Nearly all the 1.3 billion people in the world with no electricity access live in developing countries. On the one hand, electricity is a basic need. On the other hand, the environment should not be further damaged. Thus, sustainable electricity in developing countries is clearly needed. The aim of this dissertation is to analyse the mechanism of the diffusion and adoption of renewable electricity with particular focus on rural electrification among low-income inhabitants in developing countries. The dissertation is comprised of a cover essay and six appended papers with a mix of qualitative and quantitative methods based on several means of data collection.

The first paper describes diffusion theory through a novel bibliometric tool. This novel method provides an overview, structure, and explanation of a large research area; complements a traditional literature review; and can be applied to any knowledge field. Here, the structure of the recent development of diffusion research, together with its application, are presented. With a specific focus on rural electrification among low-income inhabitants in developing countries, the diffusion framework is empirically applied with complementary concepts in the second, third, and fourth papers, based on three different cases. One case study investigates the adoption of electricity among rural inhabitants in Uganda and shows that a foreign company can be an important player in the rural electrification effort. Another case study addresses a large dissemination of photovoltaic systems provided by a local firm in Bangladesh and reveals that the diffusion of renewable energy can be effectively undertaken by a private local firm, rather than waiting for full government support or large multi-national corporations. The other case study discusses a small-scale diffusion of photovoltaic systems in a remote region in Thailand and presents an extreme case where full government support is necessary. In addition, through a systematic literature review, the barriers to adoption of photovoltaic systems are identified in the fifth paper, highlighting several remaining challenges. In the last paper, issues related to the transition to using photovoltaic systems in off-grid communities are discussed.

The diffusion mechanism of renewable electricity has been shown to be a highly complicated process, having several unforeseeable and context-specific factors. A technology with superior qualities does not diffuse by itself but requires tremendous effort and close collaboration on the part of stakeholders. There are complex relations, on the one hand, between technology and society and, on the other hand, between technology providers and adopters. No single, fast, or straightforward remedy can address the complex nature of diffusion of renewable electricity in rural communities. Therefore, understanding the local context is highly important, indicating the need for empirical investigation. This dissertation offers several contributions concerning methodological, theoretical, empirical, managerial and policy. It also provides implications that may be relevant for actors who attempt to introduce, disseminate, and manage new energy technologies in rural communities.

Nästan alla av de 1,3 miljarder människor som inte har tillgång till el bor i utvecklingsländer. Å ena sidan är el ett grundläggande behov. Å andra sidan bör miljön inte skadas ytterligare. Det finns således ett behov av förnybar el i utvecklingsländer. Avhandlingens syfte är att analysera mekanismerna bakom diffusion och införande av förnybar el med särskilt fokus på elektrifiering av landsbygden bland låginkomsttagare i utvecklingsländer. Avhandlingen består av en kappa och sex bifogade artiklar som är baserade på en blandning av kvalitativa och kvantitativa metoder och innehåller flera olika typer av datainsamling.

Den första artikeln beskriver diffusionsteori genom ett nytt bibliometriskt verktyg. Denna nya metod ger översikt, struktur, och förklaring till ett stort forskningsområde; den kompletterar en mer traditionell litteraturöversikt och kan tillämpas oavsett kunskapsområde. Här presenteras strukturen av den senaste utvecklingen inom diffusionsteori tillsammans med dess applikationsområden. Med ett särskilt fokus på landsbygdselektrifiering bland låginkomsttagare i utvecklingsländer tillämpas diffusionsramverket empiriskt med kompletterande koncept i den andra, tredje, och fjärde artikeln. Dessa artiklar är baserade på tre olika fallstudier. En fallstudie berör elektrifiering på landsbygden i Uganda och visar att utländska företag kan vara en viktig aktör i denna process. En annan fallstudie tar upp spridning av solcellssystem i stor skala som utförs av ett lokalt företag i Bangladesh och visar att spridning av förnybar energi effektivt kan genomföras av privata lokala företag, snarare än att vänta på statligt stöd eller stora multinationella företag. Den sista fallstudien diskuterar småskalig spridning av solcellssystem i en avlägsen region i Thailand och representerar ett extremfall som behöver full finansiering från staten. I den femte artikeln har hindren för införandet av solcellssystem identifierats genom en systematisk litteraturöversikt, artikeln belyser också många kvarstående utmaningar. Den sista artikeln diskuterar frågor som rör övergången till, samt användandet av solcellssystem i områden som inte är anslutna till elnätet.

Diffusionsprocessen för förnybar el har visat sig vara mycket komplicerad med flera oförutsedda och kontextspecifika faktorer. Teknik med överlägsna egenskaper kan inte spridas av sig självt utan kräver stora ansträngningar och nära samarbete mellan de inblandade aktörerna. Det är komplexa relationer, å ena sidan mellan teknik och samhälle och å andra sidan mellan teknikleverantörer och användare. Det finns inte en perfekt, snabb eller enkel åtgärd för att ta itu med den komplexa karaktären av diffusion av förnybar el på landsbygden. Därför är förståelsen för den lokala kontexten av stor betydelse och detta understryker behovet av empiriska studier. Denna avhandling bidrar med kunskap som täcker områden som metodologi, teori, empiri, ledarskap och politik. Studien visar även på relevanta implikationer för de aktörer som försöker införa, sprida och hantera ny energiteknik till landsbygden.

In the literature on diffusion of innovations, it is widely known that the characteristics and socio-environmental settings of adopters do evolve in space and time. What about innovations themselves? During the diffusion process, don’t some innovations continuously alter in space and time? If so, how does the dynamic character of an innovation influence the diffusion process? In previous research, it has been often assumed that innovations do not continuously alter or get modified when diffusing from a source to potential adopters. This assumption may mean that the innovation is invariant as it diffuses in time and space—i.e., the innovation does not have a continuously dynamic character. Is it always the case in practice?   

A single form of an innovation is not always necessarily compatible with the preferences, limitations, and residential settings of adopters. The innovation might appear in different forms when it diffuses in space and time, i.e., it is “dynamic”. This PhD thesis aims to explore how dynamic innovations diffuse in space and time—a relatively understudied topic in research. In doing so, it distinguishes between the diffusion of dynamic innovations and other kinds of innovations. Anchored on the case of diffusion of residential solar photovoltaic (PV) systems, this thesis is composed of a cover essay and six appended papers. The first two appended papers are systematic literature reviews, aiming at understanding the state of the art of the theoretical and contextual research domains. The third paper is based on a case study in southern Germany and explores the diffusion of a dynamic innovation at adopter level. The fourth paper is empirically focused on a local firm’s business model, which is assumed to be a key to understanding the mechanism behind the diffusion of dynamic innovations. The fifth paper is based on lead market hypothesis and tries to explore the diffusion of innovations at the regional level. The sixth paper studies a semi-hypothetical case and offers an innovative method to forecast the diffusion of innovations in general.

The contribution of this PhD thesis lies in three research dimensions: context, method, and theory. Firstly, the thesis takes the existing theories (e.g., diffusion of innovations theory and lead market hypothesis) and methods (e.g., case study) and applies them in different contexts of the diffusion of residential solar PV systems: the individual, sub-national, and national level. Secondly, it proposes a new research method, namely the finite element method for forecasting the diffusion of innovations, based on an existing theory (e.g., wave-like diffusion of innovations in time and space) and context (e.g., solar PV systems). Last but not least, the cover essay of this thesis takes the findings of the appended papers and employs an extension of theory of diffusion of innovations. In doing so, it includes the role of the dynamic characteristic of innovations that do alter in time and space during the diffusion process.

Overall, the findings of this thesis indicate that the diffusion of dynamic innovations is different in nature, and continuous efforts of change agents are critical for enhancing the diffusion of such innovations. Change agents are especially important to help potential adopters to find out and develop the form of innovation that best fits their needs, limits, and preferences, which are heterogeneous in space and time.