• Energy Research

Although some progress has been made in recent years, ensuring universal access to electricity remains a major challenge in many countries in sub-Saharan Africa, particularly in rural areas. In light of this challenge, solar photovoltaic (PV) mini-grid systems have emerged as a promising solution for off-grid electrification. However, little is known about their actual performance and reliability when used in real-world applications. Using real-time monitored data and IEC's evaluation standard, this paper examines the performance and reliability of a 375 kWp off-grid PV mini-grid system installed in a remote small town in Ethiopia. The findings showed that the mini-grid produced 1182 kWh/day of electricity compared to the estimated generation of 2214 kWh/day, a difference of 1032 kWh/day (46.6% less). In contrast, 87% of the average daily electricity generated was delivered to the load. The discrepancies can be attributed to average PV capture losses of 2.75 kWh/kWp/day and system losses of 0.40 kWh/kWp/day. The performance evaluation results revealed that the mini-grid system is performing poorly, with average on-site module efficiency (ηpc), temperature corrected performance ratio (PRcorr), capacity factor (CF) and overall system efficiency (ηsys) of 9.85%, 42%, 13%, and 8.76%, respectively. It was found that the daily PV energy output could not meet the daily demand. As a result, the load is shed off from the power supply for 13 h a day; between 17:00 and 19:00 and again between 21:00 and 08:00. The study demonstrated that accurate demand assessment and robust system sizing, taking into account the impact of local weather conditions and prospective electricity demand growth is critical to ensure high performance and reliability of off-grid PV mini-grid systems.

Abstract The purpose of this study is to analyze the effects of introducing a common Nordic system for tradable green certificates (TGCs) on the electricity market and a future market for tradable CO 2 -emission permits (TEPs). In the analysis, the energy-system model generator MARKAL was used to model the electricity and district-heating supply systems in the four Nordic countries Sweden, Norway, Finland and Denmark. It is shown that the introduction of TGC quotas reduces wholesale electricity and TEP prices. The impact on the latter is very pronounced. Retail electricity prices may become lower or higher, depending on the TGC quota, than if obligations to fulfill TGC quotas were absent. The TGC scheme's efficiency in reducing a specific amount of CO 2 emissions is also compared to the corresponding efficiency of a TEP scheme involving a broader range of technologies. Furthermore, obligations to fulfill TGC quotas affect investment incentives for new non-renewable electricity supply. This seems especially true for gas-fired power plants. Finally, it is indicated that electricity supply based on biomass combustion dominates the TGC scheme, at least in the short run.

AbstractDespite the long history of cook stove programs, very few have been successful, often only in areas where biomass is purchased or there is a biomass shortage. Several studies have described how rural households generally rely on several different fuels; which fuels are used may depend on various household characteristics such as location and income. This article explores possible consequences of variations in fuel usage for improved cook stove programs and how this may vary between different areas. Reductions of CO2 equivalent emissions and monetary savings are calculated for hypothetical cook stove deployment using data from a rural energy survey in the Vĩnh Phúc province of northern Vietnam. The results indicate that the areas may respond differently to the various stove options, both in terms of economy and emission reductions. Furthermore, there are large differences in emission reduction calculations when only Kyoto-gases are included and when non-Kyoto greenhouse agents are added. Assumptions regarding household behavior and stove efficiencies have large impacts on the results, indicating a need for further research on how improved cook stoves may influence households’ fuel choices.

Co-creation in the societal sphere is becoming important in many parts of the world. However, empirical analysis of co-creation in local energy transitions has been understudied. This paper aims to contribute to the field of local energy transitions by integrating a model-based approach with the municipal co-creation efforts in a local energy transition setting. The study uses a mixed-methods approach, with both quantitative and qualitative methods underpinning the approach. A System Dynamics (SD) model is built to analyse the feedback loops created by the co-creation efforts of the municipalities in Skåne, Sweden to increase the uptake of household solar photovoltaics. Simultaneously, the model is conceptualized and built in coordination with the municipality actors, and qualitative validation provided by them. An iterative process is implemented, consisting of three steps: interaction with the municipality actors (MAs), developing the causal relationships between the model variables and model development. The suggestions and discussions with the MAs were very useful in understanding the social factors and processes which help in the diffusion of a technologically innovative product, such as solar PV. The MAs said that they found the explanation of the modelling variables useful in undertaking the co-creation efforts.

Abstract This paper focuses on energy system development of the three largest Association of South East Asian Nations (ASEAN) countries: Indonesia, Philippines and Vietnam. The energy infrastructures in these counties are in the process of rapid development and, therefore, technology choices are critical. Applying the energy system model MARKAL and scenario analysis, this paper examines and quantifies the role of clean and advanced energy technologies for efficient local resource exploitation and improving energy security and environmental conditions. The main focus is on the power sector and the paper also addresses the potential ASEAN markets for European energy technologies. The paper concludes that there is a large potential market for clean and advanced energy technologies in the studied countries. If adopted, these technologies will bring several benefits like reduction in primary energy requirement, reduced investments requirement in the power sector and other parts of the energy infrastructure, reduced import of primary energy, reduced CO2 emissions and local pollution, reduced energy system costs and marginal cost of electricity supply. Finally, barriers for transfer and diffusion of advanced energy technologies are discussed.

AbstractThe use of EH (excess heat) in DH (district heating) may contribute to increased sustainability through reduced use of primary energy. In Sweden, while biomass has become the most important DH fuel during the last decades, there is a significant amount of industrial EH that could be utilised in the DH systems if it could be shown to be an economically viable alternative. This study addresses the long-term system profitability of a large heat network between a cluster of chemical industries and two DH systems that enables an increased use of EH. An assessment is carried out by scenario and sensitivity analyses and by applying the optimising energy systems model MARKAL_WS, in which the DH systems of the Västra Götaland region of Sweden are represented individually. The results show heat network profitability under most assumptions, and that the profitability increases with biomass competition, phase-out of natural gas use and higher CO2 charges, whereas it decreases with the availability of other EH sources in the base load of the DH systems.

A widespread dissemination of improved cooking stoves in the developing world can lead to considerable improvement of health, to reduced pressure on natural woody resources and to substantial reductions of emissions contributing to global warming. A number of programs have aimed to achieve such dissemination, while few of the programs have had any large-scale success. It has been suggested that a more commercial approach, as opposed to subsidized or freely distributed stoves, would achieve a higher level of success. However, a majority of the households that would benefit from an improved stove are poor and cannot afford the cost of the stove, especially if no monetary savings are possible from a more efficient fuel use, i.e., if the fuel used is collected biomass. The aim of this paper is to propose and evaluate a model that might overcome some of the barriers previous programs have experienced. The proposed model involves commercialization of collected fuels. The methods for evaluation include a qualitative assessment of the proposed model aided by the literature on improved cooking stove programs, fuel wood collection and fuel switching together with a quantitative simplistic model calculation of a hypothetical application of the proposed model principles, in order to assess its financial feasibility. The assessment indicates that the model would increase both households’ incentives and means to purchase and use improved cooking stoves. Furthermore, the model could possibly be partly financed based on carbon credits achieved from the reduction of greenhouse gas emissions.