# Electricity Losses in Focus: Detection and Reduction Strategies--State of the Art
## 2 Primary Classifications of Electrical Energy Losses
### Non-Technical Energy Losses  
Non-technical losses are those which are not caused by external factors in the power system. These losses are distinct from the factors that cause technical losses. Accordingly, non-technical energy losses are predominantly attributable to external actions within the power system and are principally associated with customers. The most significant non-technical losses are attributed to energy theft, non-payment of bills, metering and accounting errors, and faulty meters [10]. Non-technical energy losses can be categorized as follows:  
1. Losses from consumer meters:  
The losses are attributed to issues with the meters themselves, resulting in meter inaccuracies within the problematic area. Significant energy dissipation can also occur due to metering inaccuracies at other points, such as transformer substations (PTs) or transformer stations (TSs). Inadequate metering can also result from voltage drops in the cables carrying energy from the PT, as well as from loose connections between cable terminations and the meter. 2. Meters overheat or are tampered with:  
Meter-related problems, such as missing meter seals and lack of regular meter checks, are also considered energy losses. Energy dissipation has been observed to occur in instances where meters are not adequately sealed or of substandard quality. Additionally, the improper installation of meters, in conjunction with the absence of inadequacy of a meter security system, has been identified as a contributing factor to energy dissipation. 3. Energy Theft  
Energy theft is a category of non-technical losses that manifests in various forms, including fraudulent connections to overhead power lines. Power theft, another form of this category, is widespread and involves direct connections to junction boxes at the ends of cable systems, also carried out fraudulently. Connecting to exposed service cables without notifying qualified personnel is also a method of fraud. Energy theft is a detrimental process that results in the loss of a substantial amount of energy. This process is also carried out by bypassing the neutral wires when connecting meters. 4. Energy accounting errors  
Energy accounting errors manifest in various forms. In the power system, these errors often result from inadequate monitoring and metering instrumentation during connections, as well as from improper energy audits. Additionally, the absence of a monthly energy accounting system to monitor losses during a given period can contribute to these losses. Another category of accounting errors involves failure to utilize proper meters, which can lead to inaccuracies in supply data. Failure to adhere to scientific methods in conducting regular energy audits is another factor contributing to energy losses. Significant errors can occur when meter reading is avoided for various reasons, such as the consumer's dwelling being closed, the meter being installed in inaccessible premises, or the meter's traceability. As the meter reading process is manual, errors in the transcription of the numbers following the readings may be made. These errors are classified as unintentional. Additionally, in the context of manual meter reading, intentional misreading of meters can occur, often arising from instances of conflict between designated meter readers in the field. This category of losses also encompasses data manipulation processes by operators entrusted with entering data into storage programs and software. The occurrence of reading losses can also be attributed to the absence of verification of field reading by qualified personnel, as well as the lack of reports containing the management of field reading reports. This category of errors is characterized by recurrent mistakes in the billing process. These errors can also occur because of incorrect or incomplete meter readings, and billing centers may lack systems to ascertain the integrity of the data being processed. Non-technical energy losses also occur when bills are not delivered to recipients, are misplaced, or become damaged.