I totally agree. Now the big difference is the cost differential between selling excess power back to the grid (feed-in price 8 cents) compared to purchasing from the grid at 25 cents per KWHr. The Tesla batteries are projected to cost $200 per KWHr of storage so for $2000 your average punter can get 10 KWHr of storage and likely never need to purchase electricty from the grid. So a $5000 5KW system plus $2000 for 10 KWHr of storage means no more $2500 bills per year. The system pays for itself in less than 4 years.
There is a truely massive market if Tesla can hit their production targets at the advertised price point. Which seems possible given the extreme amount of vertical integration in the plant. Even the energy costs are provided via renewable energy buffered by their own batteries. Feed in raw lithium, aluminum, human labor, out comes batteries.