Distributed small-scale wind in New Zealand: Advantages, barriers and policy support instruments

If future climate change goals being negotiated internationally are to have any chance of being achieved, developed countries need to undertake a major transition in their energy systems. This will require a rapid expansion of renewable energy generation, including wind electricity. Wind energy in New Zealand is commercially viable in many cases, yet opportunities for its exploitation are far from fully utilised. Many communities are showing resistance to wind farm developments, since large wind farms are often seen as intrusive. Building wind farms on a small scale may be a useful way of overcoming this problem.This study examines the pattern of recent wind industry development in New Zealand. It is argued that two key characteristics have emerged that are limiting the potential development of the industry: a trend towards large scale, leading to increased local opposition; and a small number of investors. Research methods include a review of international and local literature, and a rural mail survey questionnaire, with 338 respondents. We provide survey evidence that small wind farms, and community ownership of them, may be attractive to local communities, and that this point of advantage is helpful for the rapid expansion of wind generation in New Zealand.     

Residents' perceptions of wind turbines: An analysis of two townships in Michigan

Wind energy development has become a ‘hot topic’ across Michigan as this state seeks to achieve 10% of energy delivered to consumers from renewable sources (Huron County Planning Commission, 2005). The focus of this effort to generate renewable energy has centered around wind energy. Wind turbines have been constructed at numerous locations across the state. The lower peninsulas' eastern counties near Lake Huron and Saginaw Bay were designated by the Wind Energy Resource Zone board as one such area of strong sustained wind in the state. Turbines have been constructed in ‘pockets’ across this ‘thumb’ region, yet half a decade after the first turbines were constructed, negative perceptions are still attributed to wind turbines. This paper examines residents of wind farm locations as a whole and independently as groups (those in opposition and in support of development) to identify what, if any similarities and differences, exist between the residents' perceptions. Qualitative analysis on stated negative perceptions unveiled common issues with residents: increased price of electricity with wind energy, noise from the turbine rotation and uncertainty surrounding the long term effects of wind turbines. These areas of concern seem to persist years after construction was completed.     

Public opinion about large offshore wind power: Underlying factors

This paper address factors underlying public opinion regarding offshore wind power based on a survey of residents near a proposed development off Cape Cod, MA, USA. Supporters are found to be younger, better educated, and more likely to own their own home. Opponents are more likely to earn over $200,000/year, and more likely to expect to see the project from their daily routine. The overwhelming majority of the population expects negative impacts from the project; much smaller numbers expect positive effects. When asked which factors most affected their position, the most frequently mentioned was damage to marine life/environmental impacts, followed by electricity rates, aesthetics, and impacts on fishing or boating. When the expectations expressed by our respondents are compared with the findings of the project's draft Environmental Impact Statement, many of the beliefs upon which opinion are based appear to be factually incorrect. Finally, we tested whether change in the project would affect support. The biggest change was an increase in the level of support, by 47% of the sample, if the project was the first of 300 such projects, in sum having proportionately larger impacts as well as greater benefits. Implications of this research are discussed.     

New strategy of pitch angle control for energy management of a wind farm

In this paper, we are interested in a Wind Energy Conversion System (WECS) based on a Permanent Magnetic Synchronous Generator (PMSG). The studied WECS is made by the association of three aerogenerators. The objective of this work is to investigate a new strategy of pitch angle control to ensure a balance between the produced energy and the demanded one by the loads. The control strategy of the wind farm is composed of two parts: a local control according to the characteristics of each wind turbine « Pitch control » to protect the turbines against mechanical failure in the event of wind gust and a global control according to the total power demand and the available wind power. This strategy leads to achieving power objectives (active and reactive power targets) and system constraints.     

How wind became a four-letter word: Lessons for community engagement from a wind energy conflict in King Island,Australia

Wind is recognised as a key source of renewable energy. Despite broad public support for the sector, wind energy proposals have routinely triggered social conflict and localised opposition. To promote social acceptance and avoid conflict, the wind energy sector undertakes community engagement. This paper interrogates the community engagement undertaken in King Island (Tasmania, Australia) for a large scale wind energy development proposal which did not proceed to implementation due to external economic factors. Despite the proponent's adoption of what was described as a ‘best practice’ community engagement strategy, the proposal caused significant social conflict for the community. In-depth interviews (n=30) were conducted with members of the King Island community and were qualitatively analysed through the social identity lens. Five key drivers of the local conflict were identified: problematic pre-feasibility engagement; the lack of a third-party facilitator of the community consultative committee; holding a vote which polarised the community; the lack of a clear place in the engagement process for local opposition, and; the significance of local context. These findings are instructive for improving community engagement practice for wind energy and other energy generation and land use change sectors.     

Public attitudes to nuclear energy

The last decade has seen a marked increase in public concern about nuclear energy. As a consequence, it is now recognized that the future of nuclear energy will not only depend on technical and economic factors, but that public acceptability of this technology will play a crucial role in its long-term future. This paper summarizes trends in public reactions to nuclear power in various countries and discusses a number of studies on public beliefs and attitudes to nuclear power in general, and to the building of a nuclear power plant near to one's home. It is concluded that the qualitative aspects of the possible risks of nuclear energy play an important role in the public's perception of this technology. It is also clear, however, that differences in perception of the risks do not embrace all the relevant aspects of the public's assessment of nuclear energy. Public reaction is also related to more general beliefs and values, such as emphasis on economic versus social priorities, attitudes to technology and environmental concern.     

Modelling wind farms for grid disturbance studies

This paper analyses the simplest representation of generators on wind turbine modelling, giving the accuracy required in power system disturbance studies. The order of the generator model and the numerical integration methods employed are compared.To avoid the use of a detailed model of a wind farm, several aggregated models can be found in the literature. This paper analyses the influence of the wind farm internal network in the accuracy of the results and proposes a new equivalent model to represent the dynamic response of wind farms. The proposed aggregated model considers a weighted average where the transported power is used as weighting factor in order to ameliorate the accuracy on grid disturbance simulations.     

Dynamic model of wind energy conversion systems with PMSG-based variable-speed wind turbines for power system studies

In order to study the impact of a wind farm on the dynamics of the power system, a significant issue is to develop appropriate equivalent models that allow characterizing the dynamics of all individual wind turbine generators (WTGs) composing the park. In this sense, with the advance of power electronics, direct-driven permanent magnet synchronous generators (PMSGs) have drawn increased interest to wind turbine manufacturers due to their advantages over other variable-speed WTGs. These include the possibility of multi-pole design with a gearless construction that offers slow speed operation and reduced maintenance since no brushes are used, elimination of the excitation system, full controllability for maximum wind power extraction and grid interface, and easiness in accomplishing fault-ride through and grid support. In this way, this paper presents a comprehensive dynamic equivalent model of a wind farm with direct-driven PMSG wind turbines using full-scale converters and its control scheme. The proposed simplified modelling is developed using the state-space averaging technique and is implemented in the MATLAB/Simulink environment. The dynamic performance of the wind farm and its impact on the power system operation is evaluated using the phasor simulation method.     

Wind energy and assessment of wind energy potential in Turkey

In this study, the potential of wind energy and assessment of wind energy systems in Turkey were studied. The main purpose of this study is to investigate the wind energy potential and future wind conversion systems project in Turkey. The wind energy potential of various regions was investigated; and the exploitation of the wind energy in Turkey was discussed. Various regions were analyzed taking into account the wind data measured as hourly time series in the windy locations. The wind data used in this study were taken from Electrical Power Resources Survey and Development Administration (EIEI) for the year 2010. This paper reviews the assessment of wind energy in Turkey as of the end of May 2010 including wind energy applications. Turkey's total theoretically available potential for wind power is around 131,756.40 MW and sea wind power 17,393.20 MW annually, according to TUREB (TWEA). When Turkey has 1.5 MW nominal installed wind energy capacity in 1998, then this capacity has increased to 1522.20 MW in 2010. Wind power plant with a total capacity of 1522.20 MW will be commissioned 2166.65 MW in December 2011.     

Public attitudes of wind energy in Texas: Local communities in close proximity to wind farms and their effect on decision-making

Wind energy is now recognized as an important energy resource throughout the world. Within the United States, the state of Texas currently has the largest wind energy capacity with 8797 total megawatts and an additional 660 MW under construction. With this rapid growth, it is important to achieve a better understanding of how wind energy is being perceived by the public.     

Exergy analysis in a wind speed prognostic model as a wind farm sitting selection tool: A case study in Southern Greece

In the present paper, the wind potential of Central Peloponnese in Greece has been studied and the Exergy Analysis methodology was implemented as a wind farm sitting selection tool. The wind speed of the chosen regions of Central Peloponnese was studied and correlated based on the measurements of three specific sites in the wider area using a software based prognostic model using intercomparisons of cross-predictions among these sites. The Exergy Analysis implemented in this innovative wind speed forecasting model is used to identify the actual use of energy from the existing available energy and to evaluate the proposed sites appropriate for wind farm development ending up to an accurate wind map of the area.     

On the energy output estimation of wind turbines

During the operation of the German test field for small Wind Energy Conversion Systems (WECS) on the island of Pellworm five wind turbines were tested following recommendations of the International Energy Agency (IEA) expert group. Possible errors in the estimation of a tested wind turbine's total energy output at a potential installation site are investigated. Different wind speed frequency distributions (the measured one, the Rayleigh and the two-parameter Weibull distribution) are used to calculate the total energy output. The differences between the various distributions are mostly below 10 per cent. An improvement of the energy output estimate by a Weibull-instead of a Rayleigh distribution was not found. It is also shown that the use of the recommended 10 min averages or any other average overestimates the WECS' efficiency, up to 14 per cent on average depending on turbulence intensity. Wind power instead of wind speed is the appropriate parameter for power performance testing. Spectra of wind power and electrical power output show three areas of different correlation. A resistance length for wind turbines is shown to be dependent on the WECS operation status.     

Thermodynamic performance assessment of wind energy systems: An application

In this paper, the performance of wind energy system is assessed thermodynamically, from resource and technology perspectives. The thermodynamic characteristics of wind through energy and exergy analyses are considered and both energetic and exergetic efficiencies are studied. Wind speed is affected by air temperature and pressure and has a subsequent effect on wind turbine performance based on wind reference temperature and Bernoulli’s equation. VESTAS V52 wind turbine is selected for (Sharjah/UAE). Energy and exergy efficiency equations for wind energy systems are further developed for practical applications. The results show that there are noticeable differences between energy and exergy efficiencies and that exergetic efficiency reflects the right/actual performance. Finally, exergy analysis has been proven to be the right tool used in design, simulation, and performance evaluation of all renewable energy systems.     

Valuing a wind farm construction: A contingent valuation study in Greece

Our analysis is based on data from a double-bounded dichotomous choice contingent valuation study implemented to elicit public attitudes towards renewable energy generation and their willingness to pay for the construction of a wind farm in the area of Messanagros in the island of Rhodes, Greece. Results indicate that there are significant positive values deriving from the proposed project. Respondents report a mean willingness to pay a premium in their bi-monthly electric bills of €8.86 for the sole purpose of the construction of the wind farm. The estimated economic benefits to the local population are weighed against the investment cost in a cost–benefit analysis to inform policy making and implications for EU energy policy are provided.     

Local acceptance of wind energy: Factors of success identified in French and German case studies

The objective of this paper is to identify and analyse factors that are important for winning acceptance of wind-energy parks on the local level. The developers of wind-energy parks need to know how to manage “social acceptance” at the different stages of planning, realisation and operation. Five case studies in France and Germany focused on factors of success in developing a wind-energy project on a given site and illuminated how policy frameworks influence local acceptance. Our hypothesis is that these factors fall into two categories: institutional conditions, such as economic incentives and regulations; and site-specific conditions (territorial factors), such as the local economy, the local geography, local actors, and the actual on-site planning process (project management).     

Optimization of wind turbine micro-siting for reducing the sensitivity of power generation to wind direction

In the optimization of wind turbine micro-siting of wind farms, the major target is to maximize the total energy yield. But considering from the aspect of the power grid, the sensitivity of wind power generation to varying incoming wind direction is also an essential factor. However, most existing optimization approaches on wind turbine micro-siting are focused on increasing the total power yield only. In this paper, by employing computational fluid dynamics and the virtual particle model for the simulation of turbine wake flow, a sensitivity index is proposed to quantitatively evaluate the variation of power generation under varying wind direction. Typical turbine layouts obtained by existing power optimization approaches are evaluated for stability. Results indicate that regularly arranged turbine layouts are not suitable for stable power production. Based on solutions from the power optimization, a second-stage optimization using Particle Swarm Optimization algorithm is presented. The proposed optimization method adjusts the positions of the turbines locally, aiming at increasing the stability of wind farm power generation without damaging its advantage of high power yield. Case studies on flat terrain and complex terrain both demonstrate the effectiveness of the present local adjustment optimization method.     

Greenhouse gas emissions from electricity generated by offshore wind farms

For wind power generation offshore sites offer significantly better wind conditions compared to onshore. At the same time, the demand for raw materials and therefore the related environmental impacts increase due to technically more demanding wind energy converters and additional components (e.g. substructure) for the balance of plant. Additionally, due to environmental concerns offshore wind farms will be sited farshore (i.e. in deep water) in the future having a significant impact on the operation and maintenance efforts (O&M). Against this background the goal of this analysis is an assessment of the specific GHG (greenhouse gas) emissions as a function of the site conditions, the wind mill technology and the O&M necessities. Therefore, a representative offshore wind farm is defined and subjected to a detailed LCA (life cycle assessment). Based on parameter variations and modifications within the technical and logistical system, promising configurations regarding GHG emissions are determined for different site conditions. Results show, that all parameters related to the energy yield have a distinctive impact on the specific GHG emissions, whereas the distance to shore and the water depth affect the results marginally. By utilizing the given improvement potentials GHG emissions of electricity from offshore wind farms are comparable to those achieved onshore.     

On the wind energy resources of Sudan

The imminent exhaustion of fossil energy resources and the increasing demand for energy were the motives for those reasonable in Sudan to put into practice an energy policy based on rational use of energy; and on exploitation of new, and renewable energy sources. After 1980, as the supply of conventional energy has not been able to follow the tremendous increase of the production demand in rural areas of Sudan, a renewed interest for the application of wind energy has shown in many places. Therefore, the Sudanese government began to pay more attention to wind energy utilisation in rural areas. Because the wind energy resource in many rural areas is sufficient for attractive application of wind pumps, and as fuel is insufficient, the wind pumps will be spread on a rather large scale in the near future. Wind is a form of renewable energy, which is always in a non-steady state due to the wide temporal and spatial variations of wind velocity. A number of years worth of data concerning wind speed in Sudan have been compiled, evaluated and presented in this article. The need for the provision of new data stations in order to enable a complete and reliable assessment of the overall wind power potential of the country is identified and specific locations suggested. This paper presents the background and ideas of the development of the concept as well as the main results, and experience gained during ongoing project up to now. In Sudan, various designs of wind machines for water pumping have been developed and some designs are presently manufactured commercially. Results suggest that wind power would be more profitably used for local-and small-scale applications especially for remote rural areas. It is concluded that Sudan is blessed with abundant wind energy.     

Assessment of wind energy in Iran: A review

In this study, a ten minute period measuring wind speed data for year 2007 at 10 m, 30 m and 40 m heights for different places in Iran, has been statistically analyzed to determine the potential of wind power generation. Sixty eight sites have been studied. The objective is to evaluate the most important characteristics of wind energy in the studied sites. The statistical attitudes permit us to estimate the mean wind speed, the wind speed distribution function, the mean wind power density and the wind rose in the site at three different heights. Some local phenomena are also considered in the characterization of the site.     

A joint probability density function of wind speed and direction for wind energy analysis

A very flexible joint probability density function of wind speed and direction is presented in this paper for use in wind energy analysis. A method that enables angular–linear distributions to be obtained with specified marginal distributions has been used for this purpose. For the marginal distribution of wind speed we use a singly truncated from below Normal–Weibull mixture distribution. The marginal distribution of wind direction comprises a finite mixture of von Mises distributions. The proposed model is applied in this paper to wind direction and wind speed hourly data recorded at several weather stations located in the Canary Islands (Spain). The suitability of the distributions is judged from the coefficient of determination R².

The conclusions reached are that the joint distribution proposed in this paper: (a) can represent unimodal, bimodal and bitangential wind speed frequency distributions, (b) takes into account the frequency of null winds, (c) represents the wind direction regimes in zones with several modes or prevailing wind directions, (d) takes into account the correlation between wind speeds and its directions. It can therefore be used in several tasks involved in the evaluation process of the wind resources available at a potential site. We also conclude that, in the case of the Canary Islands, the proposed model provides better fits in all the cases analysed than those obtained with the models used in the specialised literature on wind energy.