Microgrid
ProjectsSubmit a project

Home / Directory / Fire Station 24 Charlotte, NC Microgrid

North America / Critical infrastructure

Fire Station 24 Charlotte, NC Microgrid

Current status, energy mix, organizations, suppliers, equipment, controls, reported specifications, and project updates—with source-level citations.

CoverageDetailed public record
Named organizations7
System facts16
Sources reviewed10
Evidence reviewed2026-07-20

Duke Energy's McAlpine Creek single-customer microgrid islands Charlotte Fire Station 24 using a 50 kW photovoltaic array, a BYD lithium-iron-phosphate battery, utility-owned switching and controls, and the station's pre-existing diesel generator. McAlpine has served as a Duke test site since 2006; storage was installed in late 2012, integration began in 2013, and the microgrid entered service in July 2015. Primary sources disagree on whether the battery power rating is 200 kW/200 kVA or 240 kW, but consistently report 500 kWh of energy. A later 30 kW Eos battery was connected to the same solar array by 2020; its energy capacity and present role are not published.

Research status
Operational pilot in Duke and SEL's latest project-specific descriptions, with the core system in service since July 2015. It completed automatic storm transfers in April and September 2016 and later secondary reporting says it rode through additional outages. Duke's 2020 integrated resource plan is the latest dated primary source found that describes the site's configuration, so current 2026 availability, measured reliability, battery state of health, and whether the added Eos unit remains active are unverified.
Historical classification
Building
Reported capacity
See component specifications
Coordinates
35.08755, -80.83903
Evidence note: “Every company” cannot be proven from public material alone. This page lists every organization found in the recovered record and reviewed sources, preserves unknown roles, and explicitly marks undisclosed controller or equipment details.
Report missing evidenceResearch methodology

Project delivery

Who was involved in Fire Station 24 Charlotte, NC Microgrid?

7 publicly identified organizations. Where a recovered source named a participant without explaining its work, the role remains explicitly unspecified.

Organization

BYD

Manufacturer of the original 500 kWh lithium-iron-phosphate battery system. [6][7]

Organization

Charlotte Fire Department / City of Charlotte

Host and critical-load customer at Fire Station 24; the station's existing diesel generator was incorporated as an independent backup source. [3][5]

Organization

Duke Energy

Owner, operator, and maintainer of the solar, battery, distribution, control, and communications equipment at the McAlpine Creek test site. [5][3][7]

Organization

Electric Power Research Institute

Documented and evaluated the integrated utility microgrid demonstration. [6]

Organization

Eos Energy Storage

Supplier of a separate 30 kW battery added at the test site by 2020; the reviewed source does not disclose its energy capacity. [7]

Organization

Satcon

Manufacturer of the photovoltaic inverter identified in the technical implementation paper. [3]

Organization

Schweitzer Engineering Laboratories

Supplied the real-time automation controller, advanced recloser control, communications, and microgrid control engineering. [3][4]

System evidence

Energy mix, capacity, and specifications

Values can describe different project phases, generation sources, storage systems, or other components. Source citations are attached to each figure so discrepancies remain visible.

Storage
50 KW [1]
Solar generation
50 kW photovoltaic array [3][4][7]
Original battery
BYD lithium-iron-phosphate, consistently reported as 500 kWh; Duke, EPRI, and the 2020 IRP use 200 kW or 200 kVA, while SEL's engineering paper and current case page use 240 kW [5][6][3][4][7]
Later battery addition
30 kW Eos battery connected to the same 50 kW photovoltaic resource by 2020; chemistry, energy capacity, and commissioning date are not disclosed in the reviewed IRP [7]
Island electrical service
480 V, 60 Hz microgrid serving the fire station behind the point-of-common-coupling isolation device [3]
Claimed support duration
Duke estimated that battery and solar could support the station for as long as 36 hours under favorable load and solar conditions; this was an expectation, not a measured full-duration result [5]

Controls and hardware

Equipment and controller details

Manufacturer and model are shown only when a source names them. Generic descriptions are not converted into guessed product assignments.

01

Battery energy storage

BYD

Modular lithium-iron-phosphate system assembled from roughly 1,700 small-format batteries, rated 500 kWh and variously described as 200 kW/200 kVA or 240 kW. The discrepancy likely reflects different nominal and inverter/test ratings, but the sources do not explicitly reconcile it. [5][3][6]

02

Photovoltaic inverter

Satcon

The existing inverter firmware was modified so the solar system could operate as a voltage source during an island rather than only follow the utility grid. [3]

03

Microgrid controller

Schweitzer Engineering Laboratories — SEL Real-Time Automation Controller

Coordinates island detection, source dispatch, synchronization, and transition using DNP3 over Ethernet and hard/fiber signaling including MIRRORED BITS communications. [3][4]

04

Point-of-common-coupling control

Schweitzer Engineering Laboratories — SEL-651R Advanced Recloser Control

Controls the isolation recloser and supports both manual and automatic grid-to-island and island-to-grid transitions. [3][4]

05

Dispatchable backup

Model not publicly disclosed

The fire station already had a diesel generator before microgrid integration. Its manufacturer, model, fuel storage, and kW rating were not published in the reviewed primary sources. [3]

06

Additional battery

Eos Energy Storage

A separate 30 kW unit was added to study another storage technology. Public project documentation reviewed does not give its kWh rating or establish that it is part of the automatic island sequence. [7]

Technical record

Architecture, performance, and project updates

Concise technical facts, milestones, operating results, and later developments. Dated notes distinguish historical design claims from current evidence.

  • Operating modes

    Grid-connected services include frequency regulation, reactive-power and voltage support, peak shaving, demand response, and solar smoothing. During an upstream outage the point of common coupling opens and the battery, solar inverter, and available diesel generation support the station as a local island. [3][6]

  • Transition performance

    Duke reports the first automatic storm-driven transfer in April 2016, lasting 1 minute 15 seconds before grid return, followed by another successful automatic operation in September 2016. SEL says the system supports both manual and automatic operation; no comprehensive outage log or annual availability was published. [5][4]

  • Utility-side architecture

    Duke placed the battery, transformers, distributed-energy switch, isolation recloser, controller, and communications on the utility side of the customer meter. This ownership model let the utility maintain the system without placing new operating responsibilities on the fire department. [3]

  • Evidence boundary

    The recovered legacy figure of 50 kW is the photovoltaic rating, not storage power, and a secondary claim of a 500 kW battery is inconsistent with the technical record. The supported battery values are 500 kWh and 200/240 kW. The 36-hour duration is an estimate; measured energy delivered, fuel savings, renewable share, and present battery health were not found. [3][5][6][7]

Provenance

10 sources

Primary owner, government, university, supplier, and engineering sources are preferred. Archived references preserve claims whose original pages moved or disappeared.

  1. [1]
    Recovered Microgrid Projects record

    Internet Archive · Archived source · captured 2021-04-20

  2. [2]
    Duke Energy Gets Bullish On Green Microgrids

    microgridmedia.com · Archived source · captured 2021-04-20

  3. [3]
    Implementing a Microgrid Using Standard Utility Control Equipment

    Schweitzer Engineering Laboratories · Primary source

  4. [4]
    Duke Energy Microgrid Demonstrates Simplicity, Reliability

    Schweitzer Engineering Laboratories · Primary source

  5. [5]
    Building a Smarter Energy Grid

    Duke Energy · Primary source

  6. [6]
    Duke Energy McAlpine Creek Microgrid Demonstration Final Report

    Electric Power Research Institute · Primary source

  7. [7]
    Duke Energy Carolinas 2020 Integrated Resource Plan

    Duke Energy Carolinas / Public Service Commission of South Carolina · Primary source

  8. [8]
  9. [9]
    Lessons Learned From Microgrid Projects

    T&D World · Secondary research

  10. [10]
    Duke Energy's Green Microgrids Run Smoothly Through Storm

    Microgrid Knowledge · Secondary research

Continue exploring

Related projects in North America