• Energy Research

Greenhouse gas (GHG) emissions from building activities are one of the most prominent contributors to the problem of global warming. Life-cycle assessment (LCA) is a widely used tool to investigate GHG emissions from buildings. However, there appears to be a lack of LCA studies on buildings in tropical climates, and especially in Thailand. This study aims to improve the understanding of GHG emissions from standard Thai residential buildings. LCA was conducted on five typical house designs in Thailand in order to determine potential mitigation strategies for future design of these houses. The amount of GHG emissions over the entire life-cycle of these detached houses was estimated, and the results were analysed with different viewpoints. The results indicate that emissions from the operational energies of detached houses in Thailand have the highest share of GHG emissions. Significant emissions also came from construction materials. Improvements to the building envelope and air-conditioner usage have high GHG mitigation potential in the operational stage of the buildings, while replacing cementitious and metallic materials with low-emissions alternatives can considerably reduce embodied emissions. Policy relevance The built environment has been a major source of GHG, but it also has high climate change-mitigation potential. This study explores mitigation strategies on the material and component levels of the most common building type in Thailand: detached houses. The results indicate the major sources of GHG emissions in the case study buildings, their correlation with building scale and other key design decisions. Potential mitigation solutions in different phases of the building life-cycle are identified.

Nature-based solutions (NbS) are recognized as one of the approaches that can address a range of environmental issues, often with conservation and natural resource management missions. However, the promotion of NbS often lacks a robust understanding of their actual impacts and effectiveness. To support the evaluation and implementation of NbS, there is a need for a comprehensive quantitative assessment framework. The main objectives of the study are to (1) develop an assessment framework that can be used to quantify the performance of NbS interventions and to (2) provide a step-by-step guideline for evaluating NbS. The assessment framework proposed in this study was built upon existing frameworks used in previous studies, designed to address specific gaps. Several aspects and tools were integrated in response to the NbS standard criteria provided by the International Union for Conservation of Nature (IUCN), as a result, this quantitative assessment framework can provide a comprehensive evidence based on environmental, social, and economic aspects. The study introduced one approach, viz., the System of Environmental-Economic Accounting - Ecosystem Accounting (SEEA EA), and three main assessment tools (i.e., Life Cycle Assessment (LCA), Social Life Cycle Assessment (S-LCA), and Cost-Benefit Assessment (CBA)) aimed at facilitating a comprehensive evaluation of NbS. The results provide a conceptual framework that offers a systematic approach for evaluating the performance of NbS, along with methods to address conflicting results among aspects and/or indicators. Ideas and approaches for assessing ecosystem services provided by NbS and primary concerns when conducting NbS assessments are also highlighted. In summary, the conceptual framework proposed in this study can be used to assess NbS performance and determine whether NbS interventions align with the NbS standard criteria provided by IUCN, utilizing the introduced assessment tools.

Abstract Biomass is one of the most important and emerging sources of energy. The objective of this study was, therefore, to explore the potential of energy production from biomass resources available in Ethiopia. The study involved the estimation of bio-energy potential from crop residues, forest, livestock waste, and municipal solid waste (MSW) in the major towns of the country. The paper also presents policy recommendations for sustainable bio-energy development. The crop, forest, and livestock population data were extracted from the Food and Agriculture Organization statistics database (FAOSTAT) and the country's national and regional reports. The results revealed that Ethiopia has a substantial amount of biomass residues, which are not currently being utilized and collected, that can be used without negatively affecting the socio-economic as well as environmental requirements and without compromising food security. The total bio-energy availability of the country was estimated to be 750 PJ per year (46.5% forest residue, 34% crops residue, 18.8% livestock waste, and 0.05% MSW). The study concludes that an integrated bio-energy database, research development, and identification of feasible bio-energy feedstock value chains are needed to fully realize the potential availability of biomass energy. It also recommends that assessment of the bio-energy value chain should be conducted along its life cycle.

Land use can affect ecosystems on land and their services. Because land use has mainly local effects, damage to ecosystem productivity due to land use should be modelled spatially dependent. Unfortunately, even though land use of impacts are particular importance for countries whose economies are highly agriculture-based, ecosystem productivity damage due to land use has not yet been assessed in Thailand so far. This study presents the method for assessing the damage to ecosystem productivity due to land use (land occupation and land transformation) in Thailand. Ecosystem productivity damage is expressed through net primary production (NPP). To convert the damage into monetary units, this study performs an economic valuation of NPP using the production function approach. The results show that the value of marginal product of NPP is around 10-15 Thai baht (THB) (1 USD≈36 THB), per tonne dry weight biomass. The results are applied to the case of biodiesel production. The method presented in this paper could be a guideline for future land use impact assessment research. In addition, converting the NPP damage results into monetary units facilitates integration of impact assessment and economic analysis results for supporting decision support tools such as cost benefit analysis.

Sugarcane leaves and trash burning during harvesting, and vinasse management, are major challenges of the Thai sugarcane industry. Identification of the appropriate valorization pathways for both the biomass waste streams using the sugarcane biorefinery concept is necessary. This study aims to assess the environmental sustainability of five CE models, including (1) sugarcane trash for electricity, (2) sugarcane trash to biochar, (3) sugarcane trash as a soil conditioner, (4) vinasse as a bio-fertilizer, and (5) vinasse for power generation. Life cycle assessment has been conducted using the ReCiPE midpoint impact assessment method. The results revealed that all waste utilization scenarios can help reduce the environmental impacts compared to the base case. The utilization of sugarcane leaves and trash for electricity generation brings about the lowest environmental impacts due to the environmental credits from the substitution of Thai grid electricity. The utilization of sugarcane leaves can reduce impacts on climate change, terrestrial acidification, and ozone formation by about 20–104%, 43–61%, and 12–54%. Recycling vinasse as bio-fertilizer and for biogas production for electricity generation can reduce climate change impact by about 28–29%. There is a significant improvement of the avoidance of pre-harvesting burning of sugarcane in the Thai sugar industry, which has led to the big potential of sugarcane leaves biomass utilization. Recommendations to enhance the efficiency of using sugarcane leaves and vinasse are discussed. The integrated waste circulation scenarios on cane leaves and vinasses in the sugar-electricity-ethanol biorefinery shows advancement in the bio-circular-green economy (BCG) aspects for enhancing the environmental sustainability of the Thai sugarcane industry.

As renewable energy sources and net-zero energy homes become increasingly pervasive within the residential building industry, further reductions in consumption patterns will occur through demand side management (DSM). DSM can include measures such as energy-efficient system design, automated control and energy management systems, or policies and monitoring systems intended to alter user behavior. For an energy-efficient modern residence designed within a tropical context, several DSM strategies are considered for reductions in operational-phase energy consumption: a lightweight, thermally high-performing building envelope, installation of light dimmers to enhance user control of lighting, and comparison of a solar hot water system versus a point-of-use electric water heater to produce hot water for bathing demands. The energy-consumption savings associated with the three DSM strategies are simulated and normalized to an energy savings per cost of implementation basis in kWh per 1000 Thai Baht (THB) for comparison. The results show that financial investments in low-energy hot water heaters (i.e., solar water heating systems) result in relatively higher energy savings per unit financial investment than the other two strategies. Conversely, the installation of a lightweight, well-insulated envelope is highly expensive relative to its associated energy savings over a 25-year time frame. The savings associated with the insulated envelope, light dimmers, and hot water production strategies are evaluated at 80, 609 and 657 kWh/1000 THB investment, respectively.

Abstract Using the concept of life cycle analysis, the whole life cycle of anthracite production in Vietnam was assessed and the environmental “hot-spots” were identified. These include (i) dust pollution at coal transfer points or piles in storage; (ii) noise pollution resulting from the usage of heavy equipment, and (iii) high volume of acid and turbid mine water discharged into the environment. Pollution prevention and treatment options were identified and discussed in this study which consists of wet treatment of dust, planning, collection and treatment of mine water, planting of trees for dust and noise reduction as well as minimization of erosion. Some recommendations are made for pollution abatement from coal production and improvement of anthracite production in the region.

With dramatic cost declines and performance improvements, both mini-hydropower and solar photovoltaics (PV) now serve as core options to meet the growing demand for electricity in underserved regions worldwide. We compare the net energy return on energy invested (EROI) of mini-hydropower and solar electricity using five existing mini-hydropower installations in northern Thailand with grid-connected solar PV simulations. Both assessments use a life cycle perspective to estimate the EROI. We find that distributed mini-grids with penetrations of solar PV up to 50% of annual generation can exceed the EROI of some fossil-based traditional centralized grid systems. The analysis will help planners and engineers optimize mini-grids for energy payback and utilize local resources in their design. The results suggest higher EROI ratios for mini-hydropower plants than solar PV, though mini-hydropower plants typically yield lower EROI ratios than their large-scale hydropower counterparts.