• Maintenance Strategies for Large Offshore Wind Farms 

      Scheu, Matti Niclas; Matha, Denis; Hofmann, Matthias; Muskulus, Michael (Journal article; Peer reviewed, 2012)
      Up to one third of the total cost of energy from offshore wind generation is contributed by operation and maintenance (O&M). Compared to its onshore counterpart, this fraction is significantly higher. Costs are not only ...
    • Mesh parametric study for fatigue assessment of tubular K-joints using numerical methods 

      Mendoza Espinosa, Jorge; Schafhirt, Sebastian; Muskulus, Michael (Journal article; Peer reviewed, 2017)
      Wind turbine jacket structures are complex structures, whose joints design is generally driven by fatigue. These joints, along with their complex welds, are of special interest in terms of cost reduction. Therefore, a ...
    • Moisture Conditions in Passive House Wall Constructions 

      Gullbrekken, Lars; Geving, Stig; Time, Berit; Andresen, Inger (Peer reviewed; Journal article, 2015)
      Buildings for the future, i.e zero emission buildings and passive houses, will need well insulated building envelopes, which includes increased insulation thicknesses for roof, wall and floor constructions. Increased ...
    • Numerical study of irregular breaking wave forces on a monopile for offshore wind turbines 

      Aggarwal, Ankit; Alagan Chella, Mayilvahanan; Bihs, Hans; Arntsen, Øivind Asgeir (Journal article; Peer reviewed, 2016)
      Offshore wind turbine substructures consisting of cylindrical members are exposed to highly non-linear and breaking waves in shallow waters [1]. Those structures experience extreme impulsive loads of short duration from ...
    • OC5 Project Phase Ib: Validation of Hydrodynamic Loading on a Fixed, Flexible Cylinder for Offshore Wind Applications 

      Robertson, Amy N.; Wendt, Fabian; Jonkman, Jason M.; Popko, Wojciech; Borg, Michael; Bredmose, H.; Schlutter, Flemming; Qvist, Jacob; Bergua, Roger; Harries, Rob; Yde, Anders; Nygaard, Tor Anders; De Vaal, Jacobus Bernardus; Oggiano, Luca; Bozonnet, Pauline; Bouy, Ludovic; Barrera Sanchez, Carlos; Garcia, Raul Guanche; Bachynski, Erin Elizabeth; Tu, Ying; Bayati, Ilmas; Borisade, Friedemann; Shin, Hyunkyoung; van der Zee, Tjeerd; Guerinel, Matthieu (Journal article; Peer reviewed, 2016)
      This paper summarizes the findings from Phase Ib of the Offshore Code Comparison, Collaboration, Continued with Correlation (OC5) project. OC5 is a project run under the International Energy Agency (IEA) Wind Research Task ...
    • On Fatigue Damage Assessment for Offshore Support Structures with Tubular Joints 

      Hammerstad, Benedicte H.; Schafhirt, Sebastian; Muskulus, Michael (Journal article; Peer reviewed, 2016)
      The hot spot stress approach is commonly used for fatigue lifetime estimation of tubular joints. The standard approach consists of the linear superposition of stress components from axial, in-plane, and out of plane action, ...
    • Optimization of offshore wind turbine support structures using an analytical gradient-based method 

      Chew, Kok Hon; Tai, Kang; Ng, E.Y.K.; Muskulus, Michael (Journal article; Peer reviewed, 2015)
      Design optimization of offshore wind turbine support structures is an expensive task; due to the highly-constrained, non-convex and non-linear nature of the design problem. This paper presents an analytical gradient-based ...
    • Passive Snow Repulsion: A State-of-the-art Review Illuminating Research Gaps and Possibilities 

      Andersson, Per-Olof; Jelle, Bjørn Petter; Zhang, Zhiliang (Journal article; Peer reviewed, 2017)
      Building integrated photovoltaics (BIPV) are becoming more common every day. They are used everywhere, from the cabin in the mountains to the modern apartment building, and with more common use, strengths and weaknesses ...
    • Rational upscaling of a semi-submersible floating platform supporting a wind turbine 

      Leimester, Mareike; Bachynski, Erin Elizabeth; Muskulus, Michael; Thomas, Philipp (Journal article; Peer reviewed, 2016)
      This work examines the procedure of upscaling of a semi-submersible platform in order to support a predefined wind turbine. As a result of technological progress and design changes, basic scaling based on the turbine rating ...
    • Relative assessment of fatigue loads for offshore wind turbine support structures 

      Stieng, Lars Einar; Hetland, Ruth; Schafhirt, Sebastian; Muskulus, Michael (Journal article; Peer reviewed, 2015)
      Time domain analyses of Offshore Wind Turbines involve a lot of computational effort. In this paper, we present a method for reducing this effort by using results from analyses with shorter simulation lengths to predict ...
    • Retrofit of a Kindergarten Targeting Zero Energy Balance 

      Causone, Francesco; Carlucci, Salvatore; Moazami, Amin; Cattarin, Giulio; Pagliano, Lorenzo (Journal article; Peer reviewed, 2015-11)
      Old buildings that are severe energy wasters and provide low indoor environmental quality (IEQ) form a large fraction of the European building stock. These buildings represent nevertheless, an asset that should be re-evaluated ...
    • Roof-integrated PV in Nordic climate - Building physical challenges 

      Gullbrekken, Lars; Kvande, Tore; Time, Berit (Peer reviewed; Journal article, 2015)
      Use of photovoltaics (PV) is key remedies in buildings where a large part of the energy supply should be based on renewable energy. PV in Nordic climate can be challenging because ofand temperatures below zero. The aim of ...
    • Safety Indicators for the Marine Operations in the Installation and Operating Phase of an Offshore Wind Farm 

      Seyr, Helene; Muskulus, Michael (Journal article; Peer reviewed, 2016)
      As a measure of performance, safety indicators are already used for many types of operations, such as in the offshore oil and gas industry. The indicators are used by operators to enhance the safety and performance of the ...
    • Sensitivity of wave fatigue loads on offshore wind turbines under varying site conditions 

      Ziegler, Lisa; Voormeeren, Sven; Schafhirt, Sebastian; Muskulus, Michael (Journal article; Peer reviewed, 2015)
      Considerable variations in environmental site conditions can exist within large offshore wind farms leading to divergent fatigue loads on support structures. An efficient frequency-domain method to calculate wave-induced ...
    • Simplified Space-heating Distribution Using Radiators in Super-insulated Apartment Buildings 

      Georges, Laurent; Wen, Kang; Alonso, Maria Justo; Berge, Magnar; Thomsen, Judith; Wang, Ruzhu (Journal article; Peer reviewed, 2016)
      The necessity to drastically reduce the space-heating (SH) needs of residential buildings in Europe has prompted the emergence of building concepts based on a super-insulated building envelope, such as the passive house ...
    • State-of-the-Art Building Integrated Photovoltaics 

      Jelle, Bjørn Petter; Breivik, Christer (Journal article; Peer reviewed, 2012)
      Building integrated photovoltaic (BIPV) systems may represent a powerful and versatile tool for achieving the ever increasing demand for zero energy and zero emission buildings of the near future. In this respect BIPVs ...
    • Sustainable energy in cities: methodology and results of a summer course providing smart solutions for a new district in Shanghai 

      Wang, Yu; Lobaccaro, Gabriele; Carlucci, Salvatore; Wang, Ruzhu; Li, Yong; Finocchiaro, Luca; Dai, Yanjun; Eikevik, Trygve Magne; Wyckmans, Annemie (Journal article; Peer reviewed, 2017)
      A systemic approach for integrated urban energy planning and design can increase energy efficiency, the use of renewable energy sources and bioclimatic strategies to lower the energy footprint at building, district and ...
    • Synthesis of Silica-Based Nano Insulation Materials for Potential Application in Low-Energy or Zero Emission Buildings 

      Gangåssæter, Haakon Fossen; Jelle, Bjørn Petter; Alex Mofid, Sohrab (Journal article; Peer reviewed, 2017)
      Sacrificial polystyrene (PS) templates have been used for synthesis of silica-based nano insulation materials (NIM). The PS was synthesized by a simple procedure where parameters as polyvinylpyrrolidone/styrene ratio and ...
    • The Path to the Building Integrated Photovoltaics of Tomorrow 

      Jelle, Bjørn Petter; Breivik, Christer (Journal article; Peer reviewed, 2012)
      Building integrated photovoltaic (BIPV) systems may represent a powerful and versatile tool for achieving the ever increasing demand for zero energy and zero emission buildings of the near future, offering an aesthetical, ...
    • Ventilated wooden roofs: Influence of local weather conditions-measurements 

      Gullbrekken, Lars; Kvande, Tore; Time, Berit (Journal article; Peer reviewed, 2017)
      This study investigates the influence of temperature and air velocity conditions on ventilation and condensation in spring, summer and autumn periods inside a ventilated cavity in a full-scale wooden roof construction. The ...