: 1. They can last effectively forever with periodic electrolyte topoff, proper charge control, decent thermal management, and good contaminant prevention policies. 2. They (and their electrolyte effluvia) aren't terribly toxic. Most other utility scale chemistries have limited lifespans and degrees of toxicity and disposal/recycling difficulties. Hell, this could even be a Long Now project: design and operate a 10,000 year utility-scale NiFe battery. There's no theoretical reason why not.