Optimal Allocation of Reservoir Water

The purpose of this paper is to determine the optimal allocation of reservoir water among consumptive and non-consumptive uses. A non-linear mathematical programming model is developed to optimally allocate Lake Tenkiller water among competing uses that maximize the net social benefit. A mass balance is used to determine the level and volume of water in the lake. This paper examines the effect of water management on lake resources when recreational values are and are not included as control variables in the optimization process. Results show that maintaining the lake level to the ‘normal lake level’ of 632 feet during the summer months generates more recreational benefit rather than reducing the lake level by releasing water for hydro power generation.consumptive and non-consumptive use, mass balance equation, non-linear mathematical programming, optimization, recreational uses, water allocation, Resource /Energy Economics and Policy,

Integrated Reservoir Management under Stochastic Conditions

Economic optimization, Lake levels, Marketed and non-marketed water uses, Non-linear programming, Recreational benefits, Reservoir management, Stochastic inflows, Value of a visitor day, Environmental Economics and Policy, International Development, Land Economics/Use, Production Economics, Productivity Analysis, Public Economics, Resource /Energy Economics and Policy, Risk and Uncertainty,

On the Economics of Ramping Rate Restrictions at Hydro Power Plants: Balancing Profitability and Environmental Costs

This paper examines the impact of ramping rate restrictions imposed on hydro operations to protect aquatic ecosystems. A dynamic optimization model of the profit maximizing decisions of a hydro operator is solved for various restrictions on water flow, using data for a representative hydro operation in Ontario. Profits are negatively affected, but for a range of restrictions the impact is not large. Ramping restrictions cause a redistribution of hydro production over a given day, which can result in an increase in total hydro power produced. This affects the need for power from other sources with consequent environmental impacts.

Hydropower sheduling in basins with heavy ecological and human restrictions

The problem of water resources management aims to calculate the optimal energy bids of a set of hydro plants and to estimate costs for consumptive and nonconsumptive volumes of water, when meeting European and local regulations, consumption requirements and basin rights of use, respecting environmental flows, possible congestions in the electric transmission system and other important concerns. The goal of this thesis is to advance in the development of an effective tool for the management of hydro basins with different economic, social, policy, normative, restrictions and resources characteristics. In first case, an optimisation problem for calculating the best offers of a set of hydro power plants is proposed, considering ecological flows and social consumptions. In the simulations, the costs related to the social consumptions and ecological requirements are compared in a relatively small real Spanish basin, for short-term (24-hour) planning. In second case, an improved representation of the market and the optimization of the hydro plants are integrated in a nested algorithm, to calculate local prices and optimal energy bids in a congested electrical system. The algorithm is applied to a real basin in Italy. In a third case, uncertainties in the resources, improved representations of the hydro plants and environmental constraints are integrated in a large basin, in southern Spain. Stochastic scenarios are used to evaluate the significance of uncertainties in a 72-hours horizon. The study provides a new tool for the coordinated management of large basins, complying with ecological restrictions and governmental regulation on water resource allocation and considering the technical characteristics of hydropower plants and the hydropower production profits.El problema de gestión de recursos hídricos busca determinar las ofertas óptimas de energía para un conjunto de centrales hidroeléctricas y también una estimativa de los costos del agua para los volúmenes consutivos y no consuntivos, cumpliendo normativas europeas y locales, las necesidades de consumo y los derechos de uso de las cuencas, las posibles congestiones en el sistema de transmisión eléctrica y otras cuestiones relevantes. El objetivo de esta tesis es avanzar en el desarrollo de una herramienta eficaz para la gestión de cuencas con diferentes características económicas, sociales, políticas, normativas, restrictivas y de recursos. En el primer caso estudiado, se propone un problema de optimización para el cálculo de las ofertas óptimas de un conjunto de centrales hidroeléctricas, en una cuenca española relativamente pequeña, considerando los flujos ecológicos y los consumos sociales. En las simulaciones de planificación a corto plazo (24 horas), se comparan los costes relacionados con los consumos sociales y los requisitos ecológicos. En el segundo caso de estudio, se integran en un algoritmo iterativo una representación mejorada del mercado y la optimización de las centrales hidroeléctricas, a fin de calcular precios locales y ofertas óptimas de energía en un sistema eléctrico congestionado. El algoritmo es aplicado a una cuenca real en el Norte de Italia. En el tercer caso de estudio, las incertidumbres asociadas a los recursos y una representación mejorada de las centrales hidroeléctricas, junto con las limitaciones ambientales, se integran en un modelo que representa una cuenca real de tamaño significativo en el sur de España. Se utilizan escenarios estocásticos para evaluar la influencia de las incertidumbres en un horizonte de 72 horas. El estudio proporciona así una nueva herramienta para la gestión coordinada de grandes cuencas, cumpliendo con las restricciones ecológicas y la regulación gubernamental sobre asignación de recursos hídricos, teniendo en cuenta las características técnicas de las centrales hidroeléctricas y los beneficios de producción de la energía hidroeléctrica.Programa Oficial de Doctorado en Ingeniería Eléctrica, Electrónica y AutomáticaPresidente: Luis Fernández Beites.- Secretario: María Ángeles Moreno López de Saa.- Vocal: Juan Ignacio Pérez Día

OPERATION ASSESSMENT OF RESERVOIRS IN THE SAVANNAH RIVER BASIN

Hydropower is generated from three reservoirs in the United States Army Corps of Engineer\u27s Savannah District. These reservoirs include J. Strom Thurmond, Richard B. Russell, and Hartwell. Currently, a contract in place specifies that certain amount of energy must be provided to the region. The contract for the hydropower was based upon the critical hydrologic year of 1981. Historically, this was the most severe drought on record and assumed to provide the lowest net inflows for the three reservoirs, thus providing an attainable or reliable energy amount for the system, which suggests a dependable energy yield. Reevaluating the contract amount and the period of obligation for energy production could create more consistent energy costs and allow for a more flexible basin management strategy. The analysis of factors that effects the hydropower generation would also provide insight into hydropower forecasting and strategies. This will lead to an increased control on environmental influences and higher economic benefit from the entire watershed. All of these factors would result in a greater overall benefit to regional consumers. Analysis of 25 years of operational data has shown that a 90% reliable yield is about 40% less than the current contract. Moreover, the weekly restraints on generation requirements are often set too high as the frequency of meeting the contact amount is barely 30% for most months. These inconsistencies result in a cost variation which affects the consumers. Statistical analysis of historic energy generation provides procedures to determine a reliable energy yield by observing generation amounts that occur within an acceptable amount of risk. The reliable amount of energy was found to be about 15,500 MWh, which is significantly less than the current contract. Additional conclusions from this study found that visitation could have a much greater economic impact over hydropower generation. In addition, local inflow to the Hartwell basin exhibited the strongest correlation to the system hydropower generation. These conclusions will help with new management, operation, and forecasting strategies in the Savannah River Basin

Efficient bidding for hydro power plants in markets for energy and ancillary services

In order to preserve stability of electricity supply generators must provide ancillary services in addition to energy production. Hydroelectric resources have significant ancillary service capability because of their dynamic flexibility. This paper suggests a solution for optimal bidding for hydro units operating in simultaneous markets for energy and ancillary services by estimating water shadow price from operating parameters of the hydro unit, expectations on prices of energy and ancillary services, and water availability. The model implications are illustrated on a numerical example of a hydro unit operating in markets of New York Independent System Operator. Participation in ancillary services market increases or decreases water shadow price depending on water availability. As a result of participation in ancillary services markets, a unit with water availability given by a capacity factor of 0.6 increases the value of existing generating capacity by 25% and nearly doubles the value of incremental generating capacity