After protests from power plant owners over a new plan to control deviations from its dispatch schedules, the California Independent System Operator board voted to temporarily defer ?uninstructed deviations penalties? April 25. If implemented as planned, power plant owners fear the grid operator?s dispatch instructions would be irregular and lead to volatile prices because its forecasts are not predictable enough to allow for smooth power plant operation. The new software could have power plant owners that do not throttle their plants up or down on command?in as little as five-minute segments?fined for noncompliance. The plan would cause ?significant and unnecessary wear and tear on our units,? said Katie Kaplan, Independent Energy Producers manager of state policy. Power plants responding to CAISO?s orders have to ramp up or down to meet the request, thus adding to operating strains on the equipment. The requirements were supposed to take effect May 1 so they could help alleviate potential shortages this summer. CAISO staff concluded that if power plant owners deviate from what CAISO orders, the grid operator will be unable to provide ?system relief that is required to allow the ISO to meet applicable control performance standards and transmission operating limits,? according to Eric Leuze, CAISO director of compliance. If power plants do not abide by the grid operator?s instructions and continue to produce electricity instead of backing off, for instance, transmission lines can clog up, reducing the grid?s efficiency. The new tariff to accommodate these penalties was scheduled to be filed with the Federal Energy Regulatory Commission April 20. The board is scheduled to take up the issue again May 6. Also on May 6, the board is set to contend with the latest version of the grid operator?s market redesign. Originally scheduled to be filed with federal regulators in April, it is now expected to be filed on a ?conceptual? basis in mid-May.