Utility Service Territory Research Articles

A new clustering method for the optimization of distribution networks layout considering energy efficiency and continuity of service

The electrification of final consumptions and the spreading of distributed generation have fostered the search for new and more advanced electrical grid planning techniques, considering many of the aspects affecting electrical grids operation, such as their electrical and economic performance, as well as system reliability. Distribution network clustering is defined to be the division of the utility service territory into several high voltage–medium voltage substation service areas, and it represents one of the most important steps for grids planning. In this context, the purpose of this paper is to propose an innovative clustering algorithm based on Mixed Integer Linear Programming (MILP) formulation, able to take into account some fundamental aspects of the distribution networks planning process, such as the electrical losses along lines, the existing distribution network layout, and the reliability of the system. The approach, tested on the medium voltage network of the medium-sized city of Meran in the North of Italy, has proved to effectively manage the computational burden needed to model and optimize the structure of a complex distribution grid, as those that usually cover large urban areas.

The cost-effectiveness of energy savings through water conservation: a utility-scale assessment

It is well-established that water infrastructure systems require energy to treat and deliver water to end-users. This fundamental relationship presents an opportunity to secure energy savings through water conservation. In a previous study, the energy savings linked to a statewide water conservation mandate in California were found comparable in both resource savings as well as cost-effectiveness to the energy savings achieved directly through energy efficiency programs. This study pursues a similar line of inquiry, but at the scale of an individual city as opposed to a statewide assessment. Los Angeles, California, serves as the case study for estimating the energy savings secured through water conservation programs relative to energy efficiency (EE) programs enacted in the study region. We apply three different estimates of energy intensity (EI) for the conversion of water savings to energy savings. These applied EI scenarios are differentiated by scale and system boundary, including: a direct assessment of EI within the water utility service territory, an expanded boundary that includes imported water infrastructure systems, and a broader, top-down estimate for the regional hydrologic zone. Across all scenarios, the estimated energy savings secured through water conservation programs prove to be cost-competitive with the energy efficiency programs enacted by the utility. When using estimates of EI with expanded system boundaries that include the upstream energy embedded in imported water supplies, water conservation becomes a significantly more attractive pathway for saving energy. This outcome underlines the importance of clearly defining the water-energy system boundary of interest, both to determine an accurate EI value, and subsequently, to design and implement cost-effective programs that jointly conserve both water and energy resources.

Distributed Control of Voltage Regulating Devices in the Presence of High PV Penetration to Mitigate Ramp-Rate Issues

A distributed voltage control scheme is proposed in an active distribution network in the presence of a large scale photovoltaic (PV) farm/plant to mitigate high ramp-rate issues. Multiple voltage regulating devices, such as on-load tap changers, step voltage regulators (SVRs), and switched capacitors banks are controlled in various ways based on either a centralized or a distributed coordination management scheme. This paper presents the relationship of the active and reactive power outputs of a PV plant in the presence of the conventional voltage regulating devices, and proposes a distributed control strategy to coordinate the SVRs with the PV smart inverter’s capability to improve power quality. The distributed voltage control schemes are tested on an unbalanced medium voltage feeder located in a California utility service territory with the PV integrated at the far end of the feeder.

A comparative analysis of business structures suitable for farmer-owned wind power projects in the United States

For years, farmers in the United States have looked with envy on their European counterparts’ ability to profitably farm the wind through ownership of distributed, utility-scale wind projects. Only within the past few years, however, has farmer- or community-owned wind power development become a reality in the United States. The primary hurdle to this type of development in the United States has been devising and implementing suitable business and legal structures that enable such projects to take advantage of tax-based federal incentives for wind power. This article discusses the limitations of such incentives in supporting farmer- or community-owned wind projects, describes four ownership structures that potentially overcome such limitations, and finally conducts comparative financial analysis on those four structures, using as an example a hypothetical 1.5 MW farmer-owned project located in the state of Oregon. We find that material differences in the competitiveness of each structure do exist, but that choosing the best structure for a given project will largely depend on the conditions at hand; e.g., the ability of the farmer(s) to utilize tax credits, preference for individual versus “cooperative” ownership, and the state and utility service territory in which the project will be located.

Marginal Capacity Costs of Electricity Distribution and Demand for Distributed Generation*

Marginal costs of electricity vary by time and location. Past researchers attributed these variations to factors related to electricity generation, transmission and distribution. Past authors, however, did not fully analyze the large variations in marginal distribution capacity costs (MDCC) by area and time. Thus, the objectives of this paper are as follows: (1) to show that large MDCC variations exist within a utility's service territory; (2) to demonstrate inter-utility variations in MDCC; and (3) to demonstrate the usefulness of these costs in determining demand for distributed generation (DG).

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 utility's 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.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Two-Way Utility System Communications Using AM Broadcast Radio

An electric utility load management system functions optimally in direct proportion to the reliability of the communications system employed to transmit signals to and from the utility's central control to the thousands or millions of receivers installed on customers' appliances (water heaters, air conditioners, pumps, etc) throughout the utility's service territory. The signal from the central control to a receiver on an appliance 100 miles away on the other side of a mountain range must be as readily detected as the signal to a receiver across the street from the central control.

Spatial electric load forecasting: A tutorial review

A spatial load forecast is a forecast of the future locations and magnitudes of electric load within a utility's service territory. Such forecasts are a necessary part of power delivery system planning. This paper presents a comprehensive review of spatial load forecasting techniques. A discussion of planning needs, uncertainty, spatial growth character, and forecasting error focuses attention on the essential qualities of a spatial forecast. The various approaches to forecasting are then reviewed, compared, and evaluated on a uniform basis. Emphasis is on the use of two-dimensional signal theory as a uniform framework for analysis of load, growth, error, and forecast model behavior.