A novel stochastic method to dispatch microgrids using Monte Carlo scenarios

Stochastic operating strategies have proven to achieve cheaper resource scheduling both in large power systems and microgrids, but suffer from high computational requirements with respect to traditional deterministic approaches; therefore, using stochastic formulations in advanced infra-daily operating strategies is quite challenging, especially in isolated energy systems with limited computational assets. This paper proposes a dispatching methodology for microgrids based on a novel two-stage formulation that decomposes the stochastic problem into several deterministic subproblems, whose solutions are afterwards aggregated by the aggregator using simulations and a cost-based rule. In the first stage, every subproblem is solved, then each optimal dispatching is simulated in the second stage to evaluate the corresponding expected operating cost, which is used by the aggregator to select the final optimal scheduling. When compared to traditional methods for a rural microgrid in Uganda, the proposed approach not only achieves interesting savings in operational costs, up to 5%, but also sharply reduces the computational requirements, even more than 5–100 times with respect to traditional stochastic approaches. The paper also proposes a review and first classification of this kind of methodologies, to highlight the novelties of the approach

Bioenergy and Minigrids for Sustainable Human Development

Human-caused climate change and deep disparities in human development imperil a prosperous and just future for our planet and the people who live on it. Transforming our society to mitigate global warming offers an opportunity to rebuild energy systems to the benefit of those who are harmed by global inequality today. I examine this opportunity through the lens of two sustainable energy technologies: bioenergy and miniature electricity grids (minigrids). Bioenergy requires land to produce biomass and is inextricably connected to the surrounding environment, agricultural livelihoods, and food system. I apply data science tools to study aspects of land use and food security that may intersect with increasing bioenergy production. I assess the potential to use over one billion hectares of grazing land more intensively with an empirical yield gap analysis technique called climate binning. To clarify how agricultural and socioeconomic characteristics relate to national food security, I study the relative importance of several drivers using simple linear regressions with cross validation and random sampling techniques. Minigrids can supply clean, reliable electricity to un- and under-served communities, but small and hard-to-predict customer loads hamper their financial viability. To improve predictions of daily electricity demand of prospective customers, I test a data-driven approach using customer demographic surveys and machine learning models. I also investigate opportunities to grow loads by stimulating income-generating uses of minigrid electricity in twelve Nigerian agricultural value chains. I conclude by emphasizing the fundamental complementarity of energy and agriculture as change levers for human development, especially in rural communities with low energy access and high poverty. I also provide recommendations to support the effective use of energy to solve pressing agricultural problems and drive multiplicative human development benefits

Interconnection of solar home systems as a path to bottom-up electrification

Solar Home Systems (SHSs) have revolutionised electricity access for off grid communities, but have a number of significant limitations. They have limited demand diversity, produce excess energy and lack a clear pathway to scale alongside growing energy demand. Electrical interconnection of existing installed SHSs to create minigrids could offer a way to both scale up energy demand and make use of wasted energy. This bottom-up approach has the potential to be flexible to the changing needs of communities, by using SHSs as a starting point for wider electrification, rather than the end goal. Despite this potential, little analytical work has been undertaken to model SHS interconnection, particularly accounting for demand diversity and long-term system performance. This thesis presents a time sequential stochastic model of interconnected SHSs, to investigate these systems under multi-year operational timescales at high temporal resolution. It is shown for case study systems based on real SHS topologies that there exists significant demand diversity, with small clusters of 20 houses with identical appliances exhibiting an average peak demand of less than 70% of the combined worst-case peak for individual SHSs. Excess generated energy is shown to be an average of 100 Wh a day for the smaller system types and 1000Wh a day for larger systems. Interconnection of these systems demonstrates a significant reductions in LCOE for all system types compared to islanded operation, through more optimal dispatch of battery storage assets and use of excess energy. This resulted in a final LCOE of $0.63/kWh for a network of 12 large SHSs - a reduction of 48.12$0.703/kWh for a network of 12 small SHSs - a reduction of 55.23% compared to islanded operation. This informed an investigation of possible operational business models for a network of SHSs, with three approaches proposed - an Energy System Operator with direct control over all users’ systems, an Aggregator model, where the system operator facilitates an energy market and a Peer-to-Peer model with direct consumer to consumer energy trading. This thesis provides a robust evidence base for SHS interconnection – demonstrating that the approach can lower cost of energy and facilitate demand growth for off grid energy consumers and proposes appropriate business models to deliver this affordable and clean energy.Solar Home Systems (SHSs) have revolutionised electricity access for off grid communities, but have a number of significant limitations. They have limited demand diversity, produce excess energy and lack a clear pathway to scale alongside growing energy demand. Electrical interconnection of existing installed SHSs to create minigrids could offer a way to both scale up energy demand and make use of wasted energy. This bottom-up approach has the potential to be flexible to the changing needs of communities, by using SHSs as a starting point for wider electrification, rather than the end goal. Despite this potential, little analytical work has been undertaken to model SHS interconnection, particularly accounting for demand diversity and long-term system performance. This thesis presents a time sequential stochastic model of interconnected SHSs, to investigate these systems under multi-year operational timescales at high temporal resolution. It is shown for case study systems based on real SHS topologies that there exists significant demand diversity, with small clusters of 20 houses with identical appliances exhibiting an average peak demand of less than 70% of the combined worst-case peak for individual SHSs. Excess generated energy is shown to be an average of 100 Wh a day for the smaller system types and 1000Wh a day for larger systems. Interconnection of these systems demonstrates a significant reductions in LCOE for all system types compared to islanded operation, through more optimal dispatch of battery storage assets and use of excess energy. This resulted in a final LCOE of $0.63/kWh for a network of 12 large SHSs - a reduction of 48.12$0.703/kWh for a network of 12 small SHSs - a reduction of 55.23% compared to islanded operation. This informed an investigation of possible operational business models for a network of SHSs, with three approaches proposed - an Energy System Operator with direct control over all users’ systems, an Aggregator model, where the system operator facilitates an energy market and a Peer-to-Peer model with direct consumer to consumer energy trading. This thesis provides a robust evidence base for SHS interconnection – demonstrating that the approach can lower cost of energy and facilitate demand growth for off grid energy consumers and proposes appropriate business models to deliver this affordable and clean energy

Examining justice issues in minigrids for rural electrification: a participatory and interdisciplinary study

Electricity is necessary for many basic needs, but globally over 700 million people lack access. Economic modelling suggests that minigrids or solar home systems are often the most cost-effective solution in unelectrified rural areas. There has been an increase in the role of the private sector in delivering these projects, which leads to justice questions about implementation. This thesis uses participatory and interdisciplinary approaches to explore justice issues in minigrids for rural electrification in Tanzania. Six rural minigrids were visited across the country, with one village, Mpale, forming the main case study. Data collection methods include interviews, focus groups, surveys, observations and participatory activities. Data were analysed using a grounded coding methodology in NVivo and through economic and technical approaches. This included a distributional analysis of tariff costs and a comparison of measured load profiles with customer survey data. The use of participatory methods in this research provided additional insights, developed through more equal relationships with communities, as well as outputs that benefited the communities I worked with and the minigrid sector in Tanzania. I have found that energy justice issues manifest in many ways. Poorer households often pay more per unit of electricity than others. Under some tariffs, households self-disconnect, which also influences the load profiles of minigrids. Community perspectives are often only considered to a limited amount and are not given adequate information. There is discordance between community expectations and project realities, particularly regarding tariff costs. Load-profile modelling doesn’t adequately consider the local context, particularly the affordability of tariffs and desired demand compared to actual usage. I conclude that there needs to be consideration of justice issues in rural minigrids. Increased participation of communities in policy and project planning would help to ensure their needs are better considered, which may also increase the likelihood of projects being successful

Integrating Energy Demand and Ability to Pay in the Design of Decentralised Energy Supply : A Case Study in Rural Nepal

Access to electricity is essential for socioeconomic growth, especially in developing countries. However, over 1.1 billion people still do not have access to modern sources of energy. This is particularly prevalent in rural or remote areas, where renewable off-grid solutions and particularly minigrids seem the most cost-effective solution to deliver long-term energy solutions. Comprehensively forecasting energy demand in these areas and designing the most optimal solution requires a thorough feasibility design process. A literature review of project development tasks revealed that a research gap regarding how the household’s ability to pay relates with the project’s cost exists. This frequently leads to viability gaps, which demand costly and time-consuming manual adaptations to the project’s design. The goal of the study was to adapt household’s ability to pay and energy demand assessment at early stages of minigrid design so as to avoid these adaptations at later stages. Rural Nepal was chosen as a case study, and an extensive energy household survey based onmultidimensional energy access parameters developed by the Reiner Lemoine Institute was used. The data employed was collected from 9 different rural municipalities from Province Number 1 and Province number 7, with a total of 3600 surveyed households. Households were clustered into three wealth groups, using socioeconomic variables such as education, financial status, owned and desired electrical appliances and willingness to pay. The construction of a stochastic load modeller using R allowed translating the energy needs of each wealth groups into load profiles. The most common energy services for the different clusters are lighting and communication for group 1, plus entertainment and space cooling for group 2, plus occasional thermal loads or base loads (fridge) for group 3. A cost estimator was built through a linear regression to obtain an overall project cost estimation based on the customer distribution. In parallel, household estimated-energy-expenditures were determined by allocating a literature-accepted percentage of their total annual expenditures over the entire project lifetime. This value was averaged for each municipality and wealth group, and a community’s minigrid economic potential was determined using the municipality’s average customer distribution as a reference. By using this and the cost estimator, it is possible to quantify a potential viability gap based on the customer distribution. An automated adaptation tool was designed in R to obtain the most similar feasible customer distribution when a viability gap is encountered. This is done by fixing the economic potential and using the customer distribution and its associated cost as a variable. Results show that in all but one municipality, providing households with basic energy services is viable, while an average grant of 75 USD per type 2 household and 515 USD per type 3 household for the entire project life-time is required. Additionally, only three municipalities suggest a feasible average customer distribution, while the rest required adaptation. However, a significant regional heterogeneity exists, suggesting that location-specific policies are required to optimise the effects of subsidies. The study also shows that while the demand for higher energy services exists in rural Nepal, there is a significant lack of available income that impedes this supply, and policy makers and energy planners should work to bridge this gap in order to foster socioeconomic developmentObjectius de Desenvolupament Sostenible::7 - Energia Assequible i No Contaminant::7.1 - Per a 2030, garantir l’accés universal a serveis d’energia assequibles, confiables i modern

Renewable Energy and Energy Saving: Worldwide Research Trends

Climate change mitigation and adaptation are key challenges of the 21st century. These challenges include global energy consumption and dependence on fossil fuels, which are addressed in global energy policies. About two-thirds of global greenhouse gas emissions are linked to the burning of fossil fuels used for heating, electricity, transport, and industry. Therefore, the world is looking for the most reliable, cost-effective, and environmentally friendly energy sources coupled with energy saving, which is a clean and low-cost solution to the growing demand for energy. As a clear example of this, cities are integrating renewable energies into their smart city plans. This book aims to advance the contribution of the use of renewable energies and energy saving in order to achieve a more sustainable world

Energy Production Analysis and Optimization of Mini-Grid in Remote Areas: The Case Study of Habaswein, Kenya

Rural electrification in remote areas of developing countries has several challenges which hinder energy access to the population. For instance, the extension of the national grid to provide electricity in these areas is largely not viable. The Kenyan Government has put a target to achieve universal energy access by the year 2020. To realize this objective, the focus of the program is being shifted to establishing off-grid power stations in rural areas. Among rural areas to be electrified is Habaswein, which is a settlement in Kenya’s northeastern region without connection to the national power grid, and where Kenya Power installed a stand-alone hybrid mini-grid. Based on field observations, power generation data analysis, evaluation of the potential energy resources and simulations, this research intends to evaluate the performance of the Habaswein mini-grid and optimize the existing hybrid generation system to enhance its reliability and reduce the operation costs. The result will be a suggestion of how Kenyan rural areas could be sustainably electrified by using renewable energy based off-grid power stations. It will contribute to bridge the current research gap in this area, and it will be a vital tool to researchers, implementers and the policy makers in energy sector

Assessing the areas of concern regarding decarbonisation of industrial microgrids based on a novel classification framework

This thesis is made for a technology company in Vaasa, Finland which has the focus on decarbonisation of microgrids through optimisation with different aspects in mind, such as, reducing emissions, decreasing fuel consumption, increasing grid reliability and asset availability, and lowering operation costs. The aim of the thesis is to investigate the fundamental areas of concern, when making an early assessment of the potential for decarbonisation through optimisation in industrial microgrids. This is done through a qualitative study based on semi-structured interviews with experts with different areas of expertise in the company. The interviews are then analysed and compared to relevant literature in the field. The outcome is a proposed classification framework grouped into three different sections: generation, network & control, and load. These sections are further divided into different sub-sections with own themes, where categories are listed. Additionally, some suggestions on further utilisation are also proposed in the work, for example, in customer conversations or as an aid for experts.Detta diplomarbete är gjort åt ett teknologiföretag beläget i Vasa, Finland, vilket fokuserar på utfasning av fossila bränslen (eng. decarbonisation) i mikronätverk genom optimering inom olika fokusområden. Exempel på dessa är minskning av utsläpp och bränsleförbrukning, ökning av nätverksstabilitet och tillgänglighet av elproduktionsanläggningar samt optimering av driftskostnader. Målet med diplomarbetet är att utreda inom vilka områden det kan uppstå utmaningar när man i ett tidigt skede kartlägger möjligheterna för utfasning av fossila bränslen genom optimering i industriella mikronätverk. Det här är gjort genom en kvalitativ studie baserad på semistrukturerade intervjuer med sakkunniga med olika expertisområden inom företaget i fråga. Intervjuerna är sedan analyserade och jämförda med relevant litteratur inom ämnet. Resultatet av studien är ett klassificeringssystem indelat i tre olika huvudområden: generering, nätverk & kontroll och last. Dessa är vidare uppdelade i underområden med egna teman i vilka olika kategorier är listade. Därtill i arbetet ges även förslag på användningsområden för detta klassificeringssystem, exempelvis i kundsamtal eller som hjälpmedel för experter