446 PART | IV Case Studies & Applications event, which should be zero, with the meter reading 10 minutes after the event ends when the usage should have increased by at least the amount of MW cleared in the Synchronized Reserve Market. The SR Market is cleared every hour based on the offers that are submitted by various resources. The minimum size of a DR offer is 500 kw or .5 MW. The CSP may aggregate DR to achieve the 500-kw minimum requirement. 32 The market-clearing results establish the SR assignments for each cleared resource in order to meet the SR requirement for each SR zone. Each assigned resource is paid the SR clearing price for providing the service for the hour. Should a DR or generation resource fail to respond to a Synchronized Reserve Event, the pen- alty imposed is the supply of SR during the same time period in which the resource failed to respond to the call for SR. Regulation Market Regulation service provides for the continuous balancing of generation, load, and interchange at a very granular level. Specifically Regulation maintains sys- tem frequency at 60 cycles per second (HZ). Regulation is accomplished through the raising or lowering of output by Generation Capacity Resources or the raising or lowering of loads by DR Resources as required. CSPs that