Writing from the perspective of a maintenance electrician who works hands-on with BESS yards, solar sites, SCADA systems, and real-world infrastructure every day.
Why Battery Energy Storage Systems Are Security Nightmares From a Maintenance Technician's Perspective
Battery Energy Storage Systems are often described in high-level diagrams, policy documents, and conference talks. In those materials, security risks tend to appear theoretical and distant. In the real world, they are anything but. I work as a maintenance electrician on BESS yards and solar sites every day, and what I see on the ground reveals a different story. The systems powering the clean energy transition are built on layers of equipment, vendors, access workflows, and inherited assumptions that create serious security weaknesses. These weaknesses rarely come from exotic zero-day vulnerabilities. They come from ordinary operational practices that accumulate over time.
This is not an academic viewpoint or a security consultant's interpretation. It is the perspective of someone who handles these systems with a flashlight, a toolkit, and a laptop on a cold morning. It is the perspective of someone who plugs into the switches, walks into the containers, clears the alarms, resets the inverters, and speaks with the people who operate and support these systems across utilities, OEMs, integrators, and contractors. What I see does not match the controlled diagrams. It is messier, more human, and far more vulnerable than most outsiders realize.
In this post, I want to lay out the major patterns I have observed over years of hands-on work. All examples are generalized and anonymized. The goal is to help engineers, integrators, operators, and security professionals understand how these systems function in reality and why the industry needs a much more grounded conversation about security.
1. Shared Credentials Are Everywhere
The first and most visible issue that appears across almost every site is the heavy reliance on shared credentials. It is extremely common for SCADA systems to use a single username and password that every maintenance technician uses. This is not an exception. It is normal. If you ask why, the answers tend to revolve around practicality. People rotate in and out of maintenance roles. Vendors need temporary access. There is no simple process for provisioning and revoking individual accounts. The equipment expects a small set of static logins. Changing a password risks breaking workflows that technicians rely on during urgent corrective work.
This logic may be understandable operationally, but it introduces serious security risk. When a dozen or more people share the same account, there is no accountability. You cannot attribute any action to a specific user. If a system is misconfigured, modified, or accessed improperly, the logs only show that a shared SCADA account was used. There is no way to know by whom or when.
The issue extends beyond SCADA. Commissioning software and web applications used to manipulate inverter behavior often rely on extremely simple credentials. A technician might plug into an EMS cabinet and authenticate to a commissioning interface with a username and a simple numeric password. Once authenticated, they can modify inverter parameters that affect the entire site. These interfaces are designed for speed, not for security, and the credentials tend to persist unchanged for long periods of time.
The result is a trusted internal zone that assumes anyone with physical access is authorized. In practice, this creates a situation where a compromised laptop or an insider mistake can have significant consequences.
2. Field Laptops Function as High Value Keys
Another pattern that appears across multiple sites is the role of field laptops. Utilities often issue dedicated laptops that connect to internal networks. These machines allow technicians to log into SCADA, access PowerComms interfaces, check inverter states, and in some cases access web applications hosted on BESS EMS cabinets.
These laptops are tightly controlled from an IT standpoint, but from a security perspective they are incredibly powerful. They are effectively gateway devices into sensitive control networks. A technician may carry one into inverter enclosures, BESS yards, control houses, or other restricted areas. If that laptop were ever compromised by malware, stolen, or misused, an attacker would immediately gain access to internal systems that normally cannot be reached from outside.
Because these laptops must be used in the field, they experience far more risk exposure than fixed SCADA servers. They travel between vehicles, job trailers, and equipment enclosures. They get plugged into various network switches. They sometimes lose connectivity. They are handled by multiple people across their lifecycle. Yet they often hold login credentials that provide deep access into operational systems.
This creates a single point of failure that is not always accounted for in traditional risk assessments. The operational view is that the laptop is a tool. The security reality is that the laptop is a master key.
3. Firmware and Updates Move Slowly
Battery systems, inverters, fire suppression systems, and energy management systems all rely on firmware. These firmware versions are not always updated frequently. In many cases, they can remain unchanged for a year or more. Updates depend on vendor or OEM technicians visiting the site. In most environments, updates require coordination between the utility, the maintenance contractor, the OEM, and sometimes the integrator responsible for commissioning. Because of the complexity and potential downtime associated with updates, they are often scheduled infrequently.
This is normal within industrial and energy environments, but it creates a long window of exposure. If a vulnerability is discovered in a firmware version, the affected equipment might continue running that version for months while waiting for a scheduled update cycle. Even when updates arrive, they may need to be installed on each inverter or BESS unit individually. The work is physical, slow, and dependent on vendor availability.
There is no unified patch management system across the various components of a BESS yard. SCADA may be updated by one team, the inverters by another, and the BMS modules by a third. Each component follows its own update cycle. From a security perspective, this fragmentation means the overall system can remain vulnerable even if individual components are updated correctly.
4. Fire Suppression Systems Produce Frequent Noise
Many BESS installations use fire suppression systems that integrate detectors, gas sensors, relays, and control logic. In practice, these systems generate a significant amount of noise. Troubles and faults appear frequently. Some are caused by environmental conditions, others by wiring variations, sensor drift, or intermittent communication issues. Because technicians are not authorized to repair detectors or alter fire systems, the resolution often depends on OEM support or fire alarm specialists.
High noise levels can lead to alarm fatigue. When technicians encounter frequent false or nuisance alarms, they become accustomed to seeing warnings that do not reflect real hazards. This does not mean they ignore alarms, but it does shift their expectations and increases the cognitive load required to distinguish real problems from recurring background faults.
From a security standpoint, this environment is risky. A system that constantly generates non-critical alarms is easier to exploit. If an attacker were to create additional alarm traffic or suppress real alarms, it would be more difficult for operators to immediately recognize the abnormal pattern. The safety culture in energy systems is strong, but the technology itself can work against situational awareness when alarms are not reliable.
5. Multi Vendor Environments Create Structural Gaps
A single BESS yard may involve several companies. The utility owns the equipment. A maintenance contractor performs daily checks and corrective work. OEM technicians handle firmware updates and commissioning tasks. Integrators like Flexgen manage SCADA and EMS logic. Another company may handle fire suppression. Yet another may oversee telecom or networking.
In this environment, no single party owns the full security picture. Each group is responsible for the pieces in its control, but the interactions between those pieces create systemic gaps. Password policies differ from platform to platform. Network access rules depend on equipment vendors. Documentation is scattered. Training varies widely. When an issue arises, responsibility must be traced through several layers of contractors and support structures.
Security is not neglected intentionally. It is simply fragmented. The result is a system where operational efficiency takes precedence because downtime is expensive. Security concerns often surface only when they directly affect uptime, and by then the issue may have existed for months.
6. What This Means for BESS Security
The vulnerabilities that concern security professionals are not always the same ones that matter in the field. In practice, the most significant risks arise from the combination of shared logins, high trust internal networks, slow update cycles, inconsistent vendor practices, and system noise. An attacker does not need deep technical skill to take advantage of these conditions. They need access to a field laptop, or knowledge of a shared password, or physical access to an internal switch.
Most BESS security issues are not technical achievements. They are operational opportunities created by the structure of the industry and the pressure to keep systems online. The complexity of these environments makes it difficult to enforce consistent security practices, and the speed at which renewable infrastructure is being deployed often outpaces the maturity of the supporting processes.
Recognizing these patterns is the first step toward change. The good news is that many of the weaknesses are addressable with practical improvements.
7. What Needs to Change
Several improvements would significantly reduce risk without creating major operational burdens.
First, per user credentials should become standard. Even if this requires additional effort to manage, the benefits in traceability and accountability are substantial. Shared logins make security audits and investigations nearly impossible.
Second, commissioning and internal web applications should not rely on simple or default passwords. Basic authentication hardening would raise the bar for unauthorized access.
Third, field laptops should be protected and monitored more aggressively. These devices should be considered critical security assets and treated with the same importance as control room workstations.
Fourth, patching processes should be organized with clearer ownership and tighter schedules. Delays in firmware updates leave systems exposed long after fixes exist.
Fifth, FSS systems should be tuned and maintained to reduce non-critical alarms. Less noise increases the likelihood that operators will identify truly abnormal behavior.
Finally, basic security awareness training for maintenance technicians would close a large cultural gap. Technicians do not need to become security experts. They only need to understand the implications of the systems they interact with.
8. Closing Thoughts
I am writing this because BESS security is often discussed from a distance. The people who build the diagrams do not always see the conditions that exist in the field. The people who perform maintenance do not always see how their daily routines affect security posture. The people who design security controls do not always understand the operational realities that limit implementation.
My goal over the coming months is to research these issues more deeply and to begin building small open source tools that can help identify common weaknesses in BESS and solar environments. I plan to share what I learn so that technicians, engineers, integrators, and operators can strengthen their systems without slowing operations.
If you work in solar, BESS, or industrial control systems and have insight to add, I want to hear from you. The more perspectives we gather, the closer we get to systems that are both reliable and secure.
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