Flow Storage Class

Description:

A storage located at a Flow Node

See also Flow Storage Property Reference for a detailed list of properties for this class of object.

Related Classes: Commodity, Flow Network, Flow Path, Flow Storage.

Overview

Flow Storage provides locational storage of a Commodity in a Flow Network. You do not need to specify the Commodity stored as it is inferred from the Flow Storage connection to the Flow Network via the Flow Storage Flow Node membership.

How to Use Flow Storage

The following is a basic guide to using Flow Storage:

1. Create a Flow Network
2. Create a Flow Storage object for each Flow Node in the Flow Network where storage is allowed.
3. Connect your Flow Storage objects to their respective Flow Node objects.
4. Define basic properties of the Flow Storage: Max Inventory and optionally Opening Inventory.
5. If the storage receives the Commodity from an exogenous source define the Delivery property.
6. If the storage is large consider how the end-of-period storage is handled with the End Effects Method setting.

Flow Storage implements the same storage-related features as Commodity but with a locational aspect. See that topic for details.

Features of Flow Storage

Flow Storage implements a range of properties that allow you to model most types of storage. For example, to model a battery energy storage system (BESS) you can define the Injection Efficiency and Withdrawal Efficiency representing the Charge Efficiency and Discharge Efficiency of the battery respectively.

Flow Storage includes a comprehensive list of build-in constraint types including minimum and maximum injection and withdrawal, amount of the commodity in storage, the target storage quantity at the end of each period and the number of 'cycles' performed by the storage.

Capacity Expansion

Flow Storage supports expansion of the storage capacity in LT Plan. Each 'unit expands the capacity by Max Inventory. The key input properties are Max Units Built and Build Cost and optionally FO&M Charge. Expansion costs can be treated as a lump sum or automatically annualized by defining WACC and Economic Life. Units can be built from Project Start Date or immediately if this not defined. Other available constraints related to expansion are:

• Project Start Date
• Min Units Built
• Max Units Built in Year
• Min Units Built in Year

Retirement occurs automatically after the Technical Life. Retirements can be optimized if you define Max Units Retired and will incur a Retirement Cost.

Examples

See the Flow Network topic for an example.