Fiberisation of transmission lines to be the way forward

Manish Agarwal, CEO, Solutions Business, Sterlite Power Transmission Ltd., in an interview with EPR Magazine, explains the transmission challenges, and the burden being faced by power utilities. He further highlights about their brownfield technology, to meet the growing utility demands.

What are the transmission congestion challenges due to urbanisation and fast growth in cities?

India has some of the world’s fastest growing cities. Unplanned urban evolution is putting a lot of pressure on Utilities to cater to exponential growth in power demand which ageing transmission infrastructure is unable to meet. Constructing only greenfield transmission infrastructure would entail more land acquisition, capital and time along with potential RoW challenges, as availability of free space is constrained in our country. Additionally, the sole focus on building new infrastructure alone could potentially damage environment, vegetation and inconvenience nearby inhabitants. Hence, the most environmentally friendly and cost-effective option today is to retrofit existing brownfield infrastructure to increase power transfer capacity, using the same corridor footprint without taking up any additional land or space. In this context, transmission system planning and philosophy should optimise additional capacity by augmenting existing assets. Sterlite Power partners Utilities to uprate and upgrade overhead brownfield transmission projects, thereby addressing their challenges around network congestion through the framework of time, space and capital. This helps Utilities address the exponential growth in demand for power by decongesting their transmission networks to be able to deliver power to the last mile in a timely and cost-effective manner.

What is your say regarding the burdens faced by Utilities and inability to meet the growing demand for power?

The goal for power transmission Utilities is to be able to provide 24/7 reliable and quality power and all the related industries and offices are doing their best to meet this vision. That being said, there are a few issues that need to be ironed out for robust power transmission. Firstly, Utilities need to reduce their high dependence on Greenfield transmission assets which require additional land, substantial capital expenditure and investment of time, over brownfield assets where the existing infrastructure can be modernised and optimized within the same corridor. Secondly, Utilities need to whole heartedly embrace the deployment of new state-of-the art technologies and solutions that can help resolve challenges swiftly. These may look more expensive vis a vis traditional solution, but their ROI is very high. Hence, it is important for utilities to take a long-term view and think in the direction of opting for new technologies and solutions to stay ahead and cater to growing demand for 24×7 reliable and quality power.

Tell us how does some of the work being done through your Master System Integrator/ Brownfield EPC business, has the potential to emerge as a blueprint for the rest of the country?

Planning efficient inters and intra-state transmission systems will help utilities meet their power requirements for the next few decades and provide its people with 24×7 reliable and quality power. A case in point is Kerala, which has strengthened its power delivery networks through uprate/upgrade of its existing transmission network. State of the art technologies have been used to modernise existing transmission infrastructure, like micro piles, narrow based towers, monopoles, drones etc.

The Kerala model has the potential to become a blueprint for the rest of the country. Similarly, Delhi has also invested in modernising its existing transmission infrastructure which will allow it to provide reliable and quality 24X7 power for the people. Over last few years, Delhi has uprated around 50 per cent of its 220kV network with a view to have a ‘Zero generation scenario’ grid plan and rely on imported power. The city will also now have to gear up for upgrade of its substation’s and lines on critical corridors, a case like Kerala. I am pleased to share with you that Sterlite Power has partnered with Delhi in this transition and around 80 per cent of the uprate projects have been executed by us.

Additionally,  Sterlite Power heralded in a strong capability for congested and busy cities, with Zero shutdown (live line) reconductoring. A pilot project was undertaken in Bangalore’s electronic city, where power ampacity on a 66kV transmission line was doubled without taking any shutdown, thereby avoiding any disruptions in power supply in an area that was highly inhabited and had many businesses and commercial establishments around. This solution can be customised and scaled up for other cities facing similar issues. Throw some light on the role of transmission and manufacturing in the backdrop of COVID – 19.

Despite initial setbacks from the Covid Pandemic to domestic economy and global economy, things have started improving. The role of transmission in the power sector has seen a steady evolution. Where earlier the focus was more on generation and distribution, power transmission has strongly come into focus in the last few years. Greenfield projects have until recently dominated the agenda, but given their longer gestation period, high cost and RoW requirements the attention is fast shifting to Brownfield assets and modernising them to augment capacities. Brownfield transmission can beautifully complement RE Integration. One of the emerging challenges from RE integration into the grid is that huge generation capacities are being added much faster than evacuation systems can be built. Hence, it is important that transmission systems should be planned ahead of generation. Retro-fitting existing transmission infrastructure and augmenting their capacities can be done in a timely manner as these do not require additional space/RoW which usually take a lot of time to sort out. Importantly, this is an environmentally friendly solution, which does not require any alterations to the nearby forests, habitation or vegetation, as the enhancement of capacities is undertaken within the same existing power corridor.

On the policy side, for manufacturing, Make in India and self-reliance will remain critical to the overall goal of getting the country back on a healthy growth track and also in line with the vision for ‘Atmanirbhar Bharat’. The Govt’s reforms by way of amendments to ‘General Financial Rules’ (GFR), to allow only domestic bids in tenders valued at less than `200 crore, and the revision of . The Department of Promotion of Industry and Internal Trade ‘s (DPIIT) public procurement order, to further give purchase preference only to domestic industry in public procurement projects, will all go a long way in strengthening these efforts. In the larger scheme of things, it is imperative that State Governments all adopt “Preference to Make in India” order in their procurement strategy. As public procurement accounts for almost 20-25 percent of India’s GDP, this has immense potential to boost domestic demand. Additionally, the government is working to create a framework for holistic and integrated reforms in power sector to create completely open and free electricity market based on demand and supply. To overcome barriers of infrastructure deficit, various policies and programs are being implemented by the Government. Tariff based competitive bidding has also been evolving at State level and states can build assets now at lower costs and lesser funding and deploy the remaining funds to other avenues.

What is the potential security threat for connected grid systems that can interrupt the power supply for hours, like we recently had in Mumbai?

A large integrated Transmission Grid, as we have in India, cannot function reliably without being able to know what is happening where and to be able to take quick decisions and actions based on that information, on real time basis. An event in any part of the grid, can have cascading effect, which can quickly go out of control and result in complete blackouts. Such events have occurred in the past and therefore this risk is real, and solution is imperative.

The Mumbai power failure incident of 12th October 2020 is a wake-up call for states and utilities that the Grid has to be secured on priority. Multiple contingency plans must be in place to ensure that a network can survive any contingency, whether it occurs in isolation or simultaneously, to allow sufficient time for operators to take preventive actions, while such a situation is developing.

Once again, this brings into focus the importance of conducting power systems studies on state networks to simulate varied operating scenarios including multiple contingencies, to decide the strengthening required to ride through them. Field surveys of existing lines and corridors can be quickly carried out to check the feasibility of a range of solutions, to strengthen Grid reliability and resilience while keeping an eye to minimise time, space and capital impact of the new investment.

Additionally, Fiberisation of the transmission lines (i.e. replacing existing earth wire with OPGW) is the need of the hour. CEA, in the National Electricity Plan has acknowledged that “…the complexity in Grid operation has increased manifold, which necessitates dynamic monitoring of Grid parameters / conditions on real-time basis. The existing SCADA/EMS provides the data which are steady state in nature and not suitable for dynamic monitoring and control for the Grid due to high degree of latency of tele-metered data and also non-synchronised sampling of data.” To overcome this situation, data has to flow from all lines and substations to control centres on real time basis. This in turn requires significant bandwidth and speed of communication.

As of now less than 50 percent of the transmission lines (110kV and above) in the country, have OPGW. Delay in achieving fiberisation effectively exposes the network to risks of blackout events which can be a big security threat to the nation.  It is therefore very important to speed up this process, to have OPGW installed on 100 percent of high voltage lines by all TRANSCOs. Government is extending support my making funds available from PSDF for such works. With such bandwidth available with them, TRANSCOs can also lease out the spare dark fibre and bandwidth to telecom companies and earn additional revenues.

“Utilities must have a long-term view and adapt newer technologies and solutions to stay ahead and cater to growing demand for 24×7 reliable and quality power.”