A Novel, Cost-effective Design to Harness Ocean Energy in the Developing Countries Abstract—The world's population continues to grow at a quarter of a million people per day, increasing the consumption of energy. This has made the world to face the problem of energy crisis now days. In response to the energy crisis, the principles of renewable energy gained popularity. There are much advancement made in developing the wind and solar energy farms across the world. These energy farms are not enough to meet the energy requirement of world. This has attracted investors to procure new sources of energy to be substituted. Among these sources, extraction of energy from the waves is considered as best option. The world oceans contain enough energy to meet the requirement of world. Significant advancements in design and technology are being made to make waves as a continuous source of energy. One major hurdle in launching wave energy devices in a developing country like Pakistan is the initial cost. A simple, reliable and cost effective wave energy converter (WEC) is required to meet the nation’s energy need. This paper will present a novel design proposed by team SAS for harnessing wave energy. This paper has three major sections. The first section will give a brief and concise view of ocean wave creation, propagation and the energy carried by them. The second section will explain the designing of SAS-2. A gear chain mechanism is used for transferring the energy from the buoy to a rotary generator. The third section will explain the manufacturing of scaled down model for SAS-2 .Many modifications are made in the trouble shooting stage. The design of SAS-2 is simple and very less maintenance is required. SAS-2 is producing electricity at Clifton. The initial cost of SAS-2 is very low. This has proved SAS- 2 as one of the cost effective and reliable source of harnessing wave energy for developing countries. Keywords—Clean Energy, Wave energy I. I. INTRODUCTION ESPITE technological advancement in the petroleum extraction, discovery rates of new oil reserves are falling every day. The world is using its remaining oil reserves at a prodigious rate. One reason for the increased demand of oil is the gradual increase in world population. The huge burning of fossil fuels has introduced the world with a new problem of global warming as well. The need for clean and continuous source of energy has emerged the need to explore new methods for harnessing energy around the world. There are many wind and solar energy farms built across the world but the problem is still persisting. Oceans cover almost 70% of the earth surface and they contain a tremendous amount of energy. A rough estimate concludes that there is 8,000-80,000TWh/yr or 1-10 TW of wave energy in the entire ocean [1]. This enormous amount of energy is enough to alleviate the problem of energy from the world. In the last two centuries, inventors have proposed many ideas for utilizing wave energy. The research in this field gained popularity after the oil crisis of 1973. In the same decade Stefan Salter made the most efficient wave energy device. The idea of wave energy lost its strength in early 1980s, when petroleum prices declined. The idea of harnessing wave energy has centralized the world again because now oil crisis came with a threat call of extreme global warming as well. Although developed countries have induced a heavy amount for the development of new projects but the developing countries are still dealing with their economic crisis. Now days, Pakistan is also facing the problem of energy crisis. The energy crisis in Pakistan results in heavy load shedding. Pakistan has about 1000 km long coastline [2]. The presence of strong waves along the Makran coast predicts the future of wave energy utilization in Pakistan [2]. A rough estimate shows that the wave energy density in some region near the Pakistan coastline is 15kW/m2. Although this energy density is very low comparable to other locations in world but still it can solve the problem of power shortage of a big city like Karachi. This paper intends to provide a brief introduction about wave energy, its importance and in the end a new wave energy device named as SAS-2 is also presented. SAS-2 Patent (Patent#149/2011) has been filed in the Intellectual Property Organization (IPO) of Pakistan. It is basically a continuation of work carried out at Pakistan Navy Engineering College, NUST. SAS-1 is also a successful device and it contains a linear generator. SAS-1 was a successful device but the results obtained from it were not good because of an inefficient linear generator. SAS-2 is made to operate in shallow water. It contains a rotary generator. The results obtained from SAS-2 are very good and also the money invested on it is very low. SAS-2 has proved itself as a successful cost-effective wave energy converter. SAS-2 is in its early development stages. It is expected that further research on SAS-2 will lead this device as one of the successful wave energy conversion device. II. II. OCEAN WAVE PHYSICS Like other waves, ocean waves are caused by the disturbance in medium. This disturbance is due to the wind blowing over the surface of ocean which transfers energy. This energy transfer could be seen as a hump in the medium. In an ocean instead of water energy is travelling at the speed of wave. In deep sea a resting object moves in a perfect circle. The diameter of the circle is equal to the wave height [3]. Fig. 1 illustrates the wave particle motion in deep water. The circular motion of the particles diminishes near the bottom of sea bed. S. Ayub, S.N. Danish, S.R. Qureshi D A Novel, Cost-effective Design to Harness Ocean Energy in the Developing Countries World Academy of Science, Engineering and Technology International Journal of Economics and Management Engineering Vol:5, No:4, 2011 364International Scholarly and Scientific Research & Innovation 5(4) 2011 scholar.waset.org/1307-6892/4970 In te rn at io na l S ci en ce I nd ex , E co no m ic s an d M an ag em en t E ng in ee ri ng V ol :5 , N o: 4, 2 01 1 w as et .o rg /P ub li ca ti on /4 97 0 http://waset.org/publication/A-Novel,-Cost-effective-Design-to-Harness-Ocean-Energy-in-the-Developing-Countries/4970 http://waset.org/publication/A-Novel,-Cost-effective-Design-to-Harness-Ocean-Energy-in-the-Developing-Countries/4970 http://scholar.waset.org/1307-6892/4970 Fig. 1 Wave particle motion in deep water [12] Wave length determines the size of the orbits of molecules with in a wave and the water depth determines the shape of orbits. In deep sea, wave particles move without the loss of any energy. In shallow water the water particles loses its energy due to the frictional effect with bottom. In this region wave particles move in elliptical form. Just near shore the effect of bottom friction increases so much that the crest starts moving faster than its supporting base and a wave break. III. III. WAVE ENERGY The calculation of wave energy is very important in designing a particular wave energy converter. This factor helps us in determining the size of wave energy converter. One important parameter involve in wave energy calculation is wave velocity. A. Wave velocity There are two measures for wave velocity. The phase velocity and group velocity. Phase velocity is the velocity of an individual wave [3], [7]. For deep water (1) Where (2) So (3) Where g is the acceleration due to gravity, λ is the wavelength and T is the time period of wave. The group velocity is the velocity of the packet of waves. In deep water the group velocity is half of the phase velocity. (4) In deep water the velocity of the waves remains constant. As the wave reached in shallow water the velocity of wave start decreasing. In shallow water, the frictional force acting on the wave decreases the wave velocity. B. Energy density and Power density The energy density of the wave is the mean energy crossing a vertical plane. [5],[6] (5) The power density can be found by dividing the energy density by the time period. (6) C. Power per meter of wave front Power per meter of wave front is determined by multiplying the group velocity with the energy density [5],[6]. (7) In terms of phase velocity it can be written as: (8) By using the relation of phase velocity (7) reduces to (9) In term of significant wave height (10) D. Power intensity (Iz) Power flow intensity shows the variation shows the variation in power for the different value of depth for a single wave [4]. (11) Where (12) Z is the vertical downward distance from mean surface water level. I(0) is the intensity of wind at surface of sea. In deep sea 96% of energy is stored within a range of -λ/4