Charting India’s wind resource under Anna Mani’s leadership (1982 – 2008)

Chennai, Bengaluru, Pune… everyone working in the wind industry knows these major global wind energy hubs, via the presence of R&D and manufacturing sites of turbine manufacturers.

Fewer know that they are home to Wind & Site pioneers, who worked for decades establishing one of the largest database of field measurements with several hundreds of met masts, via a program led by the legendary meteorologist Anna Mani (1918-2001), and that these studies preceeded by far the installation of turbine manufacturers in the region.

For writing this article, I relied primarily on written material and testimonies from Ramesh Muthya who has been working with Wind & Site studies in India since 1979. As detailed below, under the leadership of Anna Mani, Ramesh led the Indian Institute of Tropical Meteorology (IITM) Field Research Unit (FRU) program, including: hundreds of measurement campaigns, flow modelling testing and validation, training courses, and the Indian Wind Atlas – released in 2010 after years of turmoil.

An overview of my primary sources is provided below:

• Interview of Ramesh Muthya (April 2026), and written material received from Ramesh in a document entitled “March of Wind Power through the formative years to present”. Quotes from this document are marked in italics.
• Article by Ramesh Muthya: “Wind resource assessment in India: a program with a difference” (2007)
• National Aerospace Laboratories (NAL) and other internet archives

The main actors mentioned in the present blog article are shown in the below figure. Many more people were of course involved, and I look forward to updating this article after receiving more detailed and accurate information. Do not hesitate to suggest updates and corrections in the comments section, or by contacting me directly!

The story streches over several decades, and I thought it was important to try and summarize it in the below timeline. All details are provided below – bear with me 🙂 Four main periods have been identified:

1. The post-independence period (1948-1964), where the work of P. Nilakantan pioneered wind energy studies in India.
2. A short period after the 1970s oil crises with renewed interest for wind power at NAL and the involvement of Anna Mani, retired from the India Meteorology Deparment (IMD) from 1976.
3. A long period starting in 1982 with the establishement of the Department of Non-conventional Energy Sources (DNES) and the creation of the Field Resarch Unit (FRU) – a joint effort betwen NAL and the Indian Institute of Tropical Meteorology (IITM) – and finishing with the departure of Ramesh Muthya for the Centre for Wind Energy Technology (C-WET) in 2002.
4. The period post-2002, until the publication of the Indian Wind Atlas in 2008-2010.

Part1: the post-independence period (1948-1964)

P. Nilakantan was the funding director of the National Aerospace Laboratories (NAL) from 1959 and until his passing in 1964. He worked on wind development initially centred on water-pumping machines and small-turbine testing. At a UNESCO conference in New Delhi in 1954, Nilakantan argued that harnessing wind required observations beyond those routinely collected by the India Meteorological Department (IMD). His 1961 United Nation conference paper explains that India’s wind-power programme should focus on simple, inexpensive, locally manufactured windmills for rural water pumping. Because winds are generally moderate, it recommends multi-bladed pumps and small 1-5 kW generators, while adapting designs to withstand cyclones and thunderstorm squalls.

• P. Nilakantan, “Some considerations in the choice of areas for preliminary wind power surveys in India.” In Wind and Solar Energy: Proceedings of the New Delhi Symposium, UNESCO, 1956, beginning p. 38.
• P. Nilakantan, K. P. Ramakrishnan and S. P. Venkiteshwaran, “Windmill types considered suitable for large-scale use in India” (1961). UN Conference on New Sources of Energy, Rome.

NAL also investigated wind conditions, and derived wind map. From R. Muthya: [the below] map was based on the meteorological observations from IMD’s network of observatories which were few and far apart. At the same time they had recognized that it was not practical to depend just on IMD records when it came to wind energy. […] NAL’s wind power research came to an abrupt end when the laboratory had to concentrate on aerodynamics pertaining to aircrafts and space technologies. Wind power development was discontinued after this major shift in the laboratory goals till 1977.

Part2: Post oil crises in the late 70s

Following the oil crises, NAL was tasked to resume their investigations. From R. Muthya: by early eighties NAL had conducted long term wind surveys for Karnataka Government and at this time under the guidance of Dr. S. K. Tewari. An example of such survey is shown below, with a met mast installed in Tala Kavery, Madikeri district set up in 1981.

I may be wrong, but I think I found the location using Google Earth, it’s at {12.3820°N,75.4929°E} – could it be there?

Some of Dr Tewaris’s publications are listed below:

• Tewari S.K. and Srinath L.S. A system approach towards utilization of wind energy. A preliminary study, National Aeronautical Laboratory, Bangalore, 1975.
• Tewari, Sharat K. “Economics of Wind Energy Use for Irrigation in India.” Science 202, no. 4367 (3 November 1978): 481–486.
• Tewari S.K., Narasimhaiah and Somraj A.C. Wind energy availability at some locations in India. National Aeronautical Laboratory, NAL-WP-TB-1, 1980.
• Tewari S.K., An analysis of the appropriateness of wind and other energy systems for irrigation, water pumping in India, Agricultural Water Management, 4, 445–455, 1981.
• Tewari S.K. et al. Large scale generation of electricity using wind energy, some possibilities in India, National Aeronautical Laboratory, Tech. Note No. TN-57, 1981.
• Tewari S.K. The wind, its structure and measurement. Notes on Wind Energy Systems, Indian Institute of Science, Bangalore, 1982.
• Tewari S. K., 1985. Preliminary wind survey and recommendations for DNES wind monitoring project. Proj. Doc. WE 8507, National Aeronautical Laboratory.
• Tewari S. K., 1982. Recent Trends in Wind Energy. INSDOC, New Delhi.
• Tewari S. K., 1982. The wind, its structure and measurement. Notes on Energy Systems. Indian Institute of Science, Bangalore.

Other NAL publications include noticeable works from Roddam Narasimha (arasimha was awarded India’s second-highest civilian award, in 2013 for his contributions to advance India’s aerospace technology):

• Narasimha Roddam: The Wind Environment in India. Technical Memorandum DU 8501. NAL, December 1985.
• Narasimha R., 1982a. Wind, its structure and measurement. Part II. Wind data for structural design. Notes on Wind Energy Systems, Indian Institute of Science, Bangalore.
• Narasimha R., 1982b. Note on the history of windmills. Course Notes on Wind Energy Systems, IISc, Bangalore
• Gadgil S., Narasimha R., Savitha B., 1985. An Analysis of the Spatial Variation of Wind Speed over the Indian Region. IISc. Report, 85 AS

Other works include contributions from Udishi Shrinivasa (Indian Institute of Science)

• Shrinivasa U., R. Narasimha and S. P. Govinda Raju, Wind energy potential of Karnataka, Report 78 FM 12, Dept. Aero. Engg., Indian Institute of Science, Bangalore, 1978.
• Shrinivasa U., R. Narasimha and S. P. Govindaraju, “Prospects for wind energy utilisation in Karnataka State,” Proc. Ind. Acad. Sci., C2, 521–544, 1979.

Anna Mani’s involvment with NAL

During those years (very early 80s), Anna Mani who freshly retired from the India Meteorology Department participated to NAL studies on wind power. She was a pioneering Indian physicist and meteorologist whoe studyied physics and conducted research on diamonds and rubies under C. V. Raman. She later trained in meteorological instrumentation in Britain and joined the India Meteorological Department in 1948, where she helped standardise and manufacture nearly 100 types of instruments, contributing to India’s technological independence in meteorology. She rose to Deputy Director-General of the IMD.

Anna Mani is was an extraordinary person, still very warmly remembered. She received the INSA K. R. Ramanathan Medal (1987).

• Mani, M.A., 1982, Meteorological aspects of the utilization of wind as an energy source. Proceedings of Wind Energy Workshop, National Aeronautical Laboratory, 2-21.

• “Anna Mani – A Student Remembers” (C R Sreedharan, 2008)
• “Celebrating pioneer Indian meteorologist Anna Mani” (WMO, 2018)
• “Anna Mani’s 104th Birthday” (Google, 2022)
• “Anna Mani: Marvelous Meteorology” (A World of Women in STEM, 2022)
• “Miss Anna Mani. Interview with Dr Hessam Taba” (WMO, 1991)

The WMO 1991 interview is a must-read, I sincerely recommend it. Some wind-related excerpt below:

At the request of the newly-established Department of Non-conventional Energy Sources, all the available wind data from the IMD stations were published in a third volume, Wind Energy Data for India (1983). Realizing that the meteorological observatories did not give a correct picture of the country’s wind-energy potential, we have since (at the request of the Department of Non-conventional Energy Sources) organized wind measurements at over 600 sites using 20- and 5-metre instrumented masts. The Indian Institute of Tropical Meteorology at Pune has established a field research unit at Bangalore to look after this extensive national programme. Recently we published Wind Energy Resource Survey in India that presents three years’ accumulated data from 21 sites equipped with 20-metre masts (sensors at 10 and 20 m).

Our major tasks at present are to help in identifying potential sites throughout the country for wind farms for the large-scale generation of electric power and to compile a wind climatology over the whole country based on the existing 500 wind-measuring stations plus 500 new ones. In the light of the results of our survey, wind farms that generate over 36 MW of electric power have been set up in a number of states; 50-MW and 100-MW systems are planned for Gujarat and Tamil Nadu respectively, in the framework of a national target of at least a gigawatt of aeolian power by the year 2000.

Part3: Ana Mani and the national program, from 1982

As R. Muthya recalls: At this time S. K. Tewari and Anna Mani (retired from IMD) started discussing a possible wind measurement program to be launched across the country as both of them had clearly understood the pit falls of depending on IMD data.  These thoughts found an echo from the then Department of New Energy Systems (DNES) got into a rethink about the lack of data. The result was that Dr. J. Gururaja and his young and dashing assistant Ajit Gupta got Ms. Mani on board to conduct a wind specific survey and S. K. Tewari became the natural choice for site selection.

As his assistant I took up the implementation end to end. Most of the administrative difficulties were addressed by the pure charismatic power of Miss Mani.  She set up a Field Research Unit (FRU) under Indian Institute of Tropical Meteorology (IITM).  Dr. S. K. Tewari and myself were appointed as consultants to the project of setting up 20 m tall masts in initially four states (Karnataka, Tamilnadu, Andhra and Maharastra).

It goes without saying that setting dozens of up met masts in remote areas of Southern India was not an easy task! R. Muthya recalls walking for kilometers, climbing hills that had leopards and other wildlife to reach the site. Second Wind AL-2000 loggers were used. The first wind monitoring station under this program was set up at Sultanpet near Coimbatore in Tamilnadu.  Miss Mani witnessed the entire process sitting under an umbrella.  Such was her commitment and leadership.

In the first phase of this project 36 monitoring stations were established in four states.  Then more states were added and by early nineties, first volume of wind data for India was published by IITM (FRU) and there was no turning back from then.  With turbine heights growing, the program started using taller masts, more and more sophisticated instrumentation.

Wind Energy Data for India

Statistics from some of these measurement campaigns were compiled together with nation-wide measurements in a series of book, entitled “Wind Energy Data for India“, see the first, 1983 edition below. Its 623 tables compile surface observations from 343 stations and upper-air measurements from 65 stations, including detailed hourly analyses at 37 locations covering wind-speed distributions, persistence, calm periods and energy availability.

Beside A. Manni, the other co-authors include:

• D. A. Mooley: an IITM researcher in monsoon rainfall, droughts and climatology.
• S. Rangarajan: Anna Mani’s collaborator and co-author of Solar Radiation over India (1982), also produced through IITM’s Bangalore Field Unit.
• M. S. Swaminathan: co-authored “Computation of solar radiation from observations of cloud cover” (1984) with S. Rangarajan and A. Mani.
• D. Thomas: Technical analyst at the IITT.
• R. Sasikumar: a scientist working on Solar Radiation Resource Assessment

Introductory chapters explain atmospheric circulation, measurement techniques, Indian wind climatology, wind shear, extremes and gustiness, connecting meteorological knowledge with the practical requirements of wind energy users:

The books included many statistics such as wind roses and diurnal and monthly mean wind speeds:

They also included a wealth of details on instrumentation and synoptic meteorology:

Early and mid-90s: a first Wind Atlas attempt

R. Muthya recalls: In early nineties there was a national level effort to create an Indian Wind Atlas.  Quite a few international agencies got into this but finally the program never took off.  In those days the global weather modelling techniques were just being developed and confined to the rarefied scientific environment in agencies concerned with weather research with little connection with on the ground requirements.  Some advanced countries did have their own wind atlases and there was certainly some peer pressure coming on. 

Then two major factors influenced the next steps.  One was development of PC based wind analysis programs started appearing in the market and they were very primitive.  It was also a time when personal computer (PC) was becoming more and more popular as compared to main frames.

After testing the microscale flow models MS Micro (14 floppy disks, they would be corrupted by the time they reached us from Canada), and NOABL (with practically no help files or any recourse to any consultation) Ramesh and his team settled on Risø’s WAsP which was the best suited software, and included a responsive technical support team.

With DANIDA funding, a 4-days WAsP workshop was organised in 1996, with the visit of Lars Landberg and Niels G. Mortensen, with 24 participants, primarily from heavy industry (the principal turbine owners at the time), national agencies, and a few consultants.

In part due to restriction to accessing and sharing orography datasets, the FRU idea of a Wind Atlas for India did not materialise at that time.

R. Muthya: I realized that the Indian Wind Atlas was not coming any time soon.  Instead of depending on the top-down approach, satellite images, DTMs, creating mesoscale flow fields and so on, I thought it may be a good idea to use WAsP to calculate wind resource grid around each mast data point.  Subsequently I would also collect electrical grid availability information, type of land use patterns and possibility of making a preliminary assessment from wind power point of view.

I made this proposal to Ajit Gupta, who was by then heading the wind program at MNES.   He saw the merit in the idea immediately and got the project going for a hundred locations. Dr.Rangarajan who took over from Miss Anna Mani the mantle of running the IITM, FRU was tasked to front end the project management.  Looking at the magnitude of the work and perhaps have more people working on such ideas the ‘micro-survey’ reports that were location specific was born.  Hundreds of such reports were created by a number of consultants and early developers probably found them quite useful. Quite a few new wind farms did come up in the suggested areas and capacity.  These reports were provided in Hard Copies to concerned State Nodal Agencies who were to share them with developers approaching them. I would like to believe that this initiative did help in the initial stages as there was practically no information with prospective developers about a given area. 

Part 4: C-WET and the Indian Wind Atlas (2010)

From 2002, Ramesh Muthya worked at the Centre for Wind Energy Technology (C-WET, founded in 1998). He recalls: during my tenure at CWET the question of not having an Indian Wind Atlas came up several times and found echo even in the Parliament.  By this time we had enough data from across over 500 monitoring stations and the technology of meso scale modelling had reached some maturity level. Finally an expert committee set up for the purpose of evaluating various offers heard the proposals and accepted the offer from Riso National Laboratory.

The first Wind Atlas for India was then published 20 years after its first inception, for many reasons, but not for the lack of measurements!

Aknowledgments

I’d like to thank Ramesh Muthya for his kindness and his time, and the material he shared with me. The history of Wind & Site studies in India is long, broad and adventurous. This article barely scratches the surface, and I hope more stories will follow.

\Rémi