Project

The goal of the project is to significantly strengthen the scientific basis for the wind power industry in general and specifically the Danish wind power industry’s position in offshore applications.

To meet the goal the proposed research must have a significant potential for reduction of cost of energy from large offshore wind farms, and for contributing to reduction of the economic risks arising from inadequately founded design.

The key design driver for most offshore structures is safety. For offshore wind turbines/farms, however, the main design driver is economy and therefore there is a strong requirement for enhancing design tools and avoiding conservatism. Consequently, focus is on the following issues:

1. Mutual shadow effect between large blocks of wind turbines – ignorance of the effect may have disastrous consequences for the economy.
2. Extreme structural loading of offshore wind turbines – detailed understanding and description of extreme winds and gusts and resulting loads is crucial for the safety and economics of the wind turbines.
3. Interaction of large wind farms with waves and current – understanding and modeling may lead to reduced design loads on wind turbine units placed in the downwind end of the wind farms.
4. Grid connection and reliability – An unreliable grid caused by high wind energy penetration is an obvious barrier for the dissemination of the technology.
5. Optimized operation and maintenance for offshore wind farms – presently more than a third of the cost of energy from offshore wind farms relates to O&M and the potential for reductions is therefore large.

The project is sponsored by The strategic Research council and have participant from Risø National Laboratory, Elsam Engineering, Insitut for Mekanik, Energi og Konstruktion DTU, DHI, Svend Ole Hansen and Institute of Energy Technology AAU.

The institute of Energy Technology is especially involved in issue 4 in this project, by Birgitte Bak-Jensen, and also a Ph.D project is set up together with Risø and Elsam Engineering, with the title: Offshore Wind Power – Grid Connection and Reliability, see this project.

This Ph.D. project is carried out at Dong Energy in cooperation with Risø National Laboratory and Aalborg University.

The aim of the PhD project is to investigate the influence of wind generation on the reliability of power systems. This task is particularly important for large offshore wind installations, because failure of a large wind farm will have significant influence on the balance in the power system, and because offshore sites are normally more difficult to access than onshore installations. The reliability of power production from a wind farm depends on wind speed conditions, the wind turbines themselves, the system layout and the grid connection; besides, the offshore environment poses new challenges to face for the installers.

The project has been divided into three parts. Firstly, a model for yearly generation assessment of offshore wind farms has been developed: this model includes wind speed randomness and variability, components (e.g. wind turbines, internal cables and connectors to shore) failures, influence of site environment and some minor aspects of relevance. Secondly, this model has been used for evaluating the so-called HLI analysis (Hierarchical Level I), where the system adequacy to supply the load is assessed. The power system under study includes conventional power plants, an aggregated load and distributed generation together with offshore wind generation, whereas transmission facilities are neglected in this type of simulation. These two assessments are performed considering a sequential Monte Carlo simulation: this approach has shown more flexibility and completeness in the analysis of wind generation than analytical techniques.

With these two models, that are currently available, some sensitivity analyses will be carried out in the next months. Besides, some of the models will be used for performing an HLII analysis: in this type of study, the transmission facilities are included in the power system model and the adequacy of the system generation is evaluated including the availability of transmission lines and cables.

All analyses in the project are carried out by the use of the software Matlab and the power system analysis tool Power Factory from DigSILENT: simulations will include steady-state conditions as well as dedicated reliability analyses.

The purpose of the project is to analyze and develop models for describing the interaction of wind turbines and wind farms with other electricity production units and to analyze their properties with a view to power and frequency control and co-responsibility for system stability. Furthermore, the project will create a basis for assessing the limit for the share of wind energy in the Danish electricity system. The models will thus be able to analyze electricity systems with wind turbines, central power plants, combined heat and power units and energy storage, including the use of compensation units, etc. The project focuses on preparing the models from the transmission level, where in particular the expansion with large wind farms (onshore or offshore) and the problem of how the energy is to be transported to land from offshore farms (AC or DC transmission) are of interest. Through the project, models of the transmission network (AC and DC) with associated central combined heat and power units and loads and where the production from the decentralized combined heat and power plants is viewed from the transmission level will be built and implemented. Models of larger wind farms with different control strategies will be connected to this model. The models include and implement protection equipment and strategies for stability analysis. Wind farms with different generator/converter topologies are modeled and control strategies for power participation or frequency regulation on the grid are compared and optimized for production capability and/or stability conditions. The project is funded as a PSO project from Elkraft System and is being prepared by Birgitte Bak-Jensen, Zhe Chen and Hans Nielsen, Department of Energy Engineering, Aalborg University, Anca Hansen and Poul Sørensen, Risø, and Jesper Hjerrild, Elsam Engineering. In connection with the project, a Ph.D project is also being prepared by Akarin Suwannarat with the title Integration and control of wind farms in the Danish electricity system (see this).

The purpose of EFFORT (Electrification and Flexibility provision from Green PORT North) is to ensure successful development of Hirtshals Port through intelligent use of data for controlling the energy usage. Data is used for analyses of existing consumption and energy production and possible scenarios and management methods for future expansion of the port. A local data hub is built with associated IT infrastructure to obtain necessary data. Requirements for data for forecasting, optimization of green electricity consumption, flexibility, electricity grid capacity and services for electricity markets with help of intelligent management are analyzed along with possibilities for sector coupling at the port. The analyses help to assess a suitable transition for expected development at the port. A roadmap based on technical analyses is drawn up at the end of the project, giving Greenport North, Hirtshals Port and Nord Energi Net A/S guidelines for future development of necessary infrastructure and a basis for development of a symbiosis network and a local energy system at the port. The set up roadmap for sector coupling, provision of flexibility and symbiosis from industry in a local area, can be utilized at other industrial areas in cities and at ports both in Denmark and worldwide.

AquaBuoy is a buoy that can convert energy in ocean waves into electricity. AquaBuOY consists of a 9m high float with a diameter of 6m, under which is fixed a 25m long vertical tube with an inner diameter of 4m. AquaBuOY is designed to have large vertical movements in relatively small buoys. By mounting a special hose pump inside the long vertical tube, the wave energy can be extracted by utilizing the differential movements between the vertical tube and the water column inside the tube. The project primarily deals with the design and dimensioning of the anchoring system. AquaBuOY is being developed in collaboration with AquaEnergy Group, USA and Rambøll. (Morten Kramer, Thomas Lykke Andersen, Peter Frigaard, Anders Augustesen.)

Microgrids (MG) effectively ease the integration of renewable energy sources (RES) and energy storage systems (ESS) at the consumption level, which generally aims to increase the efficiency of the electrical system and reduce the dependency of the electrical supply on fossil fuels. On the other hand, the MGs concept has been widely studied, which focuses on overcoming these issues in a reliable, efficient, and sustainable way, but still, challenges exist. For instance, the severe power outages caused by natural disasters (ND), such as tsunamis, floods, earthquakes, etc. all of which affect industrial production, disturb business as well as home operations, and may endanger human lives. These possible natural disasters and incidents impose new challenges involving sophisticated control strategies, operations, and vulnerability to natural disasters. Most of these events directly affect the overall power system and as well communication system. After a disaster, the main grid may blackout, and gen-sets are shut down for security reasons. In this situation, low-power portable containerized Ad-Hoc MGs can provide an emergency solution for two or three days to the critical loads, and potable water pumps can be provided to relieve the damaged area. However, resilience in front of extreme grid faults is still a technical challenge for MGs to deal with NDs. Therefore, the main concerns and current challenges for increasing renewable energy penetration and resiliency in power systems should be targeted to ensure high and unprecedented levels of system resiliency and recovery under NDs. For this purpose, we need resilient energy systems that are robust against these events, moreover, they can keep the power system safe against overall collapse and complete power outages as much as possible. For sizing and siting of ad-hoc and community MGs to supply energy for emergency clinic support and clean water provision in the potentially damaged areas caused by NDs are done by using HOMER Grid/Simulink. Operational Management Systems (OMS) will be developed by using GAMS and Matlab/Simulink for the microgrid operation taking into account the priority of sensitive loads in the islands during the ND. For experimental verification, the project outcomes will also be implemented on real-time control and monitoring platform (dSPACE) in the microgrids Laboratory. This Ph.D. project part of the planning and operational management systems (OMS) is aligned with the ongoing project `Microgrid Technologies for Remote Indonesian Islands-TECH-IN` to cope with the main concerns to provide high levels of resiliency and availability of electricity supply in front of natural disasters.

Funding: ChiefMinister Merit Scholarships (CMMS), The Punjab Educational Endowment Fund (PEEF), Pakistan.

Sponsored: Ministry of Foreign Affairs of Denmark, DANIDA Fellowship Centre (Project No. 20-M06-AAU) and supported byDANIDA Fellowship Centre and TECHIN Cerner of Research on Microgrids AAUEnergy, Aalborg University, Aalborg Denmark.

Floating Power Plant (FPP) are a Danish company who develop a novel floating wind concept, with the foundation constructed using flat panels instead of cylindrical structures. Whilst this enables a fast-commercial roll-out due to the lack of competition for manufacturing facilities, a large contingency presently needs to be included in the design as hydrodynamic phenomena occur that are not well represented by industry-standard simulation tools. FPP have already taken the concept from the original idea of a Danish inventor, through a scaled offshore prototype in Danish waters to a multi-MW demonstrator (to be deployed in a parallel co-funded EU project).

This project will solve the final challenge for FPP, taking the technology from the multi-MW demonstrator stage to a cost-competitive mass-produced concept. The output will be three large demonstration activities and six innovations, including a commercially-ready simulation tool and two fully optimised commercial designs, WindFlex (a floating wind turbine with integrated hydrogen energy storage) and WindWaveFlex (a floating wind turbine with integrated wave energy converters and hydrogen energy storage).

The decision to build the world's first two offshore energy islands (or hubs) is a cornerstone in reaching Denmark's climate targets and a beginning of a new era for green Danish technology export. With an estimated value of DKK 210bn, the offshore energy islands will create significant business opportunities for Danish stakeholders. In the Offshore Energy Hubs (OEH) project we develop technical solutions for:
a) tools and control solutions for stable and resilient hub operation,
b) cost-efficient design of wind power plants (WPPs) and
c) hub-optimized offshore Power-to-X (PtX).

The value creation of the OEH solutions is both direct and indirect. The developed solutions will reduce capital costs by DKK 20bn just for the first 10 GW islands, and, most importantly, will enable a future-proof expansion of the energy islands. This opens up immense global market opportunities for the technologies developed by the top Danish industry, who are partners to this project. Therefore, the technical solutions developed in the OEH project contribute to ensuring the profitability of the OEH, while also ensuring the stability of the hub and the connected power systems.

The OEH's execution ensures timely contributions to the partners' strategy and roadmaps. OEH will deliver a framework for Bornholm as a large-scale development and demonstration center for offshore energy island technology, supporting Danish industry in maintaining its first-mover position.