Richard D. Tabors

Transmission system management and pricing: new paradigms and international comparisons

The transmission system, once the necessary but nearly invisible component of the electric power system is now the focus of physical/electrical and financial attention of the utility and, more significantly their potential suppliers/customers. This paper has three primary objectives. The first is to present a discussion of a new paradigm for the electric power industry. The second is to review transmission pricing options, specifically those utilizing either long run (LRMC) or short run (SRMC) marginal cost based approaches. The third is to provide a review of innovative approaches to transmission asset management and finance as seen from international experience. >

The Introduction of Non-Dispatchable Technologies as Decision Variables in Long-Term Generation Expansion Models

Non-dispatchable technologies (solar, wind, run-of-the-ri ver hydro, cogeneration) affect the cost of electricity production in a complex manner by modifying the probability distribution of demand for conventional generation. The lack of an appropriate methodology to efficiently derive this modification has prevented inclusion of non-dispatchable technologies as decision variables in capacity expansion models. This paper develops a stochastic approach to load modification which explicitly models two types of interdependencies between load and non-dispatchable generation: through time of day and through weather. If more than one non-dispatchable generation technology is considered, the dependency among them is also modeled. Furthermore, the total as well as the marginal impact of non-dispatchable capacity on system reliability and operating cost is derived. This allows us to model non-dispatchable generation in the context of two broad classes of optimization algorithms. Dynamic programming and mathematical decomposition are considered in this paper as characteristic examples of algorithms in each class. Load modification models already in use derive total cost impact only, and are based on hourly chronological simulation which is a computationally cumbersome method. The methodology developed here provides marginal impact in addition to total impact values, is computationally efficient and is applicable to future demand projections at almost any level of detail. Finally, its accuracy proved very satisfactory when tested on 1975 Miami load and insolation data.

Benefit optimization of centralized and decentralized power systems in a multi-utility environment

The objective is to examine the theoretical bases for benefit optimization in centralized and decentralized electric power systems. In a centralized (single control) power system, cost, revenue, and profit are used as system performance criteria for benefit optimization, and the conditions are compared. The results show that conventional cost minimization is not necessarily equivalent to benefit optimization based on other criteria. In a decentralized (multi-utility) power system, benefit optimization and its allocation are investigated at the unconstrained economic optimum, economic optimum with constraints, and conditions under which the solution is an economic suboptimum. The data from the EPRI Regional Systems are used to show practical examples of the benefit allocation with wheeling transactions. Although some rules are better for society than others, there still is not one right answer to determine the rules for benefit optimization. >

Lessons from the UK and Norway

There is more than one way to privatise a nations electric power industry. Britains new system, for instance, is highly centralized. It has a mandatory pool for purchasers and generators of electricity-and essentially just two generators-plus a privately owned transmission system operator and a single regulator with czar-like powers. Norways restructured power industry, in contrast, is decentralized. Direct contracts between purchasers and generators dominate, there are generators galore, and the electricity pool simply balances supply and demand in the light of whatever bids it receives. Yet despite their differences, the British and Norwegian systems have much in common. Both systems are adjudged more economical than before. They are both seen as successes by owners of system assets. Both systems now claim a reduction in costs to the end-user. Most significantly both can claim that restructuring has left system reliability unharmed.

An experiment in real time pricing for control of electric thermal storage systems

The authors present the results of an experiment designed to test the economic benefits of real-time pricing (RTP) used to schedule electric thermal storage (ETS) systems in a New York utilitys service territory during the winter of 1989-1990. Three customers with EST systems were placed on an experimental RTP rate for their heating load only. A complete automated RTP-based control system was designed and retrofitted in place of the existing time-of-use (TOU)-based control system. The design, development, and implementation of the experimental RTP rate, customer response algorithms, and the energy management systems are described. Costs to the utility of the provision of service went down by about 10% beyond savings achieved under the TOU-based control system for a system with no storage. >

Utility experience with real time rates

The structure of electric utilities is undergoing far-reaching changes as new and expanded service options are added. The concepts of unbundling or of priority service are expanding the options open to customers. Spot pricing, or real-time pricing of electricity, provides the economic structure for many of these new service options. It is frequently stated that customers cannot adapt to real-time prices. The authors identify the elements of real-time rates and existing rate structures in the United States and other OECD countries which incorporate these dimensions. >

Power/energy: Homeostatic control for electric power usage: A new scheme for putting the customer in the control loop would exploit microprocessors to deliver energy more efficiently

Presents a new scheme for putting the customer in the control loop that would exploit microprocessors to deliver energy more efficiently. A homeostatic control scheme (homeostasis denotes a biological balance of separate functions in an organism) calls for continual updating of electrical rates, based on supply and demand, and continual communication of those rates to customers by the electric utility. Drawing heavily on todays load-management practices while greatly expanding the scope and nature of utility-customer interactions, homeostatic control would establish a marketplace for electric energy.

A computer-based design assistant for induction motors

A computer-based design assistant for the synthesis of three-phase squirrel-cage induction motors is discussed. The distinguishing feature of the design assistant is its incorporation of a database of past designs, and its ability to synthesize and to cost new designs. Design synthesis is accomplished via a Monte Carlo procedure that allows the design assistant to transcend the limitations of preprogrammed, heuristic expert knowledge. Costing is achieved by the use of a manufacturing simulator. The design assistant discards all inferior designs, and presents to the customer a feasibility frontier of superior designs.<<ETX>>

Homeostatic control : the utilitycustomer marketplace for electric power

A load management system is proposed in which the electric utility customer controls his on-site power demand to coincide with the lowest possible cost of power generation. Called Homeostatic Control, this method is founded on feedback between the customer and the utility and on customer independence. The utility has no control beyond the customers meter. Computers located at the customers site are continuously fed data on weather conditions, utility generating costs, and demand requirements for space conditioning, lighting, and appliances. The customer then directs the computer to schedule and control the power allotted for these functions. On-site generation by the customer can be incorporated in the system. It is argued that homeostatic control is technically feasible, that the level of control equipment sophistication can be adapted to the benefits received by the customer, that such a system would encourage the use of customer-site energy storage and energy conservation equipment, and that it represents a realistic method for allowing the customer to decide how he will use electric power during an era of increasing costs for power generation. (LCL)

Planning for future uncertainties in electric power generation: an analysis of transitional strategies for reduction of carbon and sulfur emissions

The authors discuss strategies for the US electric utility industry for reduction of both acid rain producing and global warming gases. The EPRI electric generation expansion analysis system (EGEAS) utility optimization/simulation modeling structure and the EPRI developed regional utilities were used. The focus is on the northeast and east central regions of the US. Strategies identified are fuel switching (predominantly between coal and natural gas), mandated emission limits, and a carbon tax. The overall conclusions are that conservation will always benefit carbon emissions but may not reduce acid rain emissions by the offsetting forces of improved performance of new plant as opposed to reduced overall consumption of final product. Results of the study are highly utility and regional demand specific. >