Showing papers on "Electricity generation published in 1983"

Environmental Regulations and Productivity Growth: The Case of Fossil-fueled Electric Power Generation

Abstract: This paper measures and analyzes the effect of sulfur dioxide emission restrictions on the rate of productivity growth in the electric power industry over the 1973-79 business cycle. A firm-specific measure of regulatory intensity is developed which depends on the severity of the emission standard, the extent of enforcement, and the unconstrained emission rate relevant to each utility. The results indicate that emission regulations result in significantly higher generating costs, primarily from the increased use of low-sulfur fuels. The average rate of productivity growth was reduced by 0.59 percentage points per year for constrained utilities.

Development of a New Procedure for Reliability Modeling of Wind Turbine Generators

Abstract: A method for determining the impact of wind generation on system reliability is developed. This method combines the effects of wind turbine forced outage rates and varying power output due to wind speed variations. Since individual wind turbines on a windfarm all have an output related to wind speed, each turbine's output cannot be assumed to be independent random variables. Because of this situation, special steps must be taken in der to arrive at the cumulative distribution function for the windfarm. This distribution function may be combined with the system distribution function using simple convolution and so the windfarm can be easily incorporated into a Loss of Load Expectation computer program. The method can then be used to determine the effective load carrying capability of a windfarm and also to supply better estimates of the benefits of wind generation to the overall system.

Analysis of the Isolated Induction Generator

Abstract: The increasing rate of depletion of conventional energy resources and the ability of induction generators to convert mechanical power over a wide range of rotor speeds have given rise to an interest in the possible contribution of wind energy to provide fuel displacement.

Heat and power networks in process design. Part I: Criteria for placement of heat engines and heat pumps in process networks

Abstract: The general problem of heat and power integration in process networks is complex and to date not fully understood. The subject covers site combined heat and power, on-plant power generation, heat pumps, and refrigeration systems. This paper is the first of a two-part series and explains the concept of ''appropriate'' heat engine and heat pump placement in process networks based on a fundamental new insight. ''Appropriate'' placement takes advantage of integration opportunities with the remainder of the process and yields marginal efficiencies far greater than could be achieved through stand-alone heat engines. Conversely, ''inappropriate'' placement can never offer an advantage over stand-alone systems. Part II describes procedures for preliminary design, involving heat engine, and heat pump equipment selection and performance assessment.

Energy Conversion Systems

Abstract: Introduction to Power Generation. Fuels. Reciprocating Machines. Internal Combustion Engines. Rotating Compressors. Axial--Flow Turbines. Gas Turbine Power. Fossil Fuel--Fired Steam Power Plants. Nuclear Power Plants. Power Plants and the Environment. Refrigeration and Air Conditioning. Direct Energy Conversion. Nonreactive Energy Sources. Appendix. Nomenclature. Index.

Combination of supercritical wet combustion and compressed air energy storage

Abstract: A fuel efficient combination of pressurized combustion and compressed air energy storage in which combustion air compressors have excess capacity which is utilized, during off-peak periods, to charge an underground storage cavern. Air withdrawn from the cavern during peak periods is utilized as combustion air, freeing the turbines which drove the air compressors during the off-peak period to power generators producing peak load electricity.

The Simple Economics of Industrial Cogeneration

Abstract: Rising energy prices and dependence on insecure supplies of foreign petroleum have led energy consumers and energy policymakers to seek methods to use energy more efficiently. Industrial cogeneration has frequently been seen as such a method. By generating electricity in conjunction with the production of steam for industrial processes, less energy is used than when process steam and electricity are produced separately. Most recent U.S. energy policy studies have spoken favorably about the potential for cogeneration.' Some specific studies have indicated opportunities to replace central station electric power generation with industrial cogeneration capacity, and, in the process, to reduce domestic energy consumption substantially.

The timing of EV recharging and its effect on utilities

Abstract: Electric vehicles (EV's) represent an important future load on the electric utility system which, if properly managed, could increase power plant utilization and reduce the average cost of generating electricity. A future EV population of 7.5 million is addressed, together with its characteristics, vehicle use, consequent recharging loads, and the impact of EV's on electric utilities in terms of the generation of electric power, fuel use, and costs. The impact on utilities will depend in part on when the vehicles are recharged. If the price of electricity is uniform throughout the day, recharging is likely to begin when vehicles are parked at home. Most of the recharging would then occur during late afternoon and early evening hours when other demands for electricity are high. In the year 2000, peak electricity demand would increase by 5700 MW, and oil- and gas-fired power plants would generate 39 percent of the recharge power. Marginal generating costs would average 7.6 cents/kWh in 1982 dollars. If electricity were priced by time of day, recharging could shift to late night hours when the other demands for electricity are low. The peak demand would increase by only 400 MW; 27 percent of the power would come from oil and gas, and marginal generating costs would average only 5.1 cents/kWh, some 25 percent less than the marginal cost of the system load without EV's. The fuels to recharge EV's were found to vary from one region of the country to the next. Utilities in the northeast would use the most oil and gas for recharging (more than 75 percent), while those in the central part of the country would use the least.

Source Reliability in a Combined Wind-Solar-Hydro System

Abstract: This paper describes the simulation of a combined wind-solar- hydro system for electric power generation, with energy storage facilities. A simple multivariable weather model, including the wind speed, the solar radiation and the rainfall, was developed. This model is * used with the Monte Carlo simulation method to evaluate the reliability of the mixed generating system. Different percentages of wind and solar generation capacities were tried as well as the tilt of the solar arrays.

Distribution of water in deep gold mines in South Africa

Abstract: Gold mines in South Africa use large volumes of water for cooling and other purposes underground. The mines are often at great depths, for example 3600 metres below surface level. Water piped down the shaft can therefore be at high pressures unless a system of pressure reducing dams or valves is installed. Modern practice is to utilize the high water pressures wherever possible. Examples of the use of water pressure include driving turbines for power generation, moving ore by means of high pressure jets and there is the future possibility of driving mining machinery using the water. The operation and analysis of water reticulation systems is complex owing to the complex distribution system and the number of possible operating conditions. Computer programs for the optimum design of such distribution systems and for the hydraulic analysis of such pipe flow systems have been compiled. The high pressures also pose problems in the design of pipework and equipment.

Modification of Power System Operation for Significant Wind Generation Penetration

Abstract: The purpose of this paper is to discuss modification of unit commitment, economic dispatch, regulation and frequency regulation controls when the level of wind generation capacity is significant. A wind farm penetration constraint is determined, that limits worst case wind generation change from an array due to a thunderstorm to be less than the worst first contingency loss of conventional generation resource or commitment. The farm penetration constraint only acts as an indicator that additional spinning reserve, load following, and unloadable generation capability is required through adjustment of unit commitment and AGC controls if the farm penetration constraint was violated. A discussion of the methodology, costs, and benefits of changing unit commitment when WECS generation is significant (and either satisfies or violates this farm penetration constraint) is then discussed. A further discussion of the modification of regulation and economic dispatch controls to exploit the changes in response rate capability provided by the unit commitment is also discussed. A modified echelon penetration constraint that limits instantaneous rate of change and change from a wind array that must be handled by governor frequency regulation and regulation controls. This constraint is imposed to limit cycling of units which can incur additional operating and maintainance costs on conventional steam units and possibly safety concerns on nuclear units.

Power System Response to a Large Disturbance: Energy Associated with System Separation

Abstract: Formulating the power system equations with respect to the system's inertial center, it is shown that a large disturbance tends to pull each generator from the rest of the generators, forming a two-machine equivalent. The energy associated with this equivalent is related to the energy function for individual machines, previously developed by the authors. Parameters of the two-machine equivalent are derived for any generator versus the rest of the system.

Electrical Damping and Its Effect on Accumulative Fatigue Life Expenditure of Turbine-Generator Shafts Following Worst-Case Supply System Disturbances

Abstract: The paper examines the effect electrical phenomena has on damping torsional vibrations of turbine-generator shafts resulting from severe disturbances on the system supply. The effect system impedance and power factor has on time constants for decay of predominant shaft torsional vibrations and on fatigue life expenditure of the shaft following worstcase events is investigated. The impact pole slipping resulting from delayed fault clearance has on peak shaft torque and on accumulative fatigue life expenditure of the shaft is also examined.

Large Scale Security Dispatching: an Exact Model

Abstract: An exact optimal power flow model is presented for dispatching generation, transformer taps, and generator voltages to minimize operating costs while guaranteeing a steady state secure operating point after a contingency. A full ac power flow model is used, which permits including voltage and reactive power constraints in the optimization. The technique of this paper is unique in that all of the voltage and power constraints of all selected contingencies are enforced in a single optimization. No cycling between contingency evaluation and optimization is necessary in order to update the list of active constraints. Cases which have divergent power flow solutions are included in the problem with no difficulty. All non-islanding outages are guaranteed to converge to a feasible solution. The optimization algorithm solves a sequence of linearly constrained subproblems using a quasi-Newton search direction. The dispatching algorithm is tested on the IEEE 118 bus system power system.

Network topology optimization for power system security enhancement.

Abstract: Up to now, preventive or corrective actions to improve power systems' operating states mainly concern power generation rescheduling, load-shedding and tap modifications of in-phase or phase-angle transformers. A method is proposed for relieving overloads by network topology modifications. The switching between busbars and feeders in substations is considered as a control variable. The optimization of the topology is a very difficult task due to the combinatorial nature of the problem and the nonlinearities inherent to networks. The method is based on the Maximal Flow Minimal Cost algorithm. All the possible switching actions are taken into account with, if desired, generation rescheduling and load-shedding. The power system is modelled so as to obtain the same power flow distribution as with a DC load flow. Final checks of security constraints (voltage magnitudes and short-circuit currents) are performed with AC load-flow and fast short-circuit programs. The method is very efficient considering the solution time (important for real time applications).

Surge Discharge Capability and Thermal Stability of a Metal Oxide Surge Arrester

Abstract: The surge discharge capability and the thermal stability of a metal oxide surge arrester were examined experimentally.

DC power generation for telemetry and like equipment from geothermal energy

Abstract: DC power is generated from geothermal energy by use of a power generator having one or more thermoelectric elements 6 in a body 2 adapted to be secured in thermally conductive fashion to a structure constituting a geothermal energy source. The structure may for instance be a pipe carrying, e.g., crude oil from an oil well at a temperature different from ambient. The power source may be associated with telemetry or other power-demanding equipment to provide for the operation thereof. Secondary storage cells may be associated with the generator to store electrical energy produced in excess of instantaneous requirements and to supply peak demands.

Economic Evaluation of Photovoltaic Generation Applications in a Large Electric Utility System

Abstract: This paper describes the methodology used for and the results obtained from a study to assess the economic viability of long-range applications of photovoltaic (PV) generation in a large eastern electric utility system. Amorphous silicon PV technology, which has been under development by RCA Laboratories since 1974 and formed the basis for the conceptual design of a central- station PV power plant, was used in the application study. Traditional utility system planning techniques were applied to determine the capacity and energy values of PV generation. however, the system capacity reliability evaluation and production cost simulation programs; were modified and applied to more accurately account for the time- constrained and intermittent teatures of PV energy output. Statistical and mathematical procedures were developed to utilize the varying daily insolation data and convert them to appropriate patterns of electric energy output. The study results indicate that with respect to a conventional generation alternative, such as combustion turbines of more advanced design, the breakeven capital cost for PV power plants ranges from $1,100 to $1,350 (1982 dollars) per peak kW. The higher the PV capacity penetration, the lower the required breakeven cost.

Catastrophe Theory as a Tool for Determining Synchronous Power System Dynamic Stability

Abstract: A mathematical method, Catastrophe Theory, is applied to the problem of electrical power system dynamic stability. It is suggested that this offers a method for the continual monitoring of power system stability margins by the use of visual graphic display produced by a dedicated minicomputer using information monitored from the power system.

Load Following Impacts of a Large Wind Farm on an Imterconnected Electric Utility System

Abstract: A major issue encountered in the use of many of the renewable energy resources for the production of electric power is the variability of the resource itself. This paper presents the results of a dynamic simulation of the long term power system responses to changes in the load and generation patterns resulting from significant penetrations of renewable resource technologies. The renewable technology selected for this study is a large wind farm with a total output of 500 MW added to the 1979 generation base of the Los Angeles Department of Water and Power system.

Thermal Energy Storage: Basics, Design, Applications to Power Generation and Heat Supply

Abstract: A systematic treatment of thermal energy storage, an important aspect of of energy research and development. The book covers physical and chemical basics, assessment of thermal energy storage plants, as well as design and optimization of storage vessels and complete thermal storage installations.

Steam optimization and cogeneration system and method

Abstract: In a multiturbogenerator cogeneration system mass flow balancing is used to optimize the distribution of steam between the machine while meeting the demand in steam and electrical power of the industrial plant in order to choose the less costly between cogenerated power and power purchased from the tie-line. The EVOP method of optimization is used off-line with the assist of a microcomputer to determine the optimal distribution of steam.

Wind electric generation plant and system with improved alternator field excitation

Abstract: An improvement in a wind electric generation system of the type disclosed in Jacobs et al. U.S. Pat. Nos. 4,059,771, 4,228,361, and 4,228,362, with particular reference to U.S. Pat. No. 4,228,361. The improvement provides circuitry means for monitoring, controlling, regulating and indicating the complete operation of a wind electric generation plant for the advantageous purposes of: more accurately controlling, via the use of digital logic load detection and control circuitry, the selective switching and automatic diversion of the supply of alternator output energy to and from the loads of a wind electric system; supplying power to a fixed auxiliary load for a controlled programmable period of time; reducing the switching transients of load switching silicon controlled rectifier (SCR) devices; controlling and regulating, with digital logic circuit means, the excitation field current level of a wind-driven alternator during all operations of a wind electric system in which an advantageous and proficient manner as to prevent damage to various included components and structural parts thereof at times of varying favorable and/or adverse weather conditions and during times of load switching; and, supplying to a storage battery means of a wind electric plant a trickle-charge whenever it is fully charged and no alternator output is being supplied to any auxiliary loads in order to keep the individual battery cells of a storage battery means evenly charged.

Combined cycle in fuel cell generation unit

Abstract: PURPOSE:To improve all-round efficiency of fuel cell generation unit by effectively using thermal energy such as an exhaust on the anode-and cathode sides of the fuel cell proper and reaction heat of the fuel cell proper emitting outside of the system of the fuel cell generation unit in the system of a phosphate acid electrolyte fuel cell. CONSTITUTION:Reaction heat generated by electrochemical reaction inside of a fuel cell proper 5 is absorbed by cooling water in a fuel cell cooler 23 and the heated cooling water is introduced into a steam generator 10 to be separated into steam and a drain. Said steam is used for a steam turbin 29 through a steam regulating valve 28 to drive the steam turbin 29 for generating electricity with a turbin generator 30. The exhaust on the anode side and the cathode side of the fuel cell proper 5 is mixed by an exhaust mixer 26 for being effectively used in a steam heater 32 for heating the steam generated from the steam generator 10 for driving a steam turbine 29 and further for improving all-round efficiency.

DC-to-DC Converter Power-Train Optimization for Maximum Efficiency

Abstract: A new way is given to describe the independent and dependent design variables of the power train of a dc-to-dc converter in terms of a multidimensional design-parameter space. These concepts provide a framework for examining the problem of design optimization of the power train, with particular emphasis on the maximization of converter efficiency. Numerous examples of important parameterspace surfaces illustrate some of the major relationships between core volume, switching frequency, and output power and between efficiency, ripple, and temperature rise of the energy-storage reactor. Also, the difference in performance between the continuous and discontinuous magnetomotive (MMF) force modes of operation is explored.

Aerodynamic platform comparison for jet-stream electricity generation

Abstract: Wind-tunnel experiments to determine lift and power extraction capability and an economic analysis to determine the cost of electricity generation have been undertaken for four aerodynamic platform configurations: integrated diffuser augmented wind turbine (IDAWT), separated diffuser augmented wind turbine (SDAWT), separated unshrouded wind turbine (SUWT), and rotary-wing concept (RWC). For each configuration the capital and operating costs of a 22-MW jet-stream power station based on ten minimum-cost aerodynamic platforms and related ground equipment have been calculated. The IDAWT anrf SDAWT configurations would produce electricity at a capital cost of about $(Australian) 650/kW [in Feb. 1981 $(Australian)l = $(U.S.)1.15, approximately—all currency is in Australian dollars unless otherwise noted] and an operating cost of under 5C/kWh; potential improvements in diffuser performance could reduce these costs below $550/kW and 4C/kWh, respectively. The SUWT configuration would produce electricity at a capital cost of about $700/kW and an operating cost of about 5.4C/kWh, but with little prospect of further reduction. The RWC would produce electricity at a capital cost of about $800/kW and an operating cost of about 16C/kWh. The high operating cost makes the RWC unsuited to the task of generating electricity from jet-stream winds. Nomenclature A e = diffuser exit area A T = diffuser area at the turbine station CL = lift coefficient Cp = power coefficient = Pi 1/2pu30A T C*4 = pressure coefficient at diffuser exit plane D = total drag on the platform de = diffuser exit diameter k = loss parameter, Eq. (1) £ = total length of diffuser augmented wind turbine Pi = probability that the wind speed lies in the /th speed band PDi = average power density associated with the /th speed band