Indian innovator harnesses sea waves for power

An Indian innovator has come up with a technology that tweaks gravity power to harness sea waves for clean and affordable energy, a source more readily available than wind or solar power and, unlike fossil fuels, inexhaustible.

The non-polluting technology, aptly named 'Gravity Power House' (GPH), is an offshoot of Gravity Power Tower, (GPT) both conceptualised, designed and developed by B. Rajaram, alumnus of the Indian Institute of Technology-Kharagpur, which have also been granted US patents in May 2010 and October 2011.

The technology is based on a simple concept, the conversion of kinetic energy, which an object or medium possesses owing to its motion, into potential deliverable energy to drive wheels on road and rails. Some of the most visible examples of gravity power are water-driven turbines to produce electricity and huge slings that hurled 150-kg projectiles 300 metres away to breach enemy defences, in ages gone by.

"Steady supplies of coal, river water, uranium and thorium for nuclear, hydro and thermal power plants cannot be guaranteed all the time. Wind or solar energy have climatic limitations. Only gravity and sea alone are inexhaustible, unlike other raw materials," Rajaram told IANS from Hyderabad.

The World Intellectual Property Organisation (WIPO), Geneva, a United Nations agency, also approved and published the patent specifications for GPT. WIPO has been set up to encourage creativity and innovation and to protect intellectual property rights, globally.

Delegates at the Paris Conference on Transportation in May 2011 debated whether GPT could be tweaked to harness sea and show a way out of the current energy crisis. The Fukushima nuclear disaster in March last year, the worst since Chernobyl, also cast doubts on the future of nuclear energy. Besides, solar, wind and tidal energy, which require heavy subsidies, were not making much headway.

Accordingly, Rajaram outlined the concept at the Paris Conference. He told delegates that the non-polluting technology would deliver power round the clock, without being dependent on land or heavy investment, nor generate harmful byproducts tied with thermal and nuclear plants, nor upset coastal ecosystems.

"K. Kasturi Rangan, member, Planning Commission, has also backed my proposal on gravity power house, affirming its scientific validity but raised queries about the delivery mechanism. I subsequently configured the engineering equipment as a floating module to provide clean energy," Rajaram told the IANS.

The basic unit of the GPH is a dome-shaped sub-module, with a built-in water turbine.

Driven by the cyclic motion of sea waves in the shallow region, the turbine's twin cast iron masses capture their kinetic energy and work to transmit them continuously to drive the generator, to produce electricity. Each dome, anchored to the sea and housed in a steel and plastic structure, has a two-by-two metre base and a height of 12 metres, said Rajaram.

Five such domes, estimated to cost Rs.10 lakh each, make up a single floating module which delivers a minimum of 100 kw during commercial production. Dozens of modules, anchored at a depth of three metres in a straight line, within 50 to 100 metres of the shore, will make up a gravity power house. Every 100-metre section can deliver between one and five megawatts of power. If required, the GPH can be towed away to another location.

These floating modules will have gaps between them to permit free movement of the fishing boats and sea water. Using even a sixth of India's 6,000 km shoreline, GPHs could potentially generate 100 gigawatts of power at a cost of Re.1.60 per unit. A typical 200 MW plant will cost about Rs.1,000 crore. The moment the module is floated, it starts generating power.

The prototype for the first commercial unit is expected to cost Rs.50 lakh, which covers the development, testing and standardisation stages for production, which might take between three and six months. Bids have been invited for the proposal, which will close by Jan 31.