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Along with operating the power grid, the California ISO conducts reliability markets matching the supply with demand and fine-tuning the flow of electricity. The ISO is like an escrow company, acting as a clearinghouse for energy transactions, but never buying or selling power itself. The markets allow the ISO to make adjustments in power deliveries in response to changes in energy consumption.  The ISO’s three open markets, which make up less than 10 percent of the total wholesale electricity markets, help maintain operational reliability of the transmission grid by providing electrical services such as regulation and voltage support.  Ancillary Services Market This market helps adjust the flow of electricity when the unexpected happens, such as a power plant failure or a sharp rise in demand for power. The capacity that is bought and sold can be dispatched within seconds, minutes or hours. Four types of energy are for sale in the Ancillary Services Market, which is conducted the day-ahead and the hour-ahead of when electricity is used: Regulation -- Generation that is already up and running (synchronized with the power grid) and can be increased or decreased instantly to keep energy supply and energy use in balance. Spinning Reserve -- Generation that is running, with additional capacity that can be dispatched within minutes. Non-Spinning Reserves -- Generation that is not running, but can be brought up to speed, within ten minutes. Replacement Reserves -- Generation that can begin contributing to the Grid within an hour. Transmission Market This market allocates space on the transmission lines and is conducted the day-ahead and the hour-ahead of when electricity is delivered. When there’s not enough room for all the electrons on a line, congestion zones are established and Scheduling Coordinators operating in these zones can participate in the congestion management market, curtailing their power deliveries or generating more. Real-Time Imbalance Market This market is where supplemental energy is quickly bought or sold every 10 minutes to accommodate energy use just moments before it occurs. Scheduling Coordinators receive payment for extra generation they supply or are billed for extra energy they need to meet the demand of their customers. Market Participants can submit incremental (“inc”) bids to supply more power, or decremental (dec) bids to reduce power output because of oversupply or congestion on transmission lines.