With ‘power’ comes responsibility, this saying suits Maharashtra State Power Generation Company (Mahagenco), the second-largest producer of power after NTPC and the largest state power generation utilities in India. Sanjay Khandare, Principal Secretary took over as the Chairman & Managing Director, Mahagenco on August 10, 2020. He is an officer of the Indian Administrative Service (IAS) of Maharashtra Cadre, 1996 batch. He has completed B.Tech in Agriculture Engineering and M.Tech in Industrial Engineering from NITIE, Mumbai. In an exclusive interview, he chalks out the path ahead…
Today even as the country needs to ramp up energy generation, there is no escaping the requirement to be environmentally sustainable. This is more so for Maharashtra, which remains the biggest generator and user of energy. One of the reasons is that it remains the premium industrialised state in India.
Keeping in view the Maharashtra government's Power Sector Vision 2030, Sanjay Khandare aims for a sustainable power sector that will foster socio-economic growth in the region. Under his leadership, Mahagenco was recently recognized as an outstanding contributor in developing social community based green energy projects. The company produces about 13 gigawatts of energy, which includes 9.7 gigawatts of thermal 2.7 gigawatts of hydro 672 MW of gas turbine and 207 MW of solar energy.
To understand the uniqueness and enormity of the vision and work, Dominic Rebello and RN Bhaskar of FPJ spoke with Sanjay Khandare to understand how Mahagenco is operating its power generation portfolio with more responsibility towards the environment and with sustainability.
Chandrapur STPS |
Given below are edited excerpts:
Being the largest generator among the state-owned generating companies you have to produce more to meet the increasing demand for electricity. But you have to be focused on the environment and sustainability as well. How do you manage both demands simultaneously?
When you say that we have to also generate power and that too with the responsibility of sustainability, let me give a brief overview of the generation capacity of Mahagenco. We are the second-largest government owned generating company after NTPC and the largest state utility and we have a very solid mix of generation that is from coal, gas, hydro and solar. In coal power generation, we have the category of subcritical and supercritical that generates 7,560 MW and 1,980 MW of power respectively. Then we have gas that generates 672 MW, hydropower generates 2,580 MW and lastly solar that generates 207 MW. So, it's a very large mix of 13,209 MW and we have to generate this power with responsibility towards the environment and maintaining the sustainability of operations.
A new 660 MW thermal project is underway at Bhusawal because we have power generating units that will be decommissioned because of age and inefficiency. We also have a plan for about 2,795 MW of solar projects, which is in the pipeline.
We have increased our generation from 2005 when we conceptualized our requirements, and have reached 13,209 MW and we support a large path of the Discom’s energy requirements and provide electricity to around 2.5 crore consumers in Maharashtra.
Sustainability has matured and evolved over a period and it is still evolving. The vision given to us by the government of Maharashtra is to generate adequate power for the state on a sustainable basis at competitive rates in a socially and responsible manner. Till 2005, it was a period of power shortages in the state and then we came into the current avatar from that of the former MSEB.
The main objective before us was to generate power because there was a shortage. So there was more emphasis on thermal because that was the only source that was available. By 2015 we set up large subcritical units, and then we became the second-largest industrial company and then there was gradually a shift toward supercritical projects because they are more efficient, they generate more energy using the same resources and they're upgraded designs of boiler, turbine and generators. So, this too is a step toward sustainability.
And from 2015 onwards, the main guiding principles have been about the environment, emissions reduction, fly ash disposal, focusing more on the renewable portfolio, reduction of the water consumption and also recycling it. We also focused on generating power only through supercritical units which are more efficient.
So, I can only say that Mahagenco is an environment friendly and health safety power generating company and which has received various ISO certifications for most power stations.
What initiatives have been taken by Mahagenco to improve operational efficiencies?
For sustainable and reliable power generation it is important to improve operational efficiency. Now, if we operate very efficiently, we will conserve resources and now most of the units are added in accordance with the technical norms specified by the state regulatory commission, CEA. MOEF and CPCB. With regards to sustainable operations, one of our main objectives is to reduce the cost per unit of power, and for this reduction, since coal is the most important source of resource, we have undertaken coal optimization.
Taking various factors into consideration like the supply of coal to all our units, different designs of calorie requirements of each of these units and differentiated rates of coal from suppliers, we have to manage it in such a way that we generate power at the power station in the most optimized way. We have this optimization model, which has helped us to reduce the cost of fuel.
Now, we have also undertaken washing of coal to reduce the ash content and to enhance boiler efficiency. It is also environmentally friendly and helps in making our operations more efficient. We have also undertaken various other initiative improve plant load factor, plant availability, durability etc. The bottom line is that we operate units at maximum availability and at maximum capacities. We also have very unique flexibility of operations which allows us to transfer supply of coal under our coal to a more efficient unit should the need arise.
We are one of the few utilities which uses flexibility and we get the advantage of fixed costs returns because we have been able to reduce the variable cost of generation. We reduced such costs by 35 to 40 paise that is a 12 per cent reduction in the year 2021 as compared to the year 2020. We have also undertaken the use of a pipe conveyor system for the transportation of coal. This helps in significant reduction in air pollution and coal dust which can fly around in open conveyor systems. For example, earlier 170 trucks would transport coal everyday from Bhatadi Coal Mines. But with the installation of a power conveyor system coal is now transported from Bhatadi coal mines to Padmapur Wagon Loading station. We are also in the process of installing another power conveyor system from Koradi for our main power station. These things help in protecting the environment.
One of the areas of your focus is to increase your share of renewables in the electricity basket. How do you plan to achieve this?
This is a very pertinent and most pressing issue for everyone, basically as their inputs are renewable. The government of Maharashtra has given us a very aggressive vision for our sector and it has given four principles.
The first principle is improving operational efficiencies by way of digitalization. Efficiencies in the coal value chain, Asset performance management and station heat rate optimization.
The second principle is leveraging new and clean technology. So, here come the use of renewables and solar. There are advanced, mechanisms of floating solar where water bodies are used instead of land for solar power Then we have offshore wind plants, hybrid solar and wind RE storage, renewable energy generation along with the storage and solar mechanics.
The third principle is the seamless integration of RE with the grid. This is very challenging and complex for discoms. Utility-scale of battery storage and then flexibilisation of thermal power plants.
And the fourth is digital orientation. We have deployed advanced technologies such as smart appliances, analytics, machine learning, robotic process etc. This vision is for the future where we have to scale up efforts for capacity addition mainly in renewable energy, then, to achieve higher efficiencies as well as flexible generation as per the needs, then increasing supply through clean energy sources and profit old renewable energy plans with advanced technology and storage capacity and set stringent efficiency.
Koradi Power Project |
What do you mean by Flexibilisation of thermal power plants?
People may think, why not replace all our thermal power plants with wind and solar energy. The renewable sector is just evolving and we are moving towards more generation of solar power.
But we can't completely do away with thermal power plants not only now, but even for future maybe about 10 years 15 years. We will have to continue with thermal power plants because solar energy is not very reliable, because it fluctuates during the day and then it has also fluctuation during seasons.
So, when there is say more generation by way of renewables then thermal power has to come down. The thermal plant has to be ramped down when a unit is producing at a steady rate of say 50 megawatts and then when renewables increase then our power plants have to come down substantially. This is called ramp-up and ramp-down.
When solar power or renewable energy goes down, during the night or bad season, then thermal power plants have to ramp-up there to increase their production from the base loads. During this process, thermal power plants and their systems, take a hit. Thermal stresses are created and then all the systems have to accordingly operate at this floor base.
Then there is a limit to which is thermal power plants can go below. So, there is a technical minimum percentage at which we can power plants and operate. This is called the flexibilisation of thermal power plants. These thermal power plants have to be prepared for this certain ramp-ups and ramp-downs because of not-so-reliable renewable energy right now. This is another challenge for us.
What is the difference in the cost of solar and thermal power?
A unit of solar power costs much less than the cost of a thermal power unit. Currently, thermal plants are still generating more than solar, but still, we do not have that balance of thermal and solar power. For example, our current generation of thermal is to the tune of 70%.
Now, this will gradually come down to 45% - 50% as solar or renewable sources increase. During this transition, thermal power plants have to accommodate their technology and designs so, that they are efficiently still managing this ramp up and ramp down. So, that is the issue with regard to renewable energy.
In Maharashtra, for example, renewable energy generation is to the tune of 10,000 MW which is less than 25 per cent of our total generation. And in this 10,000 MW generation, wind caters, about 5,000 MW, while solar caters to just about 2,500 MW. And then there is biomass and sugar cane which generate about 2,300 MW and also there are some small hydro units which generate about 500 MW.
So which projects is Mahagenco pursuing to meet the vision of the Maharashtra government?
We have aggressive plans to ramp up solar capacity to 2,795 MW. In 2010 Mahagenco generated only one MW and by 2021 we are generating 207 megawatts. Next year, Mahagenco will have 618 MW power generated from solar. And then the year after that we have a very high target and we are working towards 1,500 MW by way of solar and by 2025 we will have almost 3,000 MW of solar power.
This will be a huge percentage of power coming from renewable energy. Our agricultural pumps normally require power during the day because during the night they are very difficult to operate. But , but right now, because of many constraints, we supply power to them only during the night. So, to work on this constraint, there is this scheme by which agriculture farmers are able to get power at their farms during the daytime and load on the grid will be substantially reduced.
Another is by EPC (Engineering, Procurement and Construction) mode which should get us 600 MW. We also plan to have a joint venture with NTPC for the UMREPP JVC power project. We also have started working towards a floating solar project at Chandrapur and now, our overall target is to achieve 40% of energy from non-conventional sources.
Another very interesting concept which has come now is the funnelling of RE with thermal generation. This is a very innovative scheme which allows us to mix thermal power with solar at the same station or from outside with the same PPA (power purchase agreement). This allows us to install a solar power project in the vicinity of the thermal power project and mix the power thermal and solar in the same PPA. So, this is going to be very, very interesting.
One of the key requirements of a thermal plant is water? It is also something that is crucial to the issue of sustainability. Tell us about your work in this area?
Yes, that is true because thermal power plants actually require a huge quantity of water. As water contains all sort of impurities it is treated with acids and de-mineralised because these impurities cause damage to the boiler system and other systems.
So not only the volume but it also the quality of water matters to us. We need water for steam generation, for cooling of the system which is heated up, for ash disposal system and then for the consumption of our colonies etc. Water to the power plant gets lower priority than say for drinking and agriculture that is as per the national and state board. So the government of Maharashtra has advocated the use of treated sewage water from the Operations Council which has to be used in power plants. This is again the very aggressive pursuit of sustainability coming from the government requires us to reuse water and also to discover new ways of reducing water consumption per unit.
There are specific norms, for example, the government says that what consumption per megawatt has to be three cubics right now, and we are operating at about 3.1 - 3.2 and most power plants operate at this level.
We were the first utility in the country to use municipal sewage water, treat it and use it for thermal plants. We have done it for Koradi power station, Khaparkheda power station and we will do it now for the Chandrapur power station.
The Koradi power station consumes about 65% of treated sewage water. It is a very huge quantity as the water requirement of Koradi power station is almost 202 million litres per day. Due to this, our dependence on dam water has come down by 130 MLD (million litres daily) because we have used sewage water and now this capacity has increased to 190 MLD. So, we will consume 193 MLD of sewage water and use it for our company. That is a very progressive step for us.
One of the biggest pollutants from thermal plants is fly ash? What do you do with it?
Indian coal has a very high ash content. Ash management involves the recognition that if ash if not managed well, it causes pollution,. It causes higher wear and tear of the systems. It also causes public nuisance and we get bad publicity.
For this, we established a separate company Mahagenco Management Services, which was formed with the objective of an innovative and economic use for ash. This ash can be used for bricks and for construction purposes. It can be used for cement production and for road construction, as has been done by some people. The government too has mandated the use of ash in highways, road construction and also in brick-making kilns because of which ash can be better managed. We too have formulated a policy to achieve 100% ash utilization so that it doesn't remain in silos.
Discussions are also underway with potential candidates to establish ash related industries in the vicinity of power stations. Since our power plants are all over Maharashtra – though more power plants are in Vidarbha. At Koradi, Khaparkheda and Chandrapur TPS, the utilization of ash is not as much as desired. Whereas for power plants in locations like Nashik and Bhusawal, 100% utilization of ash takes place. So, there is a challenge related to what to do with ash that is generated in the eastern part of Maharashtra. Hence, we have floated an expression of it interest for those units who want to set up cement plants in these three places and we will have a tie-up with them. So that they use ash for cement manufacturing and consume a lot of ash from our Vidharba region. We have also started another innovative scheme to transport ash from the eastern region to the western region by railway to save on transport costs.
Ash is also a concern as it creates environmental pollution. To overcome that we have a plantation strategy. We have planted bamboo and other trees along the ash bunds so that the pollution is limited to that particular area. We have planted about 20,000 bamboo saplings and the plantation of trees continuously goes on. Also, all the power plants have some of the other plantation [that helps reduce environment stress].
Nashik TPS - Shaktiman |
The other major pollutant in a thermal plant is noxious gases or emissions? How do you deal with this?
Thermal power stations are associated or are synonymous with pollution. Studies show that about 20 per cent of global warming is caused by the emissions of power stations. But now there are very stringent norms that have evolved for emission control. Emission norms have evolved over a period of time and with the availability of technology to control emissions, the emission norms too have gradually changed.
So for example till 2003 the norms for SO2 were 600 to 200 mg/Nm3. From 2017 they have been bought down to 100 mg/Nm3. For NOx till 2003 it was at 300 mg/Nm3, from 2017 it was bought down to 100 mg/Nm3 and SPMs which are the ones that are actually very visible and creates health issues, those norms were 100 came down to 50 in 2016 and from 2017 it is 30.
These are very stringent norms and our power stations meet these norms and it is our endeavour to take very special care to follow these norms. Sometimes people complain that they see a lot of dust or emission coming out from our chimneys that is when we ramp up or ramp down happens.
We operate at a particular level but when we are asked to ramp-up to ramp-down we have to use a lot of oil and that generates a lot of gases some of which are quite visible. It gives an impression that there are very high amounts of emissions. But that is not true it is really the effect of oil being used. When our plant is shut down It needs to start operation then to there will be a rise in emissions but that is for a small period of time. So we are very aggressively following these norms. There are monitoring agencies like MOEF CPCB and MPCB which continuously take our samples and whenever there are violations they give their feedback to us and even charge penalties at times.
Another very interesting but necessary requirement that has come up is in respect of flue gas desulfurisation (FGD). Coal has substantial sulphur content and so far there is no technology to control this emission. Now the government has made it mandatory that all power plants will have an FGD scheme. We have submitted our plans for all the power plants for the implementation of FGD schemes. We have planned a total expenditure of about 5,000 crore which will be spent on managing sulphur emission through FGD technology. This is financially taxing on us but that is necessary for the environment and we are obligated to it.
Chandrapur STPS |
