International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Solar energy has a drawback when it works individually, because it could not produce electrical energy in rainy and cloudy seasons, and during the night time. Wind energy is not constant and it varies from zero to storm force. This means that wind turbines do not produce the same amount of electricity all the time. Therefore, the need to overcome these drawbacks could be by combining two energy resources so that any one source fails the other source will keep generating electricity. In this study, a designed prototype that combines two energy resources wind and solar energy will be constructed and tested. The design will supply the sustainable energy resources without damaging the nature and gives uninterrupted power. Also it works during day time and produce DC power by the solar PV cell which is stored in the battery bank through a hybrid controller, which maximizes charging current and prevents excessive discharge/overcharge. The Wind turbine generator will generate power when wind speed exceeds cut-in speed; wind power is also stored in the battery bank through hybrid controller. Energy stored in the battery is drawn by electrical loads through the inverter, which converts DC into AC power. The inverter has in-built protection for short-circuit, reverse polarity, low battery voltage and over load. The battery bank is sizing to feed loads up to five hours, during non-sun/wind days. The designed prototype has proved to work efficiently for a sustainable electricity supply for 24 hours, the results of this work give an incentive to proceed with building and using such sustainable power generation systems (hybrid) that have proven to be efficient and economically feasible to use for continuous energy generation which is suitable for urban, rural and isolated areas.

The study addresses to an economic comparison of two proposed wind farms in the same area in Mamaj, Albania, respectively 10.8 MW and 12.6 MW. The 12.6 MW wind farm proposed is predicted to produce 34 GWh energy, with a capacity factor of 30.8%, while the 10.8 MW wind farm is predicted to produce 30.4 GWh, with a capacity factor of 32%. For the 12.6 MW wind farm since there is a higher installed power, is expected to produce more energy, but referring that they will be built in same area, the wake losses will indicate in overall efficiency of the wind farm. The wake losses calculated for the 10.8 MW wind farm are 0.98%, meantime for the 12.6 MW wind farm wake losses is calculated 2.58%, means that the overall efficiency of the 10.8 MW wind farms is higher. For the economic evaluation RETScreen Expert software is used. With a discount rate of 7%, the benefit-cost ratio is 2.9 and simple payback period 7.6 years for 10.8MW wind farm, and for the 12.6 MW the benefit-cost ratio is calculated 2.6, with a simple payback year of 8 years.

The future development of the renewable energy sector in Bulgaria is already set by the European Commission in the “Energy Map of Europe – 2050”. The goals of the Green Deal should not predominant the goals of environmental protection and reverse. Bulgaria should ensure balance and sustainability in the development especially of wind energy sources due to the fact that most energy potential areas fall in the protected areas and territories by Natura 2000. The biggest such conflict observed in that report is the region of North- Eastern Bulgaria. The production of electricity from wind is one of the activities that has a potential impact on birds. For this reason, the subject of this study analyses the available data and summarize the birds’ impacts of wind generators in the region of North – Eastern Bulgaria.

Renewable energy sources (RES) will continue to play a key role in the process of deep decarbonisation of the energy sector especially in the power branch. Effects of environmental, economic, social, political and technical factors condition the rapid deployment of various sources of renewable energy-based power generation. In this case study the optional GHG reduction credit per equivalent tonne of CO2 (tCO2) used in conjunction with the net GHG reduction to calculate the annual GHG reduction revenue of a 27MW wind farm located in Qafë-Thanë, Pogradec-Albania is analysed. As the future availability of renewable energy resources is not affected by their use, wind power can address many questions related to sustainability and flexibility of the existing fuel powered technologies. Hence, cutting carbon dioxide (CO2) emissions in Albania should be fully in line with the Paris Agreement including power sector especially. The proposed action aims at developing a high-level promotion and market penetration strategy for RES, contributing to the mitigation of GHG in EU as well as in the candidate countries including Albania. Furthermore, special support should be given to candidate countries in creating policies and programmes to facilitate and promote RES technologies.

This work is focused on CO2 credit rate impact application as one of the most feasible technology to make the wind turbines cost effective for power generation. Wind energy is clean, infinite and environment friendly source of energy. However, wind energy systems, alone or hybrid systems have a high potential to reduce CO2 emissions, fuel and total cost of the system compared to the other options applied historically in power sector. Such systems are foreseen to play a key role in a stable, costless and emission-less way especially in large scale applications. The performance, availability, costs and carbon intensity of wind power indicate that CO2 credit rate can make a very substantial contribution to reduce carbon emissions and gain the security of investment of RES technologies. The other options applied would deliver only partial emission reductions, therefore, are not sufficient to attain the 2030 national energy goals so they have to rely on renewable energy technologies. Policy makers and interest parties/investors need to focus unerringly on scaling up the actual developed few options consistent with reaching the zero-emission goal.

In this study wind potential investigated for the region to the east of Turkey’s Hakkari centers. The wind speed and direction information used in the study were taken from the measurement station belonging to the General Directorate of Meteorology in Hakkari Center. Data sets containing 5 year wind speed and wind direction between 2013 and 2017 taken from this measurement station were analyzed by the WASP program. The NASA SRTM data library in the WASP interface was used to create digital maps for the region. Regional barriers required for areas where wind potentials are searched and roughness maps were created using Google Maps. As a result of these analyzes, annual average wind speed value of 1.96 m / s and average power density of this region in Hakkari Center is calculated as 12 W / m2. The prevailing wind direction belonging to this region has been identified as Southwest, but it has been found that this dominant wind direction changes with great proximity to the Southeast-Northwest sector interval on the South side.

In the report will be presented the investigation results of the working model of rotors with variable geometry parameters in dynamics. Because of aerodynamic and economic calculations, the effectiveness of use of such designs for powerful wind stations is proved. The analysis of various designs and methods of selection of that or other design for various conditions of operation of wind installations in wide range of the wind speed change is given.
Also rather effective by cost-price method of accumulation of wind energy will be suggested that is the topical world problem and for development of which are annually spent some hundreds of millions of US Dollars.