Measures the reliability, continuity of supply, and the voltage quality of the electric system using a set of standard metrics. Overall, it relates to the ability of the electric system to perform its functions.
The continuity of supply (CoS) measuring reliability and the voltage quality are important issues in the electricity distribution sector. In general, the quality of service is related to the commercial relations with customers and technical perspectives. According to the American Public Power Association (APPA), reliability, from a system engineering perspective, is the ability of an electric system to perform its functions under normal and extreme circumstances.
Reliability indices help engineers and other operations personnel understand and demonstrate the interconnected nature of the many independent system components that make up an electric distribution system. This connection makes apparent the fact that overall system design, including construction practices, impacts fundamental reliability. From substation and distribution design to fusing schemes, various physical factors of system design impact system reliability. Among the commonly considered factors are: system voltage, feeder length, exposure to natural elements (overhead or underground conductor routing), sectionalizing capability, redundancy, conductor type/age, and number of customers on each feeder.
For most countries the main issues related to the technical aspects of quality of service can be grouped in two main fields of power quality:
* Continuity of supply (CoS) or supply quality is measured by means of interruptions in electricity supply identifying the events during which the voltage at the supply terminals of a network user drops to zero or nearly zero. These interruptions of supply are generally described by two quality dimensions, the number of interruptions and their duration. On system level, most common continuity indices related to long interruptions are SAIDI (System Average Interruption Duration Index), SAIFI (System Average Interruption Frequency Index), CADI (Customer Average Interruption Duration Index), and ENS (Energy Not Supplied). Most countries use separate classifications for planned (notified) and unplanned interruptions, and there is not a single standard if exceptional events (usually weather events) are included (or not) in the calculation of SAIDI and SAIFI.
* Product or voltage quality covers a subset of possible variation of voltage characteristics from the desired values (excluding interruptions) such as: supply voltage variations; rapid voltage change; voltage swells; flickers; voltage unbalance; harmonic voltage distortions; transient overvoltage; and mains signaling voltage. For example, delivery of high-quality, flicker-free power are important considerations for industrial or commercial customers due to equipment damage and data loss. Large industrial customers that are energy intensive can suffer significant financial losses when voltage dips occur at their sites, but this is less relevant in residential customers. Measuring the voltage quality however can be a complex task due to technical difficulties to select the proper indicator and establish the limits. Standard EN50160 establishes the limits set for voltage disturbances.
To face these challenges, due to a managerial decision or encouraged by the current regulation, the search for high levels of service must be present in the following pillars: (i) quality indicators: selecting indicators to describe their performance; (ii) performance standards: level of quality that company is expected to supply; and (iii) financial incentives to void penalization for the performance below the standard.
Multiple changes in the use of electricity are requiring the electricity systems to perform in ways and in a context for which they were not designed originally, requiring new capabilities and designs to maintain historical levels of reliability. The electric system is being asked to perform in ways and in a context for which it was not designed. The result is a system that is under stress from these and other factors and which requires greater flexibility, agility, and ability to dynamically optimize grid operations in time frames that are extremely fast. As consumers demand high-quality power with high reliability to support a digital economy, power disruptions have potentially greater consequences to customers. Moreover, there is a growing expectation for a resilient and responsive power grid in the face of more frequent weather events, cyber and physical attacks.
This section focuses on the utility’s best practice processes as enablers to improve its quality of service using industry standards. The section does not focus on the specific parameters (e.g., voltage limits, methodology for calculating the indices, etc.) of each country in LAC the region, as these are determined by each regulator as per each country's technical norms. The utility’s processes related to technical quality of service are organized in two groups:
Data and statistics from the energy sector, including indicators on electricity losses can be found at the IDB energy hub.
The energy hub is constantly updated with new information.
Designing an Action Plan
The development of an action plan is an important result from the review of the indicators and best practices of the processes for the utility. As an additional functionality of the toolkit this chapter presents the main activities to be considered to support the identification and prioritization of what are the most relevant practices to the utility and what are the best ways to develop and implement an action plan.
The definition of a comprehensive and well thought action plan is essential to attract investment opportunities and communicate the expected results. While there are different methodologies to design an action plan, most of them converge to similar activities, which are presented next as the steps in developing the plan.
Step 1 - Define problem and analyze data
Action plans usually start by clearly defining the main problem facing the utility andpolitical willingness to address it. This is done by collecting and analyzing the data and verifying previous assumptions of the problems that triggered the review. The toolkit can be an important methodology to identify areas where the indicators of the utility are below the references, benchmarks, or regulatory standards, and what are the best practices the utility can introduce. Still within this first step, usually teams define the goal and targets the utility would like to achieve, which in turn defines the level of ambition of the action plan.
Step 2 - Prioritize activities
Subsequent to the definition of the problem and expected results, the utility will need to prioritize the areas of intervention. This prioritization is done by segmenting the activities in different dimensions of: (i) impact or effectiveness (i.e., which activities Will deliver the highest impacts or benefits); (ii) timeframe (i.e., what is the best sequence of activities in the short, medium, and long term considering the expected benefits); and (iii) efficiency (i.e., based on quantitative measures such as cost benefit analysis, which of these activities will deliver the highest returns for similar levels of investment). Lastly, this prioritization should also identify synergies and complementarities among the activities to be consolidated in a single action plan.
Step 3 - Identify resources
Based on the action plan previously defined, it will be important for the utility to seek the financial and knowledge/expertise resources, as usually these activities need investments. Some utilities may have their own teams and financial resources to implement the action plan, while others will need to seek external financing and/or bringing technical expertise (example of new technology). Some sources of financing can be concessional with favorable commercial terms, which can make the action plan more feasible to be implemented. In this step it is also important to proactively seek and obtain support from the relevant country stakeholders (e.g., government authority, regulators, industry association, etc.) and clear understanding on the expected impacts and benefits of this action plan.
Step 4 - Prepare to implement
Lastly, the utility needs to develop a detailed implementation plan, not only including the activities previously defined, but also the governance model of the implementation (e.g., definition of team responsibilities and authorities, level of dedication, etc.) and how progress will be monitored and evaluated. Adaptability becomes a key ingredient of the plan, and an important reminder is to keep into perspective that11 “a business/action plan can't be a tightly crafted prediction of the future but rather a depiction of how events might unfold and a road map for change”. The results from the readiness to implement, together with seeking the political support and securing the financial resources are the last activities before implementation.
In sum, this chapter presented in general terms how utilities can develop a robust action plan and increase the likelihood of successful implementation, using the results from the areas of this toolkit.