Advertise Here [728 W x 90 H pixels]
Construction : Special Feature | February 2016 | Source : Infrastructure Today

Transmission is levelling the playing field

IS Jha, CMD, PGCIL, says transmission has become a key enabler as he embarks on a programme of modernisation and deals with the new challenges of integrating renewable energy into the national grid.

Comment on the power disparity that exists.
One has to look back a few years for proper perspective. Once power generation was de-licensed after The Electricity Act 2003, there was a boom in the sector. People started coming into power generation in a big way, both coal-based and coastal. Plants came up in Chhattisgarh, Odisha, Gujarat, Krishnapatnam and many other places. Even the ultra mega power plants (UMPP) came up during this period û Tilaiya, Sasan at the pithead and Mundra, based on imported coal. However, after the policy flip-flops by Indonesia, there was a lot of disturbance in imported coal. Costs went up. Plants planned at the coastal areas got delayed. In the southern regions in places like Krishnapatnam, Cuddalore and many others, there were lots of delays. Power generation came up in the west, but not so as planned in the south. Obviously, a disparity arose.

What is being done to address it?
When we plan a transmission system, we ask a few questions to the generator - where, how much, when and where do you want to sell your power? A lot of plants came up in Chhattisgarh earlier. They wanted to sell a major part of it to the western regions like Maharashtra and Gujarat. They did not plan to sell in the south as a lot of generation was already planned there. However, the situation changed. Later, everybody wanted to go to the south. At that time, a little congestion was felt because they were changing the direction. I´d like to highlight that during this period, while generation has come up, transmission growth has also taken place of more than 10-11 per cent CAGR. The congestion was because of the change in direction of the flow of power. However, thanks to the present government, we are planning the transmission system on a war footing, whether from Chhatisgarh to Aurangabad, Solapur to Raichur, or all the way till Tamil Nadu. This is why there has been some relief in the congestion of late.

In the northern states, a different thing happened. While power plants came up, the demand also increased. However, with so much transmission, the prices also started getting optimised. The cost of power in the northern states is higher due to the transport prices for coal over long distances. However, surplus power is available in Chhattisgarh so again, there is a bit of congestion because everybody wants this cheaper power. So, a lot of advantages have come with transmission. The last two years, transmission is playing a major role. People can take power from anywhere to any other place and there is a lot of competition. There is a disparity and transmission has become the leveller.

Over the last two years, you are saying transmission towards the south has improved?
Drastically. There was hardly 2000-3000 MW flowing earlier. Today, it is 6,000 MW.

What is the demand there?
It is about 25,000-30,000 MW. They are also generating internally. Sure, they want more but if there is more transmission, they will not generate their own power since that is costlier! Transmission has now provided an option. If you make the transmission free flow, then no local generation will be justified. At one point of time, there should be a balance.

Update us with your plans for modernising the grid.
One of the things is Right of Way (RoW). A tower takes a lot of space. For instance, if 2,000 MW is generated and a single transmission line can carry 500 MW, you need to have four lines, meaning it will occupy four RoWs. Hence, we need to modernise so that only one line can carry all the power. The basic purpose is to conserve the RoW and economise the transmission. This is the first option. We have gone for higher voltage level. Earlier, our backbone was 40 Kv. In 2007-08, we brought in the first 765 Kv which increased the capacity of the line fourfold. Since then, you can see we have more than 15,000 km already operational and majority of new transmission lines also being constructed on 765 Kv. Not only this, the next step is 1,200 Kv.

Nowhere in the world is this operational and we will be the first. For this, we have developed the substation. The beauty of this is we have made a consortium of 35 manufacturing companies playing the pivotal role with respect to design and consulting. It is now under test. Once it is commercialised, this will be a true Make in India effort! These are for AC lines.

In HVDC also, we have just commissioned 800 Kv. This means one line carries 6,000 MW. You can imagine entire load of Delhi is 6,000 MW, meaning just one wire is sufficient for all of Delhi. This, we have made from Assam to Agra, 18,00 km. We just commissioned the first part in November 2015. This technology is only China. Neither America nor the UK have it. For such reasons and others I have talked about, I believe Indian transmission is not lesser than anyone else´s in the world. At the same time, we are modernising existing lines where cannot construct a new line.

What are the kinds of losses in the old lines?
In transmission, it is 3-4 per cent. It is at par with the international scenario. For every line, there has to be some loss and this loss is accepted all over the world. When we plan, this is a part of that and we cap these losses. Then, we plan the system accordingly.

In the existing system, if a line is carrying 500 MW, one of the limiting factors is that an increase in capacity generates heat and can cause burn-outs at the user end. The capacities have to be uprated. This is what we are now doing - changing the conductor with a high-capacity conductor. A new type of conductor has come up called High Temperature Low Sag (HTLS) conductor. The more the temperature, the more the sag, so we are replacing it with HTLS conductors. The material should be such that even at high temperatures, the lines do not sag and touch the earth. This way, we can increase the capacity by double without the need to change the tower or anything else. This is a new technology.

Another new technology we are using is Gas insulated substation (GIS). If you go to the urban areas and make a 765 KV substation, you need 100 acres of land. If you make this in Delhi, you cannot get 100 acres of land and hence we go in for GIS. Otherwise, it is air-insulated. With GIS, the requirement of land gets reduced to one-fifth. We are increasing the capacity but this is a dangerous operation. If there is an increase in wattage, there will be shakes. To stop this swinging, we need a control system. We call this STAT COM. This is also the latest technology. So, these are some important technologies we are using to modernise the system.

Do you believe privatisation is the best thing for the sector?
Privatisation is required for efficiency. If you have competition, naturally, it is a healthier situation for the market. However, it is not similar to generation. Transmission is a linear path. It is a monopoly, a licensed activity and cannot be given to everybody. We have to be careful. We cannot have such type of agencies who cannot build or maintain the transmission well. That is why in the long-term, I personally feel it will settle between three-four major parties. PGCIL will be the major player linking everything. People had the feeling that privatisation will come and being a PSU, PGCIL may not be able to hold their own. However, our officers have come up well and our winning rate is about 40 per cent.

We started bidding from January 2011. In this time, 20-24 transmission systems have been bid out. We have won nine but cost-wise it is 40 per cent since we are more focused on those types of projects. We are well-placed to meet any future challenges.

Solar has been planned to come up in a big way. What are the challenges to integrating this with the grid?
There are two challenges. Generally, renewable energy (RE) is of small capacity. However, if you make a plan like the Indian Government has done of 100,000 MW, things change. The bigger the system, the bigger the disturbance they can sustain. Similarly, in RE, which is very intermittent, when there is sunlight, there is power. When the sun goes down, all of a sudden there will be no power and a big swing will be felt. Everything will burn. This is why we have to integrate into a big system. This is how the integration is required. In a stand-alone system, it cannot sustain. It is very challenging. Then, how does one balance this? Someone should supply the power just taken away. Also, the grid has a capacity. It may be able to sustain 50,000 MW or 100,000 MW, but more than that, it cannot. So, for that too, we have a control system. And when the power shrinks, somebody should support it.

The second challenge is solar projects have a gestation period of less than a year.

However, transmission lines cannot be built in one year. This is a major challenge. So, now, when we plan the transmission system for solar parks, etc., we plan for both parts - small and big parks. For small ones, we can build in up to a year. For the bigger ones, it has to be later on. The planning is currently a challenge. Finally, as I said, implementation is also a challenge because the time of implementation has to be reduced to match with the generation.

´Smart´ is the buzzword these days. What are you doing for making it a smart grid?
To me, that basically means two things. If you want to make some piece of equipment smart, it has to be able to sense.. So, have a sensor and install a two-way communication. For instance, in transmission, we have put sensors to sense everything. We have developed a power measuring unit (PMU) which can measure temperatures, swing, voltage, current, etc. All this is through a communication instrument which comes to a control room. We are implementing this all over the country. This is also the first time any country is doing it in the word full-fledged. It is an ongoing exercise and we should have it implemented within the next two years. This will help us because the whole of India, we have a national grid and power can go anywhere. At the same time, if there is a fault, there can be disturbances and that´s the last thing that we will allow! That´s why we have to very cautious and equip the grid by making it very smart.

The second aspect to this is with respect to the consumer. There should be some switch that can communicate with the consumer on his mobile. As tariff is variable, consumers need a view all the time. Again, the meter can do this, thus enabling consumers to make wise energy decisions.

There is a smart grid task force instituted thus far. Under this, 14 pilot projects have been approved by Government of India. They are being implemented at different districts and PGCIL is providing the consultancy in about seven states.

- Rouhan Sharma

 
Advertise Here [728 W x 90 H pixels]