As business models improve and the cost of energy storage assets falls, solar-plus-storage installations should help grow the industry. As a data point, SunPower has said it's attaching energy storage to about 30% of commercial solar installations right now. And its residential energy storage solution is already being installed in 20 new home communities. Sunrun has said its energy storage attach rate is 100% in Hawaii and 30% in California, which are the early movers in the storage market.