U.S. Department of Defense ESTCP

CHALLENGE:

The U.S. Department of Defense (DoD) needed to develop a standardized method to guide rapid and repeatable modeling and design of secure and resilient DoD microgrids globally.

This would provide enhanced energy reliability and enable DoD installations to safely ride-out prolonged utility power outages and sustain mission critical operations, using renewable energy resources and storage in an integrated microgrid system.

SOLUTION:

In order to efficiently model DoD Microgrids, a standard and repeatable approach was identified and detailed. The approach also included cyber security, implementation, and commissioning to complete the whole process of implementing a microgrid.

The aligned end goal was to be able to leverage the defined approach for the purpose of training users on microgrid design and the Xendee platform. 

The deliverable created a standardized process for Microgrid implementation. The process envisioned was based on upgrading critical facilities on two U.S. Navy and one U.S. Army installations.

These were the tasks identified in the deliverable, although all steps might not apply to all installations.

Task 1: Project initiation A group of stakeholders is convened to identify the requirements that drive the project and challenges likely to be encountered. The goals and objectives of the project are defined as well as a first (high-level) pass at identifying business cases and use cases. A project organization is created. Staff is drawn from the stakeholders as appropriate. Roles and functions that will be needed to complete the entire microgrid implementation process are identified and personnel capable of each role are identified. Unmet personnel needs are identified and a process to fill those needs is defined.

Task 2: Data collection for techno-economic assessment Data both technical and financial needed to establish project feasibility is collected. A project is deemed feasible if it is likely that reliability, resilience, security and economic objectives can be met. The amount and quality of data required in Phase 1 is just sufficient to establish feasibility, deferring detailed data collection to Phase 2.

Task 3: Techno-economic assessment A high-level system design is created, including distributed energy resources, network cabling and transformers, switch gear, and system support devices (such as capacitors). A first-pass system architecture and one-line diagram is defined. A 10-20% level of design is appropriate, just sufficient to establish feasibility, leaving detailed design to Phase 2. None of the SCADA system is designed, but costs are estimated based on rules of thumb. Based on this design, a rough cost-to-construct estimate is obtained.

Task 4: Data collection for engineering design Data collected in Task 2 is augmented with additional more detailed information, typically: (1) load data at building and equipment level including nameplate data for large units and data for aggregate modeling of small units; (2) more information about the existing power infrastructure; and (3) site data including existing underground services and construction constraints.

Task 5: System architecture and power subsystem design A system architecture and high-level one-line diagram is inherited from Task 3 and is further refined. This task is in parallel with Task 6, with design iterations between the two.

Task 6: SCADA subsystem design and system integration At the heart of this task is the implementation of the microgrid controller. The control methodology is as simulated in the techno-economic design produced in Task 3, or as evolved through iteration during detailed engineering design. Supporting the microgrid controller are a host of additional sensing, communication, computation and control capabilities constituting the balance of the SCADA subsystem. The SCADA and power subsystems are closely coupled and their designs influence each other in synergistic ways that can have major cost implications. Design iterations between Tasks 3, 5 and 6 with accurate cost estimates enable cost engineering tradeoffs to optimize the final integrated system design. Construction cost estimating methods and tools are used for accuracy. An accurate cost-to-construct the final design is obtained.

Task 7: Permitting and procurement All grid-connected microgrids require an interconnection agreement with the local utility/grid operator. The architecture of the power subsystem significantly affects the procurement process.

Task 8: Construction and commissioning Construction is the assembly of the system. Commissioning is testing to verify and certify correct operation according to agreed-upon use cases.

Task 9: Operation and maintenance The final task is to prepare the system for use, based on expectations about how the installation will be staffed. Training materials are prepared. Operating and maintenance manuals are created, and system and component specifications, manuals, warranties, and other data are archived. On-going technical support is arranged as needed.

As part of this analysis we detailed all the projected costs throughout the lifecycle of building a microgrid, including but not limited to, planning and feasibility studies, equipment or service, construction and installation, permitting, interconnection, metering, monitoring, and data acquisition, O&M or maintenance contract costs.

Many of these costs are inbuilt in the Xendee platform.

RESULTS:

The DoD gained a rapid and repeatable method to model and design secure and resilient DoD microgrids globally that included both cybersecure tools and proven processes for accurate and efficient design.

The primary conclusions found during the demonstration are:

• The DoD is lacking a standardized Microgrid design framework, which limits Microgrid development and Energy manager effectiveness.
• DoD energy data required to perform effective designs is classified as Controlled Unclassified Information (CUI), and requires special precautions for transfer and use including NIST 800-171 compliance
• The Xendee platform provides a standardized Microgrid design approach which cuts Microgrid feasibility/design time and expense and meets data security requirements, while being scalable across the DoD.