Pickering Barn Microgrid Adds Sodium-Ion Battery Plan

Emerald Battery Labs announced October 29 that it will develop a 60 kWh sodium-ion battery system for the Pickering Barn microgrid in Issaquah, Washington, pairing storage with an existing municipal solar array so the historic community facility can ultimately support critical loads during grid outages. The announcement advances the battery design and vendor stage, but the system is not yet certified, permitted, procured or operating.

The project is supported in part by a $671,000 TransAlta Centralia Generation grant. Pickering Barn already has a 64.9 kW-DC solar array, while the proposed battery must still complete design work and obtain UL 9540, UL 9540A and UL 1973 certifications before deployment.

Pickering Barn microgrid adds a sodium-ion design

In its October 29 project announcement , Emerald said the grant will support development and deployment of a 60 kWh sodium-ion battery energy storage system integrated with the city’s existing solar and electrical hardware.

The company’s work will cover sodium-ion integration, energy-management and battery-management communications, and system-level safety validation. Emerald also said it will support the City of Issaquah through permitting and procurement after finalizing the design and completing the required certifications.

That sequence is significant. A selected chemistry and design partner do not make the battery operational. Certification, municipal procurement, permitting, installation, controls integration and commissioning remain ahead before the project can demonstrate islanded service.

The city’s October council calendar separately identifies Agenda Bill 9256 for the TransAlta grant and Pickering Barn battery storage . The official record corroborates the municipal project and grant action, while the Emerald release supplies the new vendor, chemistry and 60 kWh design details.

The battery would complete an islandable solar-plus-storage system

Issaquah installed the first major energy component earlier in 2026. The city says its 65 kW Pickering Barn solar project is expected to generate 53.74 MWh annually and reduce municipal electricity costs by more than $6,000 per year.

Solar generation alone does not establish outage operation. For the facility to separate from the utility grid, the final design will need an islanding strategy, appropriately configured inverters and controls, protection, switching and a defined set of critical loads.

The 60 kWh energy rating also does not reveal how long the barn can operate during an outage. Duration depends on the battery’s usable capacity, inverter power rating, state-of-charge reserve, solar production, conversion losses and the size and priority of the loads that remain energized.

Microgrid Media’s guide to microgrid battery sizing explains why kWh determines stored energy while kW determines how much instantaneous load the system can carry. Emerald and the city have not disclosed the proposed battery power rating or a verified outage-duration target.

Sodium-ion changes the project’s technology risk

Sodium-ion batteries replace lithium with more abundant sodium-based materials and are being developed for applications where cost, supply-chain diversity and thermal behavior may be more important than maximizing energy density.

Emerald says its chemistry offers improved thermal stability, long cycle life and freedom from lithium and cobalt dependency. Those are manufacturer claims for the proposed product, not measured operating results from Pickering Barn.

The certification plan is therefore central to the story. UL Solutions’ energy-storage certification guidance explains that UL 1973 addresses batteries for stationary and other applications, while UL 9540 covers complete energy-storage systems. UL 9540A is the test method used to evaluate thermal-runaway fire propagation. Completing those processes would not by itself prove long-term field performance, but it is an important prerequisite for safety review and deployment.

The proposed system is much smaller than utility-scale battery projects, yet its public-facility setting gives it a different purpose. Pickering Barn is intended to function as a community resilience hub rather than as a merchant storage plant earning grid-market revenue.

A resilience hub needs defined critical services

The barn serves as an event venue and home of the Issaquah Farmers Market. During emergencies, the resilience-hub concept calls for community services such as warming, cooling, charging and other support, but the reviewed materials do not specify which electrical loads the planned battery would maintain or for how long.

That missing load definition will determine whether 60 kWh is sufficient for the intended mission. HVAC, lighting, communications, refrigeration, charging and accessibility equipment can have very different power and energy requirements.

The project is comparable in purpose to the planned Saint Paul Oxford Community Center microgrid , where a city is also pairing solar, storage and facility upgrades around a community lifeline function. The Issaquah project is distinct because it has selected a sodium-ion design and disclosed a 60 kWh energy target.

Certification and procurement are the next decisive steps

The next material milestones will be completion of the battery design, certification results, city procurement and permit approvals, installation and tests showing that the system can transition safely into islanded operation.

Commissioning should verify more than whether the battery charges. Microgrid Media’s microgrid commissioning guide describes the need to test protection, controls, load shedding, islanding, reconnection and failure scenarios before a resilience system is treated as operational.

For now, the Pickering Barn microgrid is best described as a funded municipal solar project moving into battery design and procurement with a proposed 60 kWh sodium-ion system—not as a completed resilience hub power system.