At Power Line’s 17th annual conference on “Power Transmission in India”, Upendra Pande, managing director, Gujarat Energy Transmission Corporation Limited (GETCO), talked about the current state of the transmission sector in Gujarat. He expressed his views on the state’s achievements in this domain, along with its ongoing initiatives to seamlessly integrate renewable energy sources and address emerging challenges. Edited excerpts…
Gujarat’s transmission network has undergone substantial expansion and currently includes 2,318 substations, 7,485 transformers and 74,578 ckt. km of line length. GETCO has maintained a highly efficient transmission system with 99.47 per cent availability and only 3.86 per cent losses. Its network can handle a peak load of 24,544 MW. The period between financial years 2004-05 and 2022-23 witnessed phenomenal growth in the company’s asset base. The number of substations multiplied by 2.89, while transmission line length surged by 219 per cent. MVA capacity witnessed a staggering 391 per cent increase, reflecting significant investment in infrastructure expansion. Gross fixed assets and turnover experienced equally impressive growth, expanding by 708 per cent and 894 per cent respectively. This exponential growth signifies Gujarat’s unwavering commitment to strengthening its power transmission capabilities.
Gujarat has made significant strides in integrating renewable energy sources into its power mix. As of January 2024, the state boasts a total installed capacity of 39,419 MW, excluding rooftop solar power generation of 3,400 MW. Notably, renewable energy sources account for an impressive 42 per cent of this capacity. Solar and wind power dominate the renewables landscape, with installed capacities of 8,027 MW and 7,640 MW respectively. One of the primary challenges associated with integrating renewable energy sources is the time required to develop adequate transmission infrastructure to accommodate the generated renewable power. GETCO has proactively addressed this challenge by undertaking integration initiatives under the Green Energy Corridors (GEC) project Phases I and II. These projects prioritise the efficient evacuation of power from renewable energy sources, including offshore wind generation and green hydrogen projects. Additionally, Gujarat is exploring the viability of offshore wind energy generation, a technology poised for significant growth in the coming years. The allocation of renewable energy generated within the state now adheres to a transparent online portal system, overseen by the state regulatory body. This ensures fair and equitable distribution of clean energy resources.
GETCO ensures operational efficiency by actively leveraging digitalisation across various processes. This includes initiatives such as the digitisation of asset records and geographic information system (GIS) mapping. The company fosters innovation by developing custom information technology applications, including fault locators and DR extractors. The master network serves as a robust system for monitoring critical milestones, ensuring timely project completion. Real-time monitoring of the 11 kV system is achieved through a smart feeder monitoring system, a key component of the Revamped Distribution Sector Scheme. Condition monitoring practices have also been implemented for all equipment, enabling proactive maintenance and preventing potential failures. These applications enhance system monitoring capabilities and facilitate efficient grid management. GETCO’s swift response in the aftermath of Cyclone Biparjoy exemplifies its commitment to service continuity. Through efficient restoration efforts, power was restored within 72 hours, minimising disruption for consumers. The infrastructure’s ability to handle critical component failures is paramount, and GETCO actively invests in ensuring network resilience. The apprehension surrounding elevated transmission charges is likely to diminish as the grid progressively incorporates a sufficient and cost-effective mix of power sources throughout its network in the near future. The increasing electricity demand in Gujarat necessitates the installation of a robust transmission network. As per the 20th Electric Power Survey report, the anticipated demand in the state is projected to reach 33,964 MW by 2029-30.
GETCO plans to invest a capex of Rs 1,000 billion for the addition of 55,000 ckt. km of transmission lines, 17 STATCOMs, and over 800 new substations, including 12 high voltage 765 kV substations.”
GEC projects represent a cornerstone of Gujarat’s renewable energy integration strategy. GEC Phase I is nearing completion, with over 45 per cent (848 ckt. km) of the targeted 1,888 ckt. km of transmission lines already installed. Furthermore, all eight substations envisioned under this phase, having a combined capacity of 7,980 MVA, have been successfully commissioned. This swift progress paves the way for project completion by June 2024, bolstering the state’s ability to transmit power generated from renewable sources.
Looking ahead, GEC Phase II promises even greater strides. This phase encompasses the addition of 2,530 ckt. km of transmission lines and seven new substations with a combined capacity of 7,460 MVA. Notably, the inclusion of two high voltage 756 kV systems further strengthens the grid’s backbone. These strategic expansions are projected to facilitate the integration of an additional 4,500-5,000 MW of renewable energy into the state’s power mix, significantly increasing its reliance on clean energy sources.
Previously, Gujarat supplied solar power to the agricultural sector during off-peak hours (night-time). However, this approach proved inconvenient for farmers in certain regions. Recognising this challenge, the state utilities have embarked on a pioneering initiative to provide solar power to the agricultural sector during daytime hours (from 5 a.m. to 9 p.m.). The first phase of the project encompasses 33 districts across Gujarat and is scheduled for completion by March 2024. To facilitate this, infrastructure development is well under way in 28 districts, with the project involving the deployment of 12 substations and 3,497 ckt. km of transmission lines at a total cost of Rs 32 billion. System enhancements are also being implemented to ensure reliable daytime power supply for agricultural consumers. A critical consideration associated with this project is the potential increase in electricity costs for farmers. Night-time power tariffs are generally lower than those during peak morning and evening hours. To address this concern, the state is exploring further refinement of the daytime window to precisely align it with peak solar generation hours, potentially extending beyond mornings. This optimised approach necessitates meticulous planning and targeted infrastructure development within the transmission system.
In order to achieve this, GETCO has initiated the second phase of daytime power supply to the agricultural sector. Under this, solar power will be provided from 7 a.m. to 5 p.m. during peak solar generation hours. This would eliminate the need for solar power storage and also provide cheaper power to consumers during the daytime. The infrastructure proposed under this phase has a total project cost of Rs 55.2 billion for installing 15 substations, 3,355 ckt. km of transmission lines, 35 extra high-voltage (EHV) augmentation, five static synchronous compensators (STATCOMS) and reactive compensation of 1200 MVAr.
Gujarat actively embraces technological advancements to optimise and future-proof its power transmission infrastructure. GETCO has spearheaded the introduction of digital substations at the 220 kV level in Sevaliya. The adoption of a centre tap transformer for the 66/11 kV level has addressed high voltage issues. For establishing communication highways, the company has replaced earth wire with approximately 10,000 km of optical ground wire. GETCO became the first state transmission utility to commission STATCOMs at one of its EHV substations. Additionally, the integration of GIS and hybrid switchgear with substation automation systems and the utilisation of power transformers with ester oil represent significant strides towards capacity enhancement and reliability.
GETCO has charted an ambitious roadmap for the future. It has decided to introduce the tariff-based competitive bidding model in the state to enhance its operational efficiency. It plans to utilise power transformers and instrument transformers filled with ester oil, a biodegradable alternative to traditional mineral oil, in the planned 66 kV green substations. Additionally, these substations will employ circuit breakers that forgo the use of sulphur hexafluoride gas, a potent greenhouse gas. It also plans to implement 220 kV vertical gas-insulated substations in Khajod and Velanja. This gas-insulated substation technology offers a compact footprint, reduced maintenance requirements and improved safety compared to conventional air-insulated substations. GETCO is also developing plans to enhance existing transmission lines’ power transfer capability within the same right of way by utilising high temperature low sag conductors. Furthermore, the adoption of innovative solutions such as monopoles and narrow-base towers minimises environmental impact while optimising land utilisation for transmission line infrastructure. Gujarat, in sync with India’s renewable energy goals, aims to install 100 GW of renewable energy by 2030. This comprises 47 GW, which will be added in the next seven years for the intra-state network. The state plans to integrate 65 GW of renewable energy into the state grid to address the projected increase in demand.
GETCO plans to invest a capex of Rs 1,000 billion for the addition of 55,000 ckt. km of transmission lines, 17 STATCOMs, and over 800 new substations, including 12 high voltage 765 kV substations. Furthermore, the company plans to add more than 85 66 kV substations every year. Gujarat has had a transmission system ranging from 220 kV to 66/11 kV levels, allowing the state to reach remote locations. The state also plans to introduce the 33 kV level for metropolitan cities. Additionally, ongoing maintenance and augmentation of existing projects will ensure the continued reliability and efficiency of the state’s power transmission network.