The proposed Virtual Power Plant (VPP) integrates a platform-to-ship (P2S) setup to electrify anchored and bunkering ships, while simultaneously supplying excess electricity to the country’s power grid. The system is designed to operate via a 200 MW floating wind farm and a 300 MW floating PV plant, using battery and compressed air systems for energy storage.
A Maltese-Chinese research group is proposing the development of an offshore mooring and energy platform (OMPP) operated by PV, wind and energy storage in Malta’s national waters.
The proposed Virtual Power Plant (VPP) integrates a platform-to-ship (P2S) setup to electrify anchored and bunkering ships, thereby supplying excess electricity to the country’s power grid. Numerical calculations, along with site selection methodologies, were performed to tailor the system and prove its feasibility.
“A key technology for sustainable practices in the maritime industry is shore-to-ship (S2S), which allows ships to switch off these diesel engines by drawing power from the shore-based electricity grid,” the team explains. “Very large floating construction platforms (VLFS), with their stability and carrying capacity in open water, are particularly suitable for hosting S2S systems, resulting in P2S capabilities that provide a sustainable energy solution for ships at sea, including hybrid and electric ships. ”
According to the researchers, Malta’s strategic position in the Mediterranean as a major maritime hub makes it an ideal location for the deployment of the OMPP. Based on the national policy for offshore renewable energy deployment, the academics have identified a specific area, called Area 3 – which is suitable for offshore PV and wind farms and storage, as it has relatively shallow offshore properties and is one of six designated areas. bunker areas off the coast of Malta.
“The OMPP is connected to the offshore VPP via a medium voltage direct current (MVDC) connection of approximately 20 km in length. The platform, with estimated dimensions of 1,200 x 300 meters, is designed to accommodate up to four vessels, each up to 200 meters in length,” the group added. “It has a 24 MVA P2S facility with four berths, each offering up to 6 MVA. The platform dimensions are based on a 20 meter buffer zone on either side of the ships, allowing four ships to berth comfortably with a safety margin for operational flexibility.”
After the numerical simulation and using weather data, the scientists discovered that the system would require a 200 MW floating wind farm and a 300 MW floating PV farm to support the ships’ demand and send energy to the electricity grid of the island to export. For their analysis, they assumed the use of Maxeon’s 3 SPR-MAX3-430 modules with a power of 430 W and an efficiency of 22.7%, installed in a horizontal orientation. The simulation used the wind turbine SG 8.0–167 DD, with 6.04 GWh/km2 in 2023 for the maximum wind direction.
“A detailed analysis of the dimensions of the offshore battery energy storage system and the subsea compressed air energy storage was carried out to optimize energy storage capacity and ensure seamless power supply,” the researchers said. “The analysis found that a capacity of 390 MWh battery energy storage systems (BESS) is required to meet short-term demand, while the compressed air energy storage system (CAES) with a capacity of 1,260 MWh provides additional energy security during extended periods of low renewable generation.”
Concluding their research, the team said the proposed system configuration ensures the OMPP can maintain a reliable power supply to the berths under varying operational conditions. “The simulation-based assessments confirmed the technical viability of the OMPP, although the study also identified several economic and technical challenges that remain to be addressed,” they stated. “Future work should focus on optimizing the cost structure, possibly through modular designs or alternative financing models, to increase the economic attractiveness of such systems.”
The proposed system was presented in “Renewable energy systems in offshore platforms for sustainable maritime operations”, published in Ocean engineering. The study was conducted by researchers from the Malta University of Malta and China’s Tiangong University.
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