Solar Water Heating as a Potential Source for Inland Norway Energy Mix

The aim of this paper is to assess solar potential and investigate the possibility of using solar water heating for residential application in Inland Norway. Solar potential based on observation and satellite-derived data for four typical populous locations has been assessed and used to estimate energy yield using two types of solar collectors for a technoeconomic performance comparison. Based on the results, solar energy use for water heating is competitive and viable even in low solar potential areas. In this study it was shown that a typical tubular collector in Inland Norway could supply 62% of annual water heating energy demand for a single residential household, while glazed flat plates of the same size were able to supply 48%. For a given energy demand in Inland Norway, tubular collectors are preferred to flat plate collectors for performance and cost reasons. This was shown by break-even capital cost for a series of collector specifications. Deployment of solar water heating in all detached dwellings in Inland could have the potential to save 182？GWh of electrical energy, equivalent to a reduction of 15,690 tonnes of oil energy and 48.6？kt emissions, and contributes greatly to Norway 67.5% renewable share target by 2020. 1. Introduction As the impact of fossil fuels on our precious environment is becoming more pronounced, all over the world, governments have started to implement multiple measures to increase the share of renewables in their existing fossil intensive energy systems, with these effectively emerging as political and economic issues. Within these, in 2007 the EU established the so-called 20-20-20 vision of a 20% emission reduction in reference to 1990 levels, a 20% increase in the share of renewables in the energy mix and a 20% reduction in energy consumption by 2020 [1]. In line with this, the long-term framework of EU renewable energy directives, which came into force in December 2011, has motivated the Norwegian government to set a target of increasing the share of renewables from 60% in 2005 to 67.5% by 2020 [2]. This could be accomplished by either increasing renewable energy production or increasing the share of renewables in energy consumption. The Norway-Sweden common tradable green certificate (TGC) market launched in January 2012 for 26 TWh new electricity generation cooperation is one key measure towards achieving the 2020 target [3]. On the other hand, the residential sector in Norway is energy-intensive and is a key sector to be focused on in terms of energy efficiency. In the Nordic countries, the energy used in the