Wind farm layout optimization using combined area dimensions and definite point selection techniques

The current wind turbines are the biggest rotating machines on earth, operating in the lowest part of the earth boundary layer. The layout scheme of wind farms is a challenging job to researchers having many design objectives and constraints due to the multiple wake phenomenon. The far wake effect is more prominent in wind farm layout design problems than the near wake effect. At present, wind energy industry is facing major design constraints in boosting power output. Most of the existing approaches focused only on the positioning of the wind turbines within the wind farms. They did not consider the effect of the shape of wind farm area on power output. This research proposes a novel method to find the optimized dimensions of the wind farm shape where maximum area could face the free stream velocity. This is achieved by developing an area dimension method which rotates the wind farms up to 180 degree. Afterward, a novel method called Definite Point Selection (DPS) is developed to place the turbines in order to operate at their maximum efficiency, while providing the obligatory space between adjacent turbines for operation safety. The positions within the wind farm facing zero wake effect can be identified by using DPS method. It is observed that the combined area dimension and DPS techniques are more effective than the previous approaches. Jensen’s wake model is used to calculate the wake effects among wind turbines as existing literatures illustrate that the Jensen’s far wake model is a good choice acceptably for the solution of layout problem. A wind farm of 2 km x 2 km area is divided into 10 x 10 cells for case study. Three different wind scenarios i.e. constant wind speed with uniform direction (Case 1), uniform wind speed with variable direction for equal probability of occurrence (Case 2) and variable wind speed with variable direction for unequal probability of occurrence (Case 3) are considered for the application of proposed methods. The proposed layouts are simulated to place different number of wind turbines in all wind scenarios. The optimized layout operates with efficiency of 99.15%, 96.9% and 93.9% for Case 1, Case 2 and Case 3 respectively. Results show that power output of the wind farm by using the same area in different dimension has increased even with identical number of wind turbines. The proposed method is useful for onshore as well as offshore wind farms

Economic Feasibility of Stand-Alone Wind Energy Hybrid with Bioenergy from Anaerobic Digestion for Electrification of Remote Area of Pakistan

Hybrid Renewable Energy systems (HRES) are gaining importance throughout the world because of the finite sources of oil and gas reservoirs. These have the great ability in the production of electrical energy and cleaning the environment. It is difficult to get grid electricity in the remote areas where no infrastructure exists. The utilization of renewable sources is the ultimate solution for the generation of electricity. In this paper, the economic modeling of Hybrid system consisting of Wind/biomass is explored for the remote area ‘Jangiah’ of Balochistan province, Pakistan. Anaerobic Digestion of biomass is used to get biogas. This source is used to complement the uncertainties in the wind production. Homer is used to simulate the hybrid model. Economic analysis is performed to get the net present value (NPV) and cost of energy. It is observed that wind/biomass alone is capable to meet the demand of community which consumes 60 kW peak daily along with the storage backup. This system is the most economical with COE equal to 0.118 US$/kWh following the hybrid biomass/wind/diesel system with COE 0.202 US$/kWh. The sensitivity analysis is carried out and shows that the proposed system is sensitive to the prices of fossil fuel and project lifespan. The net present value increases as the lifetime of the project increases from 15 years to 30 years. It can also be concluded that if the price of the diesel drops below 0.8 US$/liter, the traditional system using fossil fuels will become the most suitable system for the generation of electricity in remote areas

The Carbon Emission Trading Policy of China: Does It Really Boost the Environmental Upgrading?

China’s rapid industrialization has led to massive resource consumption, and the country has recently been highlighted as the World’s top carbon emitter. To pursue a sustainable economy via environmental upgrading, reductions in carbon emission levels are of great concern. The carbon emission reduction policy (CETP) is an environmental regulation aimed at cutting emissions and achieving environmental protection. Based on panel data of pilot and non-pilot regions, this study investigated the policy impact of the CETP on carbon emission reduction through difference-in differences (DID). The findings, based on pooled OLS (ordinary least squares) and LSDV (least square dummy variable) regressions, revealed that the carbon emissions of the pilot regions (Beijing, Tianjin, Shanghai, Guangdong, Chongqing, and Hubei) had reduced by 12 percent more than the non-pilot regions. Thus, this implies that the CETP causes environmental upgrading. The results were further verified using a number of robustness checks, including parallel trends, placebo test, Granger causality test, and DID regression with a longer sample period. Based on the study findings, it was concluded that to achieve higher upgrade levels related to the environment, the CETP needs to be encouraged and improved for nationwide implementation. Furthermore, sustainable economic development in China also needs strict environmental regulations and policy measures

The modelling of wind farm layout optimization for the reduction of wake losses

The objective of the present research is to find out the optimized dimensions of the wind farm area and turbines layout to reduce the overall cost per unit power. The velocity deficits caused by the wakes of each turbine were calculated by using Jensen's wake model. The optimal positions of wind turbine placement are evaluated by using genetic algorithm, while sustaining the obligatory space between adjacent turbines for operation safety. The research on the wind farm area dimensions and fully utilization of upstream wind velocity is currently lacking in literature. The logical application of area dimensions and genetic algorithm improved the overall efficiency of the wind farm. It is concluded that proposed duel level optimization method outperforms the existing ones. The total wind farm area (2km × 2km) was divided into 100 identical cells, with each cell having dimensions 200m × 200m . The performance of the proposed method is compared with the results from previous studies. The simulation results showed that power output of the wind farm was increased by using same area with different dimensions. It was observed that by using the same number of wind turbines, the total efficiency of wind farm was increased by 7 %

Feasibility and Optimization of Standalone PV/Biogas Hybrid Distributed Renewable System for Rural Electrification: A Case Study of a Cholistan Community

Now-a-days, electricity has become the most significant part of human life. For this purpose, renewable energy sources as the emergent sources are introduced in the system. In Pakistan, in spite of having abundant renewable sources and favorable climate conditions, there are some remote areas where the extension of national grid is still absent. In this research paper, one of the remote area of Pakistan, Chak 6-DRB, a village of Cholistan, is considered for the hybrid renewable sources. This research has been implemented on HOMER (Hybrid Optimization Model for Electric and Renewable) software, in which two renewable sources; solar and anaerobic biogas have been implemented in terms of COE (Cost of Energy), NPC (Net Present Cost), costs of different equipment used and then find an optimal size and costs of the system. This HDRP (Hybrid Distributed Renewable Power) system contains anaerobic biogas, and solar system which yield most accurate and inexpensive results and are quite feasible for this remote area. This standalone generation and distribution model is also analyzed through HOMER including sensitivity parameters. In future, this role model of proposed hybrid renewable system would be very effective and helpful for other remote areas of the country for implementatio

Sonographic Incidence and Characteristics of Thyroid Nodules in Various Age Groups and Gender

Background: Thyroid nodules (TNs) are among the common diseases of the endocrine system, with 3%–7% prevalence by palpation. The prevalence by high-resolution ultrasonography among randomly selected individuals is 19%–67%, with annual increasing trends worldwide. 5% to 15% of TNs is thyroid cancer, which has become the fastest growing cancer.1 Ultrasonography has become an indispensable tool in the evaluation of thyroid nodular disease, and most patients will have had a thyroid ultrasound prior to initial surgical evaluation.9 Objective: To characterize thyroid nodules in various age groups and gender.  Methodology: In this descriptive study, among 179 patients of thyroid nodule were selected with age and gender discrimination by convenient sampling, at Department of Radiology, Lahore General hospital and Inmol Cancer hospital Lahore. Mindray Z5 and Toshiba xario 100 with linear probe of 7.5-11MHz ultrasound machine was used. Results: Out of 179 collected, 105 were females and 74 were males who visited radiology department due to thyroid nodule. It shows 58.7% females and 41.3% males patients diagnosed. Out of 179 patients 106 patients 59.2% came with irregular margins thyroid nodules and remaining 73 patients 40.8% had thyroid nodules with regular margins. 127 patients 70.9% had hyperechoic thyroid nodules and 52 patients 29.1% had hypoechoic thyroid nodules. Out of 97 patients 54.2% developed (Multi Nodular Goiter) MNG, 66 patients 36.9% developed right thyroid nodules and 16 patients 8.9% developed left thyroid nodules. Females developed 56.2% MNG, 33.3% right thyroid nodule and 10.5% left thyroid nodule while males developed 51.4% MNG, 41.9% right thyroid nodule and 6.8% left thyroid nodule. Out of 179 patients 109 (60.9%) patients shows no perfusion of blood while remaining 70 (30.1%) shows some perfusion of blood on USG. Minimum age was 5 years and maximum were 90 years while their mean was 43. Age group between 41 to 50 years most likely develop thyroid nodules.  Conclusion: In this study we conclude that females most likely develop thyroid nodules than males.  Both males and females mostly develop multi nodular goiter and least develop left thyroid nodule. Patients in 4th decade most likely develop thyroid nodules. Key words: Thyroid nodules, Ultrasonography DOI: 10.7176/JHMN/80-15 Publication date:September 30th 202

Acquisition of abstract words for cognitive robots

Abstract word learning and comprehension is a very crucial and important issue because of its application and problematic nature. This problem does not just belong to the cognitive robotics field, as it also has significance in neuroscience and cognitive science. There are many issues like symbol grounding problem and sensory motor processing within grounded cognition framework and conceptual knowledge representation methods that have to be addressed and solved for the acquisition of abstract words in cognitive robots. This paper explains these concepts and matters, and also elucidates how these are linked to this problem. In this paper, first symbol grounding problem is discussed, and after that an overview of grounded cognition be given along with detail of methods/ideas that suggest how abstract word representation could use sensory motor system. Finally, the computation methods used for the representation of conceptual knowledge are discussed. Two cognitive robotics models based on Neural network and Semantic network that ground abstract words are presented and compared via simulation experiment to find out the pros and cons of computation methods for this problem. The aim of this paper is to explore the building blocks of cognitive robotics model at theoretical and experimental level, for grounding of abstract words

Effect of NPK, organic manure and their combination on growth, yield and nutrient uptake of chilli (Capsicum Annum L.)

A field experiment was conducted at the research area of department of horticulture, Institute of tropical agriculture and forestry, Hainan University, Haikou, Hainan, China, during the winter season 2016-2017. The research was arranged in randomized complete block design with nine treatments of organic manures in combination with NPK fertilizers having three replications. The highest yield was recorded with T9 treatment (N: P: K 100:50:50+FYM@8 ton per hectare). Plant height at harvesting, number of branches plant-1, number of fruits plant-1, fruit width, fruit length and fruit weight increased significantly with T9 treatment (N: P: K 100:50:50+FYM@8 ton per hectare). Similarly application of NPK100%+FYM@8 ton per hectare increased oleoresin yield and ascorbic acid content. Application of FYM@8 ton per hectare in combination with NPK100% increased the uptake of nutrients (N, P, K, Ca, S, and Fe) as compared to control. Similar results were also found in other organic manures along with inorganic fertilizer. The highest net return (Rs. 30183 per hectare) was achieved with the application of NPK100%+FYM@8 ton per hectare followed by NPK100%+ PM@6 ton per hectare, NPK100%+VC@10 ton per hectare and NPK100%+C@7 ton per hectar

Influence of wind farm area dimension on wakes and power production

During wind farm planning, the farm layout is generally optimized to minimize the wake losses, and thereby maximize the energy production. However, the scope of layout design itself depends on the specified wind farm land-shape. In this paper, a novel framework is developed to explore how the farm land-shape influences the output potential of a site under a given wind farm area directional orientation or for a set of sample land-shapes with the fixed land area. The full free stream wind speed will be utilized by using definite point selection (DPS) criteria. The DPS is then represented as a function of the wind farm area shape and land orientation. Three types of wind farm land with different dimensions and same areas are considered. The effect of the wake on wind farm power production is calculated. The extracted power is measured for all land shapes. It is concluded that the diamond shaped wind farm is the most suitable, irrespective of regular or irregular layouts of the farm following the square shape