The impact of a small hydropower plant (SHP) on benthic algae, macroinvertebrate community and ichthyofauna of the Panjica River (Serbia)

Connecting small, private & independent hydro power plants to increase the overall power generating efficiency

A new generation of small hydro and pumped-hydro power plants: Advances and future challenges

Optimal price of electricity of solar power plants and small hydro power plants – Technical and economical part of investments

Forecasting long-term power production of small hydropower (SHP) plants is of great significance for coordinating with large-medium hydropower (LHP) plants. Accurate forecasting can solve the problems of waste-water and abandoned electricity and ensure the safe operation of the power system. However, it faces a series of challenges, such as lack of sufficient data, uncertainty of power generation, no regularity of a single station and poor forecasting models. It is difficult to establish a forecasting model based on classical and mature prediction models. Therefore, this paper introduces a correlation analysis method for forecasting power production of SHP plants. By analyzing the correlation between SHP and LHP plants, a safe conclusion can be drawn that the power production of SHP plants show similar interval inflow to LHP plants in the same region. So a regression model is developed to forecast power production of SHP plants by using the forecasting inflow values of LHP plants. Taking the SHP plants in Yunnan province as an example, the correlation between SHP and LHP plants in a district or county are analyzed respectively. The results show that this correlation method is feasible. The proposed forecasting method has been successfully applied to forecast long-term power production of SHP plants in the 13 districts of the Yunnan Power Grid. From the results, the rationality, accuracy and generality of this method have been verified.

Influence of agricultural, industrial, and anthropogenic stresses on the distribution and diversity of macroinvertebrates in Juru River Basin, Penang, Malaysia

The exploitation of water flows in collective irrigation networks is promising in view of enhancing renewable energy production in agriculture. To this goal, a simplified method to estimate the electricity production of small hydro power (SHP) plants integrated in existing irrigation systems is proposed. This method schematizes the water network by an “equivalent” system, consisting of a single pipeline with homogeneous diameter and material. The proposed method only requires as input data the altimetry and the maps of the irrigated areas instead of the materials and diameters of all the conduits of a common water network (often unknown by irrigation managers). The feasibility of the proposed method has been verified to size SHP plants in seven collective irrigation systems of Calabria (Southern Italy). This application has highlighted a mean error of 20% in estimating the SHP power with a more detailed model, previously developed by the same authors and verified in the same context; these estimates are more accurate for SHP plants not exceeding 150–175 kW of electrical power. These results suggest the applicability of the proposed method for feasibility studies or large-scale projects of small SHP plants.

Hydropower plants produce renewable and sustainable energy but affect the river’s physico-chemical characteristics and change the abundance and composition of the aquatic organisms. The impact of large HPPs on the ecological conditions of surface water bodies have been extensively studied, but less attention has been paid to environmental impact studies of small hydropower plants (SHPs). The impact of hydropeaking on both the river flow regime and ecosystems has been well-studied for peaking mode plants, mainly medium to large-sized ones. However, for small hydroelectric power plants, and especially for those in lowland rivers, the available information on water quality, benthic macroinvertebrates communities and fish abundance, and biomass is not sufficient. Ten small hydropower plants were selected, and the ecological status of water bodies was assessed in different parts of Lithuania. The studies were performed at the riverbed upstream from the SHPs, where the hydrological regime has not changed, and downstream from the SHPs. It was found that the small hydropower plants do not affect the physico-chemical values of the water quality indicators. This study demonstrated that the total number of benthic macroinvertebrates taxa (TS) is influenced by the concentration of nitrogen and suspended solids, the water flow, the river area, and the current speed; the number of EPT (Ephemeroptera (mayflies), Plecoptera (stoneflies), and Trichoptera (caddisflies)) taxa is influenced by the concentration of nitrogen and suspended solids. The studied indicators do not have a significant impact on biomass. The SHPs affect the fish abundance and biomass. The Lithuanian fish index (LFI) is influenced by the average depth and area of the river. Some SHPs operating in lowland areas may yield somewhat significant hydrograph ramping but more detailed investigation is needed to support the significance of this impact on the biological indices.

In the field of renewable energy sources, hydropower is classified as economically and environmentally acceptable source where highly efficient and reliable systems are applied in energy transformation. Designing and exploiting such systems in a dynamic market-oriented environment require continuous updating and quality determination of essential energy characteristics. Determination of hydroenergy potentials of rivers, energy evaluation of new and revitalized small and large hydropower plants and the prediction of their electricity generation are carried out on the basis of numerous criteria, using energy and economic indicators and using different methodological approaches. The prerequisite for obtaining reliable data and valid predictions, regardless of the applied methodology, is based on a good knowledge of hydrological conditions, exploitation characteristics of hydropower plants in a wide operating range and consumption changes in time. Electricity generation in hydropower plants is primarily based on indicators of hydrological and meteorological conditions that are in their character stochastic, non-stationary and unevenly distributed. Consumption as a quantitative parameter belongs to the same category as above, while hydropower plants are equipped with turbines whose operating characteristics are determined by extensive and extremely expensive experimental tests. The existing standards define the conditions and measurement procedures, measuring equipment and analysis of measurement results depending on the type of required testing. In order to rationalize the conditions for obtaining the characteristics of hydraulic turbines, modern numerical experiments based on imperfect numerical simulations of flow are increasingly applied. In recent years, the application of artificial neural network methods for determining reliable parameters of hydraulic turbines, production prediction and optimizing the operation of hydroelectric power plants has shown its strengths. The paper presents the usual methods prescribed by the standards for laboratory and field testing of large and small hydropower plants, as well as trends of using contemporary approaches, pointing out their advantages and disadvantages.

Impacts of cascaded small hydropower plants on microzooplankton in Xiangxi River, China

Hydropower plants (HPPs) have a strong environmental impact on freshwater wetlands. Small diversion HPPs (SDHPPs) with 0.1–10 MW of installed power, redirect water from small mountainous rivers into several-kilometer-long tubes, disrupting complex dynamics of local aquatic food webs and their interactions with neighbor terrestrial food webs. It certainly affects local aquatic communities, but it is often neglected that two highly threatened vertebrate groups—amphibians and reptiles—which live in and around these wetlands, could be affected as well. In the Balkan peninsula, a part of Southeastern Europe, SDHPPs recently became very attractive and profitable for potential investors after they were proclaimed as eligible for subsidies from the national budget. As a result, in year 2020, the maximal projected number of SHPPs in the Balkans increased to 4,556. According to the literature data, ~28% of amphibian species in the Balkan Peninsula use small rivers and streams in the upper parts of watersheds as feeding, breeding and/or nursery habitats. Additionally, 38% of the total number of reptile species in Europe are registered in the hilly/mountainous areas of the peninsula, and 33% of these species strictly need humid habitats. The attempt of this mini-review is to present the facts which show that SHPPs and DSHPPs, in the way they are currently being installed, present harmful energy solution for the biodiversity of the mountain parts of Balkan peninsula, particularly for local amphibian and reptile populations which rely on lotic aquatic ecosystems and/or humid terrestrial habitats.

Climate change has affected rainfall patterns in tropical regions, where simultaneous demands for water and energy, habitat loss, declining biodiversity, and spread of invasive species have reflected a rapidly changing world underway. In Brazil, hydropower generation accounts for 64% of the electricity matrix, which presently includes 1007 small hydropower plants (SHPs) having many others under construction or planned. This paper aimed to evaluate changes in water quality, plankton communities, and benthic macroinvertebrates during dam construction, filling, and the first year of operation of a SHP. Suspended solids, turbidity, and silica were variables that highlighted the impact of this construction on the river. Fast changes in water quality (increases in calcium, chlorides, and nitrate) and on aquatic communities (i.e. euglenophyceans and testate amoebae increased in numbers) were detected during the filling phase. Following SHP construction, the concentrations of metals and total phosphorus tended to decrease. Two striking findings observed in the aquatic communities from the riverine conditions to the new lake were the increase in picocyanobacteria abundance, expanding population stocks throughout the river basin, and the constant presence of the invasive mollusc Corbicula fluminea in the macroinvertebrate assemblage, revealing once again its resistance to environmental variability. The lake soon became a natural trap for ions from the drainage basin, as revealed by the increase in electrical conductivity, ammonium, potassium, and magnesium concentrations and the abundance of cyanobacteria, highlighting the need for watershed management to improve ecological conditions in the lake.

The most important direction in development of electric power industry is the use of renewable energy sources. In mountain areas with their high mountain rivers, construction of high-efficient small hydropower plants (SHP) is certainly effective. Based on the example of the Fasnalskaya SHP, the paper provides the scientific and technical basis for calculation of operation and management of small HPPs, including methods of calculation of water and energy parameters, as well as control structure of the SHP. The developed techniques include generation of input data base consisting of cartograms of SHP coordinates on the local map, rivers for the SHP, estimated level of pressure, estimated length of the overhead power transmission line (PTL) of SHP-load unit, point of common coupling, SHP and energy system, point of common coupling of SHP and substation, hydrograph of a river, SHP single line diagram, basic water and energy options. In the course of comprehensive studies of water and energy parameters, we have defined conditions for an optimal schedule of SHP based on consumption of water and power generators, and control of the water and energy parameters in accordance with the schedule defined with the power grid load. Practical significance of the work is development of engineering programs and algorithms that help to resolve issues related to the design, calculation of technical parameters, operation and management of small HPPs. The obtained results may be used in other mountain areas of the world.

Small hydropower plants (SHPs) can significantly exploit the unutilised hydropower potential in Europe. In particular, this applies to run-of-the-river power plants with low heads. Variable speed technology, high-efficiency, and low-speed synchronous generators with permanent magnets (PMSGs) can significantly improve the efficiency of such SHPs. Unfortunately, the cost of design and implementation of PMSGs for a specific SHP remains significantly high compared to a classic induction generator. This study proposes to reduce the cost of PMSG production by applying a new idea of modular construction of the generator. The proposed solution assumes the possibility of using a universal segment to implement generators of different power (through parallel connection) and rotational speed (by reconfiguring the stator winding). The generator parameters are determined on the basis of an analysis of Poland's hydropower potential and matched to the hydro set with a discharge of 1 to 10 m3/s and heads of 1.5 to 3.5 m. A full-size prototype of a 120 kW three-segment generator is developed. Prototype tests for various configurations of segment windings confirmed that the idea of a modular generator is possible for industrial implementation. However, further optimization work related to improving the efficiency, symmetry, and repeatability of segments is recommended.

Impacts of small hydropower plants on macroinvertebrate communities

Small Hydro Power (SHP) plants have many advantages over large scale hydropower generation. SHP has been identified as a good alternative to conventional electricity generation for many developing countries around the world. Run-of-the river type SHP plants contain considerable economic advantages. However these are affected by various technical and economic challenges. In this paper an economic analysis and development of a small hydro power plant is presented.