The Small Hydropower in China-A Focus of World Attention

This paper describes the present situation, construction experiences, existing problems and the principal tasks in the development of small hydropower in China.

Information acquisition technology for small hydropower stations in remote areas based on high-and low-orbit satellites

With a lack of coverage in private and public power communication networks,especially for collection of information from hydropower stations in remote areas,communication coverage is a significant issue.Satellite communication provides a large coverage area suitable for a variety of services and is less affected by geographical factors;moreover,the costs are independent of the communication distance.This study investigates information acquisition technology for small hydropower stations in remote areas using high-and low-orbit satellites.The information collection needs of small hydropower stations in remote areas are analyzed,and an information acquisition system is designed using high-and low-orbit satellites.For network security protection,network anomaly detection technology based on a support vector machine algorithm is proposed.The effectiveness of information collection was evaluated and verified for small hydropower plants in remote areas.The system provides technical support for“full coverage,full collection,and full monitoring”of the measurement automation information acquisition system.

Estimating Ecological Value of Small Hydropower Using Contingent Valuation Method:An Application to Tongjiqiao Reservoir in Zhejiang Province,China

The small hydropower(SHP) will be less competitive in the absence of environmental value.The lack of information has become an important obstacle challenging decision-makers in resource-use choices.This paper is an application of contingent valuation method(CVM) in rural China to estimate the willingness-to-pay(WTP) for environmental services provided by exiting hydropower station.Using the single-bounded and dichotomouschoice CVM,the ecological value of Tongjiqiao Reservoir(TJQR) is estimated,and the annual mean WTPs of single-bounded and double-bounded CVM estimation are 141.05 and 219.52 Yuan(RMB)/a,respectively.The 95% confidence interval of annual WTP on an average is 118.47,166.79 Yuan(RMB)/a and 204.41,236.22(Yuan RMB)/a,respectively.In contrast,double-bounded model could obtain much more information of WTP of the investigated,thus reducing the confidence interval of estimation,and enhancing the estimation accuracy of the WTP.According to the estimated mean WTP of the double-bounded CVM,the total ecosystem service value of the TJQR is 15.54 million Yuan(RMB).Compared with the conventional electricity of fossil power and large hydropower,the SHP will be less competitive in the absence of non-market value,ignoring that the environmental impacts of existing SHP will undermine the healthy development of clean energy sector.

Load Frequency Control of Small Hydropower Plants Using One-Input Fuzzy PI Controller with Linear and Non-Linear Plant Model

This study presents an intelligent approach for load frequency control (LFC) of small hydropower plants (SHPs). The approach which is based on fuzzy logic (FL), takes into account the non-linearity of SHPs—something which is not possible using traditional controllers. Most intelligent methods use two- input fuzzy controllers, but because such controllers are expensive, there is economic interest in the relatively cheaper single-input controllers. A non- linear control model based on one-input fuzzy logic PI (FLPI) controller was developed and applied to control the non-linear SHP. Using MATLAB/Si- mulink SimScape, the SHP was simulated with linear and non-linear plant models. The performance of the FLPI controller was investigated and compared with that of the conventional PI/PID controller. Results show that the settling time for the FLPI controller is about 8 times shorter;while the overshoot is about 15 times smaller compared to the conventional PI/PID controller. Therefore, the FLPI controller performs better than the conventional PI/PID controller not only in meeting the LFC control objective but also in ensuring increased dynamic stability of SHPs.

Assessment Framework of Green Intelligent Transformation of Small Hydropower in China

With the comprehensive promoted construction of the establishment of green small hydropower,the defects of existing small hydropower station are gradually emerging,and it is necessary to implement green intelligent transformation to promote the construction of energy internet in China.This study focuses on constructing a green intelligent planning and transforming assessment framework,and assists management department to filtrate the small hydropower stations which can be transformed reasonably.Firstly,power station economy,ecological environment,technical safety management and social benefits are involved in the assessment index system.Secondly,multi-expert judgment aggregation based on fuzzed comparison scale is put forward to calculate the index value,and evidence synthesis is used to comprehensively assess the feasibility of green and intelligent planning and transformation for several small hydropower stations.The simulation case analysis shows the constructed assessment framework can reflect the actual situation of objectives properly and would provide decision-making basis for green and intelligent planning and transformation of small hydropower stations.

Environmental Integration of Small Hydropower Development

On the basis of cooperative research with European professionals, problems relating to environmental and ecological protection were discussed while small hydropower development in China currently was introduced in this paper. Guidelines of small hydropower development dealing with environmental protection were sug- gested hereby. Various specific technical environmental solutions focusing on small hydropower development applied in European and other developed countries were also introduced in this paper. Main environmental solutions are discussed as follows： integrated design should be advocated during plan/design stage,＂ ecohydraulic engineering and its utilization in SHP design and construction; effective technical approaches to relieve and eliminate the impact of river interception and fix the reasonable minimum biological flow; environment-friendly mitigation and compensation measures for high/low-head hydropower schemes applied in diversion works, intake, nature-like fish-passes, penstock and powerhouse design; study and application of the new technology, material and equipments; launching renovation of environmental protection in existing stations; emphasiz- ing public participation and their acceptability for the SHP environment; coordinated inter-disciplinary study at national level, etc. Two case studies in Sweden and Australia are given here.

Towards a Sustainable Development of Small Hydropower Plants, from Valley of Sperchios River to Mount Olympus

The mountainous region of Fthia, identified with the Valley of Sperchios River, in Central Greece, is rich in small watercourses and generously blessed with water and abundant water falls. The geographical configuration of Olympus and Fthia＇s mounts and the hydraulic singularities of drained lakes Askouris in Olympus, favour the installation of series of sustainable small hydroelectric plants. The present action consists of a serious effort towards the systematic sustainable small hydropower exploitation of Fthia＇s and Olympus hydraulic potential, including the Archimedean hydropower perspectives of Sperchios River.

Research on reform schemes of control methods of inlet gate in Jiaxin Hydropower Station

The simple gate control system which is made of traditional manual or proximity switch cannot meet the requirements of connecting with the computer monitoring system of hydropower station, it must be reformed. On the basis of the integrated analysis for small hydropower station, the paper discussed the singlechip as the core to realize the methods of gate automatic control system in small hydropower station. The designs for hardware and software of gate control system were introduced. And the control system was reformed from customary manual control to computer automatic control. The simulation experiment shows that this scheme is feasible.

Quo Vadis Archimedean Turbines Nowadays in Greece, in the Era of Transition？

According to recent hydropower inventories, the first aim of this paper is to prove that Greece is a real ＂Archimedean Soft Small Hydro Development Terra Incognita＂. It is a country in the Era of Transition of nowadays, having an important unexploited hydropower potential of several TWh and thousands of MW. The second goal is to present the results of rediscovering the old screw pumps and the always-modern Archimedean cochlear screw ideas as a series of soft hydropower turbines with inclined axis rotors and floating spiral screw devices. By following the similarity methodology, a few small-scale models of cochlear rotors were designed, developed and tested in an Armfield hydraulic channel. The conventional and unconventional, low or zero-head screw turbines, could efficiently harness the important and unexploited Greek small potential and kinetic hydraulic energy of all the natural watercourses, the man-made open urban or rural channels and the most important tidal or sea currents, producing useful green electricity. The very promising low-head hydropower inventory of Greece, the preliminary experimental results and the research studies of cochlear projects in watercourses, hydraulic works, tidal conditions of Euripus Strait and in the mysterious ＂Sea River Current of Cephalonia＂, seems to give a good answer to the question ＂Quo Vadis Archimedes nowadays in Greece, in the Era of Transition？＂.

Investigation of Physical and Numerical Model of Archimedes Screw Turbine

Archimedes screw turbines have been developed as they work with a low head with high efficiency, where flow energy can be exploited in small rivers, streams, regulators and others. The power can be produced using Archimedes turbines and depends on some parameters including the number of blades, flow, and angle of the shaft inclination and the length of the pitch. A physical and numerical model has been developed to determine the performance of the Archimedes turbine on the Ramadi Dam in Iraq. The physical model was made of stainless steel with the following parameters (length 1000 mm, pitch 70 mm, diameter ratio 0.536, inclination angles 30°, 35°, 40°, 45°). Work was carried out on different flow rates and inclination angles. The experimental results showed that the highest efficiency was 81.4% at 35° inclination angle and a flow rate of 1.12 l/s; the maximum power of 9.03 watts was at a 45° inclination angle and a flow rate of 2.065 l/s and 72% efficiency. Also, the impact of the pitch and the number of blades were studied. The results show that torque is increase with an increase in the pitch length, and torque is decreased with increase in several blades. The numerical results showed that the using of two blades led to a greater power produced. The comparison of the numerical and experimental results showed a good agreement, also the comparison with the published data showed a good agreement. As a final result the Archimedes screw has many positive points making it a good potential candidate. The results that emerged show the possibility of using this type of turbine in the Euphrates River in Anbar Governorate—Iraq, as the province is characterized by the presence of many regulators on the river in which turbines can be employed.

Characterization of the Constructions Materials Used in the Hydroelectric Power Plants in the Sedano＇s Valley, Burgos （Spain）

Small hydropower plants for electricity generation were first built in Spain in the early 1880s. The Spanish peninsula is characterized by its rugged landscape, fast flowing rivers and steep gradients. A clear example of this is the remarkable area of the upper Ebro river basin where powerful water flows are found that are ideal for electricity generation. Between 1900 and 1930, the river Ebro was a major source of energy for industrial areas such as Alava, Vizcaya, Vitoria, Miranda de Ebro, Burgos and La Rioja. Between 1951-1965, the use of these small hydropower plants declined due to the construction of alternatives by industrialists in the Basque Country, which in most cases led to their deterioration. They were rescued in the late twentieth century, thanks to private sector initiatives which funded their rehabilitation. This study examines two small-scale hydraulic power plants in the province of Burgos at Medina de Pomar and at Quintanilla Escalada; both buildings were used for generating electricity and had living quarters for the workers and now represent historic architectonic and industrial heritage. The study documents their architectonic features and the restoration processes that have permitted one of them to remain in operation up until the present day.

Viability of Hydro Kinetic Turbine as an Alternative for Renewable Energy Harvesting in Nigeria

The rationale behind this research is the development of a zero-heM floating system using a conventional hydrokinetic water wheel as a model to examine and determine its performance in an open channel condition for energy harvesting in Nigeria. The power is determined by flow of water in the stream which is responsible for rotating the blades. The research entails the water flow driven by a pump at 0.4 m/s and 0.6 m/s water velocities around a pool. The turbine is made to float under this free stream velocity. Feasibility study of its viability in Gari dam in Kano state of Nigeria was carried out and an average flow and discharge were determined during the dry season. Findings of this research were quite impressive and can be used to design a suitable floating zero-head turbine for energy harvesting in Nigerian rural areas where the head is low and energy is required not only for mechanization but also for lighting and irrigation purpose.