What comes to mind when I mention the phrase solar networking?
If your first thought is about swapping business cards and making small talk at exhibit hall happy hours, you’re not alone. But there is much more to solar networking than working deals, especially in the context of large-scale solar.
At a 50 MW project today, an asset manager may have anywhere between 1,500 and 2,000 networked devices — for example, tracker controllers, inverters, and weather monitoring stations — safeguarding plant infrastructure while providing secure and reliable control of the system’s energized equipment and moving parts.
In this article, I will talk about developments in networking and the internet of things (IoT), why networking within the plant has become critical for large-scale solar plant operations, and some of the leading options available for networking in large-scale solar.
It’s important to understand how the communications technology that you integrate into your next solar project can affect performance and operational efficiency for years to come.
What is power plant networking?
Networking has transformed just about every aspect of the built environment we encounter at home, on the road, and in the places we visit each day.
Pairing technologies like Amazon Alexa, Apple Home, and Google Assistant with connected devices around the home, you can now unlock your front door with the tap of a watch. Smart lighting and temperature control systems can sense who is home, what you are doing, and seamlessly make the space more comfortable. In the kitchen, you can get recipe suggestions based on what’s in the fridge, notifications so you don’t overcook the meal in the oven, and grocery orders to replenish key items as they start running low.
Around town, your car can communicate with other vehicles to avoid traffic congestion and connect with smart parking meters to locate a curbside spot near your destination. Throughout the community, public services can run more efficiently as waste management systems monitor trash bin utilization to reduce unnecessary pickups, as streetlight sensors adjust brightness to improve public safety or reduce energy costs, and smart grid technologies help consumers optimize energy use.
All these systems use the same essential networking elements:
- Computing devices, including network nodes for sending and receiving data
- Communication protocols
- Wired or wireless network links
- Other system characteristics, such as network topology and geographic scale
Just as some devices work better in home area networks than out in the field, the same is true of communication protocols and network topologies. The network characteristics that support smart home functionality will not necessarily be the best choice to orchestrate wind sensors, inverters, and other components in large-scale solar infrastructure, as I discuss below.
Why networking is important for solar
As solar accounts for an ever-growing share of electricity production, grid managers increasingly rely on solar assets for steady, predictable power. Service disruptions can not only leave the bulk power system with a shortfall in energy supply. They can also make it more difficult to maintain grid stability. Serious financial penalties can result from missing contracted energy supply quotas.
Best-in-class networking systems provide the monitoring and control capabilities for solar power plants to deliver enterprise-grade reliability on par with transmission and distribution infrastructure and established fleets of large-scale generating stations. Weather monitoring system data combined with structural and electrical performance data is helping to build a 360-degree view of solar plant performance.
In the same way that municipalities use smart cities technology to reduce costs and increase efficiency with waste management, street lighting, and public safety, smart utility networks enable solar asset managers to improve utilization of solar resources.
While 50 MW solar plants have been, and continue to be, exempt from cybersecurity standards for the largest generating stations on the grid, federal regulators have called upon smaller projects to voluntarily report on compliance, which is overseen by the North American Electric Reliability Corp. through its Critical Infrastructure Protection program (NERC CIP). Some industry analysts expect that it’s only a matter of time before voluntary reporting becomes mandatory.
Plants that lead the way on adoption of enterprise-grade networking can simplify IoT device deployment and operations. Using the latest, most advanced communication protocols, new devices can use self-forming capabilities to automatically join existing networks and self-healing capabilities to rearrange networking pathways anytime a bottleneck in the system occurs.
Networking options for large-scale solar
In home automation kits, industrial control systems, and other IoT applications, many commercial products use Zigbee communication protocols for wireless networking. The first version of the Zigbee standard was released in 2004, making Zigbee older than the iPhone. Over the past 20 years, other notable wireless networking options have emerged, including Wi-SUN in 2012 and LoRaWAN in 2015.
Each technology has enabled the creation of mesh networks with point-to-point data hopping that circumvents the need for a central hub. Solar asset managers should carefully consider sourcing, security, and other distinguishing characteristics before selecting the best available option.
Sourcing
Unlike your home, solar plants need technology that can be supported for 25 years or more, the life of the plant. The ideal architecture is one that is well supported by the industry providing multiple suppliers and active development.
Security
Wireless networks, like any network, face risks of security threats. Solar plants are subject to increasing levels of security requirements to ensure they can safely and reliably connect to the grid. An in-plant network that adopts and maintains the latest industry standard encryption and access standards is the best choice.
Range and interference
Many in-plant networks operate on the same frequencies as commercial Wi-Fi. This can impact reliability and performance in plants that are operating near urban areas. It is vital to consider the network, especially if you are installing in an urban environment.
Performance on complex terrain
Sites can range significantly in size, terrain, and proximity to other networks in use. Networks vary in their ability to support large distances between nodes or work well in hilly terrain. Zigbee uses 2.4 GHz, the same frequency as Wi-Fi. It typically supports a max range of 300 meters, subject to interference caused by nearby network usage, and is limited to line of sight. Other standards like Wi-SUN operate on a lower 900 MHz frequency are capable of ranges up to 4 kilometers and better able to cope with hilly terrain. Pick the right network type and design to match the site’s unique size and terrain challenges.
Networks all around
The trendlines for wireless networking are clear. Worldwide deployment of IoT connections reached 16.7 billion in 2023, up from 3.6 billion just eight years ago. Solar projects, like many other types of infrastructure, are now functioning more like enterprise networks than ever before.
As you evaluate the wireless networking options your supplier has chosen, compare systems based on their ability to meet plant needs across project lifetime, ability to safeguard against security risks, to operate without interference, and cope with terrain challenges.
Most importantly, engage with technology partners who bring the experience and expertise to position your projects for success from initial design through the full project lifecycle.
Gautam Ghose is the director of product line management for solar at Kinematics, where he leads the ideation, development and introduction of new products and optimization of existing products across all solar segments. Gautam brings a wealth of experience leading business teams to create products, set pricing, develop and implement marketing programs to drive customer acquisition in the solar and semiconductor industries across horizontal and vertical markets. Under his guidance, Kinematics is expanding its commercial and utility solar product portfolio by introducing the Kinematics ONE tracker actuation solution.
— Solar Builder magazine
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