Wind Energy Potential Research Articles

To the selection of technology parameters for the use of renewable energy sources on man-made disturbed lands

Renewable energy sources (RES) have become widely used in many developed countries of the world. In the article, the use of RES is considered using the example of wind energy installations (WEI). For industrial scale volumes of electricity produced, wind energy installations of large capacities and designs are used. To choose a rational design of windmills, a classification of windmills of existing designs is provided. Known foreign types of efficient wind generators are considered. Most often, wind energy installations are used in places with a strong wind flow. Wind energy installations with a horizontal axis of rotation are usually used in these areas. For example, information is given on one of the largest wind farms in Ukraine - the Botiivskyi wind farm, which consists of 65 wind energy installations with a horizontal axis of rotation. The practice of using windmills, despite the great benefits of their use, has significant drawbacks. This problem consists in deriving large plots of land for use and having an impact on the surrounding environment. This, in turn, leads to negative consequences for the ecology of these regions. In connection with this, there was a need to use wind energy installations on land plots that have been decommissioned in the conditions of Kryvbas. These include sparsely populated regions, wastelands, and decommissioned plots of land on which the facilities of mining enterprises are located. It has been proven that the placement of WEI with a vertical axis of rotation of medium power on overburden dumps has its own characteristics. For most of the territory of Ukraine, the average wind speed is 3-5 m/s, so the use of wind turbines with a vertical axis of rotation is more appropriate. The starting speed of such wind energy installation is 0.5 m/s, and at a wind speed of 3 m/s, wind energy installations can reach their nominal power. The paper analyzes the possibility of using wind energy installations on man-made disturbed lands, namely on open rock dumps, and recommends their design features. The calculation of the wind energy potential for vertical and horizontal wind energy installations in the conditions of the city of Kryvyi Rih was made. A comparison of the use of vertical and horizontal wind energy installations was made. The effectiveness of the use of wind energy installations with a vertical axis of rotation in the conditions of Kryvbas is shown.

Modeling of Wind Power Generation in Tegal Region using Matlab Simulink

The increasing energy demands require larger energy production. However, fossil energy sources are depleting, necessitating the use of renewable energy to replace fossil fuels and meet energy needs in Indonesia. Indonesia has a significant wind energy potential. Wind power generation modeling is carried out in one of the cities in Indonesia, namely Tegal. By using Matlab Simulink, it is expected to assist in predicting renewable energy production. Tegal is one of the regions with high wind speeds in Indonesia, specifically at 3 m/s. From the modeling, the optimal blade radius and rotor angular velocity that can generate maximum power at a wind speed of 3 m/s can be determined. Wind power generation in Tegal with a wind speed of 3 m/s has the potential to produce electrical power of 768.55 W.

Assessment of wind and wave energy potential along the Indian coast

Assessment of wind and wave energy potential along the Indian coast

Renewable Energy from Wind Farm Power Plants in Peru: Recent Advances, Challenges, and Future Perspectives

Peru is one of the most diverse countries in the world, and its climatic characteristics, biodiversity, cultural heritage, and location on the planet give it a vast potential for wind energy, both on its coast and within the 200 miles which comprise the Peruvian coastline on the Pacific Ocean. Likewise, the northern and central areas of the country represent the regions with the greatest potential for wind energy use. In this context, wind energy is a viable alternative to mitigate the effects of climate change in local territories and, thus, meet the Sustainable Development Goals (SDGs) outlined in the 2030 United Nations (UN) Agenda. This article presents the potential for generating wind-type electrical energy both on-shore with 20.5 GW and off-shore with 347 GW. In addition, the main advantages, benefits, and restrictions in the implementation of this type of energy plants in Peru are presented, considering the following: (i) the mitigation of climate change considering the insertion of renewable energies in the energy matrix; (ii) the potential of the available wind resource; (iii) the characterization of seven existing wind power plants, considering a total installed capacity of 668 MW; and (iv) the implementation of future wind power plants considering a portfolio of 31 projects for 7429 MW of total installed capacity projected. Finally, recent advances, challenges linked to territorial implementation, and future perspectives in developing the renewable energy sector from wind resources to address climate change are discussed.

Climate, water, hydropower, wind speed and wind energy potential resources assessments using weather time series data, downscaled regional circulation models: A case study for Mono River Basin in the Gulf of Guinea region

Hydropower and wind energy are important renewable energies source in Gulf Guinea region, but they are sensitive to climate change, because the changing climate may alter atmospheric and hydrological conditions. In this study, firstly we analyzed the historical hydro-climate data in connection with changes in Mono river of Gulf Guinea region discharge and their associated impacts on hydropower generation and assessed the future hydropower availability in different climate scenarios. Secondly, statistical methods are used to examine past and future wind speed (WS) and wind energy potential. We used historical data (1981–2010) obtained from the National Meteorology Agency in Togo and Benin and a multi-model ensemble for future projections data (2021–2050) of eight selected Regional Climate Models (RCMs) under Representative Concentration Pathway (RCP) under scenarios 4.5 and 8.5. We found in the recent past years that the temperature and evaporation increase during dry season, while flows and hydropower generation decreased. The multi-model ensemble used have announced that in general, the decreasing trend of the rainfall and increasing trend of temperature is projected to be higher in RCP 8.5 than RCP 4.5, in the near future (2021–2050). Overall, the annual hydropower potential the hydropower will decrease between 8 and 19.3% under the RCP4.5 and 9 and 29% under the RCP8.5 while the monthly hydropower potential is projected to decrease by 4–41% under the RCP4.5 and by 6–47% under the RCP8.5 in the same period. Concerning the wind speed and the potential wind power, the observed results show that both the Weibull and Rayleigh approximations provided a better fit for the wind speed data. The projected of wind speed and wind power density (2021–2050) at an annual timescale is similar to the monthly timescale of wind speed and wind power density at 90 m height. The multi-model ensemble indicate that projected wind speeds (WS) are between 5 and 10 m/s under the RCP4.5 and, between 3 and 12 m/s under the RCP8.5 while wind power density is projected by 15–250 w/m2, and by 13–357 w/m2 under the RCP4.5 and under the RCP8.5, respectively. South and North of Mono basin, have higher WPD and are promising for installing wind turbines for small-scale power generation.

Potential impacts of climate change on renewable energy in Egypt

The need for renewable energy sources is recently necessitated by attaining sustainability and climate change mitigation. Accordingly, the use of renewable energy sources has been growing rapidly during the last two decades. Yet, the potentials of renewable energy sources are generally influenced by several climatic factors that either determine the source of energy such as wind speed in the case of wind power or affect the performance of system such as the reduction in solar PV power production due to temperature increase. This highlights the need for assessing climate change impacts on renewable energy sources in the future to ensure their reliability and sustainability.This paper is intended to assess impacts of climate change on wind and solar potential energy in Egypt by the year 2065 under RCP 8.5 scenario. For this purpose, a GIS-based methodology of three main steps was applied. The results revealed that solar energy potential in Egypt is expected to be relatively less vulnerable to climate change compared to wind energy. In this respect, it was found that while wind energy potential was estimated to range ± 12%. By the year 2065 under RCP 8.5 scenario, PV module power is expected to decrease by about 1.3% on average. Such assessment can assist in developing more sustainable and flexible renewable energy policy in Egypt.

Three-Parameter Weibull for Offshore Wind Speed Distribution in Malaysia

It is usual practice to employ the probability density function in order to ascertain the wind energy potential. In this paper, the three-parameter Weibull model was suggested to distribute the low wind speed data at a site off the coast of Kijal, Terengganu. The maximum likelihood approach was used to determine the value of the distribution parameters. The Matrix Laboratory (MATLAB), better known for its user-friendly programming language, is used to carry out all of the analysis. The three-parameter Weibull was compared with the two-parameter Weibull and Rayleigh using the R-squared and the root mean square error (RMSE). These three distributions statistically model hourly ERA-5 reanalysis wind speeds. The three-parameter Weibull has a good performance, since it appears between the best R2 closest to 1 and RMSE the closest to 0. The R2 for the three-parameter Weibull is 0.9898, the two-parameter Weibull is 0.9874, and Rayleigh is 0.5153. While the RMSE Three-parameter Weibull is 0.0070, the two-parameter Weibull is 0.0082, and Rayleigh is 0.0677.

Assessment of Urban Wind Potential and the Stakeholders Involved in Energy Decision-Making

Urban wind energy has emerged as an attractive source of distributed generation in cities to achieve sustainable development goals. The advancement in technologies for the use of urban wind energy has offered an alternative for the decarbonization of cities and the energy transition. The objectives of this work are (1) to identify the potential of wind energy through numerical weather prediction (NWP) data tools and (2) to identify the roles and responsibilities of the stakeholders involved in the decision-making process. A methodology was developed in two phases and applied to a case study in the Dominican Republic. The first phase consisted of estimating the wind energy potential for the 32 provinces at a height of 10 m using open access NWP tools provided by NASA. In the second phase, 28 stakeholders were identified through snowball sampling. The Responsible, Accountable, Consulted, and Informed (RACI) matrix tool was applied to identify the roles of the 28 institutions addressed at the country level as relevant in the decision-making process for the energy sector. The annual average wind speed and energy potential for each province were determined. It was found that 24 provinces have poor potentials, below <4.5 m/s. In the northwest and east is where there is the greatest potential, between 4.83 and 6.63 m/s. The population density was established, and it was observed that the provinces with greater potential are less densely populated. Through 59 interviews, 28 institutions were identified and evaluated due to their relevance in decision making for the implementation of energy projects. According to the RACI matrix, the Ministry of Energy and Mines has been categorized as “A”, electricity distribution companies as “R”, energy associations and universities as “C”, and educational and justice institutions as “I”.

Assessing the Wind Power Potential in Naama, Algeria to Complement Solar Energy through Integrated Modeling of the Wind Resource and Turbine Wind Performance

In the context of the escalating global climate crisis and the urgent need for sustainable energy solutions, this study explores the integration of wind energy as a supplementary source to solar photovoltaic energy in Naama, Algeria. The research utilizes a decade-long anemometric dataset, along with concurrent solar radiation data, to investigate the potential of harnessing wind energy, particularly during periods of low solar irradiance. Employing advanced statistical methods, including the Weibull distribution, the study assesses the wind power generation potential of a 2 kW/day turbine. The research highlights an average evening increase in wind speeds, which inversely correlates with the diminished solar energy production after sunset. This seasonal pattern is further substantiated by a significant negative correlation between wind speed and solar radiation for most of the year (January to May and September to December), with Pearson coefficients ranging from −0.713 to −0.524 (p < 0.05). However, the study also notes an absence of a notable correlation during the summer months (June to August) attributed to seasonal wind variations and the peak of solar irradiance. These findings confirm Naama as an ideal location for integrated renewable energy systems, thereby demonstrating the natural synergy between solar and wind energy. This synergy is particularly effective in mitigating the intermittency of solar power, thus highlighting the potential of wind energy during periods of low solar activity.

A pathway to 25% reduction in greenhouse gas emission by 2030 using GIS-Based multi-criteria decision making for renewables, date palm (phoenix dactylifera), and carbon credits: a case for Qatar

Qatar is making concerted efforts at the national level to decrease anthropogenic greenhouse gas emissions. The country has set its National Determined Contribution (NDC) in line with the Paris Agreement to reduce its overall emissions by 25% by the year 2030. This study identifies several pathways, which Qatar can explore to achieve its set goals. It explores Qatar’s potential for renewable energy generation (solar and wind), carbon offset through planting trees, and the purchase of carbon offset credits. The study starts by investigating the available wind and solar energy potential in the country, by considering physical and legal restrictions, which limit the available land to be utilized for RE generation. Multi-criteria Decision is carried out utilizing the Analytic Hierarchy Process (AHP) for variable percentage estimation in ArcMap Geographic Information Systems software. Next, a review based on Qatar’s climate is performed to identify suitable tree species that would promote atmospheric CO2 sequestration in the country. Finally, the cost implication of offsetting emissions using verified carbon credits is considered and compared with other options. Results indicated that while a considerable area is available for both wind (37%) and solar (53%) energy generation, only 6.2% and 13.8% of Qatar are highly suitable for wind and solar energy installations, respectively. Also, while Qatar has the potential to meet 20% of its energy demand by 2030 from renewable sources by using solar PV and wind, this will only account for a 14.28% reduction in overall emissions. Additionally, planting date palm trees (Phoenix dactylifera) would significantly benefit the nation in the area of carbon sequestration and revenue generation as compared to purchasing carbon offset credits.

Instantaneous 2D extreme wind speed prediction using the novel Wind Gust Prediction Net based on purely convolutional neural mechanism

Accurate prediction of spatial–temporal extreme wind gust is vital for the wind farm dynamic regulation, the floating wind turbine deployment and its early warning. Deep-learning approaches have been applied for wind prediction to alleviate the computational challenges of traditional numerical models. Yet, most previous studies emphasized the prediction accuracy only employing location-specific dataset, such methodologies are site-specific and ignore the importance of spatial–temporal fidelity. Furthermore, the Recurrent Neural Networks (RNN)-based approach previous employed exhibit low efficiency in terms of model convergence and on the aspect of practical engineering purposes. This study firstly proposed the wind gust prediction net (WGPNet), using residual learning with attention modulations to predict the instantaneous spatial–temporal wind gust in the West Pacific region with great potential wind-energy. And a public reanalysis dataset with very high resolution (0.25° x 0.25°) was employed to verify the proposed method under different criteria. The overall RMSE of predicted gust fields obtained by the proposed method dropped to 0.18 m/s. Comprehensive discussions with both temporal and spatial perspective, revealing that the proposed model can offer an accurate 2D wind gust prediction along timeline (the PCC equals to 0.98).

Comparative Estimation of Onshore (Okada) and Offshore (Okerenkoko) Wind Speed for Potential Wind Energy Access in Delta State, Nigeria

Comparative Estimation of Onshore (Okada) and Offshore (Okerenkoko) Wind Speed for Potential Wind Energy Access in Delta State, Nigeria

Wind energy potential of weather systems affecting South Africa’s Eastern Cape Province

AbstractAs a percentage of the total global energy supply, wind energy facilities could provide 10% of the total global energy supply by 2050 as reported in IEA World Energy Outlook (2022). Considering this, a just transition to renewable and sustainable energy in South Africa is a genuine possibility if steps are taken immediately to achieve this. The Eastern Cape Province exhibits a strong wind resource which can be exploited towards expediting such a just energy transition. No research and related modelling have, to date, been undertaken in quantifying and relating the detailed P50 energy yield analyses of representative wind energy facilities in temporal and spatial dimensions to the occurrence of specific synoptic types in South Africa. To quantify this energy meteorology climatology for a suitably sized geospatial area in the Eastern Cape Province of South Africa (spatial focus area, latitude −30 to −35, longitude 20 to 30), the approach of using self-organising maps is proposed. These maps are used to identify the most common synoptic circulation types occurring in the Eastern Cape and can subsequently be mapped onto an equivalent time resolution wind energy production timeseries calculated based on probable wind energy facility sites. This paper describes comprehensive methodologies used to model the wind energy facilities, calculate with high confidence the P50 energy production, and then identify the predominant synoptic weather types responsible for the wind energy production in this spatial focus area. After quantifying the energy production, running a self-organising map software generates a purposely selected 35 node map that characterises archetypal synoptic patterns over the 10-year period. The synoptic types can be ranked by the highest energy production. It is shown that in this spatial area, monthly wind energy production is higher during the winter months. When the well-established high-pressure cells move northward, synoptic types associated with higher energy production are frequent and include tropical and temperate disturbances across South Africa, patterns resembling a ridging anticyclone off the west coast of South Africa and low-pressure cells occurring to the north and south. Low energy producing patterns show characteristics of the high-pressure cells moving southwards producing fine weather and mildly disturbed conditions. The purpose of this methodology is that it provides the foundation required to derive long-term frequency changes of these synoptic weather systems using global climate model ensembles and thus changes in wind energy production.

Investigation and Optimization of Integrated Electricity Generation from Wind, Wave, and Solar Energy Sources

This study investigates the potential for renewable energy-based electricity generation using existing wave, wind, and solar energies in Türkiye. A significant part of Türkiye’s energy needs is still met using fossil fuels. Considering the country’s resources, renewable energy sources appear as an alternative source to meet these needs. The objective of this study is to find an effective, efficient, economical, environmentally friendly, and sustainable way to produce electricity to reach net-zero targets and transition towards low-carbon and carbon-free energy systems. To be able to make a deep investigation about the relevant issue, six provinces from different regions of Türkiye (Antalya, Çanakkale, İstanbul, İzmir, Kırklareli, and Muğla) are assessed in terms of wave, wind, and solar energy potential, including wave data, wind speeds, sunshine duration, and global radiation values. Wind, wave, and solar energy data of the selected regions were taken from the ERA5 database, which is the weather forecast model of the European Center for Medium-Term Weather Forecasts (ECMWF), and the Ministry of Energy and Natural Resources of the Republic of Türkiye and the General Directorate of Meteorology. Calculations were made using monthly data for the last 5 years. Considering the coastal lengths in the determined regions, the annual total electrical power produced from wave, solar, and wind energies was calculated. In these calculations, the coastal length parameter was assumed to be uniform across all cities, and the electrical power potential from these energy sources was analyzed. Within the framework of these analyses, the number of houses in the selected regions whose electricity needs can be met was calculated. As a result, the potential electrical power and the amount of affordable housing units in the selected regions were compared. As an important result of the studies, it was determined that the characteristic features of the selected regions, such as wavelength, wave height, and wind speed, were directly related to the applicable coast length. The power obtained from wave energy was higher than that from other renewable energy sources, considering the determined coast lengths. Wave energy was followed by parabolic solar collector, wind, and photovoltaic solar energy systems. According to the model, the power obtained from renewable energy systems was at the highest level in the Kırklareli/Demirköy province compared to other locations. Kırklareli was followed by İstanbul, Antalya, İzmir, Muğla, and Çanakkale. It was also found that the electricity needs of 763,578 houses were met in the Kırklareli/Demirköy region, and the electricity needs of 470,590 houses were met in the Çanakkale/Ayvacık region. The statistically optimized factors using the Response Surface Methodology (RSM) for wind, photovoltaic, parabolic solar collector, and wave power were reported as 995.278, 4529.743, 2264.546, and 276,495.09, respectively. The optimal factors aim to achieve a total electricity generation rate of 2.491 × 109 (kWh/year), a total number of houses of 682,590.55 (number/year), and a total cost of USD 813,940,876. In line with the results obtained, the Kırklareli/Demirköy region becomes favorable when considering wave and wave-integrated wind and solar energies. The proposed system has the potential to meet the entire electricity demand of the Kırklareli province based on data from the Republic of Türkiye Energy Market Regulatory Authority (EMRA).

How to Decarbonize Greece by Comparing Wind and PV Energy: A Land Eligibility Analysis

To achieve sustainable development, the energy transition from lignite burning to renewable energy resources for electric power generation is essential for Greece. Wind and solar energy have emerged as significant sources in this transition. Surprisingly, numerous studies have examined the potential for onshore wind based on land eligibility, while few studies on open-field photovoltaic (PV) installations have been conducted. Therefore, based on the Specific Framework for Spatial Planning and Sustainable Development for Renewable Energy Sources (SFSPSD-RES), along with insights from previous relevant studies, this work conducts a land eligibility analysis of onshore wind and open-field PV installations in Greece using the software Geospatial Land Availability for Energy Systems (GLAES 1.2.1) and ArcGIS 10.2. Additionally, through an in-depth exploration of wind and solar PV energy potential in decommissioned lignite mines integrated with wind power density (WPD) and global horizontal irradiation (GHI) maps, this study compares the suitability of wind versus solar as energy sources for the decarbonization of Greece. Overall, despite the greater spatial eligibility for onshore wind turbines compared to open-field PV power plants, the relatively lower wind energy potential and operational limitations of wind turbines lead to the study’s conclusion that solar energy (PV) is more suitable for the decarbonization of Greece.

Impact of Corrective Switching in Wind Farms Operation

Eventually, limits violations of bus voltages or of admissible loadings of transmission lines and/or power transformers may occur by the power system operation. If violations are detected, corrective measures may be carried out aiming their elimination or to reduce their intensity. Loading shedding is an extreme solution and should only be adopted as the last control action. The control tool adopted in this work is Corrective Switching. It controls power flows in electrical networks by changing their topologies, without requiring any additional cost. Due to the large potential of wind energy in Brazil, using the technique of Corrective Switching may result in disconnection of wind farms, whose machines are not equipped with Low Voltage Ride Through function, since its wind generators are turned off when submitted to voltage sags for a short time. Thus, this works aims to verify if Corrective Switching actions, that could eliminate operational violations in electrical energy systems, can cause disconnections of wind farms, contributing to degrade power quality.

Bistable dual cantilever flutter for potential wind energy harvesting applications

This paper examines the potential of bistable dual cantilever flutter (DCF) for wind energy harvesting applications. Two cantilever beams were placed side by side and perpendicular to the direction of the wind flow to create a unique phenomenon known as the DCF. Similar pole magnets were then attached to the free end of each beam to establish a bistable condition. A theoretical model was presented and was shown to agree well with the experimental measurement. The mass of the magnets caused the frequency of the beams to drop by approximately 4.5 times compared to the monostable DCF. When the two beams were placed 21.0 mm apart, the bistable beams achieved a stable state at a critical flutter speed of 5.3 ms−1 and displayed significantly large, anti-phase oscillations that is approximately three times larger than the monostable DCF. Further increase in this distance showed a decreasing trend with the critical flutter speed, which opposes the expected trend of the monostable DCF. Due to the bistable effect, significant flutter amplitudes were also obtained during a backward sweep when the wind speeds were incrementally reduced from high to low, recording a 73.2 % increase in bandwidth for one of the tested cases. This suggests the possibility of an ultra-wide bandwidth energy harvester. Finally, it was shown that the piezoelectric conversion method is more favourable for the bistable DCF whereas electromagnetic induction is preferred for the monostable DCF.

Advances and opportunities in wind energy harvesting using plasma actuators: a review

Abstract The dielectric barrier discharge plasma actuator has been recognized as a leading technology for controlling fluid flow and has found remarkable applications in wind energy harvesting over the past decade. Wind turbine aerodynamics are critical in this concept and performance is mainly determined by flow controllers, although significant technical progress is still required. This paper examines all the critical studies to investigate the potential application of plasma actuators for airflow control over wind turbines. This approach has been divided into three categories: wind turbine airfoils, horizontal-axis wind turbines and vertical-axis wind turbines aerodynamic performance and generated power. Finally, the potential functions of plasma actuators in current and future wind turbine generators are discussed. These actuators offer promising solutions to increasing power output, minimizing torque fluctuations and enabling self-starting capabilities, particularly in vertical-axis wind turbines. By adjusting blade pitch angles in conjunction with plasma actuators, significant improvements in airflow optimization and power extraction have been demonstrated. Despite the advancements, challenges persist, such as determining optimal actuator placement and overcoming structural limitations, especially concerning 3D effects and high Reynolds numbers. While plasma actuators enhance aerodynamic efficiency, their complexity needs to be balanced against marginal gains in power production, especially in high-megawatt turbines, for which controlling flow at low wind speeds is challenging. Future research must focus on the sustainable integration of plasma actuators, pitch angle adjustments and active control mechanisms to fully exploit the potential of wind energy for a sustainable future.

Assessment of wind energy potential in Zambia

An assessment of potential for wind energy in Zambia was carried out to help address the shortage of energy due to increasing energy needs arising from energy requirements for newly opened mining industries and unreliable hydropower generation due to climate change. The assessment was carried out by collecting wind speed data of 25 sites owned by Zambia Meteorological Department. The objective of the study was to analyse wind patterns and determine areas in Zambia where production of electricity from wind can be invested. The analysis was based on the use of Weibull shape factor and yielded 3.32 m/s wind speed and 13.2 shape factor from a site with the most suitable wind speeds (Kasama Meteorological Station). A correlation study was carried out using these results and Goldwin 1.5 MW wind turbine of model GW82/1500. The study results showed that 44.46 kW power output could be obtained at 3.83 m/s wind speed by a correlation equation of this turbine power output with wind speeds. A series of similar power output results were obtained for wind speeds recorded in the years from 2013 to 2021 and compared with those obtained in the same period by using model equation due to Al Buhariri, and found that the power outputs compared very closely at low wind speeds ranging 3 to 3.2 m/s but rather widely at higher wind speeds.This study is significant in that it provides information on decision making and helps determine policy direction for wind utilization in Zambia and it can also help influence investment decision by Zambian mining companies who have financial ability to undertake large scale investments.

Is it economically possible repowering Wind Farms. A general analysis in Spain

- Protecting the environment is becoming a major concern; people are beginning to realise that their living conditions may worsen if they do not rationalise energy use and habits. Environmental pollution and emissions from greenhouse gases caused by fossil fuel use are a threat to sustainable development. With renewable energy sources, no polluting emissions are released into the atmosphere. Therefore, using these sources on a large-scale is a key to reducing emissions and meeting the commitments established by the Kyoto Protocol. At the same time, renewable energy contributes to sustainable development. This study describes economic aspects of the repowering process for the wind farms. This process was the result of a growing demand for renewable energies, facilitated by the great potential of wind energy in the north of Spain. The wind farms studied in this work were set up before 1998 and they have obsolete machinery with low power.