PowrSym Adequacy Studies

PowrSym is frequently used for system adequacy studies. PowrSym uses a Monte Carlo random draw method and multiple iterations to consider such uncertainties as:

• Generating unit forced outages and deratings

• Transmission link outages and deratings

• Load variation due to weather events

• Hydro inflow uncertainty

• Fuel availability and cost uncertainty (including use of alternate fuels and fuel storage)

• Solar and wind uncertainty

• Uncertainty of demand side (DSR) control response

In addition to the traditional independent event Monte Carlo draws, PowrSym can consider linked events, such as:

• Failure of a group of generating units, such as natural gas units on a common pipeline

• Failure of a class of units, such as all nuclear units stopped over some issue.

• Increased outages of generating units, fuels, or grid links combined with a weather event

The PowrSym outputs in adequacy mode can be expressed as an average across all iterations, by iteration, or graphically as a sorted probability curve which is usually the best way to picture the results. Some of the available outputs are:

• Energy not served and cost penalties

• Spinning reserve violations and cost penalties

• Operating reserve violations and penalties

• Emergency imports

• DSR operation

• Fuel use and costs

• Emissions and cost penalties

• Generation by type

• Grid congestion