San Carlos Apache Tribe – 2022 Project

Summary

The San Carlos Apache Tribe (Tribe) will implement a microgrid to serve the San Carlos Apache Healthcare Corporation hospital and adjacent housing. The hospital has an emergency power system that was designed to power the entire hospital when power is lost. This system comprises three diesel generators. The microgrid will integrate these generators and add a solar photovoltaic (PV) array of about 750 kilowatts (kW) in capacity, an approximately 1-megawatt (MW), 2-megawatt-hour (MWh) battery energy storage system (BESS), and a microgrid controller with electrical hardware.

The microgrid will serve a total of 41 buildings and is expected to save an estimated 1,492,000 kilowatt hours (kWh) and $263,644 in electricity and diesel costs per year. Over an estimated life of 25 years, the microgrid is expected to save an estimated 35,360,400-kWh and $6,968,476 in energy costs. 

Project Description

Background

The San Carlos Apache Tribe is located in east-central Arizona, with three main populated communities on the Reservation: San Carlos, Peridot, and Bylas. The 2010 U.S. Census determined that the overall resident population on the Reservation was 10,068 and the total Tribal membership exceeds 15,000. 

Tribal leadership during the late 2000s envisioned a strategic energy plan that would support the Tribe’s sovereignty, economy, infrastructure, and independence as it entered the new millennium. Accordingly, the Tribe began working to find sources of funding and building energy networks to support the development of their energy plans. The long-term goal of the Tribe is to become a net exporter of renewable power and to provide utility-scale energy storage to address the intermittency of renewable energy and increase the value of the Tribe’s renewable power assets. SCAT’s planning efforts over the years have resulted in clear steps toward meeting that long-term goal.

Project Objectives

The project will establish a microgrid for the San Carlos Apache Healthcare Corporation and serve the hospital as well as the small housing community adjacent to the hospital. The microgrid will serve 36 residential buildings for health care worker housing and five buildings associated with hospital operations. With the microgrid and the PV array, the project is expected to save an estimated 1,492,000 kWh and $263,644 in electricity and diesel costs per year. Over the 25-year lifespan, the microgrid is expected to save 35,360,400 kWh and nearly $7 million in energy costs, conservatively. This project is the first step in moving toward the Tribe’s long-term goal of becoming a net exporter of renewable power. 

Project Scope

The proposed microgrid will be implemented using a design/build approach. The Tribe has worked with an engineering, procurement, and construction (EPC) contractor as well as a consultant to complete a design for the microgrid system that meets the specifications of the San Carlos Apache Healthcare Corporation hospital and housing. 

The EPC contractor will serve as the development contractor to support the microgrid project, will assist in finalizing the microgrid scope, and will provide oversight during the construction period. The members of the Tribe’s team will provide technical/legal support and engage with the EPC contractor to ensure the requirements of the Tribe are included in the project.

As referenced above, consultant services have been acquired for Tribal energy development, policy, legal, and compliance services and will participate in the technical working group. The General Manager of the Tribe will oversee the project, project changes, and act as the official contact for the award with DOE. 

Project Location

The project is located in east-central Arizona, on Tribal lands, approximately 100 miles east of Phoenix, AZ, and 120 miles northeast of Tucson, AZ. The total area of the Reservation is 1.834 million acres.