Nowadays, hybrid renewable systems can be the best solution for meeting electricity demand, especially where grid extension and environmental issues are important. This study aimed to find the best combination of the typical components used in East Java, Indonesia. In this regard, four types of photovoltaic (PV) panels, four types of wind turbines, and two types of batteries were selected, and the HOMER software simulated all possible combinations of the systems, including 32 scenarios (Sen). Then, considering the most important 15 parameters, such as pollutant emissions and economic values, the results were analyzed and sorted by the multicriteria decision-making (MCDM) method to find the best scenario for the case-study region. The results showed that SunPower E20-327 as PV, Eocycle EO10 10 kW as wind turbine, and Generic 1 kWh Li-Ion as the battery could be the best selection to design a hybrid renewable system for the case-study region since it can fulfill both economic and environmental needs. The cost of energy (COE) of the best-designed system and net present cost (NPC) are 0.24 ($/kWh) and 1.64 million $, respectively, where the renewable fraction (RF) is 55.1% and the scaled annual average load is 1126 kWh/day. The results of the sensitivity analysis on the best scenario’s parameters (where the capital cost of PV, battery, and wind turbine changes from 0.6 to 1.2, from 0.7 to 1.2, and from 0.7 to 1.4 of the current price, and diesel price from 0.5 to 1.1 ($/L)) showed that the RF, COE, and NPC values ranged between 51% to 93%, 0.2 to 0.3 ($/kWh), and 1.4 to 2.1 (million $), respectively.

One of most important things now is to create smart street and smart lighting system to save enormous electrical energy. Especially Iraq is suffering shortage of electrical energy generation up to 45%. Because of this, Iraq needs to save a lot of electrical energy in the entire country so as to meet the electrical demand and reduce the large amount of CO₂ emission. However, this work presents a very unique and economic control lighting system (CLS) for main streets and sidewalks, which can control the lighting system to give sufficient illumination to the drivers and the pedestrians simultaneously. And at the same time, the CLS system can reduce a lot of electrical energy consumption and the CO₂ emissions together. However, by using these smart systems with the exciting illumination source in the streets, the CLS can minimize the electrical energy consumed for the lighting at the main roads and the footpath by about 60% and can use the surplus energies to fill the shortage of electricity in the country. Also, this system will increase the lifetime of the lighting system which means further decrease in cost. Finally, this work presents new type of illumination source, high-intensity discharge (HID), which can reduce the electrical consumption much more by up to 90%, when using the CLS with HID.

Due to its ease of control, the DC motor is a critical equipment in a wide variety of industrial applications that need changing speed and load parameters. Today’s market is flooded with high-quality motor speed controllers. Their prices, on the other hand, are rather expensive. A low-cost, high-performance speed controller will be in high demand, particularly for small mobility applications. Three techniques for regulating the speed of a direct current motor are explained. The proposed system has several advantages, including a simple structure, low cost, accuracy, quiet efficiency, small volume, and bi-directional speed control. In the second method, a linear voltage regulator was used. The benefits of a linear voltage regulator include simplicity of design and ease of use, as well as protection from high power draw due to the nature of the load or a short circuit. The advantages of the push-pull amplifier in the third method are low distortion, the benefits include the absence of electromagnetic saturation in the coupling transformer core and the elimination of power supply waves, which results in the absence of hum, while the drawbacks include the need for two identical transistors and the usage of large, costly coupling transformers. In the third method, the amplifier’s drive configuration advantages include little distortion, absence of electromagnetic saturation in the main coil of the connection, and termination of power supply ripples, which results in the absence of hum. Its disadvantages include the requirement for twin transistors that are similar and the use of coupling transformers that are large and pricey.