Net-Zero Microgrid Program Project Report: Small Reactors in Microgrids

Aug. 16, 2022
This report presents the results of technoeconomic analysis that advances understanding of the potential of small modular reactors and microreactors, collectively referred to as small reactors (SRs) in microgrids. Download this report to read more.

The Net-Zero Microgrid Program provides cross-cutting research to accelerate the use of renewable and zero-carbon generation in microgrids.

This report presents the results of technoeconomic analysis that advances understanding of the potential of small modular reactors and microreactors, collectively referred to as small reactors (SRs) in this report, in microgrids. This analysis was conducted using a proxy model for SR in microgrids based on the datapoints that were identified and explored in a predecessor report “Small Reactors in Microgrids: Technical Studies Guidance.” These datapoints―specific to SRs―are representative of what is understood as of today about the expected characteristics of SRs (costs and operational). They are the starting point for the technoeconomic analysis in this report. This report recognizes that the development of technoeconomic analysis for SRs in microgrids must
consider that:
• Microgrids built with SRs have different configurations depending on their boundaries, the loads and resources within those boundaries, energy storage, and the connection and interaction with the
distribution network. Primary technical design principles include power and energy adequacy, system economics, system reliability, and operational resilience.
• Technical studies required to evaluate the feasibility of SR in microgrids include siting, generation optimization, operational framework and feasibility, economic optimization, and risk analysis.
Technoeconomic models specific to SRs are necessary to conduct these feasibility studies. Utilizing the detailed financial and operational parameters and datasets specific to SRs, a proxy representation of SR, referred to as the proxy model in this report, is created in the XENDEE platform based on a gas generator model already modeled for microgrids. The proxy model captures the major characteristics of SRs and effectively represents them in microgrid planning studies. This report discusses the development and implementation of this proxy model and presents feasibility studies that showcase its use in a technoeconomic analysis of a practical microgrid use case.
In this report, considerable attention is given to estimating the SR’s installation costs. The factors that influence the SR’s installation cost include simpler design, lower plant footprint, smaller exclusion zones, accelerated learning with factory production, lower construction time, and co-location of multiple modules. The specific capital cost per MW ($/MW) of conventional nuclear power plants (NPPs) is lower as the size of the plant increases. The economies of scale in sizing apply to SRs as well, typically valid within the fleet of small and/or modular reactors with similar deployment models (i.e., produced in factory settings and assembled onsite). For example, the 1-MW SR plant will have more capital cost per MW than a 10-MW SR plant (single- or multi-module).

This report is organized into six sections and three appendixes:

• Section 1 provides the background on SR in microgrids and its role in the overarching aim of achieving the net-zero objective. The incorporation of SRs as a cornerstone of power and grid services in a microgrid will be of large benefit in providing resilience and greenhouse-gas reduction.

• Section 2 discusses the development of the proxy model for SR in the XENDEE platform using the existing gas-generator model to represent SR in technoeconomic analysis.

• Section 3 details a case study developed in the XENDEE platform using the proxy model in an existing military base in California. The objective is to identify the optimum generation portfolio for the microgrid system. Several scenarios were developed around the objectives of cost-minimization, CO2 emission reduction, and microgrid resilience.

• Section 4 provides a comparative analysis of different scenarios and concludes the report. The results and the subsequent comparative analysis show that SRs could be a cost-competitive generation option
when capital costs are modeled considering potential economies of scale in sizing. If the CO2 tax is iv imposed on carbon fuels, SRs would be even more attractive than gas generators. Then, SRs in microgrids would play a pivotal role in reducing the carbon footprint at the local distribution level. However, it is particularly important to identify the most suitable use cases for early adoption and the right balance of generation mix with other clean technologies as SRs achieve a level of technological
and financial maturity.

• Section 5 describes ongoing work to develop the comprehensive SR model in the XENDEE platform and adapt it for integrated energy system studies. As the next step, a model is being built that is specifically designed for SR in microgrids in the XENDEE microgrid design and planning platform. The SR model will consider all datapoints described in the predecessor report.

• Section 6 provides the list of references.