Ocean Wave Energy Generator, IIT Madras: Researchers at IIT Madras have developed and deployed a system that could generate electricity using energy from seawaves.The system, dubbed Sindhuja-I, was deployed by the researchers about six kilometres from the coast of Tuticorin in Tamil Nadu, where the sea has a depth of about 20 metres. Sindhuja-I can currently produce 100 watts of energy. It will be scaled up to produce one megawatt of energy in the next three years.
“Currently, if you want to power a city like Chennai or a small part of it, it would be very expensive to do it with wave power and it would be much cheaper to use conventional energy sources. But for remote applications like on island and offshore locations, the cost of transporting power over the sea could be higher than generating electricity from waves at the location,” Abdus Samad, who led the research, told indianexpress.com. Samad is a professor at the Department of Ocean Engineering at IIT Madras.
The Sindhuja-I system consists of a floating buoy, a spar and an electrical module. The buoy moves up and down as the waves oscillate up and down. There is a hole at the centre of this buoy that will allow the spar to pass through it. The spar is fixed to the seafloor to ensure that the waves don’t move it. But when the buoy moves and the spar doesn’t, the waves produce a relative motion between both. This relative motion is used by an electric generator to produce power.
But building such a complex system at an offshore location comes with its own set of challenges. For example, the amount of energy generated from wind energy fluctuates over the course of the day and over the course of the year as the climate changes.
“During different seasons, wave height and period change. It is okay if the system does not produce energy when the weather is calm. But what is important is to make sure that the system can endure rough weather because there is no point investing so much in a system if it gets washed away during difficult weather,” explained Samad.
This is also why the researchers tested the system in November when IMD (India Meteorological Department) issued a red alert for districts in the state of Tamil Nadu. “We were very happy to find out that our systems worked very well and did not get badly affected by difficult conditions,” he said.
Right now, there are no devices using the power generated by the system as it is still in its infancy. The research team plans to deploy a remote water desalination system and a surveillance camera at the location by December 2023. It also plans to conduct further testing to help understand how to deal with power generation fluctuations caused by weather events.
This wave energy system comes at a time when there is increased global attention for the potential of using waves to generate electricity. In January this year, the US Department of Energy announced a $25 million grant to companies demonstrating technologies that can harness waves to generate electricity. The European Union also hopes to generate 10 per cent of the region’s power demand through ocean energy by the year 2025.
While the IIT Madras researchers wave energy generation device uses a technology called “point absorber wave energy converter”, it is only one of the many such technologies being developed by companies around the world. Islay LIMPET, the first grid-connected wave energy power device in the world deployed in 2000, uses a shoreline device that uses “Oscillating Water Column” technology to generate power. It was later decommissioned in 2018. But Samad believes that such grid-scale technology is still a distant dream for Indian shores.