Fast growing and emerging economies face the dual challenge of sustainably expanding and improving their energy supply and reliability while at the same time reducing poverty. Critical to such transformation is the provision of affordable and sustainable electricity for the 1 billion peo-ple that do not have access and hundreds of millions connected to underperforming systems. However, expansion of electricity service in emerging economies is following the same century old paradigm under which power systems evolved: large central generation plants connected to load centers through a transmission grid and distribution lines with radial flows. This paradigm is now being challenged by the development and diffusion of modular generation and storage technologies. This dissertation contributes with models and results to help policy makers and pri-vate developers embrace these technological changes to develop cost-effective strategies to ex-pand electricity access.

I use the SWITCH capacity expansion model to explore low carbon development pathways for the Kenyan electricity generation and transmission sectors under a set of plausible scenarios for fast growing economies that include uncertainty in load projections, capital costs, operational performance, and technology and environmental policies. This research investigates the genera-tion and transmission costs and operational and environmental impacts on the Kenyan expansion pathway of these variables and policies. I find that the Kenyan power system presents a unique transition from one basal renewable resource – hydropower – to another based on geothermal and wind power for ~90% of total capacity. I also find that a cost-effective and viable suite of solu-tions includes availability of storage, diesel engines, and transmission expansion to provide flexi-bility to enable up to 50% of wind power penetration. Results suggest that fast growing and emerging economies could benefit by incentivizing anticipated strategic transmission expansion. “Zero carbon emission” by 2030 pathways are possible with only moderate levelized cost increas-es of between $3 to $7/MWh with a number of social and reliability benefits.

Traditional capacity expansion modeling that focuses on large-scale generation and transmis-sion does not evaluate the potential contribution of distributed resources – modular technologies that can be deployed close to load centers. To improve on these modeling limitations, I use a novel approach to assess the sequencing and pacing of centralized, distributed, and off-grid elec-trification strategies by developing and employing the Grid and Access Planning (GAP) model. GAP is a capacity expansion model to jointly assess operation and investment in utility-scale generation, transmission, distribution, and demand side resources. Contrary to the current prac-tice, I find hybrid systems that pair grid connections with distributed energy resources (DER) are the preferred mode of electricity supply for greenfield expansion under conservative reductions in PV and energy storage prices. I also find that when distributed PV and storage are employed in power system expansion, there are savings of 15%-20% mostly in capital deferment and re-duced diesel use. Results show that enhanced financing mechanisms for DER PV and storage could enable 50-60% of additional deployment and save 15 $/MWh in system costs. These re-sults have important implications to reform current utility business models in developed power systems and to guide development of electrification strategies in underdeveloped grids.

A comprehensive development of electrification strategies requires complementing modeling results with empirical observations of the electrification process. I leverage two household budget surveys developed in Kenya in 2006 and 2016 as a unique data-driven window into the drivers of electricity access and the evolution of the electrification process. I find evidence that gains in electrification have come from grid extensions into rural areas as well as from people migrating from rural areas to cities, that rural grid extensions may be underutilized, and that poorer quintiles remain vastly unsupplied. Results highlight the role that modular technologies can play to com-plement traditional grid extensions to increase the pace and coverage of electrification efforts. Ultimately, comprehensive electrification strategies will need to integrate technological advances, new modeling paradigms, and the domestic socio-cultural context into policy making to advance electricity access decisively in low-income economies.