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Conference on Transmission Lines, Towers and Substations: Key highlights [free access]

May 11, 2018

The electricity markets of the Asia-Pacific (APAC) region are poised for significant growth in the coming years. Meeting the rising demand for power, providing universal access to electricity, and connecting new fossil fuel and renewable energy generation sources are driving investments in the development of transmission infrastructure. Technology and innovation are providing an impetus to transmission expansion, and governments are supporting this with business-oriented policies and laws.

 

With this backdrop, Global Transmission hosted a conference on Transmission Lines, Towers and Substations on April 24-25, 2018 in Singapore to highlight the most promising technologies, viable solutions and best practices available to utilities that can deliver a reliable and secure transmission grid infrastructure for the expanding APAC economies.

 

The highlights and key messages from the conference are presented below.

 

Trends and Outlook


The conference kicked off with a session on trends and outlook by Suchitra Sriram, Principal Consultant Energy & Environment, Frost & Sullivan. She shared that transmission and distribution (T&D) investments in the APAC region are expected to reach USD3,127 billion during the 2014-35 period, with investments during 2017-18 forecasted to be around USD150 billion. Key drivers for investments include digital transformation and smart technology, urbanisation, rising population and industrial expansion. She also highlighted that the microgrid market in APAC was poised to expand significantly to reach USD1.6 billion in 2018, mainly due to industrial and rural/island microgrids. Also, energy storage is becoming an integral part of microgrids.

 

With respect to country-wise investment, China will lead the region followed by India and Japan. The key investment drivers in China are ultra high voltage direct current (UHVDC) lines and upgrade of the existing network. India’s ‘Power for All’ by 2019 programme and 175 GW renewable power target by 2022 will drive investment in T&D. Japan’s ongoing electricity market reforms are expected to attract sizeable investments in the form of new transmission lines and substation projects.  

 

She further highlighted that revenue from smart grids is expected to reach USD33 billion in 2018, with distributed grid management comprising a 50 per cent share. With respect to T&D equipment, high voltage (HV) switchgear equipment has the highest growth opportunity in 2018 at 9.5 per cent. Further, the APAC region is expected to contribute 49 per cent of the global solid state transformer market in 2018. Lastly, top technology trends in 2025 include HVDC and flexible alternating current transmission systems (FACTS), high temperature superconducting (HTS) cables, underground and submarine XLPE cables, HTS fault current limiters (FCL), solid-state FCL, etc.

 

Figure 1: Grids Industry: Grid Investments, Asia-Pacific, 2017-2018 fig_1_spot_552

Source: Presentation by Suchitra Sriram, Frost & Sullivan

 

Keynote Address


In the keynote address, Datuk Rozimi bin Remeli, Former Vice President, Transmission,  Tenaga Nasional Berhad (TNB), and Executive Chairman, DRR Ventures Sdn. Bhd, highlighted that the energy mix in the region is changing, given the focus on greenhouse emissions, global warming and environmental concerns. Renewable energy is now a central part of the energy policies of all APAC economies. Further, battery storage will hold the key to large-scale adoption of renewable energy. Thus, these two together will change the grid requirements. He called upon the utilities of the region to be receptive to the new and emerging mix, and to open their grid networks to these changes.

 

Utility Plans and Perspective


Rajeev Kumar Chauhan, Executive Director, Engineering, HVDC, Power Grid Corporation of India Limited (POWERGRID), presented the company’s grid expansion plans under which around 46,700 circuit km of lines, 72,500 MVA of AC capacity, 11,000 MW of DC capacity, and 41,600 MW of inter-regional capacity will be added by 2022. He also highlighted that the creation of Green Energy Corridors (GECs) is underway to facilitate the integration of over 55 GW of wind and solar capacity.

 

He pointed out that securing right-of-way (RoW) is the biggest challenge faced during execution. To address this challenge, the utility is deploying lines with higher voltages and capacity (from 400 kV AC to 765 kV AC and further to 1,200 kV AC, and from ±500 kV DC to ±800 kV DC); increasing the capacity of transmission corridors through re-conductoring/upgrades; utilising existing transmission lines though deployment of series capacitors, static VAR compensators (SVC) and FACTS; and optimising tower designs by using tall towers and multi-circuit towers. The utility is also opting for gas-insulated switchgear (GIS) substations. The company is setting up 11 renewable energy management centres (REMCs) to facilitate RE forecasting, scheduling and real-time monitoring. For effective asset management, the National Transmission Asset Management Centre (NTAMC) has been set up for the centralized, real-time monitoring and control of POWERGRID’s entire transmission system. Under this, around 150 substations are being remotely operated.

 

Some of the research and development (R&D) projects under consideration include pilot gas-insulated lines (GIL), superconducting magnetic energy storage system development, evaluation of superconducting FCL and emergency restoration systems for substations.

 

Kitti Petchsanthad, Director, Transmission System Maintenance Division, Electricity Generating Authority of Thailand (EGAT), highlighted that under the country’s Transmission System Development Plan, around 15 projects are under execution including projects aimed at improving the country’s 500 kV transmission system. He shared that digital and robotic solutions are being deployed to improve productivity and minimise operation and maintenance costs. These include geospatial data for asset management, transmission line fault location using automated correlation of big data, geographic information system (GIS)-based tracking of transmission assets, smart field force management, etc. Also, he stated that going forward, EGAT was expecting engineering, procurement and construction (EPC) contractors to provide innovative technology solutions to keep pace with the fast and constantly changing sector.

 

R.D. Chavan, Director, Projects, Maharashtra State Electricity Transmission Company Limited (Mahatransco), presented the utility’s expansion plan for the next five years under which around 13,000 circuit km of lines, 24,300 MVA of substation capacity and 76 new substations will be added to Mahatrashtra’s grid network at an estimated investment of around USD1,572 million. He highlighted that the company has experimented with various models for executing projects including EPC and turnkey. Currently, the utility is awarding projects on a turnkey basis with separate packages for line and substation, with the latter being awarded after significant progress has been made on the former. He highlighted the various new designs and technologies the utility has been using for faster project execution. Substation-related solutions include GIS substations, digital substations and digital bays, IEC 61850 testing labs, transformer health monitoring, VRLA battery and micro control base battery chargers and residual life assessments. For transmission lines, the utility is deploying compact tower design, monopoles, HTLS conductors and GIS mapping of transmission assets.

 

Transmission Line Planning: Technologies, Solutions and Best Practices


Muhammad Ariff Abidin, Engineer, Geospatial Solution/UAV, Land Planning, Grid Strategy Department, Bahagian Grid, TNB, walked the audience through TNB’s in-house Unmanned Aerial System (UAS) programme under which unmanned aerial vehicles (UAVs) are being used for transmission route selection planning. He highlighted that going forward, TNB was looking to use UAVs for Light Detection and Ranging (LiDAR)-based rentice monitoring. Also, there is a proposal to replace the current UAS photogrammetry fleet with LiDAR UAS.

 

EPC Perspective 

In the session on EPC perspective, Jones Ponudorai, Vice President & Head (ASEAN Business Unit), Power Transmission & Distribution, L&T Malaysia, and R. Murali, Head, ASEAN, L&T, discussed some of the new designs, technologies and practices being adopted by L&T during project execution. For survey works, the company has been using powerful and large drones since 2010 and going forward, they expect these to be replaced by recreational light drones, which are much smaller in size and require fewer/no regulatory approvals. The company has been undertaking panel-wise dispatch of transmission line tower members, which has reduced manpower requirements; helped prevent haphazard material handling, shortages and pilferages; and reduced costs and time. For tough and inaccessible locations, helicopters are being used for tower erection. In the future, with a shrinking trained workforce and the risky working conditions in such terrains, the company envisages replacing human manpower with mechanised equipment such as air cranes for erection and drones for stringing. Also, mobile-based applications are being used for real-time monitoring and control of projects. Key challenges that the company has faced in the region include single vendor proposal during bids, mandatory local content requirements, prohibitive immigration rules, etc.

 

            Figure 2: Key issues and challenges – Project Execution, ASEAN

fig_2_spot_628

Source: Presentation by Jones Ponudorai and R. Murali, L&T

 

Conductors and Cables


Luke Ogoshi, Tokyo Rope, highlighted that the overhead conductor market is facing the challenges of huge electricity demand, environmental concerns, sag violations, RoW issues, high construction costs and longer execution periods. To address these issues, the company has developed a next generation conductor cable—Aluminum Conductor Fiber Reinforced (ACFR) with a carbon fiber composite cable (CFCC) core, which offers the advantages of high strength, low expansion and lesser weight as compared to an Aluminum Conductor Steel Reinforced (ACSR) cable. The ACFR cable has been deployed by several utilities in APAC including Japan’s Tohoku Electric Power Company Incorporated, China Southern Power Grid and Indonesia’s PLN. Currently, the company is installing the ACFR conductor for the 350-km, 150 kV Binjai–Pangkalan Brandan project in Indonesia. The conductor will help double the capacity of the line while maintaining clearances; use existing towers without modification; maintain the existing RoW; and save installation time.

 

Switchgear Technologies

Mohit Madhok, Sales Head Asia, Transmission Solutions, Siemens, presented a case for using portable power solutions (PPS) such as mobile substations, E-houses and skids, especially in difficult terrains. He highlighted that these solutions have a potential of saving 30 per cent of installation time as compared to conventional substations in concrete buildings. These prefabricated substation solutions also offer fast and versatile grid connection or restoration. He pointed out that so far, Siemens has delivered around 100 PPS-type high voltage substations across the global to customers in industries such as grid operations, generation, oil and gas, mining, etc.

 

As per Bryan See, Regional Development Manager, Siemens, the grid is transforming with the increasing influence of renewable energy, distributed generation and prosumers. To address environmental concerns of SF6 in substation equipment, Siemens has developed a ‘Blue’ portfolio comprising 72.5 kV and 145 kV GIS, a 1,455 kV air instrument transformer and a 145 kV circuit breaker. Instead of SF6, the equipment is insulated with clean air (80 per cent N2 and O2, which is cleaned and free from humidity). As per See, clean air insulation technology is expected to provide significant economic customer value during operation due to zero global warming, zero ozone depletion, high stability, zero gas recycling requirement, etc. He also mentioned that the Blue portfolio is currently in the pilot stage and has been used mainly for offshore wind farms in Europe.

 

Digital Substations


Stefan P. Jonsson, Territory Marketing & Sales Manager - Asia, Grid Integration, Power Grids, ABB, defined a digital substation as one where a digital process bus replaces the conventional copper wires between the primary equipment and the control and protection equipment. He highlighted that increased personnel safety is a main value driver for digital substations where AC/DC voltages are replaced with fibre-optic signals, thereby reducing the risk of electrical shocks. A digital substation requires 60 per cent less space for the protection and control room, while installation and commissioning time is reduced by 40 per cent, as compared to a conventional substation.

 

Figure 3: What is a digital substation?

 fig_3_spot_624

Source: Presentation by Stefan P Jonsson, ABB 

 

Construction of Transmission Lines and Substations

Sharana Bulankulame, Chief Operating Officer, Ceylex Engineering, discussed the construction challenges faced and measures undertaken during the execution of a turnkey contract for augmentation of the 132/33 kV Kiribathkumbura grid substation in Sri Lanka. Based on this experience, he mentioned that appropriate planning and formulation of alternative plans could greatly help in overcoming execution challenges.

 

Martin Cude, Business Development Director, Erickson, emphasised that using helicopters during transmission line construction can deliver high value to utilities. Advantages include safety, speed of construction, accessibility and minimum environmental impact. He highlighted that Erickson’s fleet incorporated unique helicopter designs (for precision placement of large sling rods,             an anti-rotation rigging system, an aft-facing pilot station, etc.) to ensure accuracy in construction.  

 

Transmission Economics


Eva Wang, Director, London Economics International, presented a case study of US utilities’ spending on T&D infrastructure. She highlighted that transmission spending in the US has nearly tripled in the last decade as utilities have focused on improving grid resilience, boosting security and reducing congestion. The US utilities are now focusing on deploying smart grid technologies to improve operating efficiency and prepare for the growing influx of distributed energy resources (DER). As per Wang, investment in power transmission in the APAC region will be driven mainly by countries looking to economies on diverse regional generation resource endowments.

 

 

New Grid Technologies


As per Zubin Postwalla, Marketing Leader - China, East Asia & Pacific, GE Grid Solutions, the global T&D industry is facing several challenges such as greater risk of instabilities or blackouts, rising presence of renewable energy sources and increasing energy costs and volatility. Decarbonisation, digitisation, decentralisation and cross-sector electrification are some of the trends that are disrupting the traditional power sector. In line, the T&D industry has begun adapting—which can been seen in the increased uptake of HVDC, FACTS, automation and software—to make the grids more robust while integrating more renewables and doing it in the most cost-effective way. He further elaborated that while sufficient renewable energy is available to all nations, HVDC connections and storage will play a key role in helping to harvest these resources. Another key trend was the maturing of HVDC technology. HVDC coupled with digital technology could further drive the productivity of these critical assets. As per Postwala, storage will play a key role in balancing renewables uptake. Also, the integration of storage using automation and software technologies is now well advanced and a critical part of the utility software platforms.

 

Project Showcase


Duong Viet Duc, Expert of Investment Management, National Transmission Power Company of Vietnam (NPT EVN), walked the audience through the planning and execution process for the 220 kV Nam Mo hydropwer plant (HPP) (Laos)–Ban Ve HPP (Vietnam) interconnection project. He mentioned that several models are available for project execution. These range from the investor-only model wherein the investor constructs and operates both the HPP and the associated transmission line in both countries, to a model where the investor is responsible only for construction of the HPP while the respective transmission companies undertake construction of the transmission assets in their countries. With respect to project construction, EVN awards EPC and separate consultancy, engineering and equipment supplier contracts, depending on the scale of the project.

 

Figure 4: EVN’s project implementation organisation

 fig_4_spot_458

Source: Duong Viet Duc, NPT EVN

 

Harsh Yadav, Associate Manager-O&M, Sterlite Power, presented a pilot project under which helical grips were used to prevent dead end and mid-span joint failures in towers. In another case study presentation, Aniket Ghosh, Engineer-O&M, Sterlite Power, showcased a pilot project in which power voltage transformers were installed to directly tap power from extra high voltage (EHV) lines, which helped reduce diesel consumption for telecom towers.

 

Tower Design


During his presentation, E.V. Rao, Vice President, KEC International, underlined that every terrain has specific tower requirements and considerations, for example, extra tall towers are needed for protection of wildlife and to avoid deforestation. He mentioned that some of the new trends in towers included the chainette tower, which offers advantages such as 40 per cent less structure weight as compared to the conventional self-supporting tower, an overall reduction in transmission line cost of 6 per cent and reduction in erection time. Some of the new trends in foundations include pre-cast foundations and grillage foundations. He pointed out that an emerging technology trend in transmission lines is GILs. Also, there has been an increase in the use of drone technology for monitoring and inspection of transmission lines. With the help of drones, utilities can undertake corridor mapping, tower top inspection, LiDAR surveys, etc.

 

Conclusion

While planning projects, utilities are constantly confronted with what is called the energy trilemma—achieving a balance between energy security, energy equity and environmental sustainability. Over the years, there have been innovations in the design and construction of lines, towers and substations, and several technological solutions are now available to help utilities meet the objectives of grid reliability, cost competitiveness and environmental impact. It is now up to the utilities to determine how they can utilise these solutions to create more reliable and resilient grid networks.