Distribution utilities have been under constant scrutiny from regulators and customers alike, owing to their inefficient operations and poor financial health. In a bid to make their operations more cost-effective, prepare for an increasing shift towards renewable energy and minimise commercial losses, discoms have been adopting new and improved metering techniques.
Power Line takes a look at some of the efficiency-enhancing metering practices followed by discoms across the country and their impact on the ground…
Prepaid meters operate in a manner similar to prepaid mobile phones, wherein consumers pay for their electricity consumption in advance. The meters deployed earlier were based on token technology, which was followed by magnetic strike technology and smart card technology. Due to issues associated with the availability of writers and readers of smart cards, keypad-based technology has been adopted in modern-day prepaid meters. This gives consumers the benefit and flexibility of multiple vending options, wherein token codes can be generated anywhere through the internet or interactive voice response systems or mobile applications.
The prepayment system empowers consumers by giving them greater control over their consumption and enables them to budget it. As a result, consumers gain a better understanding of their consumption patterns and can move towards optimising their consumption. From the utility’s perspective, besides improving collection efficiency, prepaid meters significantly reduce the overhead costs associated with activities such as meter reading, data collation and processing as well as bill printing, distribution and collection. They also reduce working capital requirements as payments are received in advance.
So far, prepaid meters have been deployed across 15 states, including Manipur, Delhi, West Bengal, Gujarat and Bihar, for select consumer segments – temporary connections, government buildings and rented premises.
Delhi was among the first states to install prepaid meters. Tata Power Delhi Distribution Limited (TPDDL) installed about 3,050 meters for domestic consumers residing in multi-storeyed buildings in Rohini in 2005. Prepaid metering in the state received another major boost in 2007 when the Delhi government decided to install such meters across all state government offices with a connected load of up to 45 kW. West Bengal was also among the early adopters. About a decade ago, West Bengal State Electricity Distribution Company Limited (WBSEDCL) procured about 2,500 prepaid meters, which were installed in high-rise buildings in the Raja Ghat area of Kolkata.
Manipur started the installation of prepaid meters in 2011 on a pilot basis. Manipur State Power Distribution Company Limited has connected nearly half of its 300,000 consumers with prepaid meters. This has resulted in improved billing and collection efficiency as well as lower commercial losses. Following the deployment of prepaid meters, monthly revenues from power supply increased from Rs 55 million-Rs 60 million earlier to about Rs 105 million. It also led to a decrease in the overall financial burden of electricity consumption for consumers. Prior to the installation of prepaid meters, the Electricity Department often resorted to flat billing, wherein consumers were made to pay as much as Rs 500 per month for only six to eight hours of power supply. With prepaid meters, consumers received power supply for almost 16 to 20 hours for the same amount of money.
The concept of net metering is associated with “prosumers”, consumers who also engage in the generation of electricity. It is essentially an accounting principle wherein the final electricity bill of the prosumer is generated based on a bidirectional flow of electricity, including the amount drawn from the grid and supplied to the grid. The bidirectional meter measures the net exports and imports to generate electricity bills.
Net metering not only provides a cost-effective alternative to storage batteries, but also creates a revenue stream for consumers. Thus, net metering improves the viability of rooftop projects by maximising the benefits for rooftop owners. Tamil Nadu, Andhra Pradesh, Uttarakhand and Punjab were among the first states to come out with relevant regulations for net metering in 2013 and 2014. Over a period of three years, almost 26 states and union territories have released policies and regulations to operationalise net metering. Several states including Gujarat, Andhra Pradesh, Uttar Pradesh and Goa allow gross metering of rooftop solar plants. However, net metering based on bidirectional meters remains more popular.
To encourage implementation, the Central Electricity Authority (installation and operation of meters) Regulations, 2006 allow discoms to utilise the entire power generated from net metered rooftop solar installations towards their renewable purchase obligation targets. All customer categories are eligible for net metering; however, in West Bengal, the eligibility is limited to institutional consumers.
Automated meter reading
Automated meter reading (AMR) technology assists in gathering consumption, diagnostic and status data from electronic meters and relays it to discoms. The main advantage is that it eliminates the need for utility personnel to physically go to each location where the meter is installed. In advanced metering infrastructure (AMI), which includes smart meters as an integral apparatus, there is complete remote manageability of the devices, which means there is almost no human intervention required for checking, monitoring and rectifying equipment-related issues.
Both state and private discoms are switching to AMR- and AMI-enabled metering practices. Bangalore Electricity Supply Company Limited has introduced AMR for high-tension consumers, distribution transformer (DT) meters and feeder meters; and AMI for prepaid meters, which are primarily temporary connections.
A key project that TPDDL implemented is an AMI-based automated demand response (ADR) programme, which is aimed at managing peak demand and tackling grid stress. ADR infrastructure includes a demand response server and site controllers, smart meters, radio frequency mesh-based communication and a meter data management system. It has helped the discom realise its technological capabilities and understand customer behaviour. In addition, it has presented a case for the regulator to work on differential tariffs and financial incentives.
Utilities are also adopting various techniques such as incorporation of meter sensors and push-fit boxes to deal with the meter tampering and theft problem, which is the main reason for commercial losses. For instance, Madhya Pradesh Poorv Kshetra Vidyut Vitaran Nigam Limited replaced electro-mechanical meters with static electronic meters and intelligent meters, which can easily detect tampering by analysing the data retrieved. Further, periodic testing and rating of meters is carried out for theft prevention.
Meter data acquisition systems
Most of the discoms have acquired meter data acquisition systems (MDAS), partly because it was mandated by the Restructured Accelerated Power Development and Reforms Programme (R-APDRP). Discoms that have begun to utilise these systems are seeing very positive results, not just in load management and revenue protection, but also in areas such as outage management and condition-based monitoring. As discoms become more familiar with these systems and make a greater use of them, MDAS is likely to play a big role in improving operational efficiency.
The key components of any MDAS are field devices (such as meters), communication media (radio frequency, power line communication or cellular communication), head-end systems, meter data management systems (data warehouse or repository), and analytics. The objective of this extensive structure of multiple devices and systems is to measure, collect, transfer, store and analyse electricity consumption-related data.
CESC Limited deployed MDAS in 2007-08, following the implementation of AMR in 2005. The billing system software was developed in-house, while the MDAS platform was sourced from outside. For collection of meter data, the utility initially relied on GSM technology, but eventually migrated to a general packet radio service (GPRS)-based system. CESC also developed a close-ended mechanism to resolve issues such as communication network availability. It put in place a dynamic monitoring system, under which network health is monitored on an everyday basis. The system ensures that problems do not crop up on the final billing day. With this mechanism, CESC has been able to achieve a success rate of more than 99.6 per cent. In 2010-11, CESC deployed a DT analytics tool, which helped in identifying DTs that were overloaded, operating on low/high voltages, low power factors, etc. As a result, CESC’s procurement of DTs reduced from 350-400 units to about 50 units per year. Moreover, the utility witnessed a decline in the failure rate of transformers by less than 0.5 per cent.
There have been various advancements in metering practices across discoms over the past few years. Utilities have gradually opened up to practices such as prepaid metering and meter data acquisition and analysis for improving operational efficiency as well as enhancing the customer experience. While the adoption of practices such as MDAS have been a result of a regulatory push, utilities are also responding to challenges such as meter tampering and theft by developing in-house technical solutions such as push-fit boxes and sensors. Further, due to an increased focus on solar power generation, net metering is expected to be adopted on a wide scale.