Key highlights:
Concentrated solar thermal (CST) systems aren’t new but can be improved. A CST supplier uses Emerson PACSystems industrial PCs and Movicon HMI/SCADA software to deliver systems that empower end users to realize significant energy savings.
Technology continues to play an increasingly key role in improving productivity throughout almost every type of agriculture or farming operation, sometimes in unexpected ways. This is quite evident in the Netherlands—one of the world’s largest agricultural exporters—despite challenges presented by the climate and relatively limited space. Dutch farmers are open to applying technology that maximizes their yields, but there must be a solid business case to do so. In some cases, government grants help prompt work in this area.
Some farming operations need a heat source during harvest to properly dry or process the products. Traditionally, the heat has been supplied solely by fuel-fired systems. However, many of these applications are candidates to obtain a great amount of their heating needs, sometimes up to 50% or more, from renewable concentrated solar thermal (CST) solutions (Figure 1).
Suncom Energy was founded to help energy generation for operating companies in agriculture and other industries. By developing innovative physical and control technologies for CST, Suncom helps large and small end users efficiently meet their energy needs, while providing decarbonization.
Scaling CST effectively
CST is conceptually the simplest solar technology. It is basically heating a fluid with the sun, and efficiency can be improved by focusing the sunlight on the target. However, scaling this to work as needed for small, medium or large users introduces many challenges. The physical outdoor equipment must be designed to produce sufficient heat to heat up heat transfer fluid (HTF) to the required temperature, and to optimize operation throughout the day. A storage and distribution system must get the hot HTF—which can be thermal oil or water—to usage points, whether the sun is shining or not.
Most CST systems work in conjunction with existing traditional fired heat sources—using fuels such as gas, coal, or wood pellets (biomass)—with a preference toward using the eco-friendly CST system, but with the ability to use the other sources as needed to make up the entire heating requirements. Careful application of a thermal energy storage (TES) system for the HTF helps overcome the intermittency of the CST renewable energy source, and it minimizes the need for carbon-emitting heat generation produced using fuels with unpredictable fluctuations in cost.
Suncom’s approach includes three essential elements:
- Create a mechanical design, including a patented flat-profile receiver tube and high-efficiency SunArc parabolic reflector, which can be easily installed, maintained, and expanded (Figure 2);
- Incorporate automation for aiming and stowing the reflectors, and for pumping/storing the HTF for gathering and then distributing heat as needed, enabling fully autonomous operation; and
- Applying a modern human-machine interface (HMI) and supervisory control and data acquisition (SCADA) platform, supporting simple and intuitive local visualization, secure remote monitoring, and data gathering. It creates what Emerson calls its “Floor To Cloud” solution.
Combined, these technologies can supply a volume of HTF at temperatures up to 475 °C (although many operations require only much lower temperatures, perhaps 100 °C), sufficient to provide much of the needs for a typical operation, while realizing an overall 20% reduction in energy bills. This is significant for these types of applications because energy use is one of their main operating costs.
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Shining a light on daily operation
The Suncom reflector automation system runs proprietary tracking algorithms based on the geographic location of the site and the time/day to provide optimum solar tracking, which is verified by inclinometers built into the field equipment. A local weather station provides information to the automation system, especially if the winds become too high, which requires the reflectors to be commanded into the stowed position.
Another input is a direct normal irradiance (DNI) sensor, which measures the strength of the sunlight. The DNI information is used to confirm whether system output aligns with what is expected. If the yield goes down too much, this indicates problematic issues, such as dirty reflectors, misaligned hardware or missing insulation.
With so much configurability and data available, Suncom needed an equally high-performing HMI/SCADA system capable of working with any system size and automation elements. After researching available options, the team chose to collaborate with Emerson as the supplier most able to provide a comprehensive digital transformation solution. It is standardized on an Emerson RXi2-BP industrial PC (IPC), running Movicon HMI/SCADA software.
While the automation system operates autonomously, Movicon provides the clear and concise real-time monitoring capabilities needed to maximize operational efficiency (Figure 3).
Visualization and other features support many different user types. A typical onsite worker can see basic operational data, such as temperatures and power usage. Maintenance personnel can access tracking data and check alarms. Qualified personnel can change and optimize operational settings when needed. Through the Movicon portal, both the end user and Suncom—with the proper credentials vetted by multiple security layers—can securely access this information as well using a PC, tablet or mobile device.
Suncom uses the remote access capabilities of the HMI/SCADA system to provide a support and maintenance service for their clients. The team can monitor historical data and alarm logs and implement predictive maintenance using the HMI/SCADA.
From a fabrication and development perspective, both the physical hardware and the HMI/SCADA configurations have been designed as modular building blocks. The hardware is mass produced in a factory and bolted together in the field as easy as a do-it-yourself kit to reduce commissioning and installation time. Similarly, digital aspects such as graphical configurations were developed as typical library-based building blocks, so they can be copied/pasted to match the physical configuration. Any combination of mirror loops, headers and return pipes can be created, and easily expanded in the future.
Shining a light on daily operation
CST heating is a true renewable energy source and an effective way for industrial and agricultural operations to achieve independence from energy market conditions by taking control of their own energy production.
Suncom is a relatively young company in the field, but it has already developed mechanical and digital innovations for efficiently deploying robust and sustainable energy solutions at sites of varying sizes. The Suncom and Emerson solution with Floor To Cloud enhances productivity, decreases carbon emissions, and reduces operational costs for operating companies of all types worldwide.
