System Measures Flashcards
Load factor
Average load over peak load. For a given time period. Value 0-1. High value means power usage is relatively constant. Low value says occasionally high demand.
Capacity value (same as capacity credit according to Hart et el 2012?)
“Ratio of conventional dispatchable plant that can be retired to the capacity of of the intermittent generation that is installed in its place to meet the load without compromising the reliability”
Demand factor
Maximum load in a given time period divided by maximum possible load.
Give examples of demand measures!
Load factor
Deman factor
Which is the difference between the two demand measures “load factor” and “demand factor”?
- Major difference is that the denominator in demand factor is fixed depending on the system (maximum possible load) whereas for load factor it is the maximum load in a given time period.
- Also nominator differ: For demand factor it is max load in given time period, for load factor it is average load in given time period.
Devices with low load factors (i.e. That occasionally has a high demand) system operators has to let capacity sit idle for long time periods, causing higher cost on system, may be charged higher. What is this process called?
Load balancing or peak shaving.
Capacity credit?
Should be Capacity Factor…
Total energy output in a given time period divided by maximum possible energy (operating at nameplate capacity) in same time period (full capacity).
What is the standard measure of underlying transmission peak system demand in GB?
ACS-average cold spell…(independent of the demand in the particular year)
Before 2004 VCS was used (about 2% higher than ACS for the same year)
Very high demand could eg be >99%ACS peak
Residual load
Load
Supply minus consumption, i.e the demand that is still left
Belastning
Lead time
Eg nuclear requires high…for scheduling up to one day
“Leveranstid”
