The largest electrical grid in the U.S., the PJM Interconnection, saw prices nearly double over the last year, according to a report published yesterday by an independent monitor. The culprit? Data centers. Wholesale prices for one megawatt-hour of electricity rose to $136.53, up from $77.78 at the same time last year. Crain’s Chicago Business was first to report on the spike. Monitoring Analytics, the independent market monitor that serves as a sort of watchdog for the PJM grid, pointed the finger at data centers and PJM’s failure to handle their surging demand adequately. The market monitor pulled no punches. “The price impacts on customers have been very large and are not reversible,” Monitoring Analytics wrote. “The price impacts will be even larger in the near term unless the issues associated with data center load are addressed in a timely manner.”  PJM is a ripe target for such criticism.…