Batteries are amazing for covering ancillary services. Once that market saturates, they move into arb. CAISO is also a capacity market, so you get paid for simply existing

I think that graph is saying that 0.8% of the total electricity was lost on batteries. You don't want that number to be higher.

If you want to see the batteries at work look at an hourly graph and you can see it charging and discharging during the day.

I don't know how that utilization rate and electricity share is being calculated, but my guess is that this is because nearly all current batteries are 2-hour or less, so even if they fully discharge each day, there is a pretty low upper bound on their utilization.

But they don't shine in that sustained discharge use case. They are most useful for helping manage small fluctuations, and for time shifting energy to the daily peaks.

So I just think utilization is a less useful way to think about battery storage. Unless you're comparing them to gas peakers specifically. (That is, separating out the peakers from base load gas.)

0.8% of electricity can be very critical MWs or MWhs.. rounding to 1% is 87.6 hours of electricity. could be the top 1% of prices, or grid stability, or some other grid event where having batteries able to instantly supply tens to hundreds to thousands of MW is worth a ton of $$$ and also huge increases in grid stability.

recall batteries do not generate electricity, they store it for when it is needed most.