**What are Ancillary Services?** Short bursts of electricity provided or absorbed to maintain supply-demand balance, ensure grid stability, frequency regulation, and reserves. Grid operators pay assets to remain available and compensate for actual dispatch. **Key Service Types:** 1. **Frequency Regulation** - Second-by-second adjustments to maintain 50Hz/60Hz 2. **Spinning Reserves** - Capacity available within minutes for contingencies 3. **Non-Spinning Reserves** - 10-30 minute response capacity 4. **Voltage Support** - Maintaining voltage levels across the network ### Revenue Structure **Two Payment Streams:** 1. **Capacity Payments** - Paid just for being available ($/MW) 2. **Energy Payments** - Paid when actually dispatched ($/MWh)