Tech Insights

Old Becomes New: Retrofitting Legacy Equipment for Smart Grid

May 14, 2024 by Liam Critchley

Outdated equipment is hindering full grid digitalization. Retrofitting may be the answer. This is the fourth part in a series examining technical challenges to grid digitalization in depth. 

Energy decentralization relies heavily on digitalizing power grids. As the grid digitalizes, significant investment becomes critical. Smart grid technology allows connecting physical and data environments to improve grid performance, optimize renewable energy integration, and meet the ever-evolving demands of energy consumers.

Full grid digitalization is expected to improve productivity, security, and operational efficiencies. However, technical barriers still prevent a wider digitalization rollout. 

One barrier is legacy equipment, which is not compatible with digital systems. Changing from outdated equipment to digitally compatible systems poses several challenges.


Grid digitalization involves removing or replacing legacy equipment

Grid digitalization involves removing or replacing legacy equipment. Image used courtesy of Adobe Stock


Legacy Equipment Problems

Even though new sensors and monitoring systems are designed to digitalize the grid, the energy sector has many non-compatible systems presenting problems.

It is difficult to integrate new computing, communication, and data management technologies into IT systems used for 40 years. When this equipment was installed, the sensors, gauges, and meters were not designed to analyze the raw data and transfer it to digital spaces. As smart sensors and IT systems are integrated into existing legacy systems, compatibility issues arise as the overarching system is outdated and can’t work properly with the new IT protocols.

The infrastructure varies among distribution system operators (DSOs), as each company’s infrastructure was built using proprietary technology. These differences lead to challenges in standardizing digital upgrades across the grid since companies must consider many factors and systems.

As energy demands increase and new energy generation is integrated, digitally transforming the grid to make it more robust could significantly improve and optimize operations within the energy space. However, because legacy equipment cannot often connect to modern digital systems, it’s difficult to integrate more efficient equipment into the grid. This is because some legacy equipment cannot “communicate” with the smart equipment and the wider digital network. Smart grids now connect the network components using inter-device communication protocols such as DNP3, IEC 61850, and MODBUS. Still, the age of many legacy systems means they are not designed to communicate using these protocols.


Connecting assets with DNP3 protocols

Connecting assets with DNP3 protocols. Image used courtesy of Wikimedia Commons


Additionally, the age of legacy equipment can mean other issues like breakdown and a lack of service and support. Newer, more efficient systems are less likely to break down, and support is available. In many cases, because the newer equipment is connected to digital systems, the problem is much easier to fix because more data is available to analyze.


Financial Factors

Money is a key factor preventing the replacement or retrofit of legacy equipment. Significant investment is needed to completely digitalize the power grid because it has not been updated for a long time. Many energy companies don’t have a large enough budget to cover the transition, and it is often economically unfeasible to shut down business sectors to facilitate the installation. So, upgrading equipment is seldom done.

Needed upgrades include buying and installing smart sensors with digital-enabled capabilities, implementing connectivity and data transmission layers, integrating platform and data storage, and installing analytics capabilities.

All these digital puzzle pieces have high investment costs, and many will require subsequent reinvestments due to the short-lived nature of modern-day technology upgrades and the need to keep up with the latest and greatest capabilities. For many in the energy sector, this kind of investment is considered risky, especially because directly measuring the benefits and payback time and prioritizing investment vs. risk can be difficult. Utilities must work within budgets and avoid passing excessive costs to consumers. 


Could Retrofitting Be the Answer?

Because replacing legacy equipment has financial constraints, completely removing legacy equipment in favor of digitally-enabled equipment is highly unlikely. It is not a feasible solution for the energy sector—not in the short term, at least, and it would take a long time to transition steadily. One possible option is to retrofit existing equipment with upgrade kits, allowing them to become digitally enabled and connect with the energy sector’s IT systems.

Retrofitted systems enable the reading and communication of important data from the grid equipment without needing to change the existing software and hardware. Low-cost smart sensors may be connected to existing systems through retrofitting methods that control connectivity and data analytics.

Retrofitting can be achieved in two ways. First, smart sensors can be combined with edge gateways to gather data and transform the infrastructure into Cyber-Physical Systems (CPS). This retrofit is an Internet of Things-based approach using IoT sensors. 

To install IoT sensors, grid operators first map areas on the infrastructure needing improvement. Then, IoT sensors can be integrated into the legacy equipment at those locations. Once installed, the sensors are connected to communication infrastructure to transmit information through the digital network.

Installing switches, gateways, and network servers connects the IoT sensors to the wider network. Then, application servers containing industry-relevant applications, such as data cloud and web services, are installed. These application servers should be compatible with existing industry applications.

It’s also possible to install the gateways separately to collect data from other data collection sources already on-site. Second, retrofit kits are available from third parties. These contain a complete package of sensors, connectivity, control, and data analytics to integrate into existing infrastructure.


Transmission line sensors

Transmission line sensors. Image used courtesy of the authors


Smart sensors collect many data types, but on a macro level, they provide real-time data on energy flows across the grid. This system allows for monitoring, protecting, and controlling grid operations to improve grid reliability and resilience. The data collected enables the detection of potential equipment faults. Customized upgrade solutions can be designed to improve the performance and functional capability of the existing equipment.


Achieving Full Integration

Updating legacy equipment for grid digitalization is not straightforward. Converging the various technologies can take time and technological expertise. In some instances, AI-enabled and IoT-based solutions have been implemented into smart grids, but these technologies must be combined with digitally enabled legacy infrastructure. 

Legacy infrastructure can coexist alongside modern-day technological solutions if it can be converged through a combination of interoperability, which will be examined in Part 5, and retrofitting approaches. This process will help support the digitalization of the global energy grid in the coming years.