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Electrification scenarios dominate most plans to decarbonize the global economy and slow down the unfolding of climate change. In this work, we evaluate from a primary power perspective the impacts of electrifying the power, transport, residential and commercial sectors of the economy. We also investigate the electrification of industrial intense heat processes. Our analysis shows that, in terms of primary power, electrification can result in significant savings of up to 28% of final power use. However, actual savings depend on the sources of electricity used. For intense heat processes, these savings are very sensitive to the electricity sources, and losses of over 70% of primary power can occur during the conversion of heat to electricity and back to heat. Overall, this study highlights the potential benefits and limitations of electrification as a tool for reducing primary power consumption and transitioning to a more sustainable energy system. [ABSTRACT FROM AUTHOR]

Given the dire consequences of climate change and the war in Ukraine, decarbonization of electrical power systems around the world must be accomplished, while avoiding recurring blackouts. A good understanding of performance and reliability of different power sources underpins this endeavor. As an energy transition involves different societal sectors, we must adopt a simple and efficient way of communicating the transition's key indicators. Capacity factor (CF) is a direct measure of the efficacy of a power generation system and of the costs of power produced. Since the year 2000, the explosive expansion of solar PV and wind power made their CFs more reliable. Knowing the long-time average CFs of different electricity sources allows one to calculate directly the nominal capacity required to replace the current fossil fuel mix for electricity generation or expansion to meet future demand. CFs are straightforwardly calculated, but they are rooted in real performance, not in modeling or wishful thinking. Based on the current average CFs, replacing 1Wof fossil electricity generation capacity requires installation of 4Wsolar PV or 2Wof wind power. An expansion of the current energy mix requires installing 8.8 W of solar PV or 4.3 W of wind power. [ABSTRACT FROM AUTHOR]

Energy flows in a fertile environment drive societal development and progress. To develop a country sustainably, striking balance between environmental management, natural resource use, and energy generation is a must. However, developing a country with limited access to energy and critical levels of environmental depletion is challenging. This description fits Rwanda, which faces a dual crisis of energy supply shortages and environment depletion. Overpopulation is driving urban and agricultural expansion which in turn unbalance biomass demand to supply the growing energy needs and exacerbate environmental damage. Just when urgent actions must be taken to overcome this current debacle, political aspirations seek to turn Rwanda into a middle- and subsequently high-income country. From our analysis, the available energy resources can only maintain current population in Rwanda as a low-income country. To become an average middle-income country, Rwanda needs an equivalent of 3 M toe /yr (≈20 M bbl /yr) of oil imports, and must install a nominal capacity of 90 G W of solar photovoltaics (PV). For a high-income country, it is necessary to obtain an extra power input of 11.4 M toe /yr (≈77 M bbl /yr) of oil imports and to install a nominal capacity of 400 G W of solar PV. Comparing current power generation capacity in Rwanda against the extra power needed to achieve the middle-income and high-income status indicates a mismatch between available resources and developmental goals. [ABSTRACT FROM AUTHOR]

Lake Kivu is a great environmental and economic resource in Rwanda. Its deep-water methane reservoir can help the country to narrow its energy supply gap. However, mishandling of the lake could lead to devastating consequences, from potable water contamination to limnic eruption. To evaluate the lake's potential for energy harvesting, we have developed a numerical model and validated it experimentally. Based on this model, we propose an optimal methane harvesting strategy. The harvesting efficiency improvement is from 4 to 6% relative to the alternatives. While seemingly insignificant, a 1% improvement of harvesting efficiency extends the operational time of a gas power plant by ∼ 5%. With these improvements, the lake will sustainably supply 100 MW of electricity for up to 100 years. Potential CO 2 emissions are negligible in comparison with the low-emitting developed countries. We conclude that forestry and agroforestry can mitigate CO 2 emissions and reduce currently widespread deforestation. The degassed water after methane extraction poses another environmental concern. It must be reinjected at the depth of 190–250 m to minimize the environmental impacts on the lake and allow for continuous methane harvesting. [Display omitted] • Evaluation of methane in place and recharge rate in the deep waters of Lake Kivu. • Development of energy-efficient methane harvesting strategies in Lake Kivu. • Quantification of impacts of methane extraction on the lake (disturbing stratification and causing eutrophication). • Assessment of long-term energy production from the harvested methane. • Analysis of associated carbon dioxide emissions and a mitigation plan. [ABSTRACT FROM AUTHOR]