• Energy Research

Motivated by the environmentally driven energy transition we live in, the valorization of biomass residues from the agro-industry as renewable energy can play an essential role in GHG emissions mitigation. To overcome the debate on the production and use of solid biofuels (SBF), in this study, we apply an integrated multicriteria tool for the assessment of the sustainability use of agro-industrial residues (AIR) as solid biofuels. Mexico has a vast AIR production, but frequently, the AIR are considered waste biomass. Still, when valorized, SBF do not have adverse effects on soil quality, are not responsible for biodiversity loss, and compete against food production as first-generation SBF. Nevertheless, the AIR present other environmental, social, and economic impacts that have not been adequately evaluated; therefore, we identified the need for a sustainability assessment of energy systems based on the use of SBF–AIR as input fuels. After reviewing previous work on sustainability assessment methodologies, multicriteria decision analysis methods, and indicator weighting methods, we considered it appropriate for this problem to apply a tool that integrates the entropic indicator weighting method into the discrete multicriteria decision analysis method called PROMETHEE. In terms of selected sustainability indicators, this tool was used to assess four electric energy supply systems of a Mexican sugar mill as a case study: current bagasse cogeneration, efficient bagasse cogeneration, a power generation system fueled only with fuel oil, and grid electricity only. Finally, after evaluating the mentioned energy systems with four sustainability indicators: GHG emissions, PM emissions, employments per energy unit (JOBS), and the net present value (NPV) of each alternative, we found the net outranking flow of the efficient bagasse system (EBS). which is the most sustainable system because it has the highest outranking flow value from the four considered alternatives, since it has the lower GHG emissions, reducing the current bagasse GHG emissions by 55% and the PM emissions by 58%. The EBS also shows the highest NPV system due to surplus electricity sales, resulting in the most profitable energy system analyzed.

The COVID-19 pandemic has generated multiple impacts. In particular, in the educational sector, the virtual class modality generated changes in the patterns of energy consumption at the institutional level; the identification of this consumption will allow us to reflect on new energy saving and efficient use strategies. In this research, we present a case study of the effects of the COVID-19 pandemic on electricity consumption in 13 state universities in Michoacán, Mexico. Electric energy consumption has been evaluated before and during the presence of the COVID-19 between 2019 and 2020. The comparative analysis estimated the reduction in energy consumption and its economic and environmental impact. The results show a considerable decrease in electricity consumption, generating an average saving of 76.24 MWh/month, which translates into an annual emission reduction from 2019 to 2020 of approximately 497 TnCO2e, and in economic terms of $8,882.25 USD each month. In general, it was identified that consumption patterns in the use of machinery and computer equipment for administrative activities were drastically reduced. If education continues in virtual or hybrid modes, energy consumption schemes will continue to decline and institutions could move towards resilient, affordable, and sustainable models of energy production and consumption.

Improved cookstoves have been identified in Mexico as a key opportunity to advance sustainable local development priorities in disadvantaged regions while mitigating climate change. This paper reviews the Patsari Cookstove Project initiated in 2003 by an NGO, Interdisciplinary Group on Appropriate Rural Technology (GIRA). The project applied an interdisciplinary and participative user-centered approach to disseminate improved cookstoves in rural Mexico, with a special focus on indigenous and poor rural communities. To date, GIRA and the Patsari Network have disseminated thousands of stoves using a “training to trainers” model. Benefits from the project include tangible improvements in users’ health, as well as savings in time and money expended on fuelwood procurement and use. The project has also documented substantive environmental benefits from significant mitigation of greenhouse gas (GHG) emissions associated with traditional open fires. To sustain scaling up efforts over the long-term, two networks have been created: The Patsari Network, which includes several organizations promoting Patsari stoves for household users, and the Tsiri Network, which supports local food security and the empowerment of indigenous women through the promotion of institutional cookstoves. Through appropriately designed and implemented local interventions, the project demonstrates that the goals of advancing sustainable local development in rural areas and climate change mitigation may not be contradictory, and may in fact reinforce one another.

This study applies environmental life cycle assessment to quantify and compare the environmental profile of the production and use of wood pellets for residential heating (baseline) and compares the pellet system with two different alternative systems for residential heating in Mexico: (1) the use of LPG heater and (2) one electricity heater powered by three different sources of electricity. The baseline system boundaries include the stages of forest management, transportation, industrial, distribution, wood pellet energy conversion, and ash management. First-hand data and measurements of the emission profiles in the field and laboratory were developed. The functional unit was 1 MJ of thermal energy for residential heating. Environmental impacts were calculated for six impact categories from the ReCiPe midpoint method. Furthermore, a sensitivity analysis was performed to evaluate the influence of the allocation criteria (mass and economic) as well as adopting different values for the electricity sources (system’s hotspots). The results obtained for each impact category show a relatively wide range of variation when the five scenarios of the heating systems are compared and analyzed. Electricity heater powered with photovoltaic electricity is better for all the impact categories analyzed. The performance of pellets and LPG is very close, but the pellets have lower impacts on global warming (three times), fossil resource scarcity (four times), and acidification. Therefore, the use of pellets in an efficient boiler is a promising option for residential heating.

This paper introduces a new methodology for the development of appropriate technology that allows satisfying energy needs in rural communities. The methodology integrates the technological development, taking particularly into account the assessment of environmental impacts as well as evaluation of the functionality of the technology. Therefore, it is implemented as a case study in the development of a solar wood-dryer in an artisan community in Mexico. Relevant issues were identified for the success of the methodology, which includes identifying key participants in the community, as well as the use of specialized simulation- and computer-based design tools, and a prior evaluation of the potential environmental impacts through Life-Cycle Assessment (LCA) of the solar wood-dryer. Three geometries of a solar wood-dryer prototype were proposed and analyzed with computer-based simulations, which showed better interior heat transfer than the traditional wood brick-dryer. LCA revealed that the new solar wood-dryer prototype has environmental impacts in all analyzed categories that are 5% or smaller than those of the traditional dryer. Therefore, it was demonstrated that the solar wood-dryer developed with our introduced methodology leads to less environmental impacts compared to those of the traditional wood brick-dryer previously used by the rural community.

In Mexico, the possibility to exploit orange peels or sugarcane straw to generate heat has not been fully explored, even though they are major agronomic wastes generated in Mexico. Therefore, this paper aims to assess the heat generation’s environmental and economic performance from these feedstocks in a fruit-processing facility located in Veracruz, Mexico. The environmental performance was assessed through the life-cycle assessment methodology, while the economic performance was estimated through the total levelized cost of energy (TLCE) considering two scenarios: (1) a base scenario where orange peels are burnt to produce process steam, and (2) a second scenario where sugarcane straw is co-fired with it. Both scenarios assume to partially displace heavy-fuel–oil (HFO) for steam generation. Results indicate that the impacts of the use of residual biomass-based heat on the potential global warming, ozone layer depletion, marine aquatic ecotoxicity, and cumulative energy demand are 34–63% lower than when using HFO and decrease the TLCE by 18–21%. However, there is also an increase in other environmental impact categories such as human toxicity, photochemical oxidation, or eutrophication. The use of orange from organic farms improves the environmental results in some of these categories. The drying and combustion of the biomass, as well as the waste treatment, are the major contributors to the environmental impacts. On the other hand, capital and fuel costs are the major contributors to TLCE. Overall, the use of orange peels and sugarcane straw to generate heat is attractive from the environmental and economic point of views.

This paper introduces a methodological framework for assessing the sustainability of solid biofuels in Mexico. The designed framework comprises 13 normalized indicators and two diagnostic studies, covering the economic, social, environmental, and institutional sustainability dimensions, and their intersections. Indicators are normalized using the concept of load capacity of a system, similarly to the planetary boundaries. Thus, the graphical representation of results facilitates their multidimensional analysis. The framework was applied to three case studies: traditional fuelwood in rural households, charcoal for restaurant grilling, and electricity cogeneration from sugarcane bagasse. This was part of an iterative process of testing and refining the framework and simultaneously demonstrating its application in the Mexican bioenergy context. This led to the conclusion that the resulting framework (a) provides a useful, quantitative, and comprehensive overview of both broad and specific sustainability aspects of the assessed system; (b) requires a balance of accessible but also scattered or sensitive data, similarly to most existing frameworks; (c) is highly flexible and applicable to both modern and traditional solid biofuels; and (d) is simple to communicate and interpret for a wide audience. Key directions for improvement of the framework are also discussed.The online version contains supplementary material available at 10.1007/s12155-021-10365-2.

This study shows the energy potential of pine wood waste for the production of solid biofuels, and was carried out in an indigenous community in the state of Michoacán. One of the main economic activities of this community is the production of handcrafted furniture, which generates a large amount of wood waste. The most relevant results obtained in this research show that the community generates approximately 2268 kg of sawdust and 5418 kg of shavings per week, and the estimated energy potential per year for both sawdust is 1.94 PJ and for shaving is 4.65 PJ. Based on the particle size observed, the wood residue can be used to generate pellets or briquettes. Other average results in sawdust and (shavings) are the following: initial moisture content 15.3% (16.8%), apparent density 169.23 kg/m3 (49.25 kg/m3), ash 0.43% (0.42%), volatile material 84.9% (83.60%), fixed carbon 14.65% (15.96%), hemicelluloses 12.89% (10.68%), cellulose 52.68% (52.82%), lignin 26.73% (25.98%), extractives 7.69% (10.51%), calorific value 17.6 MJ/kg (17.9 MJ/kg). The major chemical elements in the ash were Al, K. Fe, Ca, P, Na, and Mg. Finally, the results obtained indicate that this biomass can be used to generate pellets or briquettes in this indigenous community.