Distributed Energy Resources (DERs)

Overview

In order to run an optimization scenario, at least one DER option is required to be added and configured. Keystone Designer provides the following types of DERs:

• PV
  • Rooftop
  • Ground mount
  • Carport
  • Custom
• Battery Energy Storage

Multiple of each type of DER can be added to the scenario to be considered. This equipment list is found under the Advanced tab on the Scenario Editor page:

NOTE: adding a DER to a scenario means it will be considered as part of the microgrid, but depending on the site characteristics, the tariff, operational constraints, and settings, all selected DERs may not be chosen within the optimal solution.

Selecting Equipment

Battery

Fortress Power provides a number of energy storage systems with differing inverter and battery sizes. The battery lines currently in the Keystone Designer are the eSpire 280 Base, eSpire 280 Base with Islanding, and the eSpire Mini. Clicking the Battery Energy Storage button on the dropdown will allow the user to choose between these battery lines

• Use the Filter text entry to filter on the Model/Make column of the list.
• To select equipment to be considered in your scenario, click the check box next to it.

When at least one piece of battery equipment is selected, you can use the Add button to add it to the current scenario. Selected equipment are all listed at the bottom of the dialog.

PV

Choosing PV Carport, PV Ground Mount, or PV Rooftop allows the user to choose parameters that will be used to model solar generation through the PV Watts API. Azimuth and tilt are required parameters. Clicking the Advanced tab reveals more editable parameters.

There is no significant difference in the optimization model between Rooftop, Ground Mount, and Carport. These categories are built into the Equipment list to allow the user to define different costs and equipment parameters.

Once selected, a DER can be removed by clicking the trash icon.

Advanced Equipment Constraints

When creating an optimization scenario, both considered PV and Battery Energy Storage systems can be optionally constrained to customize the scenario run.

Constraining PV Systems

To constrain PV, the following highlighted settings can be used:

• To constrain the maximum installed PV based on the available space at the site, use the Available Area field. This will ensure that we don't suggest more PV than you're physically able to fit in the identified area.
• To constrain either the minimum PV you want installed or constrain the maximum PV outside of the available area, use the Capacity - Lower/Upper Limit field(s). Values can be entered in either of these fields or both. If there is no lower limit, the optimization is free not to select any PV for the scenario.
• To constrain the PV to a set amount of capacity, enter the capacity in both the Lower and Upper Limit fields.

NOTE: some combinations of available area and capacity limits may be invalid. For example, if you enter a low available area but specify a high lower limit such that these values are mutually exclusive, the optimizer will not find a solution for your scenario.

Control Software

A microgrid used for economic optimization generally requires some degree of control, and the costs of these controls are tied to the control software type. Select the software cost in the 'Control Software' section shown below.

NOTE: in order to achieve the projected financial and operating performance generated by Keystone Designer, Fortress Power controls are required.

• The Upfront EMS subscription allows the cost of the controller to be included in the ITC credit. The Annual subscription is not tied to the ITC credit, and a 2% annual escalation is built into the Annual subscription.
• The cost of the EMS subscription differs between battery lines, so choose the correct subscription for the battery equipment proposed in the scenario.
• If Fortress Power controls are selected, the costs associated are defaulted and fixed.
• Custom: Choosing custom controls enables you to enter upfront, monthly, and escalation costs.
• None: This will add no controls costs to the optimization scenario.

Constraining Storage Systems

When considering energy storage within your optimization scenarios, you can force the optimizer to assign a number of units using the highlighted fields below.

• Values can be entered in either the minimum units field, maximum units field, or both fields.
• To constrain the scenario to a set number of units, enter the same number in both the minimum and maximum fields.
• If no minimum number is entered, the optimizer may not select any of this equipment in your optimal configuration

NOTE: The range or number of units you specify may not be the optimal configuration for your microgrid. If you want to ensure the optimizer chooses at least one unit of energy storage, set the minimum requested units to 1.