Real-World Challenges and Lessons-Learned from Cyber-Physical Security Technology Testing at a Utility Solar Photovoltaic Field Site

The electric grid is transforming rapidly with increasing installation of distributed energy resources, adaptive protection and control technologies, and resilient, modular system topologies. Additionally, cybersecurity is a prominent concern and has prompted increased development and deployment of cyber-physical security capabilities. For cyber-physical security, there is increased focus on IT/OT convergence for more comprehensive situational awareness, implementation of OT-focused cybersecurity solutions, and research into cyber-physical analyses to understand event propagation and impact to the underlying physics-based processes. It is crucial that before installation in the electric grid or other critical infrastructure systems, proper procedures for lab and field testing are conducted to ensure reliable and resilient operation post-installation. In this paper, we delve into the design of field testing for cyber-physical security technologies for the electric grid. Specifically, we focus on the use case of testing the proactive intrusion detection and mitigation system technology at the Public Service Company of New Mexico's Prosperity Photovoltaic site. We investigate and present lessons-learned for field testing setup, cybersecurity assessment metrics, and overall challenges. These lessons-learned can be used to inform future cyber-physical technology standards and certification procedures for rigorously assessing and promoting trust into new technologies.