Redflow NEWS & EVENTS, page-1765

If you can buy electricity at 10c/kWh, and sell it at 15c/kWh, then with a 10kWh lithium system with 95% RTE but 50% you can’t use, you’ll make 24c per cycle. With a 70% RTE 10kWh ZnBr but 100% depth of discharge, you’ll make 8c per cycle. That’s 3 times less.
So in this scenario, the difference in RTE means a three-fold difference in ROI, and the depth of discharge isn’t as big an advantage.
Obviously the calculation changes in favour of ZnBr if there’s a bigger difference in sell vs buy price - but as the grid stabilises, opportunities for big swings will become fewer, so you take a big risk if you set yourself up so you can’t make a profit from small price swings. Which is why RTE is so critical.
what will actually happen as more batteries connect to the grid is that systems with high RTE will kick in and stabilise prices before ones with low RTE get a look in. So if you want your battery to be competitively operational 10 years from now, you’d better have a competitive RTE.