Environmental Life Cycle Assessment of Ethiopian Electricity Generation Systems: A Case of Hydro and Wind Power
| dc.contributor.advisor | Berhanu, Assefa (PhD) | |
| dc.contributor.author | Belay, Teffera | |
| dc.date.accessioned | 2021-12-16T07:28:31Z | |
| dc.date.accessioned | 2023-11-10T15:01:13Z | |
| dc.date.available | 2021-12-16T07:28:31Z | |
| dc.date.available | 2023-11-10T15:01:13Z | |
| dc.date.issued | 2020-11 | |
| dc.description.abstract | Electricity is one of the most vital elements in modern society. Despite its significance to improve human life, there are concerns on its environmental impacts. Life Cycle Assessment (LCA) is a well-established tool for assessing the environmental burdens of products (goods and services) throughout their life cycles. Several LCA studies were conducted for electricity generation and supply systems. However, the LCA data of electricity systems are country specific in their nature. In addition, existing LCA and inventory modeling efforts are limited to the circumstances of the developed world. Therefore, the need to evaluate the environmental performance and to develop country specific LCA data that describe actual electricity systems remains important. This thesis provides a picture of current electricity system and presents for the first time the LCA results of hydro and wind power systems in Ethiopia. The assessment aims to model existing hydro and wind energy systems and develop LCI and LCA datasets of the country per 1 kWh electricity generated. For both case studies, process-based attributional LCA has been applied using SimaPro software version 8.0.1 and ReCiPe 2008 as impact assessment method. The main midpoint environmental impacts of Ethiopian hydropower system consisting of eleven hydropower plants operational in 2013-2017 were: climate change(CC): 32 g CO2 eq., fossil depletion (FD): 0.82 g oil eq., freshwater eutrophication (FWEU): 0.000132 g P eq., human toxicity (HT): 0.58 g 1, 4-DCB eq., metal depletion (MD):1.04 kg Fe eq., marine ecotoxicity (MET): 0.01 kg 1,4-DCB eq., natural land transformation (NLT): 8.3E-04 m2 eq., particulate matter formation (POF): 0.15 g PM10 eq., photochemical oxidant formation (POF): 0.03 g NMVOC eq., terrestrial acidification (TA): 0.02 g SO2 eq. and freshwater ecotoxicity (FWET): 0.005 g 1,4-DCB eq. per 1kWh electricity generated. The major midpoint environmental impacts of Ethiopian wind farms composed of 3 wind farms operational in 2015-2017 were: climate change (CC):33.36 g CO2 eq., fossil depletion (FD): 8 g oil eq., freshwater ecotoxicity (FWET): 0.023 g 1,4-DCB eq., freshwater eutrophication (FWEU): 0.005 g N eq., human toxicity (HT): 9.9 g 1,4-DCB eq., metal depletion (MD): 18.7 g Fe eq., marine ecotoxicity (MET):0.098 g 1,4-DCB eq., particulate matter formation (PMF): 0.097 g PM10 eq., photochemical oxidant formation (POF): 0.144 g NMVOC eq., terrestrial acidification (TA): 0.21 g SO2 eq. and natural land transformation (NLT): 1.4E-06 m2 eq. per 1 kWh electricity generated. The cumulative energy demand and the energy return on investment (EROI) are 0.393 MJ/kWh and 9.2 respectively. The contribution analysis shows that the pre-operation phase of hydropower plants contributes the highest share (62-99%) in most impact indicators, with the exception that the operation and maintenance phase accounts for about 50 and 90% share in POF and CC respectively. Moreover, medium-scale hydropower plants have higher potential environmental impacts when compared to large-scale hydropower plants. Similarly, the pre-operation phase of wind power is the largest contributor to all the environmental impacts, with the shares ranging between 82 and 96%. In addition, the sensitivity and scenario analyses indicate that the changes in lifespans, exchange rates for parts, capacity factors, transport routes and treatment activities would result in significant changes in the LCA results The results of the assessment show that the lifecycle of wind power generation has more impacts in most impact categories than hydropower generation, except particulate matter formation (PMF), natural land transformation (NLT) and water depletion. In many cases, a single impact category is caused by many processes associated with few lifecycle stages. This demands the engagement of many stakeholders including academia, researchers, developers, operators and policy and decision-makers. In general, these studies would give insight for operators and developers to pay proper attention on determination of sites, capacities and lifespans of power plants and end-of-life waste management options. More importantly, this study can serve as an input to a comprehensive life cycle assessment database of the national energy system in Ethiopia, which is in turn vital to develop communication metrics such as Environmental Product Declarations (EPDs) for economically significant export products in Ethiopia, including electricity itself. However, the results of this study should be interpreted within the context of the data limitations encountered during the course of the research, namely, lack of local datasets for electricity, transport and waste treatment activities relevant to local conditions. Future efforts in Ethiopia should, therefore, be dedicated to undertaking the creation of life cycle inventory databases with a focus on such background systems that will serve as a backbone for all kinds of LCAs in the country, and in and beyond the Horn of Africa region at large. | en_US |
| dc.identifier.uri | http://etd.aau.edu.et/handle/12345678/29335 | |
| dc.language.iso | en_US | en_US |
| dc.publisher | Addis Ababa University | en_US |
| dc.subject | Environmental Life Cycle Assessment | en_US |
| dc.subject | Ethiopian Electricity Generation Systems | en_US |
| dc.subject | Hydro and Wind Power | en_US |
| dc.title | Environmental Life Cycle Assessment of Ethiopian Electricity Generation Systems: A Case of Hydro and Wind Power | en_US |
| dc.type | Thesis | en_US |