Let's do a little back of the envelope on the size of the stationary energy storage market. In 2008, the globe consumed 143,851 TWh of electricity. Suppose Tesla could address 1% of that with stationary storage. That works out to nearly 3,941 GWh of daily storage. Let's suppose that Tesla systems lose out 10% capacity every year with 365 daily cycles. And suppose that the global energy market grows 3% per year. So steady state about the annual demand for new systems is about 13% of existing capacity. In 2025, then, we're looking at 5,455 GWh of existing installed capacity and annual demand of 709 GWh for new systems. At $200/kWh, that's $142B in annual sales for 1% of the global electricity market.
The above is just a steady state analysis. It doesn't really describe how we get there. The near-term dynamics are complex. There will be many different applications and critical price points at which storage becomes economical. Consider just one pathway, rooftop solar. Because of intermittency, solar without storage can only supply a fraction of the daily need for a home or business. Let's say no more than 10 kWh/day of the average 30 kWh/day per resident. This limits how much solar a resident might install. With 10 to 20 kWh in storage, one can install maybe two or three times as much solar. Basically, once the cost of storage comes down low enough to beat grid prices, it will be economical to buy storage coupled with solar. Thus, the growth rate of storage will be coupled with solar. So if solar continues to double every 2 to 3 years, then so will demand for storage coupled with solar. Moreover, this coupling could also accelerate growth in solar as solar installed per roof is doubled or tripled. Once we hit the tipping point in price, i suspect the only thing holding back storage will be supply constraints.
I don't see how Tesla could possibly exhaust the opportunity in this market. Opening one new Gigafactory every year for 15 years won't be nearly enough.