Institute for Energy Technology was established in 1948 as the Institute for Nuclear Energy . The name was changed in 1980. Its main office is at Kjeller, Norway, and slightly under half of the institute’s activities are based in Halden. In Halden IFE is host to the international OECD Halden Reactor Project, with 18 member states.IFE conducts research in the following areas: energy, environmental technology, physics, materials science, petroleum technology, nuclear safety and reliability and man-machine systems .IFE operates the only two existing nuclear reactors in Norway. Both are dedicated to research. The JEEP II reactor at Kjeller is used for basic research in physics and material science, as well as production of radiopharmaceuticals. The Halden Reactor is used for research in materials technology and nuclear fuel safety.The Institute has approximately 600 employees in Halden and at Kjeller. The President is Eva S. Dugstad. Wikipedia.
Rosenberg E.,Institute for Energy Technology of Norway
Energy | Year: 2014
Knowledge of the electricity demand for different electrical appliances in households is very important in the work to reduce electricity use in households. Metering of end-uses is expensive and time consuming and therefore other methods for calculation of end-use electricity can be very useful. This paper presents a method to calculate the electricity used for lighting in households based on regression analysis of daily electricity consumption, out-door temperatures and the length of daylight at the same time and location. The method is illustrated with analyses of 45 Norwegian households. The electricity use for lighting in an average Norwegian household is calculated to 1050kWh/year or 6% of total electricity use. The results are comparable to metering results of lighting in other studies in the Nordic countries. The methodology can also be used to compensate for the seasonal effect when metering electricity for lighting less than a year. When smart meters are more commonly available, the possible adaption of this method will increase, and the need for end-use demand calculations will still be present. © 2013 Elsevier Ltd.
Wangen M.,Institute for Energy Technology of Norway
Computational Geosciences | Year: 2013
A procedure based on the finite element method is suggested for modeling of 3D hydraulic fracturing in the subsurface. The proposed formulation partitions the stress field into the initial stress state and an additional stress state caused by pressure buildup. The additional stress is obtained as a solution of the Biot equations for coupled fluid flow and deformations in the rock. The fluid flow in the fracture is represented on a regular finite element grid by means of "fracture" porosity, which is the volume fraction of the fracture. The use of the fracture porosity allows for a uniform finite element formulation for the fracture and the rock, both with respect to fluid pressure and displacement. It is demonstrated how the fracture aperture is obtained from the displacement field. The model has a fracture criterion by means of a strain limit in each element. It is shown how this criterion scales with the element size. Fracturing becomes an intermittent process, and each event is followed by a pressure drop. A procedure is suggested for the computation of the pressure drop. Two examples of hydraulic fracturing are given, when the pressure buildup is from fluid injection by a well. One case is of a homogeneous rock, and the other case is an inhomogeneous rock. The fracture geometry, well pressure, new fracture area, and elastic energy released in each event are computed. The fracture geometry is three orthogonal fracture planes in the homogeneous case, and it is a branched fracture in the inhomogeneous case. © 2013 Springer Science+Business Media Dordrecht.
Wangen M.,Institute for Energy Technology of Norway
Journal of Petroleum Science and Engineering | Year: 2011
A finite element based procedure is suggested for the modeling of hydraulic fracturing of heterogeneous rocks on a macroscopic scale. The scheme is based on the Biot-equations for the rock, and a finite element representation for the fracture pressure, where the fracture volume appears as fracture porosity. The fracture and the rock are represented unified on the same regular finite element grid. The numerical solutions of pressure and displacement are verified against exact 1D results. The 1D model also shows how the tension forces that open the fracture decreases as the gradient of the pore pressure decreases. The fracture criterion is based on the "strength" of bonds in the finite element grid. It is shown how this criterion scales with the grid size. It is assumed that fracturing happens instantaneously and that the fluid volume in the fracture is the same after a fracture event. The pressure drop that follows a fracture event is computed with a procedure that preserves the fluid volume in the fracture. The hydraulic fracturing procedure is demonstrated on a homogeneous and an inhomogeneous rock when fluid is injected at a constant rate by a well at the center of the grid. A case of a homogeneous rock shows that a symmetric fracture develops around the well, where one bond breaks in each fracture event. A heterogeneous case shows the intermittent nature of the fracture process, where several bonds break in each fracture event. © 2011 Elsevier B.V.
Knaapila M.,Institute for Energy Technology of Norway |
Monkman A.P.,Durham University
Advanced Materials | Year: 2013
Knowledge of the phase behavior of polyfluorene solutions and gels has expanded tremendously in recent years. The relationship between the structure formation and photophysics is known at the quantitative level. The factors which we understand control these relationships include virtually all important materials parameters such as solvent quality, side chain branching, side chain length, molecular weight, thermal history and myriad functionalizations. This review describes advances in controlling structure and photophysical properties in polyfluorene solutions and gels. It discusses the demarcation lines between solutions, gels, and macrophase separation in conjugated polymers and reviews essential solid state properties needed for understanding of solutions. It gives an insight into polyfluorene and polyfluorene beta phase in solutions and gels and describes all the structural levels in solvent matrices, ranging from intramolecular structures to the diverse aggregate classes and network structures and agglomerates of these units. It goes on to describe the kinetics and thermodynamics of these structures. It details the manifold molecular parameters used in their control and continues with the molecular confinement and touches on permanently cross-linked networks. Particular focus is placed on the experimental results of archetypical polyfluorenes and solvent matrices and connection between structure and photonics. A connection is also made to the mean field type theories of hairy-rod like polymers. This altogether allows generalizations and provides a guideline for materials scientists, synthetic chemists and device engineers as well, for this important class of semiconductor, luminescent polymers. The structural hierarchies of polyfluorenes in solution and gel range from intramolecular structures to the diverse aggregate classes, network structures and agglomerates of these units including the curious beta phase. These structures can be controlled by solvent quality, side chain branching, side chain length, molecular weight, thermal history and myriad functionalisations. These different structures have profound effects on the photophysics of the polymers at the quantitative level. Here, these properties of polyfluorenes are reviewed in detail. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
REC Solar, Institute for Energy Technology of Norway and University of Oslo | Date: 2014-11-14
The surface recombination velocity of a silicon sample is reduced by deposition of a thin hydrogenated amorphous silicon or hydrogenated amorphous silicon carbide film, followed by deposition of a thin hydrogenated silicon nitride film. The surface recombination velocity is further decreased by a subsequent anneal. Silicon solar cell structures using this new method for efficient reduction of the surface recombination velocity is claimed.