Distribution utilities are increasingly adopting new technologies and equipment to stem losses, improve their decision-making through data analytics, reduce operations and maintenance (O&M) costs, and deliver consumer-friendly services. Utilities are modernising their distribution networks with covered conductors, gas-insulated switchgear and dry-type transformers. They are also adopting the latest surveillance drone technologies to improve safety, reliability and longevity of assets. In addition, they are exploring machine learning- and AI-based digital technologies, which will increase the stability of the grid with real-time diagnosis of issues and early detection of component failures.
Power Line outlines the upcoming technological trends expected to upgrade the distribution segment…
Underground electricity cables are expected to gain traction over the short term. These cables can withstand natural calamities, and bypass right-of-way (RoW) problems and environmental roadblocks. Underground cables are being installed in several densely populated cities such as Chennai, Bengaluru and Bhubaneswar. Other benefits include ease of network expansion in densely populated areas and protection against theft. These cables entail minimum RoW and require fewer clearances. While underground power cabling is undoubtedly an expensive option, it can help meet the demand for reliable supply, safety, aesthetics and availability of clearances.
Meanwhile, cross-linked polyethylene, high density polyethylene, aerial bunched cables (ABCs) and space cable systems are the most commonly used covered cables. The use of ABCs is widely gaining traction for overhead power distribution networks since they provide benefits like low power loss, negligible current leakage, protection against power theft, low maintenance requirement, lower fault rate and resilience against environmental factors (wind and falling trees).
They are step-down transformers that provide voltage transformation in the electric power distribution system, including the final stepping down of voltage to the level used by customers. Currently, most utilities in the country deploy oil-cooled (mineral oil)-type transformers. However, the use of dry-type transformers and K-Class (ester) fluid-filled transformers is on the rise since they are associated with lower failure rates. Also, these transformers offer better protection against fire hazards, have low/no risk of leakage of insulation fluids, and entail minimal maintenance.
In the switchgear segment, distribution utilities are increasingly opting for gas-insulated switchgear (GIS), hybrid switchgear and intelligent switchgear. The deployment of GIS substations is gaining momentum, primarily owing to their compact size. The other key features of GIS include high modularisation, high safety index, low maintenance requirements, and the ability to resist vibration and avoid electromagnetic pollution. Further, a GIS is housed in a metal enclosure, which offers protection against environmental conditions such as salt deposits in coastal areas, sandstorms and humidity, thereby lowering O&M costs.
Hybrid switchgear is also gaining popularity. It combines both air-insulated switchgear (AIS) and GIS technologies, striking a balance between the cost of land and the facility construction cost. Hybrid switchgear is compact with the functionalities of AIS integrated into a gas-insulated enclosure. In hybrid switchgear, the bay length is reduced as the circuit breaker and the disconnector earth switch functions are integrated into one module. This results in an overall reduction in the area required for the substation. Further, the use of sulphur hexafluoride gas for encapsulation makes the maintenance of hybrid switchgear simple and cost effective.
Blockchain and AI
Blockchain, AI and ML are the other key emerging technologies in the distribution segment. Blockchain is a distributed data processing technology, that enables all users participating in the network to distribute and store data. Applying blockchain technology to the smart grid will ensure secure management of the energy data and contribute to the development of the future smart energy industry.
Converting energy resources into digital assets that can be traded on blockchain could open up new investment and trading opportunities, allowing ease of entry to new players and fostering innovation. In December 2020, Uttar Pradesh launched the first blockchain-enabled peer-to-peer trading platform for rooftop solar power in India and South Asia. The Uttar Pradesh Power Corporation, Madhyanchal Vidyut Vitran Nigam Limited and the Uttar Pradesh New and Renewable Energy Development Agency are hosting a first-of-its-kind pilot project, which includes solar rooftop systems installed on buildings in Lucknow. The India Smart Grid Forum, along with blockchain technology partner Power Ledger, Australia, and Abajyon Consulting, will execute the project.
Other new emerging technologies such as AI and ML hold the potential to significantly transform the way power is generated and distributed. These can be used across the value chain, based on the needs and requirements of utilities as well as the desired outcome. AI and ML modules could be developed based on the analytics of the data collected by sensors installed in the system. AI and ML can help turn information into actionable insights that can help predict network failures, plan timely interventions and avoid customer interruptions. Another popular scenario that is seen among companies is the use of conversational AI or chatbots to navigate common customer queries.
Drones are another new and emerging technology in the power distribution segment, assisting utilities in maintaining and inspecting T&D lines, which can otherwise be difficult, dangerous and costly. Drones help the significantly cuting the costs of power line inspections for utilities. They also improve safety, increase reliability and reduce response time across T&D systems. In remote areas with high voltage power lines, conducting routine inspections or surveying damage after storms entails difficulties and dangerous obstacles. With the help of drones, these difficulties could be eliminated. Drones also give utilities the ability to quickly and efficiently identify threats to the grid. BSES Rajdhani Power Limited and Tata Power Delhi Distribution Limited (TPDDL) have deployed drones in the recent past to map distribution assets, detect power theft, inspect rooftop installations, assess vegetation encroachment (around discom infrastructure), for the maintenance of power lines, poles and towers, and check for faults.
Battery storage is a transformative technology, with the potential to alter the business dynamics of the industry. It can stabilise grid volatilities and mitigate peak load issues by immediately coming online to supply electricity in times of contingencies. A battery energy storage system (BESS) can charge during off-peak hours and discharge power during peak conditions. A critical feature of BESS is to support distribution transformers in managing the peak load, regulating voltage, improving the power factor, regulating frequency and settling deviations. For example, if there is sudden rainfall, affecting the power supply from solar panels, batteries could come online and supply electricity with limited ramping time, thus facilitating continuous and reliable power supply. In 2019, TPDDL, AES Corporation and Mitsubishi Corporation inaugurated India’s first grid-scale battery-based energy storage system of 10 MW in Rohini, Delhi. TPDDL has recently installed a 150 kW/528 kWh community energy storage system in collaboration with Nexcharge at the Ranibagh substation. CESC Limited also added a 315 kWh BESS in its East Calcutta substation in January 2021.
EVs are expected to grow significantly in the coming years and in the long term, with discoms entering the charging infrastructure segment. Each discom will build and manage a chain of charging stations in its supply area. It will be a win-win for both discoms and EV owners, who would benefit from lower prices owing to direct supply from discoms, instead of charging through third parties that purchase electricity from discoms and hence, are obliged to charge higher prices. Tata Power has already spearheaded the installation of 300 charging stations across 40 cities, catering to different EV makes, models and categories. Similarly, BESCOM has set up around 136 charging stations across 70 locations in Bengaluru.
Discoms are increasingly adopting digital solutions for load management and asset maintenance. A reliability-based maintenance approach is preferred. Its key components are data integration, advanced maintenance planning, inventory management of critical spares, and adoption of appropriate maintenance strategies for different processes and equipment, rather than having one approach for all assets.
Load management helps utilities in matching the power supply and demand requirements in a cost-efficient manner. Accurate forecasting and demand response initiatives can assist in load management to a large extent. Smart grid applications can significantly help in reducing demand. Besides making the grid interactive, intelligent and transparent, these solutions increase the role of consumers in the value chain. This can be done by incentivising consumers to shift their energy load from peak to off-peak hours.