Feasibility Studies for the Extraction of Energy from Current and Haliohydro-Grvity along Pakistan Coast

Abstract

This is the second and final report of the two years project “Feasibility studies for the extraction of energy from currents and Haliohydrogravity along Pakistan coast”. Sponsored by PSF. A world wide major renewable source of energy is the energy of transport of water currents. River currents, tidal currents and ocean currents are some well-known aspects of water currents. Generation of useful power has historically been accomplished by harnessing river currents. Wherever the topography is favourable and desirable most of the sources of hydropower from river currents have almost been utilized by damming rivers to about 25% of their available capacity. The huge amount of energy of transport of water in ocean currents remains hitherto untapped. Not even an experimental power station has so far been constructed although there are good number of ocean currents offering a great potential for energy production. The technology of harnessing tidal currents has not yet been fully developed and put to use. In principle, the transport energy of sea water can be harnesses both from the vertical as well as horizontal motion of water due to ideas where favourable conditions exist. A project entitled “Feasibility Studies for the Extraction of Energy from Current and Haliohydrogravity along Pakistan” under the supervision of Dr .G.S. Quraishee was executed by NIO and sponsored by the PSF for two years. Dr. M. A. K. Lodhi of Texas Tech. university was the project expert. Energy extraction from current involves the installation of long bladed slow-moving rotors in rows, and obtaining energy from their rotation by the force of flow of water. Investigations in each of the 15 creeks were designed to collect relevant field data such as currents in the flood and ebb tides from the selected places, depth, topography of the bottom, composition of the bottom, salinity, temperature, turbidity of water a dimension of the usable part of the creeks. Result have been calculated and show high and worthwhile potential in all the creeks. Estimates range 1 KW to 467 KW from one rotor. The potential for installation of rotors defers widely. Korangi and phitti creeks have prohibitive limitations. Suitability will depend upon energy potential and ease of access and installation etc. A network of creeks system formed over a period of time due to the flow of the Indus River into Arabian Sea. This creek system is spread over a distance of about 170 Km in the south-east of Karachi along the coast of Pakistan (see Fig.1). these creeks meander about 50-60 km inland where sea water flows into them with high velocity during the high tide. With the results estimated for tidal power in the Indus deltaic region it seems a power station of about 900 MW could be estimated to serve the neighbouring population in Pakistan. It is time for energy planners in Pakistan where energy is short of supply and cost high, to focus their attention on mining the sea for energy. Energy from Haliohydrogravity involves high evaporation rates in semi enclosed bay/lagoons to erect the necessary installations. Initially three sites, Damp, Kalmat Khor and Gwadar Bay were chosen for obtaining scientific data. At two sites namely Miani Hor and Gwadar Bay evaporation tank and necessary instruments were installed. Observations made at these sites indicate very promising potential. This brief case study of creeks on Pakistani coast indicates the feasibility of extracting energy from tidal plant in this unique environment is quite favourable from scientific technological and economical points of views. At least a test project power plant in one of the creeks, say Chhan Waddo creek, should be built to test the concept.