TGTransco leading transmission line modernisation with HTLS conductors

The Telangana state utility has pioneered unmanned substations and remarkably reduced transmission losses to just 2.05%.

TGTransco, Telangana’s transmission utility, is in charge of modernising power infrastructure through strategic planning, advanced technologies, and efficient execution. With a strong focus on enhancing grid capacity and reliability, the utility has adopted High-Temperature Low-Sag (HTLS) conductors, multi-circuit towers and underground gas-insulated substations. 

It has also pioneered unmanned substations, reduced transmission losses to just 2.05% and ensured seamless integration of renewable energy. A notable achievement is upgrading a 220kV line, which now carries up to 400 MW, twice the typical limit. This accomplishment has earned national recognition. TGTransco’s approach revolves around able leadership, timely technology adoption, decentralisation and long-term strategic planning. 

Jagath Reddy, Director of the PSU, shares more insights in an exclusive interview with EPR. Let us hear more from him.

How is Telangana modernising its transmission infrastructure to meet future power demands?

As we move forward in time, our transmission infrastructure is also evolving with technological advancements. We are focusing on enhancing transmission capacity by replacing conventional conductors with state-of-the-art High-Temperature Low-Sag (HTLS) conductors, which enable us to double the power transfer capability. Additionally, we are constructing transmission lines with multi-circuit towers and monopoles wherever right-of-way (RoW) constraints exist, ensuring optimal land usage and minimal disruption.

We are adopting the latest technologies and setting benchmarks in network development, becoming a reference point for several other utilities across India. Many state utilities visit our substations to learn about the advanced technologies we have implemented.

A major milestone in our modernisation efforts is the introduction of unmanned substations. We are currently operating around 12 such substations remotely, showcasing our capability in digital and automated operations. We have successfully built three to four underground substations, including a 400 kV Gas-Insulated Substation (GIS) located approximately 100 meters below ground level.

Our commitment to adopting cutting-edge technology is further evident in the Srisailam hydropower project, which houses a 400 kV GIS substation built over two decades ago. Through strategic planning, technological integration, and forward-thinking execution, we are not only meeting current transmission demands but are also well-prepared for the future needs of Telangana’s growing power sector.

What strategies helped Telangana achieve the lowest transmission losses?

Our network planning strategy minimises losses by optimising voltage levels and network topology. In our transmission network, we have successfully upgraded over 10–15 lines of 220 kV to HTLS conductors and about 5–6 lines of 130 kV by converting them to HTLS (High-Temperature Low-Sag) conductors. This conversion has effectively doubled the transmission capacity of these lines. For instance, a typical 220 kV line with a standard conductor has a capacity of around 210 MW per single circuit. However, once converted to HTLS the capacity increases significantly to approximately 400–420 MW. Upgrading the transmission voltage plays a key role in reducing line losses. This is why each district in Telangana now has a dedicated 400 kV substation, which helps us maintain low losses across the grid. This enhancement comes with minimal disadvantages and offers considerable benefits in terms of transmission capacity and system efficiency.

As a result of such network optimisations, our transmission losses have been significantly reduced. Over the past 2–3 months, we have maintained a loss rate of just 2.05%, which is currently the lowest among transmission utilities in the country. For the financial year 2024–25, our average transmission loss stands at 2.18%, demonstrating consistent performance and efficiency.

Overall, our focus on HTLS technology and strategic network planning has significantly improved our transmission system’s capacity, reliability and efficiency, placing us among the top-performing utilities in the country.

What strategies is the state government adopting to generate 40,000 MW of solar energy by 2035?

Our approach to power infrastructure development is distinct and deeply rooted in strategic planning and execution. Telangana follows a “load-side generation” policy, with approximately 6000 MW of the 5000 MW connected capacity integrated into our state network, primarily from the consumer. Remarkably, we have added 5000 MW of solar power capacity without constructing a single new transmission line, substation or transformer—demonstrating the efficiency of our existing infrastructure.

The state government has announced an ambitious solar policy targeting 20,000 MW by 2030 and 40,000 MW by 2035. To support this, we have a comprehensive 10-year plan under the Green Energy Corridor initiative, ensuring all infrastructure is in place to evacuate and manage this capacity efficiently.

Our planning is collaborative, data-driven and transparent. Every new transmission proposal is thoroughly discussed, reviewed against existing infrastructure and evaluated for its necessity, impact and optimisation. We focus on additions that genuinely enhance transmission capacity—for instance, connecting 132 kV lines from 220 kV substations and 220 kV lines from 400 kV substations, significantly improving power flow and reducing losses.

Our investment philosophy is clear: At least 90% of funds must directly contribute to increasing transmission capacity. Alongside building new infrastructure, we enhance existing lines using HTLS conductors to maximise capacity where new lines are not feasible.

Since the formation of Telangana, we have not left a single planned transmission line incomplete. Every project has been executed and put to use. For us, building and upgrading the transmission network is not just a task—it is a way of life. We approach this responsibility with commitment, foresight, and a long-term vision for a resilient and future-ready power system.

How can decentralised solar generation help manage annual load growth?

Our state is experiencing consistent load growth of about 8–10% annually. To meet this demand, we have strategically planned for the next 10 years, outlining what capacity needs to be added each year, including new transmission lines, substations, and upgrades to existing infrastructure. We are adopting various approaches to achieve these goals, such as implementing HTLS (High-Temperature Low-Sag) conductors, converting existing Aluminium Conductor Steel Reinforced (ACSR) lines, and enhancing substation capacities where required.

Rather than relying on large centralised solar parks, we promote decentralised generation, especially on the load side. The solar park model poses several challenges — acquiring large land parcels is difficult and transmitting power from remote generation centres to load centres incurs substantial capital expenditure on substations and transmission lines, alongside losses and wheeling charges. Even after achieving capacities like 500–6000 MW through solar parks, network upgrades remain a costly necessity.

In contrast, generating power closer to the consumption point minimises transmission losses and capital costs. If we meet 60–70% of the peak load through local solar generation, the need for new transmission infrastructure will be significantly reduced. Only after fully utilising this localised capacity should we consider large centralised plants.