by Ashis Sinha
Researchers at the Indian Institute of Technology Madras (IIT Madras) have invented what they call an “Ocean Wave Energy Converter”— named ‘Sindhuja-I’— can produce electricity from the motion of waves in the ocean.
During the second week of November 2022, the evaluations of this apparatus were finished off with a resounding success. The Device was placed in water with a depth of 20 metres at approximately 6 kilometres off the coast of Tuticorin in Tamil Nadu. Within the next three years, the goal of this gadget is to generate 1 MW of power from the waves of the ocean.
If this project is successful, it will contribute to the accomplishment of a number of goals, including the United Nations Ocean Decade and the Sustainable Development Goals. The accomplishment of deep water missions, clean energy, and a blue economy are among India’s stated objectives. It could assist India in accomplishing one of its climate change-related targets, which is to generate 500 gigawatts of renewable energy from renewable energy by 2030.
The Device is targeted towards remote offshore locations that require reliable electricity and communication either by supplying electric power to payloads that are integrated directly in or on the device or located in its vicinity as on the seabed and in the water column. The targeted stakeholders are the oil and gas, defence and security installations and communication sectors.
Professor Abdus Samad, Department of Ocean Engineering, IIT Madras, who has been working for over a decade on wave energy, leads the mission. He established a state-of-the-art ‘Wave Energy and Fluids Engineering Laboratory’ (WEFEL) at IIT Madras. His team designed and tested a scaled-down model. The lab is also researching other applications for this technology such as producing power for smaller devices for the ocean like navigational buoys and data buoys, among others.
Highlighting the impact of this project, Professor Abdus said, “India has a 7,500 km long coastline capable of producing 54 GW of power, satisfying a substantial amount of the country’s energy requirement. Seawater stores tidal, wave, and Ocean thermal energy. Among them, the harnessing of 40GW wave energy is possible in India.”
The device has been named ‘Sindhuja-I,’ which means ‘generated from the ocean.’ The system has a floating buoy, a spar, and an electrical module. The buoy moves up and down as the wave moves up and down. In the present design, he said that a balloon-like system called a ‘buoy’ has a central hole that allows a long rod called a spar to pass through it.
The spar can be fixed to the seabed, and passing waves will not affect it, while the buoy will move up and down and produce relative motion between them. The relative motion gives rotation to an electric generator to produce power. In the present design, the spar floats, and a mooring chain keeps the system in place, he informed.
Professor Abdus said: “The Ocean is harsh. There are forces — tidal, waves, wind, tsunamis, cyclones, etc. Sea water is corrosive, and there is an issue of marine algae growth on the machine element. The installation needs special skilled persons like divers. Deploying and maintaining this device in the ocean is also challenging. So, when we design any system, we need to consider all these factors. Finally, the whole task becomes expensive.”
“Also, the wave energy system concept came up about 100 years ago. The idea of generating electricity from sea waves is not new, but the challenges are how you develop the technology and make the system feasible, cost-effective and reliable,” he added.
This device is targeted towards remote offshore locations that require reliable electricity and communication — either by supplying electric power to payloads integrated directly in or on the device, or located in its vicinity as on the seabed and in the water column. The targeted stakeholders are the oil and gas, defence and security installations, as well as the communication sectors.
IIT Madras and a Visakhapatnam-based startup titled Virya Paramita Energy (VPE) have a joint development agreement to commercialise the technology.
About the technology and its Function
A press communiqué issued by IIT-M stated that “the system has a floating buoy, a spar, and an electrical module. The buoy moves up and down as the wave moves up and down. In the present design, a balloon-like system called a buoy has a central hole that allows a long rod called spar to pass through it. The spar can be fixed to the seabed, and passing waves will not affect it, while the buoy will move up and down and produce relative motion between them. The relative motion gives rotation to an electric generator to produce power. In the present design, the spar floats, and a mooring chain keeps the system in place.”
Professor Abdus explained the technological function: “Our system has a buoy with a central hole like a doughnut. When waves come, the buoy moves up and down with it. Now a vertical rod passing through the hole touches the sea bottom and does not move with the wave. Hence, we get relative motion between the rod and the doughnut. We put a rack and pinion system so that when the buoy moves up and down, the pinion (wheel) rotates. The wheel transfers power to a generator to produce electricity. I have a few relevant patents on wave energy. The present design will be filed shortly,” he added.
Sindhuja-1 comes from invention and rigorous academic research. Suman Kumar, who completed his Master of Science (M.S.) under Professor Abdus, left his lucrative corporate job and joined his team to develop a wave energy system. Besides him, Prof Samad’s team has four PhD scholars working on different aspects of developing the product — study of ocean waves, cost aspects, design and deployment, and numerical analysis.
“We are considering all the known aspects before designing the systems. We feel our system is robust because we tested it in the ocean when the Indian Meteorological Department (IMD) reported a red alert weather prediction, and the system produced power,” he said.
