M. Lundh1*, E. Wackelgard1 and A. Henning2

1 Department of Engineering Sciences, Uppsala University, The Angstrom Laboratory, P. O. Box 534, SE-751 21

Uppsala, Sweden

2 Solar Energy Research Center (SERC), Dalarna University, SE-781 88 Borlange, Sweden
Corresponding Author, Magdalena. Lundh@angstrom. uu. se

Abstract

Solar collector systems require an auxiliary heat source in temperate climates, and one system solution increasingly used in Sweden is combined solar and wood pellet heating. The development of integrated systems adjusted to the combination is however slow. To investigate the process towards a concept of solar and pellet heating, ten semi-structured qualitative interviews were performed with representatives for the trades during autumn and winter 2007. The present development and experienced obstacles were discussed, and conditions necessary for further progress and to reach success were identified. Other aspects found in the interview material will be analysed and reported in future papers.

The main condition to reach increased market shares is extensive marketing and information to the public, for which larger assets are required. The governmental influence, both by taking stand and making long-term regulations, as well as the installer corps influencing the costumer’s choice of system were stressed. A recent change in attitude is however clear, and the combined systems are by all informants regarded close to reaching general market establishment.

Keywords: solar heating, pellet, combined systems, interviews

1. Introduction

Solar collectors can not supply all heat demanded in a building in temperate climates; an auxiliary heating system is always required. There are several possible solutions, where the most common Swedish combination is with electrical heaters. One system solution that has become more frequently used over the last years is however combined solar and wood pellet heating. In the beginning, separate standard solar heating and pellet heating systems were combined, and still few companies offer well — integrated combined solutions. The development of a concept of combined solar and pellet, on the other hand, means that the solar collectors and pellet heating units are well-suited to be operated as one system and that the combination of two energy suppliers does not cause the end-user or installer additional effort compared to a single energy supply system. It should rather be experienced as one system. Besides Sweden, combined solar and wood pellet systems are also marketed and sold in countries like Germany, Austria and United Kingdom.

Solar heating systems as well as pellet heating have been considerably developed since the 1970’s. Although the technologies themselves are today well-developed and the heating systems have reached cost-effectiveness, the development of combined systems is slow. There are even advantages, such as

increased system efficiency and sustainability that advocate combined systems rather than individual solar/electricity and pellet heating respectively. But how does a new system solution evolve and what obstacles towards extended market dissemination are experienced by the trades? To investigate the background of the modest market introduction rate of combined solar and pellet systems an interview study was performed.

1.1. Aim

The aim of this study is to investigate the development of the concept of combined solar and pellet heating systems for single-family houses. Obstacles as well as possibilities experienced within the Swedish trades are to be distinguished. The aim has not been to cover all members of the solar and pellet industries; representatives not included in this study may have disparate opinions or proposals. The Swedish solar and pellet industries are however relatively small and a large fraction of the well — established members have been interviewed or involved in the meetings attended. This study rather aims at lifting some of the main issues experienced as important to the trade people. The outcome of this study could for example be used to direct future research, political means and market focus to increased use of combined solar and pellet systems, and in the long run towards sustainability. There are most likely similarities to other areas within the renewable energy sector.

This part of the reporting focuses on results on experienced obstacles against further development and prerequisites to increase the market shares.

2. Method

The present state of combined solar and pellet heating systems was first investigated by a literature and internet survey. Trade papers and magazines were searched for advertisements about the systems and web pages of Swedish manufacturers, producers and retailers were visited to investigate how solar and pellet systems are described. The outcome of this pre-study constituted the basis for formulation of interview questions as well as the choice of informants.

To map the process towards a complete system solution or concept with combined solar and wood pellet heating, ten qualitative interviews were performed during autumn 2007. The informant group comprised ten persons involved in the process in different ways, such as manufacturers, retailers, installers and representatives for the solar and pellet trade organizations respectively. Some of the informants have more than one role in the trades, such as being both representative for a trade organisation and a company producing or selling heating systems.

The interviews were semi-structured, which means that topics and questions were formulated in advance, but the interviews more took the form of open discussions and the order of questions was not strictly followed. During the interviews follow-ups were made on new related themes. The informants were given a brief introduction to the background and aim of the project before the interview.

The informants were first asked to give a short background to themselves and their company or organisation. The discussion was then focussed on attitude to the heating systems as well as to the solar and pellet trades, obstacles and possibilities with combined systems, but also the present and past development, prerequisites for further development and knowledge. The interviews were recorded and partly transcribed. The material was then categorized and analyzed according to [1, 2] to find trends in opinions, ideas and problem identification.

Three different meetings were also attended to study the interaction between the actors and take part in the discussion of the investigated issue. Two of the meetings were between company representatives within the wood pellet industry as part of the initiative from the Swedish Energy Agency “Pellet heating — future heating” (“Pelletsvarme — framtidsvarme”) while the third meeting was a joint gathering between the interest organisations for solar thermal, solar power, wood pellet and wind power, where the Swedish Solar Energy Association was the main organiser. All meetings took place during autumn and winter 2007.

The interviewer has a background in technology and science, but is part of an interdisciplinary research program, where interview studies have also been performed in cooperation with social scientists earlier. During this research project the interviewer have had regular contact with a social anthropologist for methodological issues.