It is predicted that “mass adoption” of household battery storage could arrive as soon as 2020, at which time the payback period for storage systems for solar households would be just five to six years if storage system costs fell at 20% per year with the rapid development of relevant technology. Thus, “hybrid households” with solar PV and storage system will be both economic from the consumer point of view and desirable from the grid’s point of view.
If utility-scale solar was priced low enough in the middle of the day, even households without solar would be incentivized to install storage systems, to charge the battery in the middle of the day and consume the cheaper energy in the evening. In the hybrid model, households use some storage to maximize self-consumption of their rooftop solar electricity whilst still being connected to, and even dependent on, the grid. Storage system would also help to manage the swing in capacity as utility scale PV output drops in the afternoon, prior to the pickup in wind generation.