Overview

This section explains how to update the SysWESM database when the Historical Load Step 6 identifies errors in the Historical Database Error Report (HistDBErr.csv).

• Required Inputs
• Step-by-step procedure
• Exercise

Updating the SysWESM Database

The Historical Database Error file (HistDBErr.csv) is generated in the scenario folder when you run a historical load. It provides a summary of system errors including capacity upgrades, missing units in the database, out-of-merit no bid, out-of-merit outage, and link outage. This file can be viewed in Apollo by right-clicking a scenario or by navigating directly to the historical scenario folder.

An up-to-date system database is crucial for accurate Short-Term Forecasting, as the WESM constantly changes (for example, new units being commissioned or existing unit capacity upgrades).

Prerequisites

• Completed Historical Load run
• HistDBErr.csv generated in the scenario folder
• For the CSV method: Units.csv, Sites.csv, and/or Stors.csv template files prepared
• For the Database Edit Utility method: access to the SysWESMXXX.db database

Historical Database Errors

The Historical Database Error Report lists five categories of error:

• Capacity Upgrade — The capacity of an existing unit has changed. Suite automatically corrects this during the historical load process. To verify, rerun the historical load after the update.

• missing in db — Units, sites, or storage entries exist in the IEMOP data but are not yet in the SysWESM database. Add these using either the CSV method or the Database Edit Utility (see below).

• Out-of-Merit No Bid — Units with missing bids. These are included in backcast simulations using the generated bid file OM_XXX.bid from the historical load process.

• Out-of-Merit Outage — Unit outage events. These are included in backcast simulations using the generated event file Ev_XXX.csv from the historical load process.

• Line Outage — Line outage events. These are also captured in Ev_XXX.csv from the historical load process.

note

Before proceeding to Backcasting, ensure that the historical load has been completed and that the only remaining Historical Database Errors are Out-of-Merit No Bid, Out-of-Merit Outage, and/or Line Outage. Capacity Upgrade and missing-in-db errors must be resolved first.

Step-by-Step Guide

• Phase 1: Using CSV Files
• Phase 2: Using Database Edit Utility

1

Prepare CSV Files

Prepare the .csv files using the provided Units.csv, Sites.csv, and Stors.csv files as base templates.

At minimum, include the necessary details such as IDs, capacity, fuel type, and operations. Make sure that all details are filled out correctly.

2

Open the Database Editor

Open Suite, then go to the Database Editor tab.

3

Open the System Database

Click Open Database and select the system database file: SysWESMXXX.db

4

Add Units, Sites, or Storages

Click any item from the tree view, then click Add Units/Sites/Storages.

5

Select Input Files and Update

Select the correct input file(s) and output path(s), then click Update Database.

6

Confirm the Update

A confirmation message will appear. Before proceeding, make sure that the details for the new units, sites, and/or storages in the .csv files are correct.

7

Review the Updated Fields

After the update is complete, review the updated fields in the Database Editor to confirm that all details were added correctly.

---

Primary CSV Files

See each tab to learn more about the primary CSV files used when adding entries via the CSV method.

• Storages
• Sites
• Units

Storages.csv

The Storages.csv file defines the physical limits of the energy reservoir. It sets the maximum and minimum energy capacity (MWh) and the PcBeg (Beginning %), which determines the initial state of charge at the start of the simulation.

For Battery Energy Storage Systems (BESS), PcBeg is typically set to 50% to provide balanced charging and discharging flexibility.

The table below describes the parameters for storage assets (e.g., STO_CLUZ) as defined in the Storages.csv data structure.

Item	Description	Example Value
StorageID	Unique identifier of the storage.	STO_CLUZ (user-defined)
Region	Region associated with the storage.	CLUZ, CVIS, or CMIN
StorageType	Classification of the storage.	BAT, HYDRO, GAS
InFlow	Rate of inflow into the storage (for hydro or similar technologies).	0 (for BESS)
Max Cap (MWh)	Maximum energy capacity of the storage (MWh).	4000 (user-defined)
Min Cap (MWh)	Minimum allowable energy level (MWh).	1 (user-defined)
Begin Level (%)	Initial state of charge at the start of the simulation.	50 (user-defined)
MoF0 – MoF12	Monthly inflow values (if applicable).	0 (for BESS)
Upstream StorageID	Upstream storage ID (if applicable).	(No input required for BESS)
Upstream Factor	Upstream factor.	1
Inflow Time Hrs	Inflow time (hours).	0 (for BESS)

Exercise

Give it a try and do this exercise:

Step 1 of 3

Review the Historical Database Error Report

Open Apollo and right-click the historical scenario

Open HistDBErr.csv and review the error types

Note any 'missing in db' or 'Capacity Upgrade' errors that need attention