• Beyond the 2D limit: étendue-squeezing line-focus solar concentrators 

      Johnsen, Håkon Jarand Dugstad; Aksnes, Astrid; Torgersen, Jan (Peer reviewed; Journal article, 2020)
      Line-focus solar concentrators are commonly designed by extruding a two-dimensional concentrator in the third dimension. For concentration in air, these concentrators are, by the nature of their design, limited by the ...
    • High-concentration wide-angle tracking integration with stacked lens arrays 

      Johnsen, Håkon Jarand Dugstad; Aksnes, Astrid; Torgersen, Jan (Chapter, 2019)
      Tracking-integration can reduce or eliminate the need for external solar tracking in CPV (concentrator photovoltaics). Previous research has shown how tracking-integrated systems can achieve high concentration ratios, wide ...
    • High-performance stationary solar tracking through multi-objective optimization of beam-steering lens arrays 

      Johnsen, Håkon Jarand Dugstad; Aksnes, Astrid; Torgersen, Jan (Peer reviewed; Journal article, 2020)
      Beam-steering lens arrays enable solar tracking using millimeter-scale relative translation between a set of lens arrays. This may represent a promising alternative to the mechanical bulk of conventional solar trackers, ...
    • New approaches to solar tracking and concentration through numerical optimization of lens arrays 

      Johnsen, Håkon Jarand Dugstad (Doctoral theses at NTNU;2020:405, Doctoral thesis, 2020)
      Solar concentrators are essential for enabling several solar energy applications, including high-efficiency photovoltaic conversion and high-temperature solar thermal energy. These concentrators require accurate solar ...
    • Novel Low Cost Solar Thermal Energy Concepts for Developing Countries 

      Johnsen, Håkon Jarand Dugstad (Master thesis, 2017)
      Small scale solar thermal energy devices such as solar cookers are promising solutions for remote areas where other energy sources are limited, for instance in developing countries. These devices can be used directly for ...
    • Pushing the limits of beam-steering lens arrays 

      Johnsen, Håkon Jarand Dugstad; Aksnes, Astrid; Torgersen, Jan (Journal article; Peer reviewed, 2019)
      An essential part of a concentrated solar power system is the solar tracker. Tracking is usually implemented by rotating the entire optical system to follow the sun, adding to the bulk and complexity of the system. ...
    • Solar tracking using beam-steering lens arrays 

      Johnsen, Håkon Jarand Dugstad; Torgersen, Jan; Aksnes, Astrid (Chapter, 2018)
      Conventional tracking solar concentrators track sunlight by rotating the concentrator optics to face the sun, which adds to the cost and bulk of the system. Beam-steering lens arrays, in contrast, allow solar tracking ...
    • Topology optimised bolt placements 

      Steen, Håkon Berger (Master thesis, 2021)
      This thesis will focus on the use of optimization algorithms to suggest an optimal bolt placement with regards to deflection. The work is inspired by and supposed to be an addition to the design process that Thomas Røkke ...