High Voltage Direct Current transmission and Supervisory Control and Data Acquisition systems are essential in the transmission of renewable power
Most of the energy sector has relied on Alternate Current (AC) transmission systems for the past one hundred years but the recent spread of renewable energy sources, often in remote places in the country, has exposed the limits of A.C. transmission particularly over long distances. HVDC transmission provides a viable answer to these challenges. HVDC systems also decrease energy loss found in this process, thus facilitating more efficient transfer of electrical power over long distances. That kind of efficiency is especially crucial when transporting windmills from offshore or solar panels from distant locations to urban centers.
A notable example of HVDC implementation is the UK’s Eastern Green Links project. The scheme will also feature two direct current subsea cables (HvDc) of (2 gW each) the first will run from the east coast of Scotland to northeast England. The links allow the intermediary passage of renewables generated via Scottish wind farms to England to strengthen the national grid to comply with UK sustainable energy requirements. The scheme is part of Britain’s biggest ever investment in electricity transmission. The two links will cost a combined £3.4 million.
SCADA systems play a critical role in the monitoring and controlling of the HVDC operations and ensure that the transmission process is safe and efficient. The SCADA systems collect real-time data from multiple devices on the energy grid, including sensors and meters that let operators monitor how the system is performing, identify faults and determine how to maintain grid stability. Real-time monitoring is essential for reaping the benefits of the intermittent nature of renewable energy including wind and solar power.
HVDC BorWin1 projects are examples of HVDC SCADA integration in Germany. The project links North Sea offshore wind farms with the German mainland’s power grid. BorWin1 is a High Voltage Direct Current (HVDC) system that conveys power of 400 MW for about 200 km via a combination of submarine and underground cables. To address the stochastic need from wind energy generators, SCADA systems are used for real-time monitoring and regulation of the transmission process.
Another large project is the HVDC DolWin1, which links offshore wind parks in the German Bight to the internal grid. It is a voltage sourced converter (VSC) based link that has a power transfer capability of 800MW. The SCADA type systems are acquired for this project which enables real time data acquisition and control in order to handle the power flow and react rapidly to abnormal conditions such as variations in energy generation.
The Netherlands is another excellent demonstration of HVDC transmission combined with SCADA systems. One of the few HVDC projects under the wings of a transmission system operator (TSO) is the HVDC connections link Norway (NorNed) and UK (BritNed) to The Netherlands (More evidence about the birth of HVDC). While enabling cross-border energy trade, these projects also help integrate renewables into the power system. The SCADA systems play an integral role in such operations, supplying the necessary data and control tools to monitor the interaction of multiple energy forms with transmission infrastructure.
VSCs are one of the main power electronics converters used in HVDC systems, particularly in connection with renewable energy generation. HVDC technology allows for the transmission of large volumes of electrical energy over long distances with low losses, making it suitable for transporting remote renewable generation resources from renewables to load centers. Second, SCADA systems provide the real-time monitoring and control required to function with the variability and intermittency of renewable energy generation. This indirectly allows transmission and distribution of renewable energy in a reliable and efficient manner, which is vital to the transition to a more sustainable energy future.
Integration of HVDC & SCADA systems is also popular subject in United States. The Department of Energy announced $11 million in funding for HVDC transmission projects that would allow the incorporation of renewables onto the grid and provide access to remote communities. The projects are a reflection of how advanced transmission technologies, storage resources, and control systems can facilitate wider integration of renewable energy to create a more resilient grid.