Potomac Electric Power Research Articles

Environmental disclosures: electric utilities and Phase 2 of the Clean Air Act

Abstract In 1999, American Electric Power, anticipating its future need to comply with Phase 2 of Title IV of the 1990 Clean Air Act (CAA), spent about $37 million to purchase sulfur dioxide emissions allowances on the spot and futures markets [EPA, 2004. Emissions tracking site for acid rain. ETS/CEMS, website: http://www.epa.gov/ardpublic/edata.html ]. This information was not disclosed in the company's 1999 annual report to shareholders or in its Form 10-K annual report to the U.S. Securities and Exchange Commission (SEC). No information was included in these reports regarding how the firm planned to achieve the emission standards of Phase 2. Potomac Electric Power Company disclosed in its 1999 Form 10-K that it planned to spend $5 million to comply with Phase 2 and would sell its remaining electric-generating plants [ PEPCO, 1999 . Potomac Electric Power Form 10-K report]. Stakeholders and regulators might view these two “events” and wonder why there is no consistency in disclosure concerning the CAA requirements. This is especially so given that the Clean Air Act mandates specific remedies for non-compliance and is known to have given rise to significant capital expenditures. In this study, we examine 1999 and 2001 CAA Phase 2 disclosures made by the owners of the named Phase 1 coal-fired plants to assess how they informed their stakeholders about plans for Phase 2 compliance. This analysis includes the emissions, along with allocated and banked allowances for each of the plants, so that a fair assessment can be made as to each owner's status in terms of Phase 2.

Analysis of a major load island outage on the Potomac Electric Power Company system

This paper reviews the events of an incident, which occurred on June 20, 1997, that resulted in the islanding of a major load area in downtown Washington DC, USA, and the subsequent power outage to that load area. It discusses the investigation and analysis of the incident and lessons learned.

98/04013 Combustion optimization using an expert system and neural networks

Lehigh University`s Energy Research Center and the Potomac Electric Power Company have been developing software for use by plant personnel in turning a pulverized coal-fired boiler to achieve optimized combustion. The software is based on the interactions of an expert system, neural network, and a mathematical optimization algorithm. It uses the expert system to safely guide the plant engineer through a series of parametric boiler tests and gather a data base which characterizes boiler operation over a wide range of conditions. The neural network portion develops non-linear mapping functions between the outputs of NO{sub x}, heat rate, LOI, opacity, and the controllable boiler input parameters. These mapping functions are then analyzed by the mathematical optimization algorithm and the optimal boiler operating conditions are identified. This paper describes the application of the software to corner-fired boilers with either conventional or low NO{sub x} burners and overfire air.

Performance Evaluation of Selected U.S. Utility Commercial Lighting Demand-Side Management Programs

This article selects 18 commercial lighting demand-side management programs of electric utilities in the United States and evaluates their performance. It first uses four conventional measures, i.e., rate impact measurement, total resource cost, total utility cost, and total customer cost, to analyze the costs and benefits of each program. Although all programs achieve good benefit to cost ratios under each measure, the rankings are not always consistent, i.e., a program`s ranking in one measure is not always the same as in another measure. To provide a unified basis for comparison, the authors use a mathematical programming model--the data envelopment analysis (DEA) model--to integrate the results of these four conventional measures for each program. Based on the DEA results, programs of Southern California Edison, New York State Electric and Gas, and Potomac Electric Power produce the best overall performance, followed by Central Maine Power, Pacific Gas and Electric, and Central Vermont Public Service. Finally, this article discusses the implications of the DEA results, which can serve as an effective means for performance benchmarking.

Upgrading the ampacity of HPFF pipe-type cable circuits

The upgrading of several 69 kV pipe-type cable feeders on the Potomac Electric Power Company (PEPCo) transmission cable system is discussed. The methods used for the ampacity calculation are described. The fluid circulation approach required to meet the feeder emergency load requirements are discussed. For the feeders that were in service for approximately 40 years, a system life evaluation was performed.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Managing life‐cycle costs: Applications and lessons learned at leading utilities

AbstractLife‐cycle cost management (LCCM) provides electric utility staff with a structured process for making decisions based on the true cost of the products and processes they use, rather than on purchase price alone or on other partial life‐cycle costs. Several utilities have used LCCM to evaluate a range of product substitution and process improvement decisions and to implement cost‐saving actions. This article summarizes some of these applications. Each utility applied the LCCM tools and techniques in a way that met their individual needs, such as selecting cost‐effective specific pollution prevention options, making product purchase decisions, making process improvement decisions, managing commodities, and setting priorities for further evaluation. LCCM has helped utilities save millions of dollars by considering the true costs of the materials, products, and processes they use. This article examines the LCCM techniques and tools that help organizations evaluate their options and make decisions with minimum effort.The authors wish to thank our utility partners for their contributions to developing the LCCM tools and techniques and for their participation in applying these tools and techniques to important decisions: Duke Power Company, Entergy Services Inc., Florida Power Corporation, Niagara Mohawk Power Company, Pacific Gas &amp; Electric Company, and Potomac Electric Power Company. The authors thank the following utility representatives for their valuable contributions: Amy Crews Baxter, Reggie Black, Jay Eingold, Shireen Fahey, Tom Fox, Tom Rooney, and Tyrone Williams. The authors also thank key members of the DFI project team: Nathan Chan, Gillian Lam, Mia Morsy, Jim Mullin, and Valerie Peoples.

Telemetering system supports load curtailment and billing

The use of computer systems designed to accommodate complex load management as well as billing and load survey programs by the Potomac Electric Power Company (PEPCO) and an innovative organizational approach to implement a comprehensive energy plan for its customers are described. The justification for purchasing a telemetering master station that supports load curtailment, automatic metering, customer billing programs, and load surveys is examined. These applications are discussed, and the telemetering system components are described. >

Network reduction program maintains external area integrity

In the latter part of 1986, Potomac Electric Power Company (PEPCO) needed to create a 1500-bus network model for its energy management system (EMS), starting from an existing 4000-bus model. The PEPCO part of the network (the internal area) was to be used as is, but the external areas needed to be reduced and consolidated considerably. A program built to help automate and streamline the reduction process is described. The program was written using the power system simulator for engineers (PSS/E) program. Future enhancements are indicated.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Local band shedding

An effective local-load-shedding scheme has been developed to alleviate equipment overloads in underground transmission networks. It offers a very fast and reliable algorithm where accuracy and speed are traded, depending on the severity of overload. For overloads greatly in excess of short-time ratings, the speed of removing the overloads within the specified time is given higher priority than the accurate minimization of load curtailments. To provide positive and reliable collective action, overloads are overcorrected by shedding more loads than is absolutely necessary, since the excess loads shed can subsequently be restored by partial restoration. The local shedding scheme has been tested by simulation at the Potomac Electric Power Company for a number of single and multiple outages in the 138 kV underground transmission network with good results.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Remote Measurement Calibration

Power system reliability and economy of operation require accurate measurements of current, voltage, real and reactive powers. These measurements are telemetered to a central location for monitoring, display, and use in power system application programs. Typically in an Energy Management System (EMS), the number of measurements is in the thousands. Routinely field technicians must calibrate transducers and/or determine other sources of metering errors. Due to the large number of measurements and the time required to check each individual measurement, field calibration procedures are impractical, expensive, and not timely. There has been a need for a more efficient approach to measurement calibration and identification of the defective instruments. This paper describes a novel approach which meets the need. Repetitive measurements are used to determine errors due to the instrument transformers, transducers, secondary leads between these devices, analog-to-digital convertors, and the scaling procedure. The amperes, volts, watts and vars scales are then adjusted to compensate for these errors, thus providing more accurate measurements. The remote measurement calibration (RMC) method has been implemented on the EMS of Potomac Electric Power Company (PEPCo) for several 230kV substations with excellent results.

Experimental Results of a Load Management System for Large Commercial Customers

Encouraging experimental results have been obtained from a two-way load management system for large commercial as well as governmental customers on the Potomac Electric Power Company (PEPCo) system. This paper peesents these results and describes the inovative two- way load management system that was developed and installed to achieve them. The Robinton Products, Inc. system operates from a central processor located in PEPCO's control center and it communicates with the customer locations through a telephone system called "Select-A- Station". Future plans for the expansion of the system are presented along with experimental results.

Experimental Results of a Load Management System for Large Commercial Customers

Encouraging experimental results have been obtained from a two-way load management system for large commercial as well as governmental customers on the Potomac Electric Power Company (PEPCo) system. This paper presents these results and describes the inovative two-way load management system that was developed and installed to achieve them. The Robinton Products, Inc. system operates from a central processor located in PEPCO's control center and it communicates with the customer locations through a telephone system called ``Select-A-Station''. Future plans for the expansion of the system are presented along with experimental results.

Developing Generation Construction Plans for the Potomac Electric Power Company: Management Science in Utility Regulation

To assist the Public Service Commission of the District of Columbia in overseeing the construction plans of the Potomac Electric Power Company, Resource Planning Associates, Inc. (on behalf of the Commission staff) independently developed long-term capital expansion plans for the utility. Such decisions in this extremely capital-intensive industry have effects for up to 50 years and involve billions of dollars in initial expenditures and several times more in future retail rates. In a publicly scrutinized, trial-like, adversary situation, in spite of the inherent uncertainties in and the complexities of the issues being addressed, our analysis showed how substantial savings could be achieved (as much as 15 billion dollars depending upon the future values of uncertain and uncontrollable variables), and convinced the Commission that their action was necessary. To do this we used state-of-the-art methods for generation planning and a new framework for strategic planning under uncertainty.

Chalk Point: A Case Study of the Impact of Brackish Water Cooling Towers on an Agricultural Environment

AbstractThe construction of two brackish water, natural‐draft cooling towers (Units 3 and 4) by the Potomac Electric Power Co. at their Chalk Point Generating Station, located in a major agricultural region in southern Maryland, aroused concern that saline aerosol emissions from the facility might significantly impact the crops and soils near the facility. Permanent research and monitoring sites were established at distances of 1.6, 4.8, and 9.6 km north, east, south, and west from the cooling towers. Over the period May 1973–May 1980, baseline and postoperational information was obtained on monthly Na and Cl deposition rates; foliar chemistry and yields of corn (Zea mays L.) and soybeans (Glycine max L. (Merr.)); soil pH and extractable P, K, Ca, Mg; Na; and electrical conductivity values on 0‐ to 15‐cm depth soil samples. Unit 3 began operations in July 1975.The quantities of saline aerosol emissions from Unit 3 were insufficient to cause detectable changes in the Na and Cl deposition rates above baseline values at or beyond the 1.6‐km sites, the closest agricultural areas to the power plant. Also, no significant changes were observed in Na and Cl levels in vegetative samples collected from corn and soybeans grown in the research sites after Unit 3 began operations. Significant reductions in corn yields that were more associated with rainfall patterns than to salt emissions were observed during post‐Unit 3 operations. Significant changes that, in most cases, could be closely associated with the general increases observed in soil acidity, were observed in each of the soil chemistry parameters with time.In conclusion, saline aerosol emissions from Chalk Point Unit 3 natural draft cooling tower did not have a detectable impact on the agricultural crops and soils adjacent to the emission source.

Role of Interactive and Control Computers in the Development of a System Restoration Plan

The duration of power system disturbances are minimized by executing a well-maintained system restoration plan (SRP). The SRP is significantly improved by the combined efforts of the operating personnel and systems analysts. The team effort is enhanced by the concurrent use of control computer and interactive computer systems. It is facilitated when botlh groups and both systems are located at the operating center. Adopting this approach, Potomac Electric Power Company, (PEPCo), has developed an efficient solution to SRP, which has proven extremely beneficial. The approach, and the results presented in this report, should be of interest to other utilities.

System Restoration Plan Development for a Metropolitan Electric System

The extended duration of recent major power system disturbances have indicated the need for development of system restoration plans (SRP), which would minimize the time required for restoration of service. This paper presents an efficient approach to SRP, from a complete collapse under peak-and light-load conditions, developed at Potomac Electric Power Company (PEPCo). The method is based on: (a) the combined effort of operating personnel and system analysts, (b) the access to data available from the on-line computer facilities, and (c) the use of an interactive load flow program. The SRP development procedure and the results described in this paper are of general interest in that they can be adopted and applied to the other electric systems.

Feasibility study for burning refuse-derived fuel in the district of columbia by potomac electric power company

This paper describes a study conducted to determine the economic feasibility of a project for producing and burning refuse-derived fuel RDF in the District of Columbia. Alternate modes of processing,transporting, handling and burning RDF were considered. The study concluded that it is economically feasible to implement the project and identifies the most cost-effective approach for utilization of existing capital facilities. The study can possibly serve as a model for implementation of this form of energy recovery elsewhere.

Operating Experience with an Experimental Crossband Frequency Diversity Industrial Microwave System

This paper describes the Potomac Electric Power Company's experience in trying to provide very reliable microwave service over a troublesome path through the use of 6/12 GHZ crossband frequency diversity techniques. The results indicate that no measurable improvement was achieved over space diversity techniques in the face of multipath fades and that rain fades on the 12 GHz frequency make its operation unacceptable.

A Winter Sport Fishing Survey in a Warm Water Discharge of a Steam Electric Station on the Patuxent River, Maryland

An interview-count sport fishing survey was conducted from January through April, 1970, along a one-mile discharge canal of the Potomac Electric Power Company’s Steam Electric station located at Chalk Point, Maryland. An estimated 20,335 fishing trips, representing 77,943 hours of fishing, were made during the period sampled. On interview days, 8,758 fishermen were counted, and 4,716 were interviewed. An estimated 58,453 fish, representing 9 species, were taken, with an average of 0.71 fish caught per man-hour of effort. White perch,Morone americana, dominated the catch during all months sampled. No significant correlation could be made between water temperature of the canal and number of fish caught per man-hour of effort.

Cluster Analysis of Fish in a Portion of the Upper Potomac River

A series of limnological surveys carried out from 1956 until 1965 were made in the vicinity of the Dickerson Plant of the Potomac Electric Power Company (located below the confluence of the Potomac and Monocacy Rivers) by the Limnology Department of the Academy of Natural Sciences of Philadelphia. These surveys were made at various stages of growth (i.e., increased generating capacity) of the power station and at both high and low water levels of the river. Cluster analyses were made of the fish data in order to provide a rapid and explicit means of analyzing the data, particularly relationships among aggregations of species. A secondary purpose was to measure the redundancy of information obtained by analysis of other groups, namely algae, protozoans, aquatic insects, and other invertebrates. On the basis of the cluster analysis of data on occurrence and distribution of fish, no changes in the environment of the Upper Potomac River can be ascribed to the operation of the Dickerson Plant of the Potomac Electric Power Company. This conclusion agrees with other results obtained by analyses of protozoan, algal, and insect species. Jaccard coefficients among aggregates of species of fish are appreciably higher than for other groups of organisms, indicating the relative mobility of fish compared to the other organisms. Comparing the fish data with that obtained for other groups of aquatic organisms indicated that there is much information redundancy when all groups of aquatic organisms are studied simultaneously. This redundancy is considered desirable since the results obtained with one group of organisms regarding pollution loads is much more significant if the same results are obtained with other groups of organisms.