Wind energy in Brazil—present and future

In Brazil, the power generation is predominantly hydroelectric, corresponding approximately to 91.4% of the installed capacity. The energy crisis in the Brazilian electric sector meant the end of the centralized generation and the launching of a decentralized generation approach aiming to add to the existing plants through small- and medium power capacity. Such a condition matches the wind energy characteristic profile. In northeastern Brazil is one of the most promising areas for wind exploitation, where the largest wind speed occurs exactly when the rate of flow in Sao Francisco river, which accounts for all the power energy supply of the northeast region, is low. Thus, during this critical period, the wind farms can produce electrical energy, saving the Sao Francisco waters and on top of that with no environmental risk, thus contributing to the overall reduction of CO₂ emission in the atmosphere. Because of those factors, the National Electrical Energy Agency (ANEEL), the Brazilian regulatory authority, has approved 77 projects for construction of wind farms, attracting foreign investment, besides the installation of wind turbine industries. The increasing use of the wind energy is prevailing over the absence of a specific legislation for the sector, but the National Congress has already taken some measures such as the act bill no. 2905/2000 and the temporary measure no. 14/2001.     

Wind hydrogen energy system and the gradual replacement of natural gas in the State of Ceará – Brazil

The original model for the solar hydrogen energy system created by Veziroglu and Basar in the 70’s was adapted to the State of Ceará – Brazil. The State of Ceará has one of the greatest wind potentials in Brazil and it is estimated to be around 35 GW. At the present year, there are 494 MW wind farms in operation. The aforementioned State also has a natural gas grid of pipelines serving a great number of consumers. There are studies in literature considering the injection of hydrogen into the natural gas pipeline up to 20% in volume without substantial modifications in the natural gas infrastructure. The main objective of this article is to use that model in order to evaluate long term scenarios in which the off peak wind generated hydrogen gradually replaces natural gas in such important State of Brazil. The system is supposed to start in the year 2015 and the economical revenue when it is fully implemented can reach respectively US$ 730 million or US$ 1 billion in the slow or fast scenario of hydrogen introduction into the energy matrix of that important State of Brazil.     

Effect of downwind swells on offshore wind energy harvesting – A large-eddy simulation study

The effect of ocean downwind swells on the harvesting of offshore wind energy is studied using large-eddy simulation of fully developed wind turbine array boundary layers, which is dynamically coupled with high-order spectral simulation of sea-surface wave field with and without the presence of a downwind swell. For the two moderate wind speeds of 7 m/s and 10 m/s considered in this study, the swell is found to induce a temporal oscillation in the extracted wind power at the swell frequency, with a magnitude of 6.7% and 4.0% of the mean wind power output, respectively. Furthermore, the averaged wind power extraction is found to be increased by as much as 18.8% and 13.6%, respectively. Statistical analysis of the wind field indicates that the wind speed in the lower portion of the boundary layer oscillates periodically with fast wind above the swell trough and slow wind above the swell crest, resulting in the observed wind power oscillation. The wind above the swell accelerates due to the strong wave forcing, causes a net upward flux of kinetic energy into the wind turbine layer, and thus acts to increase the extracted wind power of the turbines. For a high wind speed of 17 m/s, the wave-induced motion becomes relatively weak and the swell effect on the wind turbine performance diminishes.     

An investigation into the potential barriers facing the development of offshore wind energy in Scotland: Case study – Firth of Forth offshore wind farm

The Scottish Executive has set ambitious targets of achieving 100% of electricity from renewable sources by 2020. As Scotland has the best offshore wind resources in Europe, the development of this energy source is crucial for reaching these targets. However, the development of offshore wind raises a number of issues related to economic viability, grid connection and public acceptability. This paper investigates these areas in greater depth, using a case study of the Firth of Forth offshore wind farm, in order to determine if these barriers can be overcome in time to make a valuable contribution to 2020 targets. Through interviews with relevant stakeholders, it emerged that there are various obstacles which are impeding progress in offshore wind development in Scotland. It became evident that stakeholder opposition, an inadequate renewable energy support mechanism, and the insufficient grid infrastructure off the Scottish coast are posing barriers, and hindering development. It became apparent that in order to overcome these barriers, a number of changes need to take place. A more inclusive approach to stakeholder engagement is required, which facilitates the sharing of knowledge. In order to improve the economic viability of offshore wind in Scotland, adopting a new mechanism which reduces risk and provides developers and investors with more certainty, would be more effective in encouraging offshore wind development. Finally, in order to overcome the most significant barrier, the grid, a more integrated and collaborative approach is required, which will share the burden of responsibility between the developer, Ofgem, and the National Grid.     

Management of variable electricity loads in wind – Hydrogen systems: The case of a Spanish wind farm

The main obstacles of most renewable energies are their variability and availability; thus, we propose the ‘hydrogen option’ as a means of energy management, and we study its feasibility in a specific wind farm. The installation will be capable to store electrochemically the surplus energy and return the electricity to the grid during the peak hours. The solution was to connect the system, so that we store the energy as hydrogen when the wind generation exceeds a threshold; this is done by an electrolyzer set, with the appropriate nominal power, where, besides the electrical conversion devices, we have designed a control programme for tuning the voltage and current densities to the optimal operation of the cells. To utilize the hydrogen downstream the storage subsystem, we have selected a fuel-cell and the output is finally converted to the grid requirements.     

Why invest in wind energy? Career incentives and Chinese renewable energy politics

We study wind development at the provincial level in China, modelling installed wind capacities as a function of both economics and politics. We assume that the top provincial officials desire to maximize their chances of promotion under the Chinese cadre evaluation system. We expect that those with the strongest incentives to perform in order to achieve promotion would work harder to comply with the central government’s policy agenda to promote renewable energy. Collecting and testing data on provincial leaders’ characteristics, we find that provinces governed by party secretaries who were approaching the age of 65 are associated with significantly higher level of wind installed capacities. This result supports the political tournaments theory of Chinese politics. We also find that better educated party secretaries are likely to be more supportive of renewable energy, implying that education acts to encourage provincial leaders to support the central government’s policy.     

Environmental issues associated with wind energy – A review

Recognized as one of the most mature renewable energy technologies, wind energy has been developing rapidly in recent years. Many countries have shown interest in utilizing wind power, but they are concerned about the environmental impacts of the wind farms. The continuous growth of the wind energy industry in many parts of the world, especially in some developing countries and ecologically vulnerable regions, necessitates a comprehensive understanding of wind farm induced environmental impacts. The environmental issues caused by wind farms were reviewed in this paper by summarizing existing studies. Available mitigation measures to minimize these adverse environmental impacts were discussed in this document. The intention of this paper is to provide state-of-the-art knowledge about environmental issues associated with wind energy development as well as strategies to mitigate environmental impacts to wind energy planners and developers.     

Investigation of wind characteristics and assessment of wind-generation potentiality in Uludağ-Bursa,Turkey

In this study, wind characteristic and wind energy potential of the Uluda? skinning which is located in the south Marmara region of Turkey were analyzed using the wind speed data collected during the period 2000–2006. The wind speed distribution curves of Uluda?-Bursa were obtained by using the Weibull and Rayleigh probability density functions. The average Weibull shape parameter k and scale parameter c were found as 1.78 and 7.97 m/s for the period 2000–2006. The yearly mean wind speed in Uluda?-Bursa was obtained as 7.08 m/s for period of 7 years. A technical and economic assessment has been made of electricity generation from four wind turbines having capacity of (600, 1000, 1500 and 2000 kW). The yearly energy output, capacity factor and the electrical energy cost of kW h produced by the three different turbines were calculated. The cost of each kW h produced using the chosen wind turbines in Uluda?-Bursa were found to between 0.255 and 0.306 $/kW h.     

Economical assessment of a wind–hydrogen energy system using WindHyGen software

This paper considers the problem of analyzing the economical feasibility of a wind–hydrogen energy storage and transformation system. Energy systems based on certain renewable sources as wind power, have the drawback of random input making them a non-reliable supplier of energy. Regulation of output energy requires the introduction of new equipment with the capacity to store it. We have chosen the hydrogen as an energy storage system due to its versatility. The advantage of these energy storage systems is that the energy can be used (sold) when the demand for energy rises, and needs (prices) therefore are higher. There are two disadvantages: (a) the cost of the new equipment and (b) energy loss due to inefficiencies in the transformation processes. In this research we develop a simulation model to aid in the economic assessment of this type of energy systems, which also integrates an optimization phase to simulate optimal management policies. Finally we analyze a wind–hydrogen farm in order to determine its economical viability compared to current wind farms.     

Austria's wind energy potential – A participatory modeling approach to assess socio-political and market acceptance

Techno-economic assessments confirm the potential of wind energy to contribute to a low carbon bioeconomy. The increasing diffusion of wind energy, however, has turned wind energy acceptance into a significant barrier with respect to the deployment of wind turbines. This article assesses whether, and at what cost, Austrian renewable energy targets can be met under different expansion scenarios considering the socio-political and market acceptance of wind energy. Land-use scenarios have been defined in a participatory modeling approach with stakeholders from various interest groups. We calculated the levelized cost of electricity (LCOE) for all of the potential wind turbine sites, which we used to generate wind energy supply curves. The results show that wind energy production could be expanded to 20% of the final end energy demand in three out of four scenarios. However, more restrictive criteria increase LCOE by up to 20%. In contrast to common views that see local opposition against wind projects as the main barrier for wind power expansion, our participatory modeling approach indicates that even on the level of key stakeholders, the future possible contribution of wind energy to Austrian renewable energy targets reaches from almost no further expansion to very high shares of wind energy.     

Existing buildings – Users,renovations and energy policy

This paper deals with the energy consumption of existing owner-occupied detached houses and the question of how they can be energy renovated. Data on the age of the Danish housing stock, and its energy consumption is presented. Research on the potential for energy reductions in the Danish housing sector is discussed, and it is shown that there is a huge potential for reductions. It is a well-known problem that even if there are relevant technical means and even if it is economically feasible, the majority of house owners do not energy renovate their homes. This paper intends to address what can be done to solve this problem. The paper draws on different sources of why, when, and how, people do not energy renovate their homes. These results are then compared and discussed together with a presentation and discussion of the Danish policy measures aimed at encouraging people to energy renovate their homes. These policy measures include building regulations, energy tax and different types of incentives and information dissemination. The conclusion calls for new and innovative policy measures to cope with the realities of renovations of owner-occupied houses and how energy efficiency improvement could be part of that.     

Photovoltaic energy generation in Brazil – Cost analysis using coal-fired power plants as comparison

We make a brief analysis of the evolution of photovoltaic systems, highlighting the present situation worldwide and in Brazil. We compare costs of energy generation associated to photovoltaic and to coal-fired power plants. Coal-fired generation represents the eligible choice for the Brazilian State of Rio Grande do Sul, where thermal plants may use locally extracted coal. The production cost of the energy generated with coal is evaluated taking in account the effect of the invisible cost represented by externalities that affect human health. The price evolution of Photovoltaic modules is presented, as well as trends on decreasing costs for new installations. We also calculate the production cost of the AC energy generated by three photovoltaic plants, with different power, derived from a model. The model is used to make sensitive analysis based on the adjustment of some factors that directly affect Brazilian costs such as: insolation, module's custom and transportation taxes, effect of economy of scale, cost of money. A cost comparison is made between the two technologies and some government incentives are proposed to narrow the existing financial gap.     

A review on wind energy and wind–hydrogen production in Turkey: A case study of hydrogen production via electrolysis system supplied by wind energy conversion system in Central Anatolian Turkey

Studies about investigation of hydrogen production from wind energy and hydrogen production costs for a specific region were reviewed in this study and it was shown that these studies were rare in the world, especially in Turkey. Therefore, the costs of hydrogen, hydrogen production quantities using a wind energy conversion system were considered as a case study for 5 different locations of Nigde, Kirsehir, Develi, Sinop and Pinarbasi located in the Central Anatolia in Turkey. Annual wind energy productions and costs for different wind energy conversion systems were calculated for 50 m, 80 m and 100 m hub heights. According to wind energy costs calculations, the amounts and costs of hydrogen production were computed. Furthermore, three different scenarios were taken into account to produce much hydrogen. The results showed that the hydrogen production using a wind energy conversion system with 1300 kW rated power had a range from 1665.24 kgH₂/year in Nigde at 50 m hub height to 6288.59 kgH₂/year in Pinarbasi at 100 m hub height. Consequently, Pinarbasi and Sinop have remarkable wind potential and potential of hydrogen production using a wind–electrolyzer energy system.     

Drivers and barriers to rural electrification in Tanzania and Mozambique – Grid-extension,off-grid,and renewable energy technologies

Mozambique and Tanzania are countries with very low rural electrification (RE) rates as only about 5% of the rural population use electricity. Despite efforts to extend the national grid in rural areas, most remote areas will not be reached within the foreseeable future. Off-grid (decentralized) electricity grids are seen as a complement and forerunner to the national grid, making electricity available many years in advance and creating demand and a customer base. Renewable energy sources are plentiful in the region and may be particularly useful for off-grid systems. The countries' power sectors are undergoing interesting changes with potential to speed up the pace of RE. However, there are significant barriers to effective RE by grid-extension and off-grid installations.In this study, the specific drivers and barriers for RE in Mozambique and Tanzania are explored across a spectrum of involved actors. By qualitative methodology, drivers and barriers were first identified through literature survey, then data was collected both in semi-structured interviews carried out with power sector actors from national to local level and in visits to off-grid electricity users in Tanzania and Mozambique during eight weeks in 2010. Findings illustrate generic, country-specific, and renewable-energy-technology-specific drivers and barriers to grid and off-grid rural electrification, as perceived by different power sector actors. Results were validated and discussed with three external specialists. Drivers and barriers strongly relate to the roles of national and local actors in planning and implementation. The main drivers are political ambitions based on expected growth of demand, but bottom-up drivers such as local initiatives by industries or churches also exist. The barriers are related to lack of access to human capital, to difficulties in planning and donor dependency, to low rural markets and little interest from private sector, and to more straightforward technical matters such as difficulties with installing electric equipment in traditional buildings. Although off-grid systems and renewable energy sources are recognized by the actors, specific barriers to these systems are related to young organizations responsible for implementation and to guilt-by-association with dysfunctional diesel-based off-grid systems.     

Life cycle cost assessment of wind power–hydrogen coupled integrated energy system

Aiming at the economic evaluation of wind power-hydrogen coupled integrated energy system (WPHCIES), a life-cycle economic assessment method of integrated energy system is proposed. Firstly, the integrated scheme and operation mode of integrated energy system are given. Secondly, with the net profit of the integrated energy system in the whole life cycle as objectives and the energy flow and stable operation of the system as constraints, a mathematical model for the economic evaluation of the given integrated energy system in the whole life cycle is constructed, and the payback period and net profit of life cycle of the given system can be reckoned by the model. Finally, taking a wind farm in South China as background, the life cycle economic evaluation model of the proposed system is simulated and calculated, and the effects of both the ratio of hydrogen production from wind power and the ratio of hydrogen to fuel cell on the net profit of wind power-hydrogen coupled integrated energy system during the payback period and the whole life cycle are further analyzed. In addition, the comparison demonstrated that the capital return period of the wind farm can be reduced from 11 years to 8.13 years, and the cumulative net income can be increased from 0.67 billion yuan to 0.93 billion yuan by reasonably choosing the power ratio of hydrogen production from wind power.     

Dynamic hydrogen production from PV & wind direct electricity supply – Modeling and techno-economic assessment

Renewable hydrogen from water electrolysis could contribute to the defossilization of various energy intensive sectors but continues to suffer from unfavorable economics. Attention is being paid to the direct supply of renewable electricity to electrolyzers; in particular from photovoltaic (PV) and wind units, whose fixed remuneration period has expired. However, detailed analysis of such operating strategies via modeling and simulation of the dynamic behavior of alkaline electrolysis (AEL) and polymer electrolyte membrane electrolysis (PEMEL) is lacking. In this work, an electrolyzer model is developed for both AEL and PEMEL and analyzed for PV and wind power input data sets from the region of northwest Germany. It is shown that key performance indicators (KPI) such as hydrogen production efficiency, electricity utilization rate, product output and net production costs are highly reliant on the shape of transient power input signals as well as the electrolyzers ability to cope with them. PEMEL technology generally has higher electricity utilization rates than AEL, while AEL still achieves relatively large hydrogen production quantities due to its higher efficiency. Thus, the better operational flexibility of PEMEL cannot generally be considered advantageous in terms of hydrogen production quantities – the same applies for economics. The most competitive hydrogen production costs were 4.33 € per kg for the AEL technology with direct electricity supply from old wind farms, which no longer receive fixed remuneration.     

Energy,environmental and economic comparison of different powertrain/fuel options using well-to-wheels assessment,energy and external costs – European market analysis

The well-to-wheels assessment is widely used in the automotive sector to analyze the efficiency and competitiveness of different powertrain/fuel options. The paper proposes a global index that takes into account both the energy and environmental aspects on an uniform basis, through the assignment of the costs associated to the energy and to the pollutant emissions. The European market is analyzed and other pollutants (NO_x, PM and SO_x) are added to the traditional well-to-wheels evaluations (energy and GHG). The proposed well-to-wheels global index offers a useful place-list that takes into account both energy and environmental aspects and, at the current market conditions, it results that the energy cost prevails (70–85%) over the environmental costs, and among the analyzed external costs, the main contribution is due to the GHG emissions. Natural gas-derived fuels seem to be the most promising. The global index for battery electric vehicle from a European mix are closely linked to the driving range. Conventional biofuels are very critical at present, while significant improvement of the well-to-wheels global index is foreseen for when new generation biofuels will be mature (2030 forecast). In short, even though the proposed global index is not an exhaustive index, it could be a useful tool for decision makers.     

The development and application practice of wind–solar energy hybrid generation systems in China

China is the largest developing country in the world. At present, more and more energy demand gives immense pressure to Chinese government. The inappropriate energy structure must be improved by Chinese government in order to achieve the sustainable development of economy and society. Development and application of renewable energy, such as wind energy, solar energy, biomass energy, etc., have been regarded by the government and the local people in the past 10 years, and more and more actual examples have been established, which are supported by government and plants in China. It is well known that there are abundant wind and solar resources in China. This paper presents the distribution zone and development and application practice status in China. However, a common drawback is existing in the stand-alone wind energy and solar energy generating power system, which is the unpredictable output electric power, and the output power depends on the unpredictable weather and climatic changes. Fortunately, the wind–solar hybrid generation system can partially overcome the problems. The conventional structure and key technology of stand-alone wind–solar hybrid generating system, the current status and outlook of wind–solar hybrid energy system are presented in the paper, for example, the city road lighting system, distributed generation, photovoltaic (PV) water pumping for irrigation, etc. At the end, the policies and laws of China central government and local governments are described, and the development barriers and recommendations are introduced.