Small Hydropower Facilities Research Articles

Socioeconomic impact of the war on the hydropower sector of Ukraine

The invasion of Ukraine on February 24, 2022, caused significant military damage to the hydropower sector, critical for energy security and economic development. The article provided an overview of the Ukrainian hydropower sector and the war’s socioeconomic impact on it in 2022-2024. Based on open source data, the research focused on large and small hydropower facilities, examining their roles in electricity generation, stability of the unified energy system of Ukraine, and water supply. The authors’ findings offer insights into the extent of damage for policymakers, scientists, and sector experts.

We Have Eaten the Rivers: The Past, Present, and Unsustainable Future of Hydroelectricity in Vietnam

Vietnam has one of the most intensively energy-exploited riverscapes in Asia with at least 720 hydropower facilities of various capacities currently in operation or in some stage of construction. These facilities represent about 26 GW of installed capacity. This degree of domestic exploitation is often overshadowed by the geopolitically contested manipulation of the waters of the international Mekong River. In contrast, the utilization of Vietnam’s hydropower resources has unfolded gradually and largely unremarked for more than half a century. This perspective argues that the harnessing of rivers and streams for electricity generation is the result of not only the country’s abundant hydrologic resources, but also its history, culture, and (geo)politics. The paper traces the processes that have produced this high level of river exploitation, its ambiguous history, and the uncertain future of hydropower in Vietnam in the context of sustainability. Further, the renewed interest in dam-building in recent years is part of a “theater of decarbonization” that masks the operation of powerful domestic and international lobbies with an interest in “heavy engineering” projects that will do little to meet the nation’s rapidly growing electricity needs but will likely incur detrimental ecological and sociological impacts. The paper ends by positing that rather than forging ahead with the construction of additional small hydropower facilities, a more ecologically and socially equitable policy could instead critically examine the sustainability of existing capabilities, resolve the factors limiting the development of other renewable sources of energy, and face the fundamental challenge of curbing energy use.

Bidirectional connectivity in fishways: A mitigation for impacts on fish migration of small hydropower facilities

Abstract Most freshwater fish need to move freely through rivers to complete their life cycles. Thus, river barriers (e.g. dams, culverts and gauging stations) may delay, hinder or even block their longitudinal movements, affecting fish conservation. The most widespread solution to allow upstream fish migration are fishways, whereas downstream migration is basically facilitated through spillways, turbines or specific solutions such as bypass systems. So far, studies and scientific discussions concerning bidirectional movements through fishways are scarce and focused on large dams and reservoirs, mainly with large migratory species such as salmonids, rather than smaller facilities and lesser known species. This study investigated bidirectional movements through a small run‐of‐the‐river hydropower plant with a pool‐and‐orifice type fishway, using the Iberian barbel (Luciobarbus bocagei), a potamodromous cyprinid, as the target species. Passive integrated transponder and radio tracking data were collected over 4 years and combined to characterize upstream and downstream movements. The study focused primarily on fish movements through the fishway, but also estimated the multiple associated routes of passage. The results show diverse fish movements with inter‐ and intra‐annual variability, with several individuals performing bidirectional movements and even some fish returning over the years. The documented movements and observations indicate that fishways can serve as an effective bidirectional migration corridor for fish, potentially enhancing the conservation efforts for potamodromous species. This study supports the decision to use fishways as an overall mitigation tool to reduce the impact of small hydropower facilities on fish.

Modelling and assessing how small hydropower facilities affect sediment transport by using fuzzy inference systems

Small dams for power generation are increasingly being built around the world, and the reported impact caused by these structures on sediment transport varies widely, ranging from substantial to minimal or non-existent alterations among different dams. Such variability is still poorly understood. In this study, we present an original application of fuzzy inference systems (FIS) to extract knowledge concerning the effect of small dams on sediment transport, providing understandings of how different variables related to watershed characteristics, dam characteristics and hydrological variations can affect sedimentological responses of these structures. Numerous small dams have been built, and many more are in development or proposed, in rivers that drain into the Pantanal, a world-renowned tropical wetland, where we apply the methodology. Data on 23 hydropower facilities from the uplands of the Pantanal region were used, with a total of 535 records. The models presented very good results (NS equal to 0.92 for the most detailed FIS model) and provided a better understanding of the phenomenon through their explicit linguistic rules. The upstream suspended sediment concentration (SSC) is the most determinant variable for the alteration caused by dams. Higher SSC entering the reservoir is related to higher sediment retention. Vegetation cover and soil type of the drainage area of dams also influence the alterations on SSC caused by these structures. Dams located in basins with greater vegetation cover tend to affect less sediment transport, and dams located in basins with high percentages of agriculture and pasture tend to alter more. FIS models also confirmed that the size of dams is directly proportional to their capacity to alter sediment transport. The methodologies developed for the interpretation of fuzzy rules proved to be useful for assessing how small dams affect sediment transport along river systems.

Метод оценки теоретических характеристик малых осевых гидротурбин

Energy supply to remote areas remains a technical and social challenge. Construction of transmission lines to provide electricity to such areas is expensive and not always possible. One of the promising areas in this area is local energy generation based on local resources, in particular small watercourses, using small hydroelectric power plants. Small hydroelectric power plants are small hydropower facilities that use the energy of small watercourses to generate electricity. They have a number of advantages over traditional energy sources, such as environmental friendliness, low operating costs and high efficiency. However, the widespread introduction of small hydroelectric power plants is hampered by the lack of mass production of small hydraulic turbines and difficulties in designing low-power plants. Designing hydraulic turbines is a complex task that requires solving the inverse problem of hydrodynamics and finding the optimal shape of the flow path. To simplify the design of hydraulic turbines in the modern world, specialized software is used using various methods, including flow analysis, energy loss and blade shape optimization. This article based on an analysis of existing methods for designing and using a mathematical model of a hydraulic turbine with simplified blades, proposes a method for designing and analyzing the theoretical characteristics of the resulting hydraulic turbine. In conclusion, taking into account the use of the methodology for designing a hydraulic turbine for given parameters, its assessment is given, as well as ways to possibly improve the accuracy of the results obtained. Possible areas of application of the outlined design methodology are indicated.

ПОТЕНЦИАЛ ТЕХНОЛОГИЙ ВОЗОБНОВЛЯЕМЫХ ИСТОЧНИКОВ ЭНЕРГИИ В УСЛОВИЯХ СИБИРИ

The use of both main and alternative energy sources to ensure energy security is considered. The incentives for the development of renewable energy in the conditions of Siberia have been determined. The analysis of the potential for the use of cogeneration plants, small hydropower facilities, solar energy, wind energy, the use of low-grade heat and bioenergy has been carried out. The prerequisites for increasing the capacity of renewable energy generation are determined

Hydropeaking by Small Hydropower Facilities Affects Flow Regimes on Tributaries to the Pantanal Wetland of Brazil

Hydroelectric facilities often release water at variable rates over the day to match electricity demand, resulting in short-term variability in downstream discharge and water levels. This sub-daily variability, known as hydropeaking, has mostly been studied at large facilities. The ongoing global proliferation of small hydropower (SHP) facilities, which in Brazil are defined as having installed capacities between 5 and 30 MW, raises the question of how these facilities may alter downstream flow regimes by hydropeaking. This study examines the individual and cumulative effects of hydropower facilities on tributaries in the upland watershed of the Pantanal, a vast floodplain wetland system located on the upper Paraguay River, mostly in Brazil. Simultaneous hourly discharge measurements from publicly available reference and downstream gage stations were analyzed for 11 reaches containing 24 hydropower facilities. Most of the facilities are SHPs and half are run-of-river designs, often with diversion channels (headraces). Comparison of daily data over an annual period, summarized by indicators of hydrological alteration (HA) that describe the magnitude, frequency, rate of change, and duration of flows, revealed differences at sub-daily scales attributable to hydropeaking by the hydropower facilities. Results showed statistically significant sub-daily HA in all 11 reaches containing hydropower facilities in all months. Discharge indicators that showed the highest percentage of days with increased variability were the mean rates of rise and fall, amplitude, duration of high pulses, maximum discharge, and number of reversals. Those that showed higher percentages of decreased variability included minimum discharge, number of high pulses, duration of stability, and number of low pulses. There was no correlation between HA values and physical characteristics of rivers or hydropower facilities (including installed capacity), and reaches with multiple facilities did not differ in HA from those with single facilities. This study demonstrates that SHPs as well as larger hydropower facilities cause hydrological alterations attributable to hydropeaking. Considering the rapid expansion of SHPs in tropical river systems, there is an urgent need to understand whether the ecological impacts of hydropeaking documented in temperate biomes also apply to these systems.

Further Development of Small Hydropower Facilities May Alter Nutrient Transport to the Pantanal Wetland of Brazil

Small hydropower (SHP) facilities, defined variably but usually by installed capacities of <10–50 MW, are proliferating around the world, particularly in tropical and subtropical regions. Compared to larger dams, SHPs are generally viewed as having less environmental impact, although there has been little research to support that assertion. Numerous SHPs have been built, and many more are in development or proposed, in rivers that drain into the Pantanal, a world-renowned floodplain wetland system located mostly in Brazil. The upland tributaries are important sources of nutrients to the Pantanal, affecting the biological productivity of downstream floodplains. This study presents measurements from upstream and downstream of 25 current hydropower facilities, most of which are SHPs, throughout the upland watersheds of the Upper Paraguay River basin to reveal how these facilities may affect the concentrations and transport of nutrients in rivers flowing to the Pantanal. Artificial neural network models estimated the impact of building 80 future SHPs on nutrient transport into the Pantanal, based on observations at current facilities as well as the spatial distribution of future facilities. Overall impacts of current hydropower facilities were not large, and in most cases were indistinguishable based on comparisons between upstream and downstream. The short water residence times of reservoirs associated with SHPs likely explain their tendency to have little or no effect on nutrient transport. However, model predictions for hydropower facilities that may be built in the future, many on rivers with higher discharge and sediment loads, point to significant reductions in overall TN (8%) and TP (29%) transport, with potential negative consequences for river and floodplain productivity. Negative impacts may be either because the rivers carry low nutrient concentrations and are thereby sensitive to oligotrophication, or they are particularly important overall nutrient sources supporting ecosystem productivity in downstream rivers and floodplains. Together with a parallel study of sediment transport, these results support recommendations that several river systems presently lacking dams in their lower reaches should be excluded from future hydropower development to maintain the nutrient and sediment supply to the Pantanal.

Further Development of Small Hydropower Facilities Will Significantly Reduce Sediment Transport to the Pantanal Wetland of Brazil

Small hydropower (SHP) facilities, are commonly being built around the world. SHPs are viewed as less environmentally harmful than larger dams, although there has been little research to support that assertion. Numerous SHPs have been built, and many more are in development or proposed, in rivers that drain into the Pantanal, a world-renowned floodplain wetland. Three river systems with the largest contributions of sediments to the Pantanal—the Cuiaba, upper Taquari, and Coxim rivers—remain largely undammed. The upland tributaries transport sediments and nutrients into the Pantanal, thereby affecting geomorphological dynamics and biological productivity of downstream floodplains. This study presents measurements from upstream and downstream of current hydropower facilities, most of which are SHPs, throughout the upland watersheds of the Upper Paraguay River basin to reveal how these facilities may affect the transport of suspended sediments and of bedload sediments. In addition, a predictive model using artificial neural networks estimates the impact of building 80 future SHPs on sediment transport based on observations at current facilities as well as the spatial distribution of future facilities. More than half of current facilities retained suspended sediments: 14 of the 29 facilities showed >20% net retention of suspended sediments, two others retained between 10-20%, seven were within 10%, and six showed >10% net release. Bedload sediment transport was a small component of total sediment transport in rivers with high total sediment loads. Multiyear series of satellite images confirm sediment accumulation in several cases. Model predictions of the impacts of future hydropower facilities on suspended sediment concentrations and transport show retention of a large fraction (often much >20%) of sediment inputs. Summing riverine transport rates for inflows into the Pantanal indicates that currently envisioned future hydropower development would reduce the suspended sediment transport by ~62% from the current rate. This study shows that if SHPs are built on sediment-rich rivers, this may prove problematic for the facilities as well as for downstream ecosystems. These results support recommendations that several river systems presently lacking dams in their lower reaches should be excluded from future hydropower development to maintain the sediment supply to the Pantanal.

Construction and Operation of Small Hydro Power Plants in the Ukrainian Carpathians: New Challenges for Environment

Purpose. Analysis of environmental problems and risks associated with the construction and operation of small hydroelectric power facilities (SHEPP) in the Ukrainian Carpathians. Methods. Field studies, statistical, hydrological, hydroecological, analysis and synthesis. Results. Potential environmental risks arising from the construction and operation of SHEPP in the Ukrainian Carpathians are considered. The influence of Yavіrska hydroelectric power station on water discharges in the Stryi river was investigated. The daily water discharges for the two hydraulic sections located above and below the station for low-water (2003) and high-water (2008) years are analyzed. Possible risks in the construction and operation of the hydroelectric power plant for the movement of flood waters, river sediments, the development of riverbed deformations, and others, are indicated. The difference in water discharges between the two hydrological stations is presented, and it is confirmed that in the spring of 2008 and 2003 and the autumn and winter of 2003 and 2008 minimal differences in water consumption were observed as a result of the water retention in the reservoir above the dam of Yavіrska hydro power station for the maximal electrical power generation. The impact of the Yavіrska SHEPP on the biota of the Stryi river during 2014–2015 was analyzed. The obtained results indicate that the main negative factors affecting the communities of river hydrobionts are the creation of reservoir of limnethic conditions in the continuum of the river ecosystem; the accumulation of sediments and dead organic matter on its bottom and banks and the demolition of these sediments on the lower sections of the channel bed; also a decrease of water in the riverbed downstream of the dam after the closure of the floodgates in June. The analysis of the environmental impact assessment reports made it possible to analyze the major environmental threats, which are possible during the building and operation of a small hydroelectric power plant on the Stryi river in the Dovhe village (Drohobych district, Lviv region). Conclusions. To prevent the impact of the projected SHEPP in the Carpathian region it is necessary to prescribe the mechanism of carrying out the environmental impact assessment, to specify the natural-geographical, hydrological and hydro-ecological restrictions on the construction and operation of the hydroelectric power station. It is also necessary to identify sections of mountain (“wild”) rivers with high values of natural landscapes and prohibit the construction of small hydropower facilities.

К ВОПРОСУ ИСПОЛЬЗОВАНИЯ МИКРОГИДРОЭЛЕКТРОСТАНЦИЙ ДЛЯ ЦЕЛЕЙ ОРОШЕНИЯ

Purpose: to assess the technological and regulatory and technical capabilities of developing and applying power supply complexes using the energy of water flow, in relation to Russian standards to meet the electricity needs of decentralized reclamation (irrigation) systems. Materials and methods. Scientific and technical materials of Russian and foreign authors, as well as the regulatory and technical base of the Russian Federation were used as the initial data. The information processing methods were comparison, analogy, classification and systematization. Results and discussion. Among various design features of the hydropower equipment under consideration, capable of meeting local needs for electricity and at the same time having the ability to combine with elements of an irrigation network (based on relative dimensions, shape, efficiency, etc.), micro-hydroelectric power plants stand out: with propeller, radial axial, axial and capsule hydraulic turbine. The most effective schemes for installing hydraulic turbines are horizontal direct-flow and vertical Z-shaped ones. Analysis of the register of standards in the field of technical regulation in the sphere of hydropower showed that out of 131 standards under consideration, 106 can be partially applied to micro hydropower plants. Providing low-power hydropower facilities with standardization documentation has a priority in the direction of operation (21 %), monitoring and state control (19 %), and repair and reconstruction (19 %). Conclusions. The functioning of a micro-hydroelectric power station based on the energy of water movement provides for the use of a set of design solutions, which requires additional study in order to be linked to the elements of reclamation (irrigation) systems. The scope of the considered standardization documents can be extended to small hydropower facilities, taking into account the specific features of their operation. In this regard, there is a need for the development of scientifically grounded provisions of existing or being developed regulatory documents.

ORGANIZATIONAL AND ECONOMIC MECHANISM OF RATIONAL USE OF RESOURCE POTENTIAL OF WATER OBJECTS AT THE REGIONAL LEVEL

One of the promising areas for the development of renewable energy in Ukraine could be the expansion of the small hydroelectric power plant (HPP). The main obstacle to this is the absence of a sharp increase in the profitability of such facilities, since the operation of small hydropower facilities is based on the use of only one of their resource function, which is not consistent with the need to intensify the use of nature and integrated use of natural resources. The most expedient direction of increasing the efficiency of functioning of small hydropower facilities, increasing their economic, social and ecological significance is the organization of regional natural-economic complexes (RPGK) whose activity is based on the combination of electricity production, maintaining the sustainability of the recreation ecosystem, can significantly increase their market value. Also important is the issue of software to solve this problem.

Some critical comments on the quality of environmental impact assessment reports for small hydropower plants in Ukraine

Nowadays, small hydropower in Ukraine has a small share in the national energy balance. However, in Ukraine small hydropower has been still developing, but its development is largely spontaneous, not accompanied by scientific and technical researches of small rivers, as well as an appropriate analysis of the impact of small hydropower plants on the environment. As a result, there is an increasing resistance to the building of new hydropower plants in the country by environmentalists, activists and the public.The issue of small hydropower in our country has become a new topical challenge in connection with the adoption in 2017 of the Act of Ukraine “On Environmental Impact Assessment”. According to this Act, all hydropower plants on rivers, regardless of their capacity, including small hydropower plants, are classified as planned activities and objects that can have a significant environmental impact and are subject to environmental impact assessment.Since 2017, in accordance with the Act, a large number of environmental impact assessment reports have been submitted to the Unified Register concerning planned activities related to the construction of new small hydropower plants, which were prepared by various entities, including universities.The main objective of the research was to analyze the reports presented in the Unified Register and the formulation of practical comments on the quality of their preparation, the accuracy and completeness of information on the environmental impacts of the planned small hydropower plants. The purpose of the article is to familiarize professionals in the various fields of knowledge relevant to the issue, in particular, hydraulic engineers, hydropower engineers, environmentalists, as well as potential investors in small hydropower, public activists and the general public with these remarks.Totally, 16 of reports were analyzed in detail. The main shortcomings of the performed environmental impact assessments of the new small hydropower plants planned to build were noted, including the lack of proper analysis of alternatives and scientifically sound forecasts, the incompetence of experts in the issues related to the environmental impacts of hydraulic structures. Practical recommendations were formulated that can help improve the quality of the environmental impact assessment of small hydropower plants, with the aim of avoiding environmentally hazardous decisions, taking into account the various environmental and social risks associated with small hydropower facilities.

Proposed methodology for evaluation of small hydropower sustainability in a Mediterranean climate

The Mediterranean region is characterised by a temperate climate and scarce water resources; therefore, minimum flows must be maintained in high mountain basins to ensure the sustainability of the ecosystem. Small hydropower facilities allow for energy utilisation that is compatible with this goal. A methodology has been proposed using historical climatic data to evaluate the percentage of regulation required in a basin according to its surface area and slope in order to guarantee a minimum percentage of energy supply. Two methods for hydroelectric generation by small hydropower facilities were analysed in this case study: dam-toe and diversion techniques. The model has been generalised according to the surface area of the basin and the degree of regulation for application to this climate. Flows were calculated from a 39-year series of climatic data using the hydrological calculation program HEC-HMS and its SMA tool, which is particularly suitable for this type of analysis. The model was adjusted using runoff data available for a river basin gauging station in the Sierra Nevada (Spain). In this case study, the highest basins (above 1100 m and with an area greater than 25 km2) were the most promising. The usefulness of the proposed methodology was illustrated by assessing the effect of uncertainty through a sensitivity analysis varying the precipitation of the area by 20%, both in defect and excess, and all this in different scenarios of channel regulation, from 25% to 100% of it. A model was developed based on the conditions in a Mediterranean climate to evaluate the sustainable use of water resources in high mountain areas for energy utilisation, while considering the cost of regulating the flow and guaranteeing supply to the population. As the main conclusion of this study, basins above 1100 m in altitude with an area greater than 30 km2 are the most interesting for locating SHPs, and if the altitude is lower, basins with an area greater than 60 km2 would be needed to obtain similar results. This research provides a guide for selecting the most suitable basins and heads for the selection of different small hydropower facilities. These considerations are important in many Mediterranean mountain systems, where conflicts often arise between supporters on either side of the debate on renewable energy generation versus the preservation of the ecosystem. Additionally, the main advantage of hydropower generation from an environmental point of view is to avoid the emission of greenhouse gases, which has a positive influence on collective well-being.

Research of the spatial aspects of using renewable energy sources for sustainable development of the territory

The object of research is renewable energy sources as the basis for the development of renewable energy in Ukraine. Problems in the implementation of objects in this industry are the need to apply measures for their safe operation and less profitability of renewable energy sources compared to traditional ones. This is due to the high cost of equipment and significant costs to ensure technological processes. Increasing the share of renewable energy sources in the total energy balance will require government subsidies to the industry. It has been proven that the application of the cartographic approach allows determining the optimal locations of renewable energy facilities from an economic point of view and taking into account a number of equally important factors, in particular, social and environmental impact. The next methods are used: cartographic – when applying modeling techniques for building maps of renewable energy resources; geo-informational – in the process of collecting and processing information about resources, objects and factors for the development of renewable energy; statistical – at the stage of calculating the energy potential of wind energy, solar energy, geothermal and hydrological resources. The maps for the above-mentioned renewable energy directions are presented, recommendations on the optimal areas for the construction of energy facilities are given on the example of Kharkiv region (Ukraine). So, location: wind power plants are recommended in Vovchansk, Kharkiv, Velykyi Burluk regions; solar power plants – in Blyzniuky, Pervomaiskyi, Balakliia, Izium, Lozova and Borova; geothermal power plants – in the south of Barvinkove and Blyzniuky, southeast of Izium, Borova and Lozova districts. Perspectives for locating small hydropower stations within the study area are sections of the Siverskyi Donets, Udy, Berestova, Mzha, Merla rivers. The dependence of the economic efficiency of wind, solar, geothermal energy and small hydropower facilities on factors such as: distance of transportation of energy raw materials and finished energy to consumers; heat loss; cost of investment in the construction of infrastructure (power lines, electrical substations, heating networks).

RENEWABLE ENERGY POTENTIAL OF KRASNODAR TERRITORY

The paper deals with the urgent problem of using renewable energy sources for uninterrupted and reliable power supply of centralized and decentralized consumers. The paper gives the analysis of the features of the climatic zones of the Krasnodar Territory, taking into account the economic and energy potential of renewable energy sources. The characteristics of the small hydropower facilities and potential of solar and wind energy in the Krasnodar Territory are estimated. The data of the System Operator of the Unified Electric Power System of Russia with the total installed capacity of Russia's solar power plants as of January 1, 2017 are given, as well as data of the centralized and isolated energy systems operating in Russia using renewable energy sources such as wind and solar radiation. The analysis of existing and projected objects of renewable energy in the territory of the Russian Federation was carried out.

Abiotic Characterization of Brown Trout (Salmo trutta f. fario ) and Rainbow Trout (Oncorhynchus mykiss ) Spawning Redds Affected by Small Hydropower Plants - Case Studies from Austria

Salmonid rivers in Austria are considerably regulated by small hydropower facilities, resulting in potential declines of the spawning habitats of salmonids. To assess the restrictions and possible quality of hydropower-influenced river sections for salmonid, spawning redd densities of brown trout and rainbow trout were monitored in two rivers in 2014 and 2015. The results showed spawning close to small hydropower facilities for both investigated species — with similarities in redd characteristics like pit and tail length. Differences occurred concerning the distance of redd construction to the next shore. Brown trout spawn close to the banks in comparison to rainbow trout which use the entire active channel width. In addition to the preference of brown trout for certain cover types, it turned out that the presence of high quality spawning gravel in the river is the dictating abiotic variable (probably bottleneck) in the control of salmonid populations even for river reaches impacted by small hydropower plants. Moreover, the assessments of spawning redd densities enabled a discussion of different opportunities for spawning habitat enhancement of salmonids in river sections regulated by small hydropower facilities. Here, in conclusion, it was found that the fill-up of the backwater sites by transported sediments or the structural modification (e.g. boulder placement) in the tail of the backwater could improve the spawning situation in a sustainable way. Copyright © 2016 John Wiley & Sons, Ltd.

Cumulative biophysical impact of small and large hydropower development in Nu River, China

[1] Support for low-carbon energy and opposition to new large dams encourages global development of small hydropower facilities. This support is manifested in national and international energy and development policies designed to incentivize growth in the small hydropower sector while curtailing large dam construction. However, the preference of small to large dams assumes, without justification, that small hydropower dams entail fewer and less severe environmental and social externalities than large hydropower dams. With the objective to evaluate the validity of this assumption, we investigate cumulative biophysical effects of small (<50 MW) and large hydropower dams in China's Nu River basin, and compare effects normalized per megawatt of power produced. Results reveal that biophysical impacts of small hydropower may exceed those of large hydropower, particularly with regard to habitat and hydrologic change. These results indicate that more comprehensive standards for impact assessment and governance of small hydropower projects may be necessary to encourage low-impact energy development.

Electricity Generation from Existing Multipurpose Dams in Turkey

The aim of this article is to investigate the hydropower potential of multipurpose dams constructed with the purpose of supplying irrigation, domestic water supply, flood control, navigation, recreation, sanitation, and wildlife conservation but not for electricity generation in Turkey. One of the functions of multipurpose dams is to produce electricity when released water from the reservoir. More than 1175 dams in various sizes and types have been constructed so far in Turkey and according to the International Commission on Large Dams (ICOLD) definition, 555 dams have already been in operation by 2005. At the present research, out of 1175 dams, 78 multipurpose dams with an installed capacity less than 20 MW still in operation can be rehabilitated as small hydropower facilities. For this purpose, existing 78 of multipurpose dams which do not generate electricity so far have been investigated. By using these existing multipurpose dams, only minor new civil works and ready-to-use turbine generator are required, which reduces the cost of electricity generation. It has been calculated that the electricity generation using this potential is 1090.89 GWh/yr with 287.83 MW installed capacity. This potential will add an important monetary value to Turkish economy.