Page of Offshore Application of the Flywheel Energy Storage
Page 2 of TABLE OF CONTENTS. Executive summary... 2 2. Objective... 3 3. Background... 3 4. Project overview:... 4 4. The challenge... 4 4.2 Work Packages Overview, description and achievements... 5 5. WattsUp Power (WUP)... 6 5. Accomplished results... 7 6. University of Aalborg (AAU)... 9 6. Accomplished results... 9 6.2 Publications... 0 7. Conclusion... 0. Executive summary The project was completed on st of February 206. The project was successful in simulating the expected forces acting on the flywheel and proved that the intended suspension system was able to absorb and counteract the expected environmental forces. Evaluations of the results also reveals that there is potential for a significant simplification of the suspension system. This is a positive discovery which will benefit the design for the offshore and marine application and will therefore be pursued further. In addition to above simulations, successful models for calculations of optimal energy storage have also been developed, as well as a strategy for verification of the model by use of scale flywheels in lab. environment.
Page 3 of 2. Objective The scope of this project is an important part of, and contribution to, the overall flywheel development project which comprises power integration and interface of energy storage by flywheels into power distribution systems onboard offshore and marine vessels. The full project runs over a period of 3 years and is also supported by the Innovation Fund Denmark. The objective of this part of the project is to develop a mechanical flywheel that meets the demanding requirements and specifications applicable for marine and offshore use. During the project a flywheel unit shall be build as a prototype and tested accordingly. 3. Background Traditionally engines onboard offshore and drilling vessels operate at low average loads, due to high power peak loads, varying DP (Dynamic Positioning) Thruster loads and redundancy considerations. The low average load make the overall power production and engine operation inefficient due to increased fuel consumption, as well as increased maintenance. By implementing flywheel energy storage, it is expected that the operation can be improved in several scenarios; energy savings at constant load, energy savings at high power peak loads, energy and maintenance savings by reduction of start/stop of engines, as well as number of engines in operation. Figure : Typical fuel consumption curve for diesel engine
Page 4 of 4. Project overview: The project application was submitted on the 22 nd August 204 and final signed by The Fund on the 25 th November 204, with agreed project start st of November 204. The project was finalized in February 206, as per the agreement. The consortium consists of following partners: Maersk Drilling (MD) WattsUp Power (WUP) University of Aalborg (AAU) 4. The challenge The overall purpose of the project is to further develop an onshore flywheel for offshore/ marine application. This is a challenge as the flywheel design have to be adapted and sized to the requirement of the offshore / marine applications, integration into closed micro grids, exposed to external environmental forces and formal assessment and approval by the relevant regulatory bodies. The project scope within, was distributed in the 0 work packages as listed below. During the project period each work package has been subject to additional iteration to ensure that they were consistent, effective and adapted to the actual progress of the project. Maersk Drilling: WattsUp Power: Project Management, Technical support. Suspension, Flywheel design, Flywheel housing, Test rig, Test Flywheels, Business Plan. Aalborg University: Simulation of dimensioning, Lab. test of simulation model with Flywheels.
Page 5 of 4.2 Work Packages Overview, description and achievements Work packages WP Project management WP 2 Development of flywheel suspension WP 3 Development of flywheel box for offshore use WP 4 Building of test rig WP 5 Building of test flywheels WP 6 Dimensioning based on load balance Achievements Detailed simulations have been made of the reaction forces from both internal and external impacts, which is feeding into the foundation design. The project has finalized the first iteration of the specifications and test scenarios for the first :3 size flywheel, which has now been produced and is spinning. Test rig facilities completed at WUP premises, with the first flywheel spinning and undergoing detailed testing. The units have been produced and advanced testing has begun in order to validate the design and simulation model, as well as documenting the performance prior to certification by ABS and DNV. Methodology for determining optimal power and energy capacity of FESS (Flywheel Energy Storage System) has been fully developed. Several load scenarios have been tried out and preliminary sizing for FESS has been computed accordingly. Calculated power and energy for FESS is to be implemented into RTS (Real Time Simulation) computer model. Proposal and details of a control strategy to optimally exploit installed capacity has been developed and is being tested on the first spinning flywheel at WUP. WP 7 Testing with Power Lab The initial work package and scope is
Page 6 of Work packages WP 8 Integration on vessel WP 9 Testing / final design - WattsUp Power facilities WP 0 Development of a business plan Achievements completed. The activity is continuing and the team (WUP/AAU) have now moved to advanced testing. Documentation for Class certification is under preparation. The initial work package and scope is completed. The activity is continuing and the team (WUP/AAU) have now moved to advanced testing for validation of the simulation results. The initial work package and scope is completed. Tests are now continuing to prove stability. Test facilities at MAN has been inquired to improve the environmental tests. A specific offshore strategy has been developed. MD and WUP will pursue this strategy further in due course. 5. WattsUp Power (WUP) WattsUp Power have now produced a spinning flywheel in the final design construction made for Maersk Drilling and this project. The first flywheel is designed and built in :3 power ratio compared to the full scale version. WUP is testing a new and advanced converter and inverter technology, which allows us to use the strengths from a flywheel reaching the required 9MJ s of power per flywheel that has been specified by the project. But more interesting for this project is that the flywheel now has a design of a foundation, which can handle the offshore requirements. The team behind this work and accomplishment have worked dedicated to obtain the results and the final solution is both novel and unique.
Page 7 of 5. Accomplished results First the team have defined the conditions where the flywheel had to operate. Both DNV, ABS and MAERSK participated in defining the fundamental boundary conditions. Following was defined; Ship Motion assessment from: List: +/- 5 degrees Trim: +/- 5 degrees F/A Deck Angle +/- 5 degrees (assumed) Roll +/- 45 deg; 2 sec Pitch +/- 2 deg; 9 sec Heave 0.4 g Surge 0.25 g Ship length 600 ft Ship Beam 80.7 ft MIL-S-90 Grade A Shock MIL-STD-46 EMI (electromagnetic compatibility) MIL-STD-67 Vibration Then advanced mathematical models was developed;
Page 8 of Pictures: AAU, DTU, WUP and MAERSK Drilling The expected forces of both internal and external environmental impacts to flywheel bearing and suspension system were successfully determined by simulation. The results proved that the intended suspension system was fully able to absorb and counteract the expected forces leading to a suspension and control strategy. Detailed evaluation of the results further revealed that there is a high potential for a significant simplification of the suspension system, which will positively influence the design of the offshore and marine application. Due to ongoing patent applications, WUP and partners can unfortunately not at this this stage present drawings or illustrations in this respect. The next focus point of the project is therefore to continue the development, with focus on implementing design measures, both for an enhanced simplified suspension system and also design measures which will allow a 20 years life time of the mechanical part of the flywheel. This will add further benefits to the already proven benefits of the flywheel technology and thus add the value project. WUP is working on the documentation material required for preparation of the final approvals with the regulatory bodies, a process which were initiated in Q4 205 and is planned to be finalized during summer 206.
Page 9 of 6. University of Aalborg (AAU) Aalborg University was involved in three different work packages in this project. 6. Accomplished results WP6 was focused on dimensioning based on the load balance. Here, optimal energy storage system sizing together with economic design of a drillship power system was analyzed. A power management optimization model was proposed so that ship operation cost was minimized while system s technical and operational constraints were not violated. Compared to the conventional approaches, the proposed method not only addressed the question of how much energy storage to install, but also provided insight into the scheduling of different electric power plants in a drilling vessel thorough various loading levels and mission profiles. Simulation results demonstrated that including wellsized energy storage options together with optimal operation management of generating units can improve the economic operation of the test system while meeting the system s constraints. WP7 was run in parallel with WP6 and was focused on developing real time simulation model of the drilling vessel. To that end, it could be said that WP6 was done in static environment, while WP7 was done in dynamic simulation environment. The modeling language was Matlab/Simulink SimPowerSystems and the whole shipboard power plant was modeled and can be simulated with variable time steps. However it shall be noted that very small time steps put a heavy computational burden on the CPU cores and it is not necessary to simulate the system that fast in shipboard plants due to a fact that most of the electronic loads (the ones directly connected to AC plant) are actually diode rectifiers that chop the input voltage at 360Hz. Depending on converter topology and size of the input filter, there will appear more or less high-order harmonics in the plant (arising from active switching). Their impact on the plant however, cannot be studied in real time due to limitations of the simulator. WP8 has focused on the integration of the flywheels onboard a vessel. AAU has come up with a strategy on how to use the reduced scale models to study the interaction of high number of distributed flywheels with a shipboard power system and validation tests are now being performed on the first spinning flywheel at WUP premises. The simulations done at AAU were made in the manner to evaluate worst case power scenarios, thus allowing WUP and MD to evaluate the mechanical torque from the flywheel to the ship.
Page 0 of 6.2 Publications The work on the project has resulted in the publication that has been forwarded to all the partners within the project and is now in the process of being reviewed for possible conflicts with ongoing patents prior to final publication. The tentative title of publication is Optimal Planning and Operation Management of a Ship Electrical Power System with Energy Storage System. 7. Conclusion The project Off-Shore Application of the Flywheel Energy Storage was successful in the process of bringing an on shore spinning energy storage technology - offshore. Dedication and a highly skilled team made in possible to achieve both analyzing of the challenge, modeling the challenge and reaching a solution in less than year. The support from has made a significant contribution to the success of the project, which is highly appreciated. The work done in this project has also made it clear that a number of additional functionalities are needed to successfully introduce the product to the market. A longer life time is needed on the project along with a fully standalone operational system, to make the energy storage system 00% independent from daily human interaction. These new improvements has been planned to be implemented over the next 2 months, and will gradually be introduced once the different features is released.