Approximately 40% of global CO2emissions are emitted from electricity generation through the combustion of fossil fuels to generate heat needed to power steam turbines. Burning these fuels results in the production of carbon dioxide (CO2)—the primary heat-trapping, “greenhouse gas” responsible for global warming. Applying smart electric grid technologies can potentially reduce CO2emissions. Electric grid comprises three major sectors: generation, transmission and distribution grid, and consumption. Smart generation includes the use of renewable energy sources (wind, solar, or hydropower). Smart transmission and distribution relies on optimizing the existing assets of overhead transmission lines, underground cables, transformers, and substations such that minimum generating capacities are required in the future. Smart consumption will depend on the use of more efficient equipment like energy-saving lighting lamps, enabling smart homes and hybrid plug-in electric vehicles technologies. A special interest is given to the Egyptian case study. Main opportunities for Egypt include generating electricity from wind and solar energy sources and its geographical location that makes it a perfect center for interconnecting electrical systems from the Nile basin, North Africa, Gulf, and Europe. Challenges include shortage of investments, absence of political will, aging of transmission and distribution infrastructure, and lack of consumer awareness for power utilization.

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Energy-related CO 2 emissions increased to a global peak of 33 Gt in 2019, resulting in an unprecedented level of "Global Warming". Egypt emitted 250 million tons of CO 2 in 2018, thereby ranking 27th among the countries of the world in terms of energy-related CO 2 emissions. Approximately 40% of CO 2 emissions in Egypt orginate from the electricity generation sector, which is predominately dependent on oil and gas (90%), followed by renewables (10%; solar, wind and hydroelectric). To achieve its development goals, Egypt plans to build new power plants with a total generating capacity of 30 gigawatts (GW). Added to the current generating capacity of Egypt's power plants (60 GW), the new power plants will enable electricity generating capacities to reach approximately 90 GW by 2030. Egypt has three scenarios to achieve this goal. In the first scenario, a diversified energy mix scenario, dependence on oil and gas will be decreased in favor of a more diversified energy mix of coal, nuclear power, in addition to renewables and hydro. The second scenario, a fossil fuel-based scenario, is based on recent discoveries of proven natural gas reserves, possibly shifting Egypt's vision towards more dependence on natural gas, as well as renewables, nuclear and hydro. These two scenarios might lead to increased amounts of released CO 2 into the atmosphere. Here we suggest a third scenario, the environmentally friendly scenario or the green scenario, in which more dependence is placed on renewables, hydro and nuclear power, in addition to natural gas, with no coal in the suggested energy mix. In this article, we analyze CO 2 emissions derived from electricity generation under these three futuristic scenarios. The results of our comparison show that building new power plants will lead to CO 2 emissions of 307, 330 and 128 million tons (Mt), respectively, according to the first, second and third scenario, respectively, compared to the current 100 Mt of emissions. These results clearly demonstrate that the third (green) scenario is the only scenario that allows the country to build new power plants to achieve its goals of development while only slightly increasing the amount of CO 2 emissions. In addition, this scenario may be incorporated into the Nationally Determined Contributions ratified by Egypt in the Paris Agreement to limit global warming.

Problem statement: Process continuity of industrial plants (like a refinery) is subjected to several shutdowns due to voltage sags causing large induction motors to trip, either by undervoltage or by overcurrent relays, sometimes by the mechanical protection. These unplanned shutdowns cost the plant tens of thousands of dollars per shutdown in addition to material damage costs, restart charges and any penalties due to delay in product delivery and shipping. Approach: The behavior of induction motors during voltage sags was investigated. In addition to the well-known parameters of voltage sags (time and duration), other parameters such as three-phase unbalance, point on the wave of sag occurrence, harmonics, loading percentage and pre-sag voltage were also examined through computer simulations using the MATLAB/SIMULINK toolbox. Motors' ride-through capability during sags was also studied and guidelines for adjusting the protection relays of the induction motors were highlighted. Results: Results showed that response of induction motor to voltage sags is dependant on sag characteristics, as well as motor and load parameters. Three-phase voltage sags and sags occurring at zero crossing were the most severe events. Transient currents occurring at the instants of voltage sag and voltage recovery are directly proportional to the voltage drop, not to the remaining voltage magnitude. Transient currents and torques induced at the instant of sag recovery are higher than those induced at the instant of sag occurrence. Lightly-loaded motors and motors operated at voltages higher than the nominal voltage are less affected by voltage sags. Conclusion: Manufacturers of induction motors impose strict protection settings to protect their machines from any possible damage. However, the starting process of the motor inherits starting currents and torques much higher than those occurring during voltage sags. Readjusting of the protection relay settings especially the undervoltage relay may be adequate to counteract voltage sags. No conditioning equipment was required.

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