- Feb 7, 2009
Some data might be helpful in your revenue models. Any grid storage device will be on the wholesale market, so forget about your retail rates. The gap between on- and off-peak wholesale prices is far smaller than you are supposing. Here are numbers for purchase today of annual strip power products for 2014:
These prices are $/MWh, so we're looking at 1.0 to 1.7 cents/kWh of price swing. Admittedly, you can do better than this: there are some hours when the prices go way above the average on-peak price. But you'd be lucky to get $0.03/kWh on average with storage.
PJM PJM CAISO CAISO CAISO
East Hub West Hub CA/OR Border NP15 SP15 On-Peak 52.71 47.93 40.98 45.84 51.90 Off-Peak 35.75 33.43 29.33 35.72 38.60 Delta 16.96 14.50 11.65 10.12 13.30
OTOH, there is additional value in providing synchronous reserves and regulation; these are typically priced around $4/MW/hour, though, so we're not talking big bucks (except in times of extreme scarcity).
If you are banking on scarcity to make your bucks, remember that the scarcity you're hoping for begins to disappear as you add more resources to the bulk power system that can respond to the potential shortfalls.
My analysis of ERCOT shows that there are enough large price swings plus high enough ancillary services prices to make a couple million a year playing the optimal storage game. It could help increase Tesla's revenues but not be one of the larger sources of revenue. At most $10-$20 million a year if you covered all of the nation.