Introduction
Resource Adequacy Viewer Tool (or RAVT) is a calculator and a visualization tool developed at EPRI to analyze results from any resource adequacy (RA) models. This tool reads the unserved energy results and calculates various RA metrics. This tool also categorizes the shortfall events based on the storage constraints defined by Telos Energy and five criteria for severity assessment.
RA Metrics
1. LOLH stands for Loss of Load Hours. This is the average event-hours per year across all of the simulated random samples. The unit of LOLH is hours/year.
2. LOLD stands for Loss of Load Days. This is defined as the average number of event-periods per year across all of the random samples simulated. The LOLD metric can be applied to any time period length and must be clearly defined by the user. The unit of LOLD is days/year . In some regions, LOLD is assumed the same as LOLE or Loss of Load Expectation.
3. LOLP stands for Loss of Load Probability. This is calculated as the total number of event-periods divided by the total number of time periods sampled. The LOLP metric can be applied to any time period length and study horizon, and must be clearly defined by the user. The unit of LOLP is % .
4. LOLEv stands for Loss of Load Events. This is defined as the average number of events per year across all the simulated random samples. The unit of LOLEv is events/year .
5. EUE stands for Expected Unserved Energy. This is the average load not served per year due to shortfall events across all the simulated random samples. The unit of EUE is MWh/year .
6. NEUE stands for Normalized Expected Unserved Energy. This is the average load not served per year due to shortfall events across all of the random samples simulated, calculated as a percentage of system load. The unit of NEUE is ppm or parts per million.
Telos Energy's Four Categories of Shortfall Events
1. Capacity Constrained - Storage went into the event with full charge and exited the event with energy available, but shortfall experienced during an hour when storage was at the maximum MW output
2. Energy (Duration) Constrained - Storage went into an event with the full charge but exited with no available energy (or storage MWh was depleted).
3. (Energy) Charge Constrained - Storage went into an event without a full charge because there was no surplus energy available (i.e., multi-day low wind and solar event).
4. Capacity and Energy (Duration) Constrained - Storage went into an event with full charge but experienced unserved energy even when all storage is at the maximum output and during hours when storage MWh was depleted.
Severity Scale Criteria
At time t,
Criterion 1: available in-region supply < demand + operational reserve requirement
Criterion 2: available in-region supply < demand + operational reserve requirement - net dependable imports
Criterion 3: unserved load > 0
Criterion 4: unserved load > 5% of the demand
Criterion 5: unserved load > 10% of the demand
Limitations
1. This tool is developed to analyze one-year planning horizon. Users will need to create separate CSV files for different planning horizons.
2. The CSV file to be uploaded in the File Upload 1 tab has a required format. This file shall contain nine column headers: Scenario_Name, Weather_Year, Sample_Number, Zone_Name, Year, Month, Day, Hour, and Unserved_Energy_MWh when hourly resolution is selected.
For monthly resolution, remove the two columns: Day and Hour and add a new column: Unserved_Energy_Hours_h .
For yearly resolution, remove the three columns: Month, Day, Hour and add a new column: Unserved_Energy_Hours_h .
3. The CSV file to be uploaded in the File Upload 2 tab has a required format. This file shall contain five column headers: Scenario_Name, Weather_Year, Zone_Name, Year, Month, and Load_MWh when monthly resolution is selected.
For yearly resolution, remove one column: Month .
4. The resolutions of File Upload 1 and File Upload 2 shall align.
The resolution of File Upload 1 shall be hourly or monthly when the resolution of File Upload 2 is monthly.
The resolution of File Upload 1 shall be yearly when the resolution of File Upload 2 is yearly.
5. The CSV file to be uploaded in the File Upload 3 tab has a required format. This file shall contain twelve column headers: Scenario_Name, Weather_Year, Sample_Number, Zone_Name, Year, Month, Day, Hour, SOC, Generation_MWh, Max_Power_MW and Capacity_MWh .
Max_Power_MW is the rated power capacity (or the total possible instantaneous discharge capability) of the storage in MW, while Capacity_MWh is the energy capacity (or the maximum amount of stored energy) of the storage in MWh.
6. The CSV file to be uploaded in the File Upload 4 tab has a required format. This file shall contain thirteen column headers: Scenario_Name, Weather_Year, Sample_Number, Zone_Name, Year, Month, Day, Hour, Unserved_Energy_MWh, Demand_MWh, Available_Supply_MWh, Net_Dependable_Imports_MWh and Reserve_Requirement_MWh .
7. File Upload 1 and File Upload 3 are inputs to Event Categories tab. The resolution of these files shall be hourly.
File Upload 4 is the input to Severity Scale tab.
File Upload 1 and File Upload 2 are inputs to the rest of the tabs.
8. Time zones are not defined in this tool.
9. Only two seasons are considered in this tool: Summer and Winter .
10. Equal weights are assigned to weather years and samples.
11. Hours are labelled with numbers from 0 (first hour of the day) to 23 (last hour of the day).
12. Inclusion of the no load zone could only impact the calculation of RA metrics in the Load Zone tab and heat map by zone in the Time of Day tab. When distribution of unserved energy in no load zone (if any) is enabled, the unserved energy in the no load zone is equally distributed among the rest of the load zones.
13. Load zones without any unserved energy will not be not shown as they are not reported in the CSV file uploaded in the File Upload 1 tab.