Small-scale Hydroelectric Plant Research Articles

Hydrokinetic turbines in microgrids based on small hydroelectric plants

The article deals with the problem of enhancing the operation efficiency of microgrids based on small-scale hydroelectric plants (HEPP). Most of the water kinetic energy in HEPP is used to drive the main hydro turbines. But the water that has run out of the main turbines still has a significant amount of kinetic energy. This energy of water flow usually is suppressed in a lower pool using weirs in order to avoid gnawing the riverbed. This is energy wastage. We propose an energy-saving decision - to increase the power production of HEPP using additional hydrokinetic turbines (HKT) to suppress the water flows. Lowpower hydro turbines are presently being produced and can be used for this purpose. Usually, HKTs are immersed in torrential streams to generate electricity. Submersible HKT can be used for exploiting the powerful water flows in lower pools of various HEPPs. HKTs can work mounted in parallel when the HEPP has a higher power. The second row of HKT could be installed if the water behind these turbines still has a sufficiently high flow rate and if it pays off. This paper also proposes creating microgrids based on HEPP by supplementing them with floating solar and wind power plants. Several effective measures are proposed to increase the amount of electricity produced by this microgrid without using any fuel.

Geometrical Optimization of Pelton Turbine Buckets for Enhancing Overall Efficiency by Using a Parametric Model—A Case Study: Hydroelectric Power Plant “Illuchi N2” from Ecuador

In Ecuador, the implementation of hydroelectric power plants has had a remarkable growth in the energy sector due to its high efficiency, low environmental impact, and opportunities to generate employment. One of the sectors with the greatest benefits from this type of energy has been the rural sector, where several small-scale hydroelectric plants (0.5 MW–10 MW) have been installed, usually with Pelton turbines. Although these turbines are highly efficient, one of the challenges is to obtain the optimal geometry of the bucket to take advantage of the greatest amount of energy from the water, avoiding the separation of the fluid. In this context, this study focuses on the development of an analytical and iterative methodology that allows for the determining of the appropriate dimensions of the buckets to achieve maximum turbine efficiency. For that, a parametric model has been proposed considering the dimensions and main angles of the bucket, the net hydraulic head and the working flow, as well as the power losses. The results of the model have been validated by means of CFD and by contrasting the experimental data obtained from the “Illuchi N2” Hydroelectric Power Plant in Ecuador, and it is concluded that it is possible to improve the turbine efficiency by up to 4%.

Environmental Administration of Dams in the Idukki District: An Analysis

Environmental administration can be defined as the process of directing and managing public policies and activities in the area of environmental affairs. (UNEP, 1984). Obligation to the future generations from the governmental and private players lay on the advancement of small-scale hydroelectric plants. The development of hydroelectric projects is amenable with the United Nations’ Sustainable Development Goal (SDG) seven. The dams and water stored in dams have become a matter of dispute between the different states. The water, food, energy of a particular area can be satisfied with establishment of new multi-purpose power plants which will lead to irrigation of crops, drinking water for consumption by the population, energy generation as well as employment for many people in the form of dam administration staffs as well as the economics of tourism involved. Ongoing debate on the feasibility studies on dam from the views on harms it can cause to environment and social development it can bring out needs an extensive study based on the available data on dams from a historical perspective. The need for emphasizing environmental impacts and economic virtues of a dam from a sustainable point of view are a need. The present paper intends to portray the need for environmental administration based dam protection and the major effects of dam in the Idukki region. The paper further elaborates on the need for interventions to solve the disputes related to water resources actively by stakeholders.

Investigation into Pump Mode Flow Dynamics for a Mixed Flow PAT with Adjustable Runner Blades

The adoption of pumps as turbines (PATs) in both small-scale hydroelectric plants and water supply systems has brought about various advantages, the most recognized being cost-effectiveness compared to other hydroturbines. However, due to their lack of flow control ability, their intolerance to off-design operations constitutes a tough shortfall. Moreover, since this technology is new, PAT flow dynamics are not yet well understood. Therefore, this study intends to numerically investigate the mixed-flow PAT’s pump mode flow dynamics for five operating conditions from optimum (1 QBEP) to deep part-load (0.41 QBEP) conditions. Moreover, the effect of runner blade angle on them is investigated, considering three angles, namely −2°, 0°, and 2°. PAT flow stability was found to deteriorate as the flow decreased, where associated pressure pulsation level worsened at different flow zones. In addition, the blade angle increase led to correspondingly increasing flow unsteadiness and pressure pulsation levels, where the pulsation frequencies from rotor-stator interactions were dominant for most flow zones. This study’s findings are of crucial importance to both scientific and engineering communities as they contribute to a thorough understanding of PAT flow dynamics.

Economic Sustainability of Small-Scale Hydroelectric Plants on a National Scale—The Italian Case Study

The feasibility of hydroelectric plants depends on a variety of factors: water resource regime, geographical, geological and environmental context, available technology, construction cost, and economic value of the energy produced. Choices for the building or renewal of hydroelectric plants should be based on a forecast of the future trend of these factors at least during the projected lifespan of the system. In focusing on the economic value of the energy produced, this paper examines its influence on the feasibility of hydroelectric plants. This analysis, referred to as the Italian case, is based on three different phases: (i) the economic sustainability of small-scale hydroelectric plants under a minimum price guaranteed to the hydroelectric operator; (ii) an estimate of the incentives for reaching the thresholds of “acceptability” and “bankability” of the investment; (iii) an analysis of the results obtained in the previous phases using a model of the evolution of the electricity price over the 2014–2100 period. With reference to the Italian case, the analysis suggests that, to maintain the attractiveness of the sector, it is necessary to safeguard the access to a minimum guaranteed price. With the current tariff plan, complete sustainability is only achieved for plants with p ≤ 100 kW. For the remaining sizes, investments under current conditions would not be profitable. The extension of minimum guaranteed prices could make new medium-large plants (500–1000 kW) more attractive. The current incentive policy is not effective for the development of plants larger than 250 kW, as systems with lower capital expenditures are preferred. Uncertainty about the evolution of the price of energy over time is a concern for the sector; the use of evolutionary models of technical economic analysis tried to reduce these criticalities, and it was shown that they can be transformed into opportunities. It was also found that profitability due to the growing trend expected for the price of energy cannot be highlighted by a traditional analysis.

In transitions we trust? Understanding citizen, business, and public sector opposition to wind energy and hydropower in Chile

This article discusses the relevance of citizen, business, and public sector trust in risk management regarding socio-environmental conflicts over renewable energies in Chile. The study was qualitative, on a simple case of embedded design, and analysed employing a content analysis, two wind projects (Renaico and La Cabaña) and two small-scale hydroelectric plants (Picoiquén River and Los Aromos) in the Region of La Araucanía, Chile. The results show the importance of trust in risk management due to socio-environmental conflicts, revealing the affective/subjective dimension through variables such as the Sense of Justice, Integrity, Transparency, Benevolence, Honesty, and Commitment with the interests of others, and variables such as Efficiency, Competence, and Consistency of Behaviour in its technical dimension.

Analysis of economic impact from erosive wear by hard particles in a run-of-the-river hydroelectric plant

Small-scale hydroelectric plants, primarily run-of-the-river designs, are regularly subjected to hard particle wear and cavitation erosion due to the wide range of operating points. Depending on the severity of the operating conditions and erosion damage experienced by the machine throughout its service life, the operating companies of these facilities will be impacted. The impact will be technical, operational, logistical, and economic. A small-scale generation plant located in Amaime River in Colombia, is one such case, where severe wear occurs in the turbine components, with a consequent reduction of efficiency. In this study, the analysis of the erosion damage has been expanded and supplemented by computational fluid dynamics (CFD). From this approach, correlations between the wear rate and power output were obtained. Likewise and in conjunction with the computer estimates, a methodology to analyse the costs associated with wear based on historical data of operation was developed, creating a strategy of operation based on a stopping criterion that depends primarily on sediment concentration, turbinated flow, and wear level. The methodology optimizes the use of generators, which takes into consideration the revenue generation and the costs associated with operation and maintenance of pieces under conditions of intrinsic erosion wear in the facility.

Electrifying Rural Guatemala: Central Policy and Rural Reality

Towards the end of the 20th century Guatemala embarked on an ambitious rural electrification plan: central planners in the Ministry of Energy and Mines hope to connect 90% of homes to the national electricity grid by 2004. Energy for the increased demand comes from floating power plants anchored in Guatemala's Pacific port, a new coal-fired power plant, and numerous small-scale hydroelectric plants. So far, rural electrification, in terms of connected households, has proceeded to plan. However, the success of the rural electrification program belies energy realities and the development needs of rural Guatemala. Data from in-depth interviews and household surveys in Ixcán, Guatemala, show that rural residents prefer other forms of development—like the introduction of potable water, or improved schooling. Electricity, farmers state, only provides rural families with a few hours of light at night because they cannot afford to pay for appliances or for increased consumption of electricity. Fieldwork in rural areas also reveals that the introduction of electricity will not change patterns of firewood consumption; firewood is the basic survival fuel for most rural Guatemalans. Development funds may be better spent on locally run and organized forestry initiatives to ensure reliable sources of firewood for the future.