News and Analysis

Utililizing the immense wave power in the world’s oceans could emerge as a possible solution to our energy problems. But utilization of the energy of the oceans has proved to be pretty slow paced- the first wave farm started operations as late as 2007.

Slow Growth

Although government and privately owned energy companies are showing immense interest in generating and buying electricity from such renewable sources, inventors have been filing patents for systems to capture power from the waves since the last two centuries. The overall growth rate of this particular sector is significantly lower than the wind and solar energy.

The commercial challenge poses the main difficulty. The cost at which a unit of power can be produced and sold is the primary factor determining the success of this particular source. The designs have to be worked and reworked to ensure the devices endure the severest of weather conditions, especially storms.

Secondly, these devices have to be towed to the sea by giant vessels that are used for collecting oil. The main problems are with regards to handling these equipments in water and also the availability of such vessels because of the cost competition from the oil industry.

What’s in the market?

Salter’s Duck, known after a Scotland based scientist, is a house-sized, curved, floating canister that are strung together and then tethered to the ocean floor. The canisters (also called Ducks) would follow undulating motion when hit by waves. The installed hydraulic system would convert the rocking and undulating motion to rotational motion, which would in turn drive a generator. Although each duck was capable of powering 4000 average households, the costs associated with the production of electricity were much higher as compared to that from nuclear energy. Subsequent research did lower the prices substantially but lobbying by the ‘nuclear’ group ultimately led to shelving of the project.

The Pelamis, another such device, boasts of lower maintenance costs; ‘hands free’ operation and lowest electricity generation cost in the market. The 140 meter long structure bends sideways when hit by waves generating electricity through the complex make-up of the machinery. A single device is estimated to produce electricity that is sufficient to meet the annual consumption of around 500 average homes.

Aquabuoys, developed by Finareva Renewables, Vancouver, are 25m long tubes that float vertically and are tethered to the ocean floor.  The bobbing motion is used to pressurize the water entering the tube below. Once the pressure reaches a thresh-hold level, the water is released, rotating a turbine and generating electricity. But initial experiments failed. According to the firm, the devices are profitable only if each device generates 250 KW- a capacity that has not yet been realized. Other similar devices are also under tests.

The Oyster, another wave-power device, is very different in operational terms. The device comprises of a big oscillating metal flap (12 metersX 18 meters) installed close to shore. As the waves hit the device, the flap flexes in either direction driving the mechanical parts that pump seawater at high pressure through a connecting pipe to a special generator developed for the purpose. The generator that is positioned onshore can be connected to lots of similar Oyster devices. Each oyster device is expected to generate 600 kW of electricity. The testing is slated to start later this year.

What do we expect?

In the wave energy device market, there seems to be no dearth of ideas or their practical applicability. Developments of devices that can sustain rough weather of the seas and take-on the assault for longer period are the need of the hour and entrepreneurs don’t seem to be holding back. The core idea is to keep delicate devices out of water and build sturdy devices that can take on the sea assault for long. After all it makes much sense to commence utilizing the renewable sources of energy at our disposal as soon as we can!