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Implementing smart microgrids for Non-Interconnected Zones (NIZs) has become an alternative solution to provide electrical energy by taking advantage of the resources available through the generation of renewable energy within these isolated areas. Within this context, in this study, the challenges related to microgrids and data analysis are presented, and different relevant data architectures described in the literature are compared. This paper focuses on the design of a data architecture for a smart microgrid for NIZs whose microgrid contains two 260 W solar panels, a 480 W inverter, and two 260 Ah batteries. Regarding the Colombian context, this paper describes the limitations (connectivity, isolation, appropriation of technologies) and opportunities (low demand, access to natural resources, state interest) from which the functional and non-functional requirements for the architecture are established. Finally, a data architecture is proposed and implemented in a NIZ in Colombia, and this paper also includes a description of the architecture, its characteristics, its associated opportunities and challenges, and discussions regarding its implementation. [ABSTRACT FROM AUTHOR]

This paper highlights the importance of accurately modeling the operational constraints of Combined-Cycle Gas Turbines (CCGTs) within a unit-commitment framework. In practice, in Colombia, when given an initial dispatch by the Independent System Operator, CCGT plants are operated according to the results of heuristic simulation codes. Such heuristics often omit technical operating constraints, including hot, warm, or cold startup ramps; the minimum operation hours required for a gas turbine to start a steam turbine; the relationship between the dispatched number of steam and gas turbines; the load distribution among gas turbines; and supplementary fires. Most unit-commitment models in the literature represent standard technical constraints like startup, shutdown, up/down ramps, and in some cases, supplementary fires. However, they typically overlook other real-life CCGT operating constraints, which were considered in this work. These constraints are crucial in integrated energy systems to avoid equipment damage, which can potentially put CCGT plants out of service and ultimately lead to lower operating costs. [ABSTRACT FROM AUTHOR]

Electricity is crucial for daily life due to the number of activities that depend on it. To forecast future electric load, which changes over time and depends on various factors, grid operators (GOs) must create forecasting models for various time horizons with a high degree of accuracy because the results have a huge impact on their decision-making regarding, for example, the scheduling of power units to supply user consumption in the short or long term or the installation of new power plants. This has led to the exploration of multiple techniques like statistical models and Artificial Intelligence (AI), with Machine-Learning and Deep-Learning algorithms being the most popular in this latter field. This paper proposes a neural network-based model to forecast short-term load for a Colombian grid operator, considering a seven-day time horizon and using an LSTM recurrent neural network with historical load values from a region in Colombia and calendar features such as holidays and the current month corresponding to the target week. Unlike other LSTM implementations found in the literature, in this work, the LSTM cells read multiple load measurements at once, and the additional information (holidays and current month) is concatenated to the output of the LSTM. The result is used to feed a fully connected neural network to obtain the desired forecast. Due to social problems in the country, the load data presents a strange behavior, which, in principle, affects the prediction capacity of the model. Still, it is eventually able to adjust its forecasts accordingly. The regression metric MAPE measures the model performance, with the best predicted week having an error of 1.65% and the worst week having an error of 26.22%. Additionally, prediction intervals are estimated using bootstrapping. [ABSTRACT FROM AUTHOR]

This paper compares the effects of adding solar and wind power to the power system of Colombia's Caribbean region and its connections to the National Interconnected System. A base scenario was simulated in the PowerFactory 2003 software considering the actual data of the power system in 2023, and then, they were compared with the results obtained for 2033, considering the growth of the network and the addition of new power plants based on variable renewable energy. The comparison analyzes the impact of the newly added renewable energy in the power system on the voltage stability and system frequency. The results obtained show that the addition of new variable renewable energy plants generates voltage fluctuations in the lower voltage levels, ranging from 1% to 3.1%, which indicates potential challenges in maintaining the voltage stability. In higher voltages, no significant variations were found. Regarding the system frequency, the transient value tends to increase but is within the regulatory range, with variations of less than 0.2 Hz. [ABSTRACT FROM AUTHOR]

This paper describes the development of a deep neural network architecture based on transformer encoder blocks and Time2Vec layers for the prediction of electricity prices several steps ahead (8 h), from a probabilistic approach, to feed future decision-making tools in the context of the widespread use of intra-day DERs and new market perspectives. The proposed model was tested with hourly wholesale electricity price data from Colombia, and the results were compared with different state-of-the-art forecasting baseline-tuned models such as Holt–Winters, XGBoost, Stacked LSTM, and Attention-LSTM. The findings show that the proposed model outperforms these baselines by effectively incorporating nonlinearity and explicitly modeling the underlying data's behavior, all of this under four operating scenarios and different performance metrics. This allows it to handle high-, medium-, and low-variability scenarios while maintaining the accuracy and reliability of its predictions. The proposed framework shows potential for significantly improving the accuracy of electricity price forecasts, which can have significant benefits for making informed decisions in the energy sector. [ABSTRACT FROM AUTHOR]

Generation dispatching is a challenge in islanded microgrids due to the operational and economic restrictions in isolated zones. Furthermore, the impact of usual operational network changes in topology, load demand, and generation availability may become significant considering the grid size. This research paper presents a detailed multiple cost function modeling methodology of an optimal power flow algorithm applied to a non-interconnected zone in Colombia. The optimal power flow (OPF) formulation includes cost functions related to renewable resources as presented in the isolated zone and a complete model of the charging and discharging of batteries. Additionally, the flexibility of the proposal is tested using three different network topologies with a characteristic daily load curve from the zone. The main contribution of this paper lies in the implementation of an optimal power flow including cost functions of renewable sources for isolated microgrids. A test case for a non-interconnected zone in Colombia is performed for various operation cases. [ABSTRACT FROM AUTHOR]

The primary aspiration of this paper is to learn about the effects of economic growth (GDPG) and energy consumption (ENRC) on environmental pollution (EP) in G-3 countries and to show the significance of renewable energy consumption (RENEW) on environmental pollution (EP). The data covers the period from 1970 to 2020 by applying the "Pooled Mean Group-Autoregressive Distributed Lag" (PMG-ARDL) model. The results indicate that GDPG is negatively co-integrated with CO2 emissions (pollution) in the short run (SR) but positively co-integrated in the long run (LR). Energy consumption has a positive impact in the long run, but there is no positive impact in the short run to accelerate pollution. In both the short and long run, renewable energy has a significant role in reducing environmental degradation. However, according to the Dumitrescu Hurlin panel, there was bidirectional causality (BC) involving energy consumption and pollution. Because of the large volume of energy emphasized in economic growth and development activities, energy use increases pollution. In addition, there was a BC involving energy consumption and economic growth. At the country level, a significant contribution implies sustainable development and the implication of environmental quality assurance policies. [ABSTRACT FROM AUTHOR]

Energy determines the social, economic, and environmental aspects that enable the advancement of communities. For this reason, this paper aims to analyze the quality of the energy service in the Non-Interconnected Zones (NIZ) of Colombia. For this purpose, clustering techniques (K-means, K-medoids, divisive analysis clustering, and heatmaps) are applied for data analysis in the context of the NIZ to identify patterns or hidden information in the Colombian government data related to the state of the electricity service in these localities during the years 2019–2020. A descriptive statistical analysis and validation of the results of the clustering techniques is also carried out using R software. Through the implementation of clustering algorithms such as K-means, K-medoids, and divisive analysis clustering, potential areas for the development of renewable and alternative energy projects are identified, considering places with deficiencies in their current electricity service, higher consumption, or places with very low daily hours of electricity service. Additionally, relationships were identified in the dataset that can be considered as tools that would support decision-making for academia and industry, as well as the definition of guidelines or strategies from the government to improve energy efficiency and quality for these places, and consequently, the living conditions of the residents of Colombia's NIZs. [ABSTRACT FROM AUTHOR]

This paper develops and analyzes four energy scenarios for Colombia that consider the El Niño phenomenon and the inclusion of renewable energies in the energy generation matrix for the period 2020–2035. A comparative analysis is presented between the results of the different scenarios proposed. The most relevant finding is the use of the reserve margin as an indicator of system reliability. A scenario which included 7214 MW of large-scale non-conventional renewable energy, 10,000 MW of distributed generation, and 12,240 MW of hydroelectric power was assumed, with a reserve margin of over 50%. Additionally, it was found that for the scenarios in which a generation capacity with non-conventional renewable energies of less than 10,000 MW in 2034 was assumed, the reserve margin of the system in the seasons of the El Niño phenomenon will be less than historical records of the system. Alternatively, it was found that the scenarios in which the inclusion of at least 9600 MW of the electric power generation capacity of non-conventional renewable energies proposed by 2034 offer benefits in the reduction in greenhouse gas (GHG) emissions, which contributes to the achievement of the emission reduction objectives of the Paris Agreement. [ABSTRACT FROM AUTHOR]

This paper addresses the energy efficiency issue in household appliances, which has led to the establishment of policies at a global level in favor of setting minimum energy performance standards (MEPS), which guarantee end users are able to select more efficient equipment. The countries of the United States, Brazil, Mexico, Chile, and the Community of the European Union were taken as references to review their policies and implementation strategies, in order to be compared with the Colombian panorama (at the market, technical and political levels). This allows the establishment of common aspects and differences related to the determination of energy consumption, adjusted volume, and formalization of efficiency ranges, and in the specific case of domestic refrigeration. Managing to distinguish the most relevant aspects for the successful adoption of these policies in Colombia. It is evident that the implementation of these guidelines has a positive impact on the market of the countries and communities of reference. Similarly, the MEPS are shown as a mechanism to regulate energy consumption in the residential sector. [ABSTRACT FROM AUTHOR]

This paper deals with the optimal sizing of islanded microgrids (MGs), which use diesel generators to supply energy in off-grid areas. The MG under study integrates photovoltaic (PV) and diesel generation, a battery energy storage System (BESS), and an inverter for the connection between AC and DC voltage buses. Levelised cost of energy (LCOE) and annual system cost (ASC) are considered economic indicators, while the loss of power supply probability (LPSP) is used as a reliability indicator. Fiscal incentives such as the tax benefits and accelerated depreciation applied in Colombia are considered for the optimally sizing of each MG element. Solar measurements were taken at a weather station located in the main campus of Universidad de Antioquia in Medellin, Colombia at a latitude of 6.10 and longitude of −75.38. The objective function is the minimization of the total energy delivered from the power sources that successfully meets the load. The model was implemented in Python programming language considering several scenarios. Two cases were evaluated: the first one considered PV panels, a BESS and a diesel generator, while the second one only considered PV panels and a BESS. The option that does not include the diesel generator turned out to be the most expensive, since additional PV and BESS resources are required to meet the load profile. Furthermore, it was found that the LCOE was lower when tax benefits were taken into account. [ABSTRACT FROM AUTHOR]

Since no solutions have been proposed in Colombia that seek to reduce the consumption of electricity at the residential level, this paper describes the design and implementation of a simple prototype of a low-cost home energy management system (HEMS). The objective of this platform is to monitor the energy consumption of typical household devices so that users can access the consumption of each device separately and then establish the strategy that allows them to reduce energy consumption at home. In order to demonstrate that our system is viable, the system has been evaluated by measuring weekly energy consumption with the on-line and off-line HEMS using a test bench with typical household devices in a Sincelejo typical household. The evaluation has shown that with the installation of this HEMS, consumption is reduced by 27%. This shows that it is possible to achieve a good reduction percentage with a low-cost system. [ABSTRACT FROM AUTHOR]

To meet Colombia's energy needs by 2050, a total installed capacity of 42 MW across its power generation infrastructure is required. To achieve this, transitioning to cleaner energy sources, such as biomass—a non-conventional renewable energy—is necessary. Biomass is a promising renewable source for thermal and electrical energy production. This study researched the production of biogas from swine manure using a UASB reactor to valorize this waste. Swine manure was collected every 20 days from a pig farm with a capacity of 200 sows, located in Santa Rosa de Osos, Antioquia. The flow rate was increased three times (1.30 L d−1, 1.62 L d−1, and 2.08 L d−1) to reduce the hydraulic retention time (HRT) and enhance biogas production. The volatile and total solids, chemical oxygen demand (COD), alkalinity, and biogas composition were measured over one year. The proposed system achieved 87.40% COD remotion from the feed stream and generated a yield of 507 mLCH4 gVS−1, with an HRT of 19 days and an OLR of 4.27 gCOD L−1 d−1. The reactor produced biogas with a CH4 content of 67.7%, CO2 content of 18.1%, and H2S content of 1413 ppm. This study highlights the effectiveness of the UASB reactor for biogas production using swine manure as a substrate. [ABSTRACT FROM AUTHOR]

The signatory countries of the Paris Agreement must submit their updated Intended National Determined Contributions (INDCs) to the UNFCCC secretariat every five years. In Colombia, this activity was historically carried out with a wide set of diverse non-interconnected sector-specific models. Given the complexity of GHG emissions reporting and the evaluation of mitigation actions on a national scale, the need for a centralized platform was evident. Such approach would allow the integration and analysis of potential interactions among sectors, as well as to guarantee the homogeneity of assumptions and input parameters. In this paper, we describe the construction of an integrated bottom-up LEAP model tailored to the Colombian case, which covers all IPCC sectors. An integrated model facilitates capturing synergies and intersectoral interactions within the national GHG emissions system. Hence, policies addressing one sector and influencing others are identified and correctly assessed. Thus, 44 mitigation policies and mitigation actions were included in the model, in this way, identifying the sectors directly and being indirectly affected by them. The mitigation scenario developed in this paper reaches a reduction of 28% of GHG emissions compared with the reference scenario. The importance of including non-energy sectors is evident in the Colombian case, as GHG emission reductions are mainly driven by AFOLU. The first section describes the GHG emissions context in Colombia. Next, we describe the model structure, main input parameters, assumptions, considerations, and used LEAP functionalities. Results are presented from a GHG emissions accounting and energy demand perspective. The model allows for the correct estimate of the scope and potential of mitigation actions by considering indirect, unintended emissions reductions in all IPCC categories, as well as synergies with all mitigation actions included in the mitigation scenario. Moreover, the structure of the model is suitable for testing potential emission trajectories, facilitating its adoption by official entities and its application in climate policymaking. [ABSTRACT FROM AUTHOR]

The objective of this research was to analyze energy security in Ecuador, which is interconnected with water and food security. As a methodology, 21 indicators grouped into the following dimensions were analyzed: availability, infrastructure, energy prices, efficiency, social impact, environment and governance. For each indicator, a cross-sectional analysis was carried out with the countries of Colombia, Peru and Bolivia, along with a longitudinal analysis from 2011 to 2021. The main contribution of this study is the characterization of the Ecuadorian energy system as available, accessible, affordable and renewable in an electrical matrix but inefficient and heavily dependent on fiscal resources. The factors that may affect Ecuador's energy security were determined to be the risk of a reduction in income due to it becoming a net importer of energy, climate change, socio-environmental conflicts, poor diversification, energy subsidies and weak governance. A policy is proposed aimed at decoupling development from fossil fuels, with a systemic vision considering the complexity of interactions with other economic sectors, such as water and food, among others. [ABSTRACT FROM AUTHOR]

Energy transition to renewable sources and more efficient technologies is needed for sustainable development. Although this transition is expected to take a longer time in developing countries, strategies that have been widely explored by the international academic community, such as advanced combustion modes and microgeneration, could be implemented more easily. However, the implementation of these well-known strategies in developing countries requires in-depth research because of the specific technical, environmental, social, and economic conditions. The present research relies on the use of biogas-fueled HCCI engines for power generation under sub-atmospheric conditions provided by high altitudes above sea level in Colombia. A small air-cooled commercial Diesel engine was modified to run in HCCI combustion mode by controlling the air–biogas mixture temperature using an electric heater at a high speed of 1800 revolutions per minute. An experimental setup was implemented to measure and control the most important experimental variables, such as engine speed, biogas flow rate, intake temperature, crank angle degree, intake pressure, NOx emissions, and in-cylinder pressure. High intake temperature requirements of around 320 ∘ C were needed to achieve stable HCCI combustion; the maximum net indicated mean effective pressure (IMEPn) was around 1.5 bar, and the highest net indicated efficiency was close to 32 % . Higher intake pressures and the addition of ozone to the intake mixture were numerically studied as ways to reduce the intake temperature requirements for stable HCCI combustion and improve engine performance. These strategies were studied using a one-zone model along with detailed chemical kinetics, and the model was adjusted using the experimental results. The simulation results showed that the addition of 500 ppm of ozone could reduce the intake temperature requirements by around 50 ∘ C. The experimental and numerical results achieved in this research are important for the design and implementation of HCCI engines running biogas for microgeneration systems in developing countries which exhibit more difficult conditions for HCCI combustion implementation. [ABSTRACT FROM AUTHOR]

This article provides an extensive examination of the interconnectedness between energy and water in island regions, particularly those heavily reliant on tourism, as exemplified by the present case. This study explores the present state and trends of research in this field with the objective of attaining a sustainable system in future scenarios. Specifically, this analysis delves into the water–energy–CO2 nexus of the Colombian island of San Andrés. Currently, there is no energy generation from the water sector, with 76.18% of water consumption directed towards the cooling of thermal power plants and a mere 1.54% of the energy employed for water extraction, desalination, and purification. In 2019, the island's total energy consumption reached 138 ktoe (kilotons of oil equivalent), and renewable energies have yet to contribute to the system. These findings emphasize the necessity for the island to implement measures that will bolster its sustainability, self-sufficiency, and resilience. This entails mitigating and managing the intensity of resource consumption, particularly in areas experiencing economic growth. According to the Sankey diagram obtained, some political implications and recommendations have been listed. [ABSTRACT FROM AUTHOR]

The United Nations established 17 Sustainable Development Goals (SDGs), and the fulfillment of the 7th, defined as "Ensure access to affordable, reliable, sustainable, and modern energy for all", requires energy industry transitions and digital transformations, which implies that diverse stakeholders need to move fast to allow the growth of more flexible power systems. This paper contains the case report that addresses the commercial digital transformation process developed at AES Colombia, through the implementation of a modern platform based on specialized applications that use Industry 4.0 tools. The Chivor hydropower project, a 1000-MW powerplant that covers 6% of Colombia's demand, which is owned by AES Colombia and constitutes its primary asset, is first described. Then, a description of Colombia's complex market (energy matrix, trading and dispatch mechanisms, and future projects) is presented. Then, the methodology followed for the digital transformation process using modern tools is described. The project, conceived as a broad framework, comprises applications for the management of hydrological, operational, and market information, commercial information systems and platforms to facilitate consultation and analysis by different users. Such an innovative project in the Latin American context has been developed in order reduce risks and to contribute to a sustainable energy supply for the future. [ABSTRACT FROM AUTHOR]

In preparation for the electric mobility technological transition in Colombia, an impact assessment of the electric power system is required, considering the increasing loading that must be able to be managed in the future. In this paper, a plug-in electric vehicle (PEV) charging simulation methodology is developed in order to dimension the impact of this type of load on power grids. PEV electric properties, user charging behaviors, geographic location, trip distances, and other variables of interest are modeled from empirical or known probability distributions and later evaluated in different scenarios using Monte Carlo simulation and load flow analysis. This methodology is later applied to the transmission network of Antioquia (a department of Colombia) resulting in load increases of up to 40% on transmission lines and 20% on transformers in a high PEV penetration scenario in 2030, increases that are well within the expected grid capacity for that year, avoiding the need for additional upgrades. [ABSTRACT FROM AUTHOR]

This research presents the findings of an evaluation of off-grid photovoltaic (PV) systems and their sustainability models in Colombia within the "Evaluation of Isolated Photovoltaic Systems and Their Sustainability Models" project supported by the Global Environment Fund (GEF). It involves the analysis of primary and secondary information on the photovoltaic energy projects for rural electrification in this country. Part of the information was obtained through interviews with different stakeholders who work in solar electrification in non-interconnected zones (NIZ), covering rural and island contexts. It was complemented by a comparative analysis of international projects implemented in Latin America. The results are shown as lessons learned, with a SWOT (strengths, weaknesses, opportunities, and threats) study representing the current situation of rural electrification with PV technology as perceived and describing the opportunities for the improvement of rural electrification strategies based on the successful experiences in the region. This research offers a comprehensive overview of how Colombian electrification could be led to address the last mile gap, integrating a solid sustainable perspective for the long-term view and ensuring community involvement towards a just energy transition. Therefore, this study proposes a series of guidelines to support those public policies that foster access to energy in the rural non-interconnected zones of Colombia. [ABSTRACT FROM AUTHOR]

This paper presents a methodology to calculate day-ahead wind speed predictions based on historical measurements done by weather stations. The methodology was tested for three locations: Colombia, Ecuador, and Spain. The data is input into the process in two ways: (1) As a single time series containing all measurements, and (2) as twenty-four separate parallel sequences, corresponding to the values of wind speed at each of the 24 h in the day over several months. The methodology relies on the use of three non-parametric techniques: Least-squares support vector machines, empirical mode decomposition, and the wavelet transform. Moreover, the traditional and simple auto-regressive model is applied. The combination of the aforementioned techniques results in nine methods for performing wind prediction. Experiments using a matlab implementation showed that the least-squares support vector machine using data as a single time series outperformed the other combinations, obtaining the least root mean square error (RMSE). [ABSTRACT FROM AUTHOR]

In emerging countries, energy service users generally pay high rates of return to transmission system operators (TSOs). One of the causes of this situation is the application of the CAPM with the comparable beta method when estimating the cost of equity in the WACC. The purpose of this article is to present a new methodology for calculating the cost of equity of TSOs in Colombia. To achieve this objective, a multifactor model has been built to explain the variation in returns on the electric utilities portfolio in Colombia between April 2008 and March 2022 and then recalculate the WACC approved by the country's regulatory commission. It was found that, in addition to the estimated market risk in the CAPM, there is a risk due to the regulatory framework and changes in interest rates, which helps to explain 73% of the variations in the electric utilities portfolio, resulting in a lower cost of equity, and therefore a lower WACC of 5.28% compared to the WACC estimated by the regulator of 11.79% in 2019. These results can support regulatory commissions in emerging countries in establishing a more accurate rate of return for users. [ABSTRACT FROM AUTHOR]

Colombia, a privileged country in terms of diversity, availability of natural resources, and geographical location, has set a roadmap for hydrogen as part of the energy transition plan proposed in 2021. To reduce its emissions in the mid-term and foster its economy, hydrogen production should be green and blue, with specific targets set for 2030 for the hydrogen costs and produced quantities. This work compares the state-of-the-art production of blue and green hydrogen and how Colombia is doing in each pathway. A deeper analysis considers the advantages of Colombia's natural resources, the possible paths the government could follow, and the feedstock's geographical location for hydrogen production and transportation. Then, one discusses what may be the next steps in terms of policies and developments to succeed in implementing the plan. Overall, it is concluded that green hydrogen could be the faster, more sustainable, and more efficient method to implement in Colombia. However, blue hydrogen could play an essential role if oil and gas companies assess the advantages of carbon dioxide utilization and promote its deployment. [ABSTRACT FROM AUTHOR]

The electrical sector in the Caribbean region of Colombia is currently facing problems that affect its reliability. Many thermo-electric plants are required to fill the gap and ensure energy supply. This paper thus proposes a hybrid renewable energy generation plant that could supply a percentage of the total energy demand and reduce the environmental impact of conventional energy generation. The hybrid plant works with a photovoltaic (PV) system and wind turbine systems, connected in parallel with the grid to supply a renewable fraction of the total energy demand. The investigation was conducted in three steps: the first stage determined locations where the energy system was able to take advantage of renewable sources, the second identified a location that could work more efficiently from an economic perspective, and finally, the third step estimated the number of PV solar panels and wind turbines required to guarantee optimal functioning for this location using, as a main method of calculation, the software HOMER pro® for hybrid optimization with multiple energy resources. The proposed system is expected to not only limit environmental impacts but also decrease total costs of electric grid consumption from thermoelectric plants. The simulations helped identify Puerto Bolivar, Colombia, as the location where the hybrid plant made the best use of non-conventional resources of energy. However, Rancho Grande was found to offer the system more efficiency, while generating a considerable amount of energy at the lowest possible cost. An optimal combination was also obtained—441 PV arrays and 3 wind turbines, resulting in a net present cost (NPC) of $11.8 million and low CO2 production of 244.1 tons per year. [ABSTRACT FROM AUTHOR]

Solar and wind energy systems, without storage, cannot satisfy variable load demands, but their combined use can help to solve the problem of the balance between generation and consumption. Energetic complementarity studies are useful to evaluate the viability of the use of two or more renewable energy sources with high variability in a specific interval of time in a determined region. In this paper, the monthly energetic complementarity study of solar and wind resources of Colombia is carried out. A novel approach to conduct the study is proposed. A dataset with the average monthly solar radiation and wind speed values is obtained from high-resolution images of renewable resources maps, using image processing algorithms. Then, the dataset is used to calculate the energetic complementarity of the sources employing the negative of the Pearson correlation coefficient. The obtained values are transformed to energetic complementarity maps, previously eliminating the protected areas. The obtained results show that there is a good energetic complementarity in the north and northeastern regions of the country throughout the year. The results indicate that projects related to the joint use of solar and wind generation systems could be developed in these regions. [ABSTRACT FROM AUTHOR]

The large-scale integration of variable renewable energy sources into the energy system presents techno–economic challenges. Long–term energy system optimization models fail to adequately capture these challenges because of the low temporal resolution of these tools. This limitation has often been addressed either by direct improvements within the long–term models or by coupling them to higher resolution power system models. In this study, a combined approach is proposed to capitalize on the advantages and overcome the disadvantages of both methods. First, the temporal resolution of an energy model was enhanced by approximating the joint probability of the electricity load and the supply of intermittent sources. Second, the projected electricity mix was simulated by a power model at an hourly resolution. This framework was used to analyze mid–century deep decarbonization trajectories for Colombia, subject to future uncertainties of hydroclimatic variability and the development of the bioeconomy. The direct integration method is found to consistently reduce the overestimation of the feasible penetration of VRES. However, its impact is marginal because of its inability to assess the short–term operation of the power system in detail. When combined with the soft–linking method, the reliable operation of the power system is shown to incur an additional overhead of 12–17% investment in flexible generation capacity, 2–5% of the annual energy system cost, and a 15–27% shortfall in achieving the aspired GHG mitigation target. The results obtained by combining both methods are found to be closer to the global optimum solution than using either of these methods individually. [ABSTRACT FROM AUTHOR]

This study evaluated leachate recirculation (LR) as a stabilisation strategy for landfills using bioreactor experiments with excavated waste from a tropical landfill in Colombia. The experimental evaluation was performed in two 115 L bioreactors, one simulating the operation of a landfill with LR, Br2, where the leachate produced was recirculated at a rate of 0.8 L d−1, and a control system without LR, Br1. Both systems reached stabilisation indicator values on a dry matter (DM) basis for volatile solids VS (<25% DM) and a biochemical methane potential BMP (≤10 mL CH4 g−1 DM). Likewise, towards the end of the experiment, the leachate generated in Br2 reached stabilisation indicator values for BOD5 (<100 mg L−1) and the BOD (biological oxygen demand)/COD (chemical oxygen demand) ratio (<0.1). Although the stabilisation criterion for COD was not met in any bioreactor (<200 mg L−1), LR helped to release 19% more oxidisable organic matter in Br2 than in Br1, indicating a reduction in the contaminating potential of the waste in the case of uncontrolled discharges of leachate to the environment. Regarding biogas production, the generation of CH4 in Br2 was more intense and its cumulative production was 34.5% higher than Br1; thus, Br2 achieved CH4 emission rates, indicating waste stabilisation (<1.0 L CH4 m−2 h−1) sooner than Br1, showing an accelerating effect of LR on waste degradation. A carbon mass balance indicated that waste degradation, in terms of the initial total organic carbon mineralisation and the C gas discharge via CH4, was greater in Br2. These results demonstrate the LR potential to accelerate the stabilisation of a landfill but also to reduce greenhouse gas emissions in final disposal sites where biogas is also captured and utilised for energy production; a key aspect when improving the sustainability of landfill operations in developing countries. [ABSTRACT FROM AUTHOR]

Electricity access is strongly linked to human growth. Despite this, a portion of the world's population remains without access to energy. In Colombia, rural communities have energy challenges due to the National Interconnected System's (NIS) lack of quality and stability. It is common to find that energy services in such locations are twice as costly as in cities and are only accessible for a few hours every day due to grid overload. Implementing market mechanisms that enable handling imbalances through the flexible load management of main loads within the grid is vital for improving the rural power grid's quality. In this research, the energy from the rural grid is primarily employed to power a heating, ventilation, and air-conditioning (HVAC) system that chills flowers for future commerce. This load has significant consumption within the rural grid, so handling HVAC consumption in a suitable form can support the grid to avoid imbalances and improve the end-user access to energy. The primary responsibilities of the flower greenhouse operator are to reduce energy costs, maximize flexibility, and maintain a proper indoor temperature. Accordingly, this research proposes a flexible energy market based on the bi-level mixed-integer linear programming problem (Bi-MILP), involving the Agricultural Demand Response Aggregator (ADRA) and the flower greenhouse. ADRA is responsible for assuring the grid's stability and quality and developing pricing plans that promote flexibility. A flower greenhouse in Colombia's Boyacá department is used as an application for this research. This study looked at the HVAC's flexibility under three different pricing schemes (fixed, time-of-use, and hourly) and graded the flower greenhouse's flexibility as a reliable system. [ABSTRACT FROM AUTHOR]

Because electricity retailers must ensure that energy supply matches end-user demand, electricity that is not traded through bilateral contracts is typically traded in power exchanges which are subject to great price volatility. In Colombia, the spot price is a reflection of climate variability because approximately 70% of the country's electricity is generated by large hydropower stations. In this study, we forecast 2018′s prices and calculated its corresponding purchase margins using the 2015 to 2017 bilateral contract prices for electricity plus power exchange price information and climate information. Our forecasts included climate uncertainty and evaluated two multi-period portfolio methods for deciding among three purchasing strategies: bilateral contracts in the regulated market, bilateral contracts in the non-regulated markets, and purchases in the power exchange. The results indicate that retailers should follow a middle course that is neither conservative nor risky. Creation of portfolios independent of the multi-period method can balance purchases through bilateral contracts and in the power exchange in a way that considers climatic uncertainty. This type of balanced portfolio could control medium-term risks of price volatility and result in good levels of purchase margins. [ABSTRACT FROM AUTHOR]

Despite recognizing that climate change and its impacts are not gender-neutral, only few studies address the arising complexities. While in some climate-relevant sectors, such as the transport sector, there already is some initial research on the relationship between climate and gender, research on the climate–gender nexus in the coal sector is still underdeveloped, and the few existing studies focus on dichotomous relations (gender–coal and coal–climate). This article discusses the currently neglected climate, coal, and gender triad and develops a conceptualization along the following aspects: (i) common lines of arguments, (ii) shortcomings in predominant arguments, and (iii) the state-of-the-art regarding the climate–gender–coal triad. To illustrate this outline, it uses the empirical case of the Colombian coal sector. Based on original data obtained via semi-structured interviews, it analyzes how imminent national-level climate policies for the coal sector, i.e., an energy transition, can be made gender-responsive and thus contribute to a just transition. The empirical example shows that women are already important change agents at the local level and in informal decision-making spaces. Although more research is needed to obtain further insights and evidence, this article contributes to the findings of more recent research which allow for the assumption that addressing climate and gender simultaneously may be mutually beneficial for both policy objectives. [ABSTRACT FROM AUTHOR]

In this study, the use of compressed and liquefied natural gas is evaluated for heavy-duty passengers (HDPV) and freight vehicles (HDFV). The evaluation is conducted considering the socioeconomic and vehicle fleet characteristics of Colombia. The energy consumption, the CO2, and the pollutant emissions of a baseline and four natural gas penetration scenarios are analyzed. The results show that the inclusion of natural gas reduces the energy consumption per capita of the HDPV and HDFV by up to 40% by 2050. Furthermore, PM2.5 emissions per capita are reduced up to 77% for HDPV and 90% for HDFV, while CO emissions per capita decreased by 82%. Additionally, the technological renovation of HDFV emerges as an effective way to reduce pollutant emissions in the medium term. The establishment of strategies to make HDFV cleaner and more efficient is imperative for the long term. Finally, a sensitivity analysis is conducted to evaluate the influence of the gross domestic product per capita (GDPc) over the indicators analyzed. The results show that higher GDPc demands more ambitious actions to decarbonize the transportation sector, since a considerable increase in energy consumption and emissions from heavy-duty vehicles is identified. [ABSTRACT FROM AUTHOR]

For every nine tons of produced biodiesel, there is another ton of glycerol as a byproduct. Therefore, glycerol prices dropped significantly worldwide in recent years; the more significant biodiesel production is, the more glycerol exists as a byproduct. glycerol prices also impact the biodiesel manufacturing business, as it could be sold according to its refinement grade. The primary objective of this work was to evaluate the economic potential of the production of 1,2-propanediol derived from the biodiesel produced in Colombia. A plant to produce 1,2-propanediol via catalytic hydrogenation of glycerol in a trickle-bed reactor was designed. The plant comprised a reaction scheme where non-converted excess hydrogen was recycled, and the heat generated in the reactor was recovered. The reactor effluent was sent to a separation train where 98% m/m purity 1,2-propanediol was attained. Capital and operational costs were estimated from the process simulation. The net present value (NPV) and the modified internal return rate (MIRR) of the plant were used to assess the viability of the process. Their sensitivity to key input variables was evaluated to find the viability limits of the project. The economic potential of the 1,2-propanediol was calculated in USD 1.2/kg; for the base case, the NPV and the MIRR were USD 54.805 million and 22.56%, respectively, showing that, for moderate variations in products and raw material prices, the process is economically viable. [ABSTRACT FROM AUTHOR]

Energy supply in remote areas (mainly in developing countries such as Colombia) has become a challenge. Hybrid microgrids are local and reliable sources of energy for these areas where access to the power grid is generally limited or unavailable. These systems generally include a diesel generator, solar modules, wind turbines, and storage devices such as batteries. Battery life estimation is an essential factor in the optimization of a hybrid microgrid since it determines the system's final costs, including future battery replacements. This article presents a comparison of different technologies and battery models in a hybrid microgrid. The optimization is achieved using the iHOGA software, based on data from a real microgrid in Colombia. The simulation results allowed the comparison of prediction models for lifespan calculation for both lead–acid and lithium batteries in a hybrid microgrid, showing that the most accurate models are more realistic in predicting battery life by closely estimating real lifespans that are shorter, unlike other simplified methods that obtain much longer and unrealistic lifetimes. [ABSTRACT FROM AUTHOR]

Most of the evaluations of thermal enhanced oil recovery (EOR) methods in numerical simulations mainly focus on the identification of recovery processes with the greatest potential to increase oil recovery. In some cases, the economic aspects of the EOR methods evaluated are also considered. However, these studies often lack the evaluation of the energy efficiency of the proposed methods as a strategy to support the selection of profitable recovery processes. Therefore, this study aimed to identify the potential of different hybrid cyclic steam stimulation (CSS, with flue gas, foam, nanoparticles, or solvents) methods based on a numerical simulation study using a radial model representative of a large heavy oil reservoir in the Middle Magdalena Basin, Colombia. The simulation results were used to estimate the benefit–cost (B/C) ratios and energy efficiency (EE) indices that can be used to screen and rank the hybrid CSS methods studied. When comparing different hybrid methods, it was found that CSS with nanoparticles or solvents performed better during the first two steam cycles (higher oil saturations). However, CSS with foam and flue gases showed higher incremental oil production (≥3564 bbls or 567 m3) during the sixth steam cycle. Based on an energy cost index (ECI = [(B/C) / EE]), CSS with foam outperformed (ECI ≈ 453) cyclic steam injection with flue gases (ECI ≈ 21) and solvents (ECI ≈ 0.1) evaluated during the sixth steam cycle. The results show that this methodology can be used to guide decision-making to identify hybrid CSS methods that can increase oil recovery in a cost-effective manner and provide an efficient energy balance. [ABSTRACT FROM AUTHOR]