Interview | Prof. Dharendra Yogi Goswami


DTU Times interviewed Prof. Dharendra Yogi Goswami, who was the chief guest at the inauguration ceremony of Invictus 2019.

Can you please tell us more about your journal which focuses on Solar Energy and Heat Transfer?

This journal is the oldest in its field, and I think it is the most prestigious too, I tend to be biased towards it as I am the Editor-In-Chief! But, it is a comprehensive journal which covers many areas that include Solar Resources, Solar Radiation prediction and its modeling for large and small scale use, Solar-Thermal applications like desalination, High Temperature Solar Applications i.e. concentrating solar power to produce fuels like hydrogen, and Photovoltaics. These areas then have many sub-areas which the journal also covers.

Due to the vastness of this journal, I, as the Chief, cannot know everything, so I have team of editors around the world who help me, one in Solar Resources and Meteorology, one in Solar-Thermal Applications, one in Photovoltaics and one in Concentrating Solar Power, and acting under them are 56 other Associate Editors who have done years and years of research and are known as ’experts’ their respective fields. What is published in the journal is results of research that people will hear only about 10 years from their time, because for a research to be applied in a product is time consuming.  

Even though your prime focus remains Solar Energy, are you considering other forms of energy that which may provide the same advantages?

Solar energy is the direct energy that comes from the sun, there are other forms of solar energy which are indirect like Biomass - to produce biofuels, Ocean Energy, Wind Energy and my interest lies in Renewable Energy, the forms of energy which will not be exhausted and will be renewed by nature. My research is in Solar Energy, but my interest lies in the field of Renewable Energy.

What betterment in Solar Energy can be made to make it more efficient?

Be it Nuclear Energy, energy from Fossil Fuels, or Solar Energy; if we are converting it to heat and then to power, it is done by a thermodynamic cycle, and in a thermodynamic cycle, a part of the heat needs to be rejected and hence the efficiency of the process is anywhere from 10-15 percent to at most 50-55 percent. The remainder energy is rejected in to the environment. We are looking into ways where that rejected energy can also be utilized. I developed a thermodynamic cycle which is known as the Goswami Cycle, where the energy that is dissipated is utilized to give some other output for example, it can be used for desalination i.e. converting the sea water to fresh water, as the temperature required to do so is very low. In my cycle we use it to produce cooling.

After I developed this cycle, people started to look into other possible outputs that can be obtained from the dissipated energy. This is when you convert sunlight to heat and then heat to power, but that is not the only way to convert sunlight into power. There is another method of conversion that is known as Photovoltaics i.e. the direct conversion of sunlight to power and its limitation comes with the bandgap of the material. All the Photovoltaic Panels that are available on the market have an efficiency of 22 percent, whereas the panels that have been developed in labs have an efficiency of over forty percent. The third way of conversion is by using the wave nature of light, with the help of nano-scale antennas. The theoretical efficiency in this method is around 80 percent. So, the efficiency is only increasing. Even in the thermal processes, the energy which was supposed to be rejected can now be utilized with the advancements in research.      

We would like to know more about the incident that pushed you to work in the field of Solar Energy and how important the motive for the researchers to enter that field is.

During my there were many areas that were considered very important, and I could have gone into any of those. But, just because of the oil embargoes imposed by the Arab countries, there was a shortage of Petrol or Gasoline in the western countries. There would be huge lines for buying gas for the vehicles. Upon seeing this, I thought to myself if oil was the future source. It led to a chain of thought, ‘Oil comes from the ground, it will end eventually’, in fact if the rate of consumption of oil and natural gas remains the same, it will be exhausted within forty to fifty years. Whereas coal may last for over hundred years. As the time was limited, I started to think of the future sources of energy, and indulged myself with the knowledge of Solar Energy.

If you have the motivation, and a certain reason to pursue, you become passionate, once you become passionate, you will achieve something big.

What role has DCE played in all that you’ve achieved?

Your first college is where you learn a lot. That is where your basic development takes place. In that respect, DTU or its predecessor DCE, has played a very important role in my life. Not just the education part, but the camaraderie of all the classmates, who were also among the best in the country, as well as the faculty members who guided us. All of that had a tremendous impact on how I developed.

You spend most of your time in the US. How do you think India has changed since then?

There are many welcome changes in India. We’ve moved into the new century, and there’s progress all over. At the same time, India has not kept pace with some of the other countries of the world. For example, around year 2000, India and China were considered to be equal, and yet China has moved so far ahead of India. I don’t know where to put the blame for this, but there is definitely some blame to go around. We need to now start thinking as to how India can take its rightful place in the world in terms of technology, in terms of development, in terms of opportunities for the young people. I met with Prime Minister Modi in September, and I’m very happy to know that he has that vision that he wants India to be not even equal to China but be ahead of China, be among the two or three countries in the world that are the topmost countries. That’s the kind of vision we need, and we also need an action plan to achieve that vision.

Would you like to give any message to our readers?

Firstly, I feel very optimistic seeing the students today, it is nothing like the old times, students are more active given various situations. Students need to take up the entrepreneurship spirit and create jobs for others. Even if five percent of the students do so, they will create jobs for the rest of them!

When I graduated, it was a very small college, although very prestigious in India. There were only 3 departments: Mechanical, Electrical and Civil. The enrollment was fixed: 80 in Mechanical, 80 in Electrical, 40 in Civil, so only 200 students in one batch. It was highly, highly competitive. But now, we have many departments, which is good, and it is a university, so it’s not just an engineering college anymore. Although engineering is still the dominant part, it has other areas also.

Another change is that when we were young, we were missing one thing: almost all of the students were boys. Now you have a mix, which makes life more interesting, because if it’s just a men’s college or just a women’s college, life is not that interesting.

The other thing I like about DTU now is that the university has kept its standards and it is still among the best in the country.

Posted by Mandeep Singh

Almost always avoid alliteration!