Wind Energy (Engineering)

Light detection and ranging systems are able to measure conditions at a distance in front of wind turbines and are therefore suited to providing preview information of wind disturbances before they impact the turbine blades. In this study, preview-based disturbance feedforward control is investigated for load mitigation. Performance is evaluated assuming highly idealized wind
measurements that rotate with the blades and more realistic stationary measurements. The results obtained using idealized, "best case" measurements show that excellent performance gains are possible with reasonable pitch rates. However, the results using more realistic wind measurements show that without further optimization of the controller and/or better processing of measurements, errors in determining the shear local to each blade can remove any advantage obtained by using preview-based feedforward techniques.

This study assessed the viability of wind electricity production at a local meteorological site in Sokoto State, Nigeria. 21 years monthly mean wind speed data at 10 m height obtained from the Nigerian meteorological station were employed to carry out monthly, seasonal, yearly and whole years wind profile
characteristics. The data were subjected to the Weibull 2-parameter and other statistical analyses. The econometrics analysis of wind electricity generation from the site was also studied using three wind turbine models of AV 928, V90 and SWT-3.6-107. The outcome showed that the wind speed data ranged from 2.4 to 12.1 m/s while the modal wind speed range was from 6.9 to 9.0 m/s. 98% of the data were found to be greater than 3.0 m/s and better potential exist for wind power generation in the dry season than in the wet. It was also discovered that potential exist for electricity generation of between 60.0MWh and 1.5GWh per month and between 2.1 and
10.8GWh per annum. The least cost of generating 1kWh of wind electricity with the turbine models at the site is estimated to be € 0.014

District heating networks are commonly addressed in the literature as one of the most effective solutions for decreasing the greenhouse gas emissions from the building sector. These systems require high investments which are returned through the heat sales. Due to the changed climate conditions and building renovation policies, heat demand in the future could decrease, prolonging the investment return period. The main scope of this paper is to assess the feasibility of using the heat demand – outdoor temperature function for heat demand forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 buildings that vary in both construction period and typology. Three weather scenarios (low, medium, high) and three district renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were compared with results from a dynamic heat demand model, previously developed and validated by the authors. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications (the error in annual demand was lower than 20% for all weather scenarios considered). However, after introducing renovation scenarios, the error value increased up to 59.5% (depending on the weather and renovation scenarios combination considered). The value of slope coefficient increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and renovation scenarios considered). On the other hand, function intercept increased for 7.8-12.7% per decade (depending on the coupled scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations. Abstract This study aims to examine the nonsterilized fermentation conditions for coproduction of pectinases and lipase enzymes using several fruit wastes as an energy source. Thermophilic fungal strain, Penicillium expansum CMI 39671 was used as a fermenting strain. The effect of process conditions including; nitrogen sources, pH, temperature, time and moisture contents, on the production of both enzymes were studied. The highest activities of pectinase and lipase (2817, 1870 U/g dry substrate) enzymes were found with orange peel feedstock, whereas the lowest activities of 1662 U/g and 1266 U/g were found with banana peel and papaya peel feedstocks respectively. Overall, pectinase showed higher enzymatic activities than lipase enzymes, both having similar increasing and decreasing trends, at all studied conditions. The optimum process conditions of peptone as a nitrogen source, pH 7, 40°C, 5 days and 70% moisture contents, were found to show highest enzymatic activities for both enzymes. The orange peel feedstock showed no significant difference in both enzymes' activities at sterilized and nonnotarized process conditions. Pectinase and lipase enzymes showed (13791 U/g) and (8114 U/g) for sterilized and (14091 U/g) and (8324 U/g) for nonnotarized process conditions respectively. In addition, the fungal strains also produce bacteriocin-like compounds that could inhibit microbial growth. These findings will help to design and develop robust, cost-effective and less energy intensive enzyme production processes and consequently an efficient fruit waste to energy system through open fermentation. Abstract This study aims to examine the nonsterilized fermentation conditions for coproduction of pectinases and lipase enzymes using several fruit wastes as an energy source. Thermophilic fungal strain, Penicillium expansum CMI 39671 was used as a fermenting strain. The effect of process conditions including; nitrogen sources, pH, temperature, time and moisture contents, on the production of both enzymes were studied. The highest activities of pectinase and lipase (2817, 1870 U/g dry substrate) enzymes were found with orange peel feedstock, whereas the lowest activities of 1662 U/g and 1266 U/g were found with banana peel and papaya peel feedstocks respectively. Overall, pectinase showed higher enzymatic activities than lipase enzymes, both having similar increasing and decreasing trends, at all studied conditions. The optimum process conditions of peptone as a nitrogen source, pH 7, 40°C, 5 days and 70% moisture contents, were found to show highest enzymatic activities for both enzymes. The orange peel feedstock showed no significant difference in both enzymes' activities at sterilized and nonnotarized process conditions. Pectinase and lipase enzymes showed (13791 U/g) and (8114 U/g) for sterilized and (14091 U/g) and (8324 U/g) for nonnotarized process conditions respectively. In addition, the fungal strains also produce bacteriocin-like compounds that could inhibit microbial growth. These findings will help to design and develop robust, cost-effective and less energy intensive enzyme production processes and consequently an efficient fruit waste to energy system through open fermentation.

The paper offers an analytical formulation of the two errors embodied in the momentum theory. The first one originates from to the use of the differential form of the axial momentum equation and the second one from the linearisation of the tangential velocity terms. Both errors are evaluated comparing the axial velocity at the disk as predicted by the momentum theories with that one obtained thorough a semi-analytical actuator disk method based on the exact solution of the flow. Several cases characterised by different values of the thrust and advance coefficient are analysed, and the range of validity of the momentum theories is discussed in depth.

Due to their potential to beat the Betz-Joukowsky limit for power extraction, diffuser-augmented wind-turbines have experienced a great research interest, especially in the last two decades. This paper presents a thorough critical-analysis and review of the most important theoretical models conceived for the performance analysis and design of this wind-concentrator system. The models are classified and compared between each other, and their main analogies and differences are highlighted and explained. New bridging relations between several models are also laid down. All methods are verified and validated using new and/or existing numerical and experimental data. For the first time, the impact of the simplifying assumptions, typically used in these models, is evaluated and discussed on a quantitative basis. Attention is also paid to the optimization procedures aimed at evaluating the maximum power-coefficient attainable by a diffuser-augmented wind-turbine. It is revealed that none of these procedures is valid for a given duct geometry, whereas they still offer some usefulness from a design point of view. Finally, the review points out the main limitations, shortcomings and open-issues associated with theoretical models, paving the way for future research lines and improvements of this kind of models.

We show that the measurement of the power curve of a small-scale wind turbine system following the IEC 61400-12-1 standard might lack consistency. This is due to characteristics specific to small-scale wind turbines. We give recommendations to ensure consistency, accuracy and reproducibility of the measurements. Besides, in the hope of making the standard more accessible, we clarify the impact of various parameters such as generator heating, battery voltage, controller settings, furling system and anemometer position. Our Matlab code used for data processing is included.

In India, most of the microgrids consisting of wind turbines are located in rural areas to mitigate the energy deficiency and these are weak in nature. In a typical microgrid with a radial topology, power flows from its point of common coupling (PCC) to the end bus in one direction. Low short circuit capacity and high grid impedance are the main electrical characteristics of weak grid.

This project deals with the design and fabrication of three blade Giromill wind turbine. The Giromill wind turbine is a type of vertical axis wind turbine which is used to produce power. The turbine consists of three straight blades which is technically an airfoil which is connected to the rotating main shaft. In this project the components required for this wind turbine like airfoil, main shaft and bearing are designed properly. The power calculation with respect to the velocity of wind is included. The components are fabricated with appropriate materials and assembled. Finally this project was tested and implemented successfully.

The articles in this issue look at how the development and use of free and open source hardware (FOSH or simply “open hardware”) are changing the face of science, engineering, business, and law.

Free and open source software (FOSS) has proven very successful and now dominates the development of software on a global scale. It is available in source code (open source) and can be used, studied, copied, modified, and redistributed either without restriction or with restrictions only to ensure that further recipients have the same open source rights.
Similarly, FOSH provides the “code” for hardware—including the bill of materials, schematics, instructions, computer-aided designs, and other information needed to recreate a physical artifact. Use of FOSH can improve product innovation in a wide range of fields. In this issue authors from a variety of disciplines and work environments discuss how this open model of innovation will drive the future of engineering.
First, Alicia Gibb, founder and executive director of the Open Source Hardware Association (OSHWA) and director of the ATLAS1 Blow Things Up (BTU) Lab at the University of Colorado Boulder, argues that hardware is the next step to open sourcing everything. She touches on intellectual property (IP) issues, cites the benefits of open source hardware, introduces and explains the role of OSHWA, and hints at the future of open hardware.

The open source paradigm is already making deep inroads in the hardware space in 3D printing. With the development of the open source RepRap project (a 3D printer that can print itself) the cost of 3D printers has dropped to a point where nearly anyone can afford one for rapid prototyping and small batch manufacturing.

Ben Malouf and Harris Kenny of Aleph Objects describe their company’s approach to the use of open hardware in every aspect of their business to create the popular Lulzbot 3D printer. Their primary product is open—and consistently wins one of the top spots in Make: Magazine’s annual 3D printer shootout, ahead of proprietary 3D printers from much larger companies with far greater resources. Lulzbot printers, and those of many other manufacturers, are rapidly increasing in sales as the number of free and open source 3D printable designs erupts on the Web, making distributed manufacturing a reality.

In this context, law professor Lucas Osborn at the Campbell University School of Law takes us on a deep dive into how IP law will need to change in this new 3D printing era. After summarizing the basics of IP law and explaining why it was created, he discusses how it could both benefit and hinder 3D printing technology. His arguments will challenge readers independent of their views on patent law. For those with conventional IP leanings, he shows how IP law can hinder innovation. For those born in the Internet age, where sharing is second nature and little thought is given to licenses as long as the code is posted on Github, he offers some important lessons. He ends with a challenge for engineers to make more of an effort in helping form IP law that will benefit innovation.
If these lessons on IP and open hardware replication with 3D printers are turned to experimental research in science and engineering, there is an important opportunity to radically reduce the costs of experimental research while improving it. In the next article I argue that by harnessing a scalable open source method, federal funding is spent just once for the development of scientific equipment and then a return on this investment (ROI) is realized by digital replication of scientific devices for only the costs of materials. With numerous examples I show that the ROI climbs into the thousands of percent while accelerating any research that the open paradigm touches. To harness this opportunity, I propose four straightforward and negative-net-cost policies to support FOSH development and improve access to scientific tools in the United States. The policies will directly save millions in research and STEM education expenditures, while providing researchers and students access to better equipment, which will promote advances in technology and concomitant benefits for the American economy.

Thinking about the future and the changes needed to support this development in STEM education, AnnMarie Thomas and Deb Besser of the St. Thomas School of Engineering consider how engineers and engineering educators can use maker methods to introduce students to engineering and build their technological literacy. They show that the maker movement is closely tied to open hardware and sharing as well as the traits of successful engineers. Makerspaces and fabrication (fab) labs (what Gibb calls hackerspaces) are physical hubs of the maker culture.
Although these trends are clearly important for the United States, this cultural change and open hardware ethos can have dramatic impacts in the developing world. Matthew Rogge, Melissa Menke, and William Hoyle of TechforTrade explain the potential for open source and 3D printing to produce many needed items in low-resource settings, where lack of infrastructure makes local production impractical and high tariffs, unreliable supply chains, and economic instability make importation costly. Saving 90 percent on medical or scientific tools is nice in my lab, for instance, but it literally saves lives in a developing world context.
The issue concludes with an op-ed by Tom Callaway, a senior software engineer at Red Hat, Inc., an open source software company with revenue over $2 billion last year (up 15 percent year over year). What makes this business accomplishment so impressive is that all of the company’s software products are available for free. Although old ways of thinking demand that companies secure a monopoly and certainly not give away “intellectual property” for free, Red Hat’s success comes from offering its customers support, collaboration, control, and a high-quality product. Tom argues that the proven open source software mentality is porting to hardware, opening up incredible opportunities for humanity. He concludes, “open source and open innovation work…. They also empower society and make it possible to push the limits of what is possible. When the barriers to collaboration are lifted, people can accomplish incredible things.”

As all of the articles show, open source tools in the hands of this and future generations of engineers will be incredible indeed.