As stated in Section III.F. Questions Regarding Eligibility (page 31) of the Funding Opportunity Announcement (FOA), “DOE will not make eligibility determinations for potential Applicants prior to the date on which applications to this FOA must be submitted. The decision of whether to submit an application in response to this FOA lies solely with the Applicant.”
However, for your purposes in making that decision, we offer the following information you may consider in determining whether to submit an application, based on the limited information provided in your question:
Section I.B. (beginning on page 9) of the FOA states, “Except for projects proposing energy efficiency measures (Subtopic Area 1.b.), projects proposed under Topic Area 1, Topic Area 2, and Topic Area 3 are intended for Tribal Building(s) that are either (1) grid-connected (which, for the purposes of this FOA, means the Tribal Building(s) are connected to the traditional centralized electric power grid), or (2) connected to a stand-alone (isolated) microgrid that operates autonomously from the traditional centralized electric power grid.”
As described in your question, the proposed system appears to be for Tribal Buildings that are “connected to a stand-alone (isolated) microgrid that operates autonomously from the traditional centralized electric power grid;” it may therefore be eligible under Subtopic Area 2.a., provided the proposed system meets the requirements of that Subtopic Area.
Under Section I.B.2.a. (page 18), specific to Subtopic Area 2.a. (Community-Scale Clean Energy Generating System(s)), applications are being sought for the “deployment of community-scale energy generating system(s) to provide electricity and/or heating or cooling to a substantial number of the total buildings within a community, or a substantial portion of the total community’s energy load, or an entire tribal community.” As such, under Topic Area 2.a., only clean energy generating system(s) are being sought and, for the “purposes of this FOA include: (1) renewable energy system(s), or (2) combined heat and power system(s) using renewable fuels such as biomass, biogas, renewable natural gas, or renewable hydrogen,” not energy storage systems.
Therefore, a solar photovoltaic (PV) system may be eligible as a clean energy generating system under Topic Area 2.a.; however, battery energy storage would not be eligible under Topic Area 2.a. See the definitions of “clean energy generating system(s)” and “renewable energy system(s)” in Appendix A.
You may, however, wish to consider whether your described project may be eligible under Topic Area 3 (Integrated Energy System(s) for Autonomous Operation), provided it meets the definition of an integrated energy system as defined under Section I.B. (page 10) and Appendix A. That definition requires that ““Integrated Energy System(s)” under Topic Area 3 and Subtotal Area 4.a. must, as a minimum, provide power to Essential Tribal Building(s) or unelectrified Tribal Buildings, respectively, and include: (1) clean energy generating system(s); (2) controls and management system(s); and (3) energy storage system(s). Such systems may also include (4) conventional energy generation device(s); however, conventional energy generation device(s) are eligible only if used solely as a dispatchable stand-by power source.”
Finally, for Topic Area 3 (see page 21), “some components of the proposed integrated energy system(s) may already exist and, therefore, not all of the components must be proposed for DOE funding; however, the integrated energy system(s) as a whole must meet the requirements under Topic Area 3.”
We therefore recommend that you read the FOA thoroughly to ensure the project meets the requirements published in the FOA.