Weir removal for river restoration; observations on best practice and issues for a lowland UK river

Ciria has published River Weirs: Design, Maintenance, Modification and Removal to replace the Environment Agency's River Weirs Good Practice Guide of 2003. Although the previous guide was comprehensive, many lessons have been learned on the safety and operation of weirs since its publication. The water framework directive has also increased the emphasis on weir removal, lowering or modification to restore fish passage and natural geomorphological processes. In addition, interest in green energy has increased the use of weirs for hydropower generation. The new guide is aimed at all those with an interest in weirs and is freely available online. This briefing describes the functions of weirs and typical construction, potential impacts on safety and the environment, and what can be done to address shortfalls in performance. Finally, it highlights the need to raise awareness of the potential impacts of weirs among professionals and those responsible for weirs.

This book goes beyond the traditional methods of power generation. It introduces the many recent innovations on the production of electricity and the way they play a major role in combating global warming and improving the efficiency of generation. It contains a strong analytical approach to underpin the theory of power plants—for those using conventional fuels, as well as those using renewable fuels—and looks at the problems from a unique environmental engineering perspective. The book also includes numerous worked examples and case studies to demonstrate the working principles of these systems. Conventional and Alternative Power Generation: Thermodynamics, Mitigation and Sustainability is divided into 8 chapters that comprehensively cover: thermodynamic systems; vapor power cycles, gas power cycles, combustion; control of particulates; carbon capture and storage; air pollution dispersal; and renewable energy and power plants. Features an abundance of worked examples and tutorials Examines the problems of generating power from an environmental engineering perspective Includes all of the latest information, technology, theories, and principles on power generation Conventional and Alternative Power Generation: Thermodynamics, Mitigation and Sustainability is an ideal text for courses on mechanical, chemical, and electrical engineering.

The last several decades have seen a rise in efforts to remove weirs, but there is little research investigating how projects are carried out, potential areas for improvement, or sharing of lessons to facilitate reconnection of more rivers. The aim of the study presented here was to explore how people involved in weir remediation perceive project processes, factors that facilitate or hinder action implementation, and possible ways processes could be improved to reconnect more rivers. We carried out semi‐structured interviews with people (n = 11) who had been actively involved in weir remediation processes in the Severn River Catchment, United Kingdom, and used their responses to create a group mental model. The group mental model was created to support learning and communication about weir remediation projects between individuals and groups. We found broad agreement from those involved in creating the group mental model about weir remediation project processes and potential areas for improvement. One of the only points of divergence within the group mental model was associated with the impact of different weir remediation actions, particularly weir removal. Based on the group mental model, we set out three calls to action to reconnect more rivers in the UK. First, move beyond opportunistic projects and establish national goals and catchment‐scale plans for weir remediation. Second, reform fish passage legislation and legislate weir ownership. Doing so would support more effective remediation solutions by recognizing the diversity of fish species that reside in UK rivers and help mitigate risks from hazardous weirs through owner accountability. Third, build cross‐sector and public partnerships to encourage removal or improved fish pass designs. We direct the three calls to action to policy makers and anyone already engaged in or envisioning weir remediation projects in the UK. The calls also have potential implications and relevance to people in other countries in Europe and beyond.

Object and purpose of research. The object and purpose of this study is generation of electric power for electric propulsion of ship and vessels; methods and problems, state-of-the-art and trend analysis are presented. Materials and methods. The main principles and methods of electric power generation using various generating and power conversion systems are briefly discussed. Their advantages and disadvantages are identified based on publication in this field. Main results. Achievements in the modern methods of power generation for ships, as well as ways of its transformation are highlighted. A detailed analysis of the state-of-the-art and trends in ship electric power generation is given. Various options of engines and generators are considered, including advanced types. Their characteristics are thoroughly analyzed based on the international publications. Conclusion. Conclusions are formulated regarding achievements and current problems in ship electric power generation systems.

Economic and environmental estimated assessment of power production from municipal solid waste using anaerobic digestion and landfill gas technologies

Power Generation by Tide and Tidal Current

This paper reports the method of electric power generation from tidal currents and test results of the system which is specially designed for this purpose. The system consists of a vertical axis turbine, a accelerator, an electric generator, and a control unit. The turbine is vertical axis Darrieus rotor, and has three blades. The real test in tidal currents was conducted from 1983 to 1988, at Kurushima straits, and its results are discussed.

The power generation from tidal currents by darrieus turbine

With the growing interest in protecting the environment by using renewable energy sources as alternatives for power generation and its application in the concept of distributed generation, this research focuses on the comparison of the efficiency of each of components of photovoltaic systems, including grid-connected photovoltaic system to isolates. Using mathematical models that characterize each of the components getting itself to determine the key factors affecting the efficiency of each of the systems. And finally it was determined how to increase efficiency and reduce the value of the electrical losses in photovoltaic systems; to optimize solar resources in electricity generation.

This study investigated the effect of solar radiation’s intensity and ambient temperature on the current-voltage (I-V) characteristics of monocrystalline and polycrystalline photovoltaic (PV) systems in the generation of electricity in Calabar and Okuku, Cross River State, Nigeria. Appropriate measuring devices were employed to record daily readings of these parameters at the study locations, from July to August 2022. The data were collected and results graphically analyzed and calculated. The results indicate that current (Isc), voltage (Voc) as well as the maximum power (Pmax) of both module types increased positively with increase in solar radiation and ambient temperature. Results from collected and computed data also show average daily readings across the locations for solar radiation ranging between 271Wm-2 and 409Wm-2 and ambient temperature between 320C and 370C. The calculated Pmax ranges between 49W and 63W from the 130W solar modules used for the investigation. Another notable result is that the polycrystalline module exhibits higher Pmax than the monocrystalline module in both locations. In spite of the low solar radiation and ambient temperature obtained during this study period, which is considered the worst climatic period of the year (July and August), it is desirable and recommendable to employ solar modules as an alternative power generation in Calabar and Okuku, Cross River State, Nigeria.

Saudi Arabia is moving towards economical and technological development and to be an active player in the dynamics of the international community. The economic growth in the country requires significant additional electrical power generation in order to supply this increasing demand. At present, fossil fuel (petroleum and natural gas) reserves in Saudi Arabia are reliable in terms of feeding the needs of its conventional power plants. Fossil fuels, however, are not sustainable, are subject to eventual depletion and plants using these fuels produce large amounts of CO2 emissions. The authors have examined other power generation alternatives with an eye towards achieving sustainability. These requirements have led them to propose a renewable energy source—radiant energy from the sun as the way to achieve long-term success. The region is blessed with an abundant solar flux throughout most of the year. Recognizing this, the authors propose building solar-powered electrical generation plants in the Saudi deserts, but are faced with the problem: “Which solar technology is the ideal choice for this application?” Several different technologies have been identified and analyzed. A mathematical model was constructed and used to make a selection of the optimal technology. The decision model employed to determine the optimal technology, taking account of the fact that in making such a technology selection subjective judgment is required, is the Hierarchal Decision Model (HDM). This research relied on data extracted from scientific journals and industry sources as the inputs for the Decision Model. The authors also validated their research and derived expert opinion weighting factors with international experts in the solar technology. They have applied the model to a case study to demonstrate the use of it.

The power electrical generation at Brazil has been more and more discussed and required due to the huge economic and industrial expansion that our Country has been living. One of the methods of electrical power energy generation is the thermoelectric power plants which are capable of transform thermal energy, arising from the combustion chambers, into mechanical energy due to the rotation of the turbine blades and furthermore, transform this mechanical energy at the turbine into electrical energy. Therefore, the thermoelectric power plants have been playing a crucial role in the electric Brazilian sector, mainly as an emergency method of power generation, used when the most standard methods of generation are not capable of support the demand. This paper presents a zero dimensional analyses, through Matlab compiler, of an ideal system composed by combustion chamber, nozzle and turbine applied to a thermoelectric power plant. Three different types of mixture are compared for the combustion chamber: natural gas/air, CH4/N2O and C7H16/O2 yielding as a result 11 products: CO2, CO, H2O, H2, O2, N2, H, OH, O, NO, N. Parameters are adjusted in order to have an optimal electric generation system. Results are shown.

The authors proposed a very large floating structure (VLFS) installing the oscillating water column (OWC) type wave energy absorption, and the response control on VLFS and the estimation of the electric power generation on OWC type wave energy absorption system were carried out. In the present, paper, a prediction method of electric power generation and also the photovoltaic power generation equipment was considered in order to carry out the examination of compound-type ocean wave power generator.A number of researches on the utilization system of natural environment energy in ocean have been performed. In general the electric power generation is calculated from the characteristics of generator, energy and rate of operation. In the present study, the system simulation method power generator of oscillating water column type by dividing into the primary and the secondary converters was adopted. The hydrodynamic forces on oscillating water column were calculated by three-dimensional singular distribution method, and the time history simulation on primary converter was carried out, . Secondary converter was expressed by using the equation of motion on turbine. Photovoltaic power generation used existing technique.

Since Michael Faraday and Joseph Henry made their great discovery of electromagnetic induction, there have been continuous developments in electrical power generation. Most people today get electricity from thermal, hydroelectric, or nuclear power generation systems, which use this electromagnetic induction phenomenon. Here we propose a new method for electrical power generation, without using electromagnetic induction, by mechanically modulating the electrical double layers at the interfacial areas of a water bridge between two conducting plates. We find that when the height of the water bridge is mechanically modulated, the electrical double layer capacitors formed on the two interfacial areas are continuously charged and discharged at different phases from each other, thus generating an AC electric current across the plates. We use a resistor-capacitor circuit model to explain the results of this experiment. This observation could be useful for constructing a micro-fluidic power generation system in the near future.

Method of transportation and drinking among club patrons