PJM's 10-hour duration requirement doesn't pass the sniff test when you look at how the system actually operates on the most challenging peak days - a thread Some background: PJM has proposed that a resource can only get paid from the capacity market if it can inject over 10 continuous hours. So if you build a 100 MW energy storage system w/ 4 hour duration, your check will be 40% of the check sent to the owner of a 100 MW gas peaker.