Technology Projects > Energy and Fresh Water > Introduction
Introduction
In the times when continuous use of non-renewable energy resources is upsetting the ecological balance, the world has started to increasingly focus on renewable energy resources. The energy and fresh water group of National Institute of Ocean Technology, focuses on harnessing energy from the ocean in the form of waves, seawater currents and ocean thermal gradient to generate electricity and desalinate sea water. The mandate of the group is to develop cutting edge technologies which can produce fresh drinkable water and generate electricity from ocean.The large Indian coastline makes it important to harness ocean energy and find suitable technologies onshore and offshore for augmenting depleting water sources through desalination. Development of technologies for Low Temperature Thermal Desalination (LTTD) using coolant water discharge from thermal power plant and offshore deep sea cold water, wave energy conversion using floating devices such as navigational buoy, marine hydrokinetic turbine development, heat exchangers for LTTD and turbines for Ocean Thermal Energy Conversion (OTEC) are the focal areas of research.
Past major completed projects
- Oscillating water column based wave energy powered desalination plant at Vizhinjam
- Establishment of LTTD plants in Kavaratti, Agatti and Minicoy Islands
- Demonstration of barge mounted LTTD plant of 1 MLD capacity offshore in deep waters
- Establishment of LTTD plant at NCTPS, Chennai using power plant condenser reject water
- DPR preparation of 10 MLD offshore desalination plant
Projects underway:
- Development of turbines for harnessing energy from OTEC /Wave energy/Ocean currents which could be stand alone units or used to power LTTD plants or small loads
- Establishment of an OTEC powered desalination plant of 100 m3/day capacity at Kavaratti in U.T. Lakshadweep.
- Installation and commissioning of a 2x1 MLD LTTD plant using condenser reject heat in Tuticorin Thermal Power Station for producing the drinking and industrial quality water
- To install a floating wave powered device to power loads or to meet the lighting requirements of coastal areas or remote locations
Overview of Projects:
The group has been working on the floating wave powered device called the backward bent ducted buoy (BBDB) and recently on wave powered navigational buoy (WPNB). Several numerical and experimental studies and open sea trials off Chennai were conducted which led to successful power generation with improved performance. The technology for WPNB has been transferred to industries. The team has developed a small ocean current turbine for harnessing kinetic energy from seawater bidirectional currents as in tidal streams which was demonstrated in Macpherson Strait in Andaman. All the sub-components in wave and current energy were indigenously designed and locally fabricated.The open sea testing has paved the way for scaling up for off-grid units for remote locations.
The group has been extensively working on desalination utilizing the ocean thermal gradient by a process called LTTD. LTTD plants were successfully demonstrated and are in operation in various Lakshadweep Islands. For scaling up of technology for mainland requirements, the group also demonstrated an experimental floating barge mounted LTTD plant off Chennai of 1 MLD capacity. Now a design for 10 MLD offshore desalination plant is ready. The technology has also been demonstrated in a thermal power plant using the condenser reject water having a higher temperature than ambient at North Chennai Thermal Power Station (NCTPS) plant and demonstrated successful.Following the thissuccessful demonstration, a 2 MLD plant using the condenser reject heat will be shortly setup in Tuticorin Thermal Power Station to produce drinking water and boiler feed water
Using the OTEC cycle for powering the desalination plant, is the most suitable and reliable alternative that uses environment friendly energy resource, thus reducing the carbon footprint and diesel usage for islands. A new LTTD plant powered with OTEC is being set-up in Kavaratti.
The group has set up a state of the art laboratory for carrying out studies on various components of OTEC and Low Temperature Thermal Desalination (LTTD) inside NIOT campus. Various modes of separate and combined cycles of LTTD and OTEC can be tested in this laboratory.
