
Copyright and moral rights for the publications made accessible in the Research Explorer are retained by the authors and/or other copyright owners and it is a condition of. . Postgraduate Student, Bogazici University, Istanbul, Turkey . Senior Lecturer, Department of Civil and Environmental Engineering, The University of Auckland, Auckland, New Zealand . Senior Engineer, Research and Development Committee, Qatar General Electricity and Water Corporation KAHRAMAA, Doha, Qatar [pdf]
We find that insufficient public charging piles would significantly limit the sales of electric vehicles, in particular when the public charging piles are built up for specific users or in developed regions where private parking spaces are limited.
... The popularity of charging piles can improve the adoption rate of electric vehicles . Travel anxiety caused by insufficient charging points or occupancy of electric vehicle parking spaces are factors that hinder the development of electric vehicles.
In this paper, it is assumed that the construction costs of the CS is proportional to the number of charging piles with a proportion coefficient , then, (6) The EVs end costs mainly include charging costs, driving costs, and waiting time costs as shown in Eq. (8).
According to the changes in average power of new public DC charging piles over the years (Fig. 5.5), the high-power charging piles with 120 kW and above was proliferating, with a proportion of 24.4%, up 4.7 percentage points over 2017, indicating a momentum towards higher power.
According to the statistics of China Electric Vehicle Charging Infrastructure Promotion Alliance (hereinafter referred to as “EVCIPA”) (Fig. 5.1), by the end of 2022, the number of charging infrastructure in China reached 5.209 million. Stimulated by the NEV market, the market demand for charging piles also kept growing swiftly.
In Wu and Yang's study, the authors explored the impact of insufficient public charging piles on EV sales in China. The study revealed that the lack of charging infrastructure had a negative effect on EV sales and improving its availability could promote EV adoption .

In an electrical system, a ring main unit (RMU) is a factory assembled, metal enclosed set of used at the load connection points of a ring-type distribution network. It includes in one unit two switches that can connect the load to either or both main conductors, and a fusible switch or and switch that feed a . The metal enclosed unit connects to the either through a bus throat of standardized dimensions. [pdf]
In an electrical power distribution system, a ring main unit (RMU) is a factory assembled, metal enclosed set of switchgear used at the load connection points of a ring-type distribution network.
Ring main units can be characterized by their type of insulation: air, oil or gas. The switch used to isolate the transformer can be a fusible switch, or may be a circuit breaker using vacuum or gas-insulated interrupters. The unit may also include protective relays to operate the circuit breaker on a fault.
The oil insulated ring main units are commonly seen in mining and oil field applications. Gas insulated ring main units use SF6 S F 6 gas as the insulating medium and are used in low to medium voltage distribution networks to provide uninterrupted power supply and protect the electrical equipment.
Ensuring the safety of electrical systems is paramount, particularly when it comes to sophisticated equipment like Ring Main Units (RMUs). The occurrence of an electric arc is a serious concern in electrical switchgear, including RMUs.
The harmony between ring main units (RMUs) and switchgear is critical for the optimal performance of electrical distribution systems. Ensuring that these pivotal components work efficiently together is a design preference and a necessity for reliable power distribution.
Ring main cables enter and leave the cabinet. This type of switchgear is used for medium-voltage power distribution, from 7200 volts to about 36000 volts. The ring main unit was introduced in the United Kingdom and is now widely used in other countries.

According to the , Yemen has the lowest level of electricity connection in the Middle East, with only 40% of the population having access to electricity. Rural areas are particularly badly affected. Industrial concerns, hospitals and hotels have their own back-up generators. To address these shortages, a 340-MW is under construction-and close to completion-at . Further expansion to the facility, which will add an additional 400 MW of ou. [pdf]
Yemen consumes approximately 4.133 billion kWh of energy (2007 estimate). The country is also looking into the development of wind power, although plans for the construction of a nuclear power generating facility have been shelved. Electrical production is 5.665 billion kWh.
Yemen will generate annual revenue from carbon trading and the sale of unused fossil fuels (such as oil and its by-products) and natural gas by relying on renewable energy to generate electricity. The total generating capacity of wind and solar energy is 18600 + 34,286 = 52886 MW (52.886GW).
Therefore, the remaining power of wind and solar energy is about 33.59GW and according to case two, the total power required which is 9.648GW needed by the Yemeni population in 2030 only accounted for about 18% of the total available power of 52.886GW of wind and solar power, and the remaining power is 43.238GW.
However, Yemen’s current energy mix is dominated by fossil fuels (about 99.91%), with renewable energy accounting for only about 0.009%. The national renewable energy and energy efficiency strategy, on the other hand, sets goals, including a 15% increase in renewable energy contribution to the power sector by 2025 (Fig. 11).
According to the International Energy Agency, in 2000, oil made up 98.4% of the total primary energy supply in Yemen with the remainder comprising biofuels and waste (International Energy Agency). Natural gas and coal were introduced into the energy mix around 2008, and wind and solar energies were added around 2015.
The Yemeni government is committed to economic reform, hoping that it will lead to further economic stability and recovery in the upcoming future. The energy sector is one of the key elements of these improvements (The Republic of Yemen 2013). Besides, Yemen’s power industry is currently witnessing the worst crisis in the nation’s history.
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