Introduction to GEISA
Event Recap: LF Energy Summit Europe 2025
TL;DR
At LF Energy Summit Europe 2025, Michael Stuber (Southern California Edison) presented GEISA, the Grid Edge Interoperability and Security Alliance, a project designed to address interoperability at the grid edge. GEISA defines a management API, a data API, and two execution environments, Linux and virtual, to enable applications to run across devices from different vendors, beginning with electric meters and intended for use on distribution automation devices such as capacitor bank controllers and load tap changers.
Watch the full presentation:
https://www.youtube.com/watch?v=szQcZZV-9wU
Presentation Overview
GEISA, the Grid Edge Interoperability and Security Alliance, is described in the session as a project designed to address interoperability at the grid edge. The formal mission statement presented is: enabling secure interoperability at the grid edge to accelerate adoption of advanced analytics.
Stuber defined “grid edge” specifically as devices in the distribution network. The initial focus is electric meters, with interest in other distribution automation devices such as capacitor bank controllers and load tap changers. The session clarifies that GEISA does not address substations, secondary substations, internet of things (IOT) environments, smart devices, data center edge, or general IT edge.
The session describes changes in the generation mix, including increasing penetration of renewable assets and associated reductions in spinning inertia. It also describes changes in smart meter capabilities. First generation AMI meters are characterized as having limited memory and running a single image. Next generation meters are described as capable of one second data, waveform data, gigabytes of storage, running operating systems such as Linux, and using multiple processors.
A recent EPRI report is referenced stating that about 60 percent of US utilities are going to be replacing their AMI meters in the next five years.
GEISA is described as addressing four areas: supply chain security, innovation constraints due to proprietary vendor environments, future proofing in light of vendor strategy changes, and efficiency through a standardized baseline environment. An analogy is presented comparing early light bulb incompatibility to the current state of grid edge execution environments.
Architecture and Core Components
Stuber described three primary areas within GEISA.
The first is a management API. This defines how applications are deployed and managed across fleets of devices. The session references lightweight MTOM transactions, expected over UDP, along with REST APIs over HTTPS for device and application management.
The second is a data API. This provides consistent access to device functionality such as disconnect switches, waveform data, billing data, and instantaneous measurements. The implementation described uses MQTT as an internal message bus that is not externally exposed, protocol buffers for data exchange, and Unix sockets for waveform data due to throughput and latency requirements.
The third area is the execution environment. Two execution environments are defined. One is a Linux execution environment that uses container technology for application isolation without mandating a specific container implementation, provided requirements are met. The other is a virtual execution environment, described as conceptually similar to a JVM model. The session notes that applications cannot be assumed to run across both environments without differences, so the specification defines them separately.
The design approach described during the session is selection over invention, meaning the project specifies how existing technologies are used rather than creating new protocols.
FAQ
What is GEISA?
GEISA, the Grid Edge Interoperability and Security Alliance, is a project designed to address interoperability at the grid edge.
What devices are in scope?
The initial focus is electric meters, with interest in other distribution automation devices such as capacitor bank controllers and load tap changers.
What does GEISA define?
GEISA defines a management API, a data API, and two execution environments to support application deployment across grid edge devices.
Is there a reference implementation?
The project is not planning a full reference implementation. A dummy implementation exists for conformance testing purposes.
About LF Energy
LF Energy is an open source foundation within the Linux Foundation focused on advancing collaboration in digital energy infrastructure.
Learn more: https://lfenergy.org
Last updated: February 19, 2026
