From a pure energy standpoint, there's always a certain round-trip efficiency, which varies depending on the technology. We would be running at around 80%.
To the question of whether the cost of pumping is worth the cost of generating, the answer is no, if we think only in kilowatt hours. If you're thinking, as a consumer for example, that you buy the electricity at retail and sell it to the grid when the rates are higher, there's no storage project right now that can actually make it on that arbitrage. You need to have a mechanism that values the other products that this provides, which are that flexibility, the frequency regulation, and all the ancillary services.