There is relatively little total stored energy in the rotating kinetic energy of the grid's electrical machines, typically only a few seconds of rated power or

There is relatively little total stored energy in the rotating kinetic energy of the grid's electrical machines, typically only a few seconds of rated power or so. From fastest to slowest, the response time of the grid to a load change is: - Stored capacitance of the distribution lines (sub-ms response time). - Stored kinetic energy of the spinning machines, both generators and loads (sub-cycle response time). - Automatic throttle management (sub-second response time). - Spot market for electricity (intervals vary, but 15 min is typical). - Futures market for electricity (up to a year in advance). Not all suppliers bid for the frequency control market. Those that do are paid to adjust their throttle back and forth automatically, providing what's known as primary frequency reserve. Normally, every hydrocarbon power plant is bidding for primary frequency reserve. Typically all of the supplier bids for for short-term frequency control have the same ramp rate for automatic throttle management, set to provide a 100% power step per 5% frequency deviation. It makes up the difference between what the spot market cleared and what customers actually demanded during the interval. Normally, (in deregulated electric markets in the US anyway), a frequency decrease translates directly into a higher price for power, which is cleared by the spot market to return frequency back to 60.0 Hz. A sustained frequency decrease, combined with a net sink of power into this particular geopolitical region, is caused by suppliers in that region failing to provide enough power to clear the spot markets. The difference is being made up by the PFR suppliers throughout the rest of the grid.