Tidal Energy Potential in the Center Zone of the Colombian Pacific Coast

Introduction: Tidal energy is evidencing interest worldwide because it can be accurately estimated due to the cyclical behavior of the tides. This energy can be extracted from differences in sea level height through the use of gates and turbines of a reservoir (tidal power plant), or extracted from tidal currents through a grid of reversible horizontal axis microturbines as proposed in this study. Thus, the Colombian Pacific region has the opportunity to implement microturbines in strategic areas with the challenge of optimizing them to extract energy with local tidal heights up to 4 m and current velocities up to 1.5 m/s. Objective: Calculate the energy potentials from tidal currents in the central zone of the Colombian Pacific coast obtained through hydrodynamic modeling (Delft3D) validated it with in situ information. Methodology: The present study starts from level 1 of technological development (Technology Readiness Levels, TRL) till reaching the TRL 2. Then, the research performed a documentary review of national and international experiences related to tidal energy, evidencing the great opportunity that Colombia has to take advantage of this type of energy and join to the growing international interest in the development of clean and renewable energies. In addition, this study characterized the tidal heights and did calculations of energy potentials from tidal currents in the Colombian Pacific derived from hydrodynamic modeling (Delft3D) validated with measured in situ data. The results of this study encourage the application of these technologies in Colombia and represents a contribution to the fulfillment of the UN sustainable development objectives (Affordable and non-polluting energy, SDG 7). Results: From the 4 analysis points, the point B (Buenaventura) registered the highest accumulated potential for electricity generation per month (31,546.56 Wh / month). The maximum tidal heights at points A, B, C and D during 2018 were 1.88 m. Furthermore, the mean velocity range at points A, B, C and D was 0.28 m/s to 0.54 m/s, and the maximum velocity for these points were 0.54 m/s, 0.49 m/s, 0.31 m/s and 0.28 m/s respectively. Then, by means of 5 tidal microturbines with a reversible horizontal axis of 1 m sweep area for the point of highest potential (B), it is possible to generate electrical energy to meet the electrical consumption of a house, and with 544 microturbines the consumption of 99 houses. The tidal farm (544 microturbines) would require an area of 2079.36 m2 (e.g. 45.6 m x 45.6 m) and an average depth of 5 m; these requirements are feasible to be met because of the study area characteristics. Conclusions: This research determined the tidal energy potential in the central zone of the Colombian Pacific for 4 points of interest, (A, B, C and D) and the highest potentials were found in points A and B located in Bahía Málaga and Buenaventura respectively. In addition, the minimum velocities, the duration of these and the diurnal tidal regime (12 h) were analyzed, and it was found that points A and B showed the lowest times (1 h and 2 h) of minimum velocity, evidencing a capacity of daily electricity generation of 22 h and 20 h respectively. In consideration of the obtained results, this research shows the opportunity to perform studies for promoting the development of reversible horizontal-axis microturbines for the exploitation of tidal energy. The generated energy could be supplied to communities with access difficulties to the electricity distribution network, what would reduce poverty and the emission of Greenhouse Gases (GHG) due to the burning of fossil and plant-based fuels (firewood).   Conclusions: It was determined that the tidal energy potential in the central zone of the Colombian Pacific for 4 points of interest, (A, B, C and D) and the highest potentials were found in points A and B located in Bahía Málaga and Buenaventura respectively. In consideration of the results obtained, this research shows the opportunity performe studies for promoting the development of microturbines for electricity generation from tidal energy. The generated energy would supply to communities with difficulties in accessing the networks of electricity distribution, thus reducing poverty and the emission of Greenhouse Gases (GHG) due to the burning of fossil fuels and of vegetable origin (firewood).