Viswanath Devarajan | Managing Director, Valmont Structures Pvt Ltd, India
What are the advantages and disadvantages of monopoles when compared to angular, riveted towers in use in T&D sector for several decades now?
Advantages of monopole in comparison to conventional tower are: Less right-of-way (RoW), better appearance, less components resulting in faster installation, better reliability under extreme conditions, design flexibility, vandalism proof, reliable performance and longer service life.
The only thing which seems to be a disadvantage is the cost of monopole. Which is not a fact, when you consider the complete solution it provides and the life-cycle cost of lines running through urban and suburban areas, it is comparatively less with use of poles. Monopoles are not only structures, but are solutions to the perennial right of way problem and tower failure problem faced by Indian utility Sector.
What are the differences in carrying capacities between monopoles and lattice towers and the frequency levels in a transmission line? Can they be adapted to both AC and DC lines?
Shape and Geometry are the only differences between monopole and conventional tower. Monopole can carry equal loads with ease and still can serve longer. This is same for AC and DC lines. Due to flexibility built in, monopoles are very less susceptible to failure during severe wind storms. This is not the case with conventional towers.
What are the obstacles in spreading the use of monopoles in the current scenario and what are the measures that are required to speed up their adoption on a wider scale?
The major obstacle is the lack of awareness in the market. In India, Valmont is helping state-owned power transmission utilities.
Understanding the concept of steel poles and few of the prestigious utilities like UPPTCL, MPPTCL, RRVPNL, KPTCL, HVPNL, MSETCL etc., have shown interest and have started adopting the concept of monopole as a solution and an alternative.
What is the possibility and need of replacing the existing T&D tower infrastructure with monopoles in the years to come?
Replacing conventional towers completely with monopoles is not possible. Monopole is a concept, which brings in solution for critical lines, lines moving through urban and suburban areas, lines for land locked substations, upgradation of lines in the existing corridor or bringing in multiple lines using existing/same corridor etc. But opportunities are countless.
Are there any global standards evolved for monopoles? What is the status of R&D in monopoles in India?
With the presence of Valmont in India, now we have all the expertise and facility locally available. Valmont is continuously busy with its R&D and has type tested 17 monopoles of 66 kV to 400 kV grade in India in the last 4 years´ time. With our rich international experience, we have also brought in world class galvanizing solution to India, which provides much longer life. With the growing use of monopole, the confidence level of utilities is definitely going up. And nowadays utilities have started planning for lines with monopole as an alternative in part or full. Even PGCIL has started taking interest and have recently floated tenders using monopoles for lines with RoW issues.
What are the categories of monopoles you make for the power sector, any joint venture partner you are associated with and who are your major clients in the power sector?
Valmont India manufactures high quality steel poles of different types for power transmission, distribution and substation applications. We design, manufacture, supply steel monopole types ranging from 11 kV to 400 kV voltage grade with Multi-Circuit designs.
When was monopoles introduced for T&D use in India and what is its current size, and what is the lag with which it was introduced here in India when compared to the US and Europe?
Steel poles are of different type in terms of geometry, but monopole is the option mostly used in India as on date. Steel poles were first tried in India in 2007, but the response was not encouraging due to non-availability of technology and expertise at that point in time. But after coming to India, Valmont successfully re-introduced monopoles in India in 2012 by co-partnering one of the local EPCs in construction of 11.2 km of 132 kV line near Ghaziabad under UPPTCL completely on monopoles. Here the 132 kV line was constructed successfully in the existing 33 kV corridor with expertise Monopole Solution from Valmont.
Use of steel poles started in late 1960s in US with extensive research, engineering and testing in early stages. It received wider acceptance in ´70s and ´80s. Today steel poles are the dominant type structures for new age power transmission and are commonly used in many countries, gradually being adopted in more new markets. Valmont has solid business experience worldwide and a pioneer in India. Currently, the size of utility pole market in India is of Rs 40 crore.