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Oslo, Norway

Carlsson B.,Linnaeus University | Persson H.,Linnaeus University | Meir M.,Aventa AS | Rekstad J.,University of Oslo
Applied Energy | Year: 2014

To assess the suitability of solar collector systems in which polymeric materials are used versus those in which more traditional materials are used, a case study was undertaken. In this case study a solar heating system with polymeric solar collectors was compared with two equivalent but more traditional solar heating systems: one with flat plate solar collectors and one with evacuated tube solar collectors. To make the comparison, a total cost accounting approach was adopted. The life cycle assessment (LCA) results clearly indicated that the polymeric solar collector system is the best as regards climatic and environmental performance when they are expressed in terms of the IPPC 100 a indicator and the Ecoindicator 99, H/A indicator, respectively. In terms of climatic and environmental costs per amount of solar heat collected, the differences between the three kinds of collector systems were small when compared with existing energy prices. With the present tax rates, it seems unlikely that the differences in environmental and climatic costs will have any significant influence on which system is the most favoured, from a total cost point of view. In the choice between a renewable heat source and a heat source based on the use of a fossil fuel, the conclusion was that for climatic performance to be an important economic factor, the tax or trade rate of carbon dioxide emissions must be increased significantly, given the initial EU carbon dioxide emission trade rate. The rate would need to be at least of the same order of magnitude as the general carbon dioxide emission tax rate used in Sweden. If environmental costs took into account not only the greenhouse effect but also other mechanisms for damaging the environment as, for example, the environmental impact factor Ecoindicator 99 does, the viability of solar heating versus that of a natural gas heating system would be much higher. © 2014 Elsevier Ltd.

Carlsson B.,Linnaeus University | Meir M.,Aventa AS | Rekstad J.,Aventa AS | Preiss D.,AEE - Institute of Sustainable Technologies | Ramschak T.,AEE - Institute of Sustainable Technologies
Solar Energy | Year: 2016

The pros and cons of replacing traditional materials with polymeric materials in solar thermosiphon systems were analysed by adopting a total cost accounting approach. In terms of climatic and environmental performance, polymeric materials reveal better key figures than traditional ones like metals. In terms of present value total cost of energy, taking into account functional capability, end user investment cost, O&M cost, reliability and climatic cost, the results suggest that this may also be true when comparing a polymeric based thermosiphon system with a high efficient thermosiphon system of conventional materials for DHW production in the southern Europe regions. When present values for total energy cost are assessed for the total DHW systems including both the solar heating system and the auxiliary electric heating system, the difference in energy cost between the polymeric and the traditional systems is markedly reduced. The main reason for the difference in results can be related to the difference in thermal performance between the two systems. It can be concluded that the choice of auxiliary heating source is of utmost importance for the economical competiveness of systems and that electric heating may not be the best choice. © 2015 Elsevier Ltd.

Rekstad J.,University of Oslo | Rekstad J.,Aventa AS | Meir M.,University of Oslo | Meir M.,Aventa AS | And 2 more authors.
Energy and Buildings | Year: 2015

Abstract Detailed measurements of the auxiliary energy consumption for space heating and domestic hot water preparation in two detached passive houses south of Oslo are reported for the full year 2013. The study compares two equal, new built houses heated with different technologies, one by solar thermal heating and the other with an air-to-water heat pump. The houses are built by central actors from the building industry with high potential of being representative for a sizable, new-built housing stock rather than with focus on system optimisation. The results show that the need for additional energy, corrected for differences in domestic hot water consumption and indoor temperature, is 15-20% higher in the heat pump heated house than in the solar heated house. However the general energy consumption exceeds significantly the dimensioned figures for passive houses in Norway. The measurements demonstrate that solar thermal heating is competitive with heat pump technology even at high latitudes under Norwegian climate even in the case of a non-optimised system. With the available data potential heating system design improvements were pointed out.

Meir M.,University of Oslo | Meir M.,Aventa AS | Murtnes E.,University of Oslo | Dursun A.M.,University of Oslo | And 2 more authors.
Energy Procedia | Year: 2014

Energy monitoring has been performed for two passive houses in Oslo during 2012-2013. One house is heated by a solar heating system, the other with an air-to-water heat pump. The objective has been to investigate the need for additional energy supply in order to provide the required indoor comfort and prepare domestic hot water. If corrected for differences in domestic hot water consumption and indoor temperature the two houses require almost equal amounts of auxiliary energy. The solar energy gain would increase significantly if the solar collectors were placed more appropriate, with less shading due to neighboring buildings and vegetation. Both heating technologies could improve performance with minor system adaptations. It was shown that solar thermal heating can compete with heat pump techology even for locations as far north as Oslo, Norway.

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