The current rules pertaining to the calculation of costs used in cost-based offers into the energy market allow Market Sellers to include an opportunity cost under certain conditions, such as environmental limitations. PJM developed an opportunity cost calculator, which is included in Markets Gateway, to enable Market Sellers to calculate an opportunity cost. Separately, Monitoring Analytics has developed its own opportunity cost calculator. There is some question about whether the two different opportunity cost calculators produce the same or comparable results and whether either calculator captures all scenarios. When PJM implemented CP, it established potential penalties for failure to deliver during emergencies. The opportunity cost calculators were not updated to reflect the penalty rates. As such, the opportunity cost calculator may be calculating an opportunity cost that is too low as the resource approaches a run hour limitation.