S.K. Singal

A stochastic approach for the operation of a wind and pumped storage plant under a deregulated environment

ABSTRACT To improve the competiveness in the energy market, it is necessary that the wind power plants provide guaranteed power generation, although, it is not possible to forecast power availability from wind power plant accurately. This paper presents a stochastic model and solution technique for the combined operation of wind and pumped storage power plants to improve the power availability and increasing the profit considering uncertainties of wind power generation. In this model, uncertainties in wind data have been forecasted for grid connected day-ahead market using Weibull distribution model. The imbalances in the forecasted wind data and the market demand have been reduced by operating the pumped storage power plant. In this stochastic mixed integer problem, pumped storage plant can take the supply either from the grid or from the wind power plant for the pumping operation to store the energy in order to utilize this energy during peak hours for increasing the overall revenue. The reliability of the pumped storage is improved by replacing the conventional unit with the adjustable speed type pumped storage unit. In order to prove the optimality of the solution, two case studies were considered. In case study–I, scheduling is provided by operating the conventional pumped storage unit, whereas in case study–II, adjustable speed pumped storage unit has been used. It has been found that the adjustable speed pumped storage unit has further reduced the imbalance between generated power and demand. The complete approach has been formulated and implemented using AMPL software.

Cost Analysis for Electromechanical Equipment in Small Hydropower Projects

Small hydropower (SHP) is one of the most favorable and environmentally benign energy technologies for generation of electrical power. For development of a SHP project, its technical feasibility and economical viability are considered as the foremost requirements. From cost point of view, the most important elements are the electromechanical equipment, since their cost shares a high percentage in the total cost of the project. In the present study, an attempt has been made to develop correlations for cost of the electromechanical equipment used in SHP projects considering head, installed capacity, and rating such as kilo volt amperes (kVA), power factor (pf), and turn ratio of transformer as cost-influencing parameters. The cost correlation has been developed for high head schemes with head ranging from 100 m to 500 m. To validate the analytical results, the cost of electromechanical equipment determined by the developed correlations is compared with the cost data collected for recently developed such projects. It has been found that the developed correlation for cost of electromechanical equipment may be used for cost estimation of future SHP projects with reasonable accuracy.

Sizing and Quantity Estimation for Desilting Tank of Small Hydropower Projects—An Analytical Approach

In small hydropower (SHP) projects, desilting tank is an important component, which protects the mechanical equipment specially turbine from the silt carried by the water conductor system. Desilting tanks are used in water treatment plants and hydropower channels to remove objectionable sediment of a specified size and quantity. Design of desilting tank requires evaluation of sediment removal efficiency over the range of sediment particle sizes. In the design of desilting tank, various combinations of width, depth, and length of the tank are possible to achieve desired silt removal efficiency. In the present study, an attempt has been made to develop correlations for sizing of desilting tank and estimation of quantities of various materials required in the construction of desilting tank. The results obtained were verified with the data collected on desilting tanks of recently developed SHP projects. The results are found within maximum error of ±12%. The correlation developed can be used for sizing and cost estimation of the desilting tank.

Optimization of low-head, dam-toe, small hydropower projects

In most developing countries, such as India, there exists a large amount of hydropower potential. This is especially true in the small hydro plant capacity range of up to 25 MW. Only a small fraction of this potential has been tapped so far, perhaps due to higher per kilowatt installation cost as compared to large hydro. Small hydropower sites can be classified as (i) run-of-river; (ii) canal based, and (iii) dam-toe schemes, depending on their location. Dam-toe schemes need low investment and can be developed in a shorter period of time. In the present study, an attempt has been made to estimate the cost of the low-head, dam-toe, small hydropower schemes. A methodology for cost optimization of such schemes has been developed considering the quantities of various items for each component of the scheme and prevailing prices. Further, to determine financial viability of the scheme at different load factors, sensitivity analysis has also been carried out. It has been found that low-head, dam-toe, small hydro...

An Approach for Wind-Pumped Storage Plant Scheduling Under Uncertainty

The combined operation of wind-pumped storage plant (PSP) system under day-ahead market has been carried out by applying stochastic technique considering uncertainty in the wind data. Such uncertainty causes risk to the scheduling of wind-PSP system. The orthogonal arrays based Taguchi method is used to manage the risk during the scheduling of wind-PSP system by maximizing the total revenue, where the numbers of experiments are performed in order to access the criticality of possible outcomes. In this study, an adjustable speed type PSP unit is considered for better reliability.

Economic Analysis of Power Transmission Lines using Interval Mathematics

A major portion of the capital costs in the present day power transmission systems are due to the cost of equipment and construction process. Transmission utilities in the recent years are drawing greater attention towards performing life cycle costing studies for cost management and decision making. However, the data involved in these studies are highly uncertain and the effect of these uncertainties cannot be directly included in the study process, resulting in inaccurate solutions. Interval mathematics provides a method for including these uncertainties throughout the cost analysis and provides final solution range in the form of intervals. In this regard, it is essential and extremely important that significant research has to be carried out in understanding the principles of life cycle costing methodology and its applicability to cost analysis of transmission lines along with uncertainties involved in the cost assessment process. In this paper, economic analysis of power transmission lines using interval mathematics has been studied. Life cycle costing studies are performed using net present value analysis on a range transmission lines used in India and the results are analyzed. A cost break even analysis considering right of way costs was carried out to determine the point of economy indifference.

Cost Optimization of High Head Run of River Small Hydropower Projects

Small hydropower (SHP) is one of the most reliable and environment friendly source of electrical power among different renewable energy sources. For making a decision regarding development of a SHP project, its financial viability is to be assessed along with technical feasibility. In the present study, a methodology has been developed for cost assessment of high head run of river (ROR) SHP projects in order to determine their techno-economic viability before undergoing detailed investigation. This will enable the planners and developers to carry out detailed investigation and implementation of only those projects which are financially feasible. In the analysis of cost, capacity and head have been considered cost-influencing parameters. The correlations for cost based on different types of head race conduit, penstock materials, types of turbine and types of generator for various layouts have been developed. The project cost determined from the developed correlations is validated by the cost data collected from recently developed projects. It has been found that the developed correlation for cost may be used for reasonable cost estimation of hydropower projects for planning of such projects. The cost analysis of different layouts based on generation cost and installation cost were evaluated. Particle Swarm Optimization (PSO) based technique has been employed to work out the optimal layout. Based on cost analysis, nomogram has been developed for selection of optimum layout for high head RoR SHP projects.

Off grid rural electrification using integrated renewable energy system

Unavailability of electricity is still one the big enigma to solve for the millions of poverty stricken communities specially located in remote region. Today, renewable energy is one of the key prospects in research, as it can perform important role to enlighten millions of people daily life by satisfying their electricity needs. Rural electrification can improve the socio-economic status of remotely located communities. The locally available renewable energy resources can be used to form the integrated system to fulfill the needs of community. In the present study, integrated renewable energy system using solar, wind and biomass resources is presented to meet the electricity demand of the community. The Khatisitara village located in Banaskantha district of Gujarat state, India is considered as study area having 101 households with population of 562. A detailed exercise is carried out for the load estimation and resource assessment of the study area. Based on estimated load demand and available renewable energy resources, the system is designed and analysed by using HOMER software. From the optimization results, the cost of energy for the proposed system is found to be 0.084

Review of mathematical modeling on latent heat thermal energy storage systems using phase-change material

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