Optimization-based modeling of Kenya’s energy system for pathways towards access to secure, affordable, and sustainable energy services

Global climate change is one of the most significant challenges that need urgent action in this century. Energy production and consumption, particularly for heat and electricity generation, account for the highest GHG emissions from anthropogenic activities. The world energy demand is projected to increase as the population grows and efforts double to bridge the demand-supply gap in countries yet to achieve universal access to modern energy services. Currently, out of the 770 million people who lack access to electricity worldwide, 580 million live in Africa, predominantly in the Sub-Saharan Africa region. Using advanced energy planning tools to guide national energy objectives and decisions will be critical in addressing energy poverty while shifting to low-carbon fuels in Sub-Saharan Africa. Advanced energy planning tools have a detailed technological representation, account for greenhouse gas (GHG) emissions and cost, and assess low-carbon policies optimally. This work aims to develop a quantitative energy system planning model for Kenya to evaluate pathways towards access to secure, affordable, and sustainable energy services for the 2020 to 2050 period. This thesis is composed of three journal articles that describe the outcome of this work. The first article reviews the existing integrated energy modeling studies done for the Sub-Saharan Africa region at a country or regional level. The reviewed studies show that the models, based on different mathematical approaches and assumptions, inadequately addressed some fundamental energy themes, such as low-carbon policies and energy cost. It is recommended that the SSA countries develop national-scale energy planning models using advanced planning tools, which could be expanded into a regional model. The second article develops a national-scale energy model for Kenya using the advanced bottom-up energy optimization Integrated MARAKAL-EFOM (TIMES) framework. Using the developed Kenya-TIMES model, the study assesses the environmental and techno-economic assessment of power system expansion for three projected demand levels for Kenya for the 2020 to 2045 period. The results indicate that the government will not meet its nationally determined contribution (NDC) GHG reduction targets in the vision demand scenario without implementing low-carbon policies. The third article develops the Kenya-TIMES model further to assess the low-carbon development strategies for Sub-Saharan Africa, using the case of Kenya. This study evaluates the implication of the carbon tax, renewable energy subsidy, renewable portfolio standards, and a hybrid of renewable subsidy and carbon tax policy instruments on Kenya’s power generation expansion for 2020 to 2050 under vision demand level. The GHG emissions are evaluated against Kenya’s NDC emission reduction targets. The results indicate the evaluated low-carbon policy instruments could help achieve emission cuts below the government’s NDC targets. Overall, this work sets a benchmark for developing a national-scale energy planning model using advanced energy planning tools and using it to guide the national energy objectives and decisions that Sub-Saharan Africa countries could adopt.Kenya Electricity Generating Company (KenGen) GRO-Geothermal Training Programme Reykjavik UniversityThesi

Sub-surface petrochemistry, stratigraphy and hydrothermal alteration of the domes area, Olkaria geothermal field, Kenya

Wells OW-905A, OW-910 and OW-917 have been drilled in the Domes area of the Olkaria geothermal field. Wells OW-905A and OW-910 have been drilled inside the caldera while OW-917 has been drilled on the eastern margins of the caldera rim. The caldera rim is characterised by a ring of rhyolitic domes to the east, south and southwest margins. Plans are underway to expand production drilling to the east of the Domes field. This study presents an in-depth look at the variation in reservoir characteristics across the Domes field and to the east of the ring structure. The study also delineates magma differentiation processes involved in the evolution of the GOVC. Wells OW-905A and OW-910 cut across seven stratigraphic units namely basalt, trachybasalt, basaltic trachyandesite, trachyandesite, trachyte, rhyolite and tuff. Well OW-917 only cuts across trachyte and rhyolite. Intrusives cut by the wells include micro-granite, syenitic, trachytic and basaltic dykes. Well OW-910 has a high abundance of high-temperature alteration minerals, OW-905A has moderate abundance while OW-917 has low abundance of these minerals. Higher temperatures are observed at shallower depth in OW-910, at relatively greater depth in OW-905 and at greater depth in OW-917. High permeability is observed in wells OW-905A and OW-910. Well OW-917 shows poor permeability. Well OW-905A is located in a recharge zone, OW-910 in the up-flow zone close to the heat source and OW-917 in a down-flow zone. The main magma differentiation processes involved in generation of the basalt-trachyte suite are fractional crystallisation and magma mixing. Rhyolites have been generated through fractionation of trachytes and anatexis of syenites. The GOVC has had different episodes of eruptions. Its plumbing system consists of independent discrete magma chambers and conduits in which magma underwent modification before eruption.Jarðhitaholur OW-905A, OW-910 og OW-917 voru boraðar á Domes-svæði Olkaria-jarðhitasvæðisins. OW-905A og OW-910 eru staðsettar innan ætlaðrar öskju, en OW-917 á austurjaðri hringbrotsins. Áætlanir eru um að bora fleiri vinnsluholur austan Domes-svæðisins. Í þessari rannsókn eru breytingar í eiginleikum jarðhitakerfisins þvert yfir Domes-svæðið allt austur fyrir hringmyndunina skoðaðar nákvæmlega. Í rannsókninni er líka fjallað um kvikuþróun sem átti sér stað við upphleðslu Olkaria-megineldstöðvarinnar. Holur OW-905A og OW-910 liggja gegnum sjö mismunandi gerðir jarðlaga, þ.e. basalt, trakýbasalt, basaltískt trakýandesít, trakýandesít, trakýt, rhýólít og túff. Í OW-917 er einungis trakýt og rhýólít. Þær gerðir innskota sem holurnar voru boraðar gegnum eru míkrógranít, sýenít-, trakýt- og basaltgangar. Hola OW-910 er mjög rík af háhitasíðsteindum, OW-905A hefur minna magn, en OW-917 er snauð af slíkum steindum. Hátt hitastig kemur fram á tiltölulega litlu dýpi í OW-910, á meira dýpt í OW-905 og á mestu dýpi í OW-917. Mjög góð lekt er í borholum OW-905A og OW-910, en OW-917 hefur lága lekt. Hola OW-905A er staðsett í aðfærslustreymi, OW-910 í uppstreymissvæði nærri varmagjafa og OW-917 í niðurstreymissvæði. Helstu kvikuferli sem áttu sér stað við þróun basalt-trachýtsyrpunnar voru hlutkristöllun og kvikublöndun. Rhýólítkvika hefur myndast við hlutkristöllun á trakýtkviku og uppbræðslu á sýeníti. Olkaria-eldstöðin hefur gengið gegnum eldgosahrinur. Kvikufærslukerfi hennar samanstendur af sjálfstæðum kvikuhólfum og kvikuæðum þar sem kvika þróaðist áður en gos urðu