Electricity can be generated at very low RPM of the alternator at as low as 4 RPM at 0.6 meter per second (2.16 kilometer per hour) for 12V system voltage with simple rotor-stator arrangement. I have erected a windmill developed by me on roof top in August 2002 and generating electricity for my domestic & office use.

The most optimised Wind mill is of 1000 W (1 KW) rated capacity at 12 m/sec rated wind speed.

Cut-in wind speed – 0.6 m/s for 12V, 1.2 m/s for 24V, 2.4 m/s for 48V system

The power output at 48 volt (4x12V battery) system at 50 feet hub height is as below.

Considering the average wind speed and its duration at any place one can calculate daily generation from above table.

Theoretically / hypothetically this windmill will generate 24000WHr i.e. 24 KWH (24 units) per day. We can say that it will generate anything between zero to 24 units per day totally depending on wind condition. It varies from season to season.

Generation depends on wind availability, its duration & wind speed. It cannot be guaranteed. Wind mill electricity should not be treated purely on cost economics on state electricity billing rates. Why do we think of alternate source? Because the present supply is erratic, scarce and situation is going from bad to worse to worst and more & more costly in future. It can be compared with diesel generator power not only from costing but with all its bad points like pollution, noise, vibrations etc. Direct & indirect advantages should be considered.

• There will be no darkness in the premises.
• Peace of mind and no fear.
• Safety of electrical equipments due to constant voltage supply through inverter.
• Think of cost paid and trouble to get connection from state electricity board.
• The one time investment is like getting a new connection from state electricity board and then free electricity forever (except replacement of batteries).
• No maintenance, no repairs, no fuel or greasing or no recurring expenditure.
• Most eco-friendly, pollution free, least transmission losses, directly from the terrace.
• And many more one can think of. It is like comparison of keeping own car and using taxi instead.

This domestic windmill is erected on roof top on highest point of terrace such as staircase top or RCC water tank slab. The tower requires hardly 2 x 2 feet space. No separate land. If tower is to be erected on ground then hardly 3 x 3 feet space is required for tower base.

• Paper presented on “KW-Range Domestic Windmill Generator Set” at 17th Indian Engineering Congress, Patna, Bihar, December, 2002.
• Paper presented on “Low RPM Aero-Generator” at The Institution of Engineers (India), Nagpur Local Centre on 21, Jan. 2003.
• Paper presented on “Domestic Windmill” at Rotary Trade Fair, Ahmednagar on 27, Jan. 2003.
• Paper presented on “Low RPM Aero-Generator” at The Institution of Engineers (India), Pune Local Centre on 12, May 2003.
• Paper presented on “Low RPM Aero-Generator” at National Design & Research Forum, Bangalore on 30, Aug. 2003.
• Paper presented on “Low RPM Aero-Generator” at The Institution of Engineers (India), Kerala State Centre, Trivandrum on 2, Jan. 2004.
• Paper presented on “Low RPM Aero-Generator” at Indian Space Research Organisation (ISRO), Trivandrum on 2, Jan. 2004.
• Paper presented on “Low RPM Aero-Generator” at The Institution of Engineers (India), Maharashtra State Centre, Mumbai on 21, June 2004.
• Lecture given on “Electricity generation by Domestic Windmill” in Kalidas Kalamandir, Nashik on World Environment Day on 5, June 2004.
• Paper presented on “Low RPM Aero-Generator” at 21st National Convention of Electrical Engineers at Delhi on 10th November 2005.
• Paper presented on “Low RPM Aero-Generator” at “Marathi Vigyan Parishad” Mumbai on 19th January 2006.
• Paper presented on “Low RPM Aero-Generator” on “National Science Day” at NDMVP College of Engg. Nashik on 28th February 2006.
• Paper presented on “Low RPM Aero-Generator” at Swami Ramanand Tirth Marathwada University Nanded on 1st March 2006.
• Paper presented on “Low RPM Aero-Generator” at Jaiprakash Narain University, Chhapra, Bihar on 10th March, 2006.
• Paper presented on “Environmental awareness through use of non-conventional energy resources” at Environmental awareness Workshop at Nashik in 2008.
• Paper presented on “Renewable Energy Sources” at R. C. Patel Institute of Technology at Shirpur on 11th March 2009.

• Details of research & development work appeared in “Sampada” Marathi magazine in Sept. 2003.
• By way of Interview in “Daily Lokmat” in all editions in Maharashtra in May-June 2004.
• By way of Interview in “Times of India” in Nashik Times on 26th June & 16th July 2004.
• Article appeared in Chamber Patrika, a Maharashtra Chamber of Commerce & Industries bulletin.
• By way of Interview in “Loksatta” on 22nd August, 2005.
• By way of Interview in “Daily Lokmat” in all editions in Maharashtra in May 2006.
• By way of Interview in “Business Standard” in all editions in India on 18th May 2006.
• Article published by Ministry of Non-Conventional & Renewable Energy, Govt. of India Magazine “Akshay Urja” in May-June 2006 issue.
• By way of Interview in “Daily Gaokari” in May 2007.
• By way of Interview in “DNA Mumbai English Daily” in May 2007.
• In many more Magazines in India.

• Interview in English on “Kairali” satellite TV channel of Kerala on 8, Jan. 2004.
• Interview in Marathi on “E-TV Marathi” satellite TV channel in its “Samvad” programme on 14, May 2004.
• Interview in Marathi on “Najar Vahini” TV channel, Nashik, on 15,16 & 17, June 2004.
• Interview in Marathi on “Sahyadri Vahini” of Doordarshan in its “Aajche Pahune” (Today’s Guest) on 12th May, 2005.
• Interview in Hindi on “Sahara Samay Bihar & E-TV Bihar” on 12th March, 2006.
• Interview in Marathi on “E-TV Marathi” satellite TV channel as a news item on 28, May 2006.
• Interview in Marathi on “Z-TV Marathi” satellite TV channel as a news item on 26, May 2006.
• Interview in Hindi & English on “CNBC-Awaz & CNBC-TV 18” satellite TV channel as a news item.
• Interview in Hindi on DD National in its “Bhoomi” programme sponsored by the Ministry of Environment & Forests, Govt. of India and produced by Siddhartha Kak (Surabhi) telecast on 6th January, 2007.

• Renewable Energy Award-2003 by Maharashtra Energy Development Agency (MEDA), a Govt. of Maharashtra Undertaking.

• Felicitated by Collector of Nashik on 20th August 2004 on Rajiv Gandhi Akshay Urja Din.
• Felicitation by Central Minister Hon. Oscar Fernandez at 21st National Convention of Electrical Engineers at Delhi on 10th November 2005.
• Felicitation by Ex-Chief Minister and present Speaker of Goa Assembly Hon. Francisco Sardinha at 21st National Convention of Architectural Engineers at Panaji, Goa on 20th November 2005.
• Felicitation by Padmashree Amitav Mallik, National Security Advisory Board Member at Pune Local Center, Institution of Engineers (India), during Energy Conservation Week.
• Felicitation by Shri Uday Nirgudkar, eminent IT Consultant at Computer Society of India Nashik on CSI day on 5th March 2006.
• Felicitation by Shri Janardan Singh Sigriwal, Minister Govt. of Bihar at Seminar on ‘Alternate Sources of Energy’ at Chhapra, Bihar on 10th March 06.
• Felicitation by “Deshdoot” News Paper, Nashik on 4th September 2007.