Students make low-cost lightning arrester, school applies for patent
Times of India | 28 July 2025
Kolkata: An experiment at a school workshop in Madhyamgram is all set to bring down the cost of lightning conductors to less than half and save lives of thousands from being electrocuted in the fields. The lightning conductor, devised by students at Sodepur Deshbandhu Bidyapith (Boys), already passed tests at institutes like Central Power Research Institute and was awarded at the National Children's Science Congress in 2020.
The school has now applied for its patent. The project took off nearly eight years ago with school students trying to devise a lightning conductor from household and garage waste. A thin aluminium sheet is fitted at the edge of a structure that looks like the wheel of a cycle. There are pores on the rim of the wheel, and copper wires are inserted through them as spokes. There is a hub in the middle, and there are threaded holes connected to the wires going inside the earth.
Lightning conductors have sharp edges, which help in converging electric field lines on the lightning conductor more. This further helps reduce damage to the nearby areas from lightning. Also, the lightning conductor's pointed ends help it to acquire more positive charges on its tip. While commercially available lightning conductors have three to four pointed edges, the lightning conductor devised by the students has nearly 450-500 pointed edges.
"When the negative charge is discharged by the cloud, it first strikes the pointed tip of the lightning conductor and quickly travels to the earth. The discharge process gets over very quickly, and a house, people or animals in its surroundings will be saved from damage," said Pashupati Mandal, physics teacher of the school who heads the project.
It costs less than Rs 1,000, while commercially available lightning conductors with one or two pointed ends cost nearly Rs 2,100. "The initial prototype was made at a cost of Rs 350. But we decided to modify that after tests were done at the central laboratories. The modified lightning conductor costs around Rs 1,000. This is at least 10 times more useful and can be installed by anyone. It can easily be purchased by farmers who pay more than double to buy lightning conductors from the market," Mandal said.
Normally, lightning conductors are used at the top of buildings or towers. But this can be put on the field, which is watery and marshy. "So far, we have installed lightning conductors at 40 locations across districts in north Bengal, and we are closely monitoring them," said Ambarish Nag Biswas of West Bengal Radio Club, which is assisting the school in developing the lightning conductor. "There are hundreds of farmers and animals who die every year from lightning. Apart from that, fishermen also use lightning conductors," Nag Biswas said.