While not wanting to be disparaging , IMHO your product is best suited for remote applications such as mines.not households.
Its all a question of horses for courses.
Ultimately its gunna come down the product that can via economies of scale which necessitates the product able to span over several market segments to achieve this.
Disclosure= I own Ionic Industry shares-Graphene Super Capacitors
I was waiting for my car to be serviced this morning,pretty sure it was the weekend AFR,its circa $ 80 K,to be totally self sufficient with renewable storage.