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Marine Currents Energy Resource Characterization for Morocco
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Energy Procedia 157 Energy Procedia 00(2019) (2017)1037–1049 000–000 Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, www.elsevier.com/locate/procedia 19–21 September 2018, Athens, Greece
Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, Marine Currents Energy Resource for Morocco 19–21 September 2018,Characterization Athens, Greece Salma HAZIMa,b, Ahmed El Ouatouatia, Mourad Taha Janana, Abdellatif Ghenniouib
The 15th International Symposium on District Heating and Cooling Marine Currents Energy Resource Characterization for Morocco LM2PI, ENSET Mohammed V University of Rabat, Avenue des Forces Armées RabatGhennioui 10100, Morocco. Salma HAZIM , feasibility Ahmed El Ouatouati Mourad Taha Janan ,Royales, Abdellatif Assessing the of , using the demand-outdoor Research Institute for Solar Energy and New Energies (IRESEN), Greenheat Energy Park, Benguerir, Morocco. temperature function for a*[email protected] long-term district heat demand forecast LM2PI, ENSET Mohammed V University of Rabat, Avenue des Forces Armées Royales, Rabat 10100, Morocco. a,b
a
a
a
b
b
a
b
Abstract a
Research Institute for Solar Energy and New Energies (IRESEN), Green Energy Park, Benguerir, Morocco.
a I. Andrića,b,c*, A. Pinaa, P. Ferrão , J. Fournierb., B. Lacarrièrec, O. Le Correc *[email protected]
IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
b Over the last two decades, there has been a great interest in marine renewable energy exploitation Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France (70% of the globe are c ocean) due to the limitation of fossil resources and the effect of climate change. The marine current a huge Département Systèmes Énergétiques et Environnement IMT Atlantique, 4 rue Alfred Kastler, 44300energy Nantes,constitutes France Abstract potential of marine renewable resources for producing electricity using a Hydrokinetic turbine. the assessment of the potential resources thedecades, most necessaire adequate location for implementing and choosing Over of thesites last istwo there hasstep beento aselect great the interest in marine renewable energy exploitation (70%theofcorresponding the globe are conversion systems. The main objective of this work is to calculate and map with a high resolution (200 m) current velocity ocean) due to the limitation of fossil resources and the effect of climate change. The marine current energythe constitutes a huge of some Moroccan in orderresources to select for the producing items with electricity high resource potential. In this sense, the the current velocityofwas Abstract potential of marinesites renewable using a Hydrokinetic turbine. assessment thecalculated potential using the 3D dimensions’ hydrodynamic model addition,fortheimplementing accurate dataand of Copernicus center with have resources of sites is the most necessaire numerical step to select the SWAN. adequateInlocation choosing the corresponding been employed with the main SWAN parameters to work perform high potential. The obtained show the of the sites District heating networks are objective commonly the literature one of results the most effective solutions decreasing the conversion systems. The of addressed this isintothe calculate andasmap with a high resolution (200 m)potential theforcurrent velocity selected to facilitate the choice of the adequate technology which can be employed to extract the kinetic energy of the marine gas emissions from to theselect building sector.with These require highIn investments are returned the heat ofgreenhouse some Moroccan sites in order the items highsystems resource potential. this sense, which the current velocitythrough was calculated current. sales.the Due the changed climate conditions and building renovation policies, heat demand the futurecenter couldwith decrease, using 3D to dimensions’ hydrodynamic numerical model SWAN. In addition, the accurate data of in Copernicus have prolonging the with investment returnparameters period. been employed the SWAN to perform the high potential. The results obtained show the potential of the sites selected to scope facilitate the paper choiceis of adequate technology which employed to extract the kinetic energyfor of heat the marine The main of this to the assess the feasibility of using thecan heatbedemand – outdoor temperature function demand current. forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 ©buildings 2018 Thethat Authors. Published by Elsevierperiod Ltd. and typology. Three weather scenarios (low, medium, high) and three district vary in both construction © 2019 The Authors. by Elsevier Ltd. This is an open accessPublished article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were This is an and openpeer-review access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, compared with results from a dynamic heat demand model, previously developed and validated by the authors. Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. © 2018 The Authors. Published by Elsevier Ltd. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications Environment and Sustainability, TMREES18. This an open accessdemand article under the CCthan BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) (theiserror in annual was lower 20% for all weather scenarios considered). However, after introducing renovation Keywords: Marine renewable energy, Potential, current velocity, kinetic powercombination density, Morocco Selection peer-review under responsibility of the scientificmarine committee of Technologies andscenarios Materials for Renewable Energy, scenarios,and the error value increased up toSWAN, 59.5% (depending on the weather and renovation considered). Environment Sustainability, The value ofand slope coefficient TMREES18. increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and Keywords: Marine renewable energy, Potential, marine current velocity, kinetic power density, Moroccoon the renovation scenarios considered). On theSWAN, other hand, function intercept increased for 7.8-12.7% per decade (depending 1.coupled Introduction: scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
2017 The Authors. Published by Elsevier Ltd. 1.©Introduction:
Peer-review under of thebyScientific Committee of The 15th International Symposium on District Heating and 1876-6102 © 2018 Theresponsibility Authors. Published Elsevier Ltd. Cooling. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment Keywords: Heat demand; Forecast; Climate change and Sustainability, TMREES18. 1876-6102 © 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. 1876-6102 © 2019 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. 10.1016/j.egypro.2018.11.271
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Salma Hazim et al. / Energy Procedia 157 (2019) 1037–1049 Author name / Energy Procedia 00 (2018) 000–000
Nomenclature MRE MCE MCED R&D SWAN CMEMS N Cx, Cy σ Ө S P V A ρ
marine renewable energy marine current energy marine current energy devices research and development simulating wave nearshore copernicus marine environment monitoring service local rate of change of action density in time. propagation of action in geographical space (with propagation velocities Cx and Cy in x and y space, respectively) the relative frequency due to variations in depths and currents wave propagation directions source/sink term for: wind-wave generation, wave breaking, bottom dissipation, nonlinear wavewave interactions theoretical power cross-section density currents velocity (m/s) cross section area (m²) sea water density (~ 1025 Kg/m²/m)
The depletion of fossil resources and the acceleration of greenhouse gas emissions indicate a growing threat of climate change that makes the energy issue a global problem. The research of other kinds of energy sources becomes a great interest of all scientific and industrial communities in the world concerned with energy production, consumption and management. This research is not only limited to find new sources but also gives an important interest to get sources that have a weak impact on the environment, such as renewable energies [1]. Many kind of renewable energy resources are in use like wind, water, solar, water dams, etc… In the last two decades, a big interest has been given to marine renewable energy (MRE) (70% of the earth are covered by ocean), especially marine current energy (MCE), by several communities like UK [2][3], Iran [4], France [5,6], Mexico [7], Canada [8]. Marine currents are generated from tidal movements and ocean circulation. Tides are the result of the interaction of the gravitational fields of the Earth, Moon, and Sun. The kinetic energy contained in marine currents can be harnessed using hydrokinetic turbine similar to that used to extract wind energy. The MCE resources has many advantages than the other renewable energy resources, it’s characterized by its predictability over long time [10], the density of seawater is greater than the density of air [9], no impact on the environment [10]. MCEDs provide an important source of energy without any effect of climate change, radioactivity and global contamination which associated with conventional systems. The potential of marine currents is very important in many sites around the world. The knowledge of this sites containing a very high potential is a preliminary task for the implementation of the infrastructure allowing the extraction of the energy contained in the marine currents. To do this, many methods are used among them we find numerical modeling. Due to advances in computer technology and hydrodynamic numerical modeling, it became possible to consider the direct calculation of the currents characteristics from the marine hydrodynamic equations. Nowadays, the ability of a numerical model to describe the currents of a marine area is practically constrained only by the computing power of computers and the knowledge of bathymetry [11]. Numerical modeling tools are mostly used for the site selection process across the continental shelves [12] [13]. Some of interesting approaches have used for this purpose. Benoit et al., 1996[32] use TOMAWAC numerical model for the construction of a database of marine currents and
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waves for the Atlantic region. Thiebota an al. [13] use the TELEMAC 2D for modeling tidal stream on Alderney Race (Raz Blanchard). A numerical model of marine currents in Bangka strait used a semi-implicit finite difference method for the numerical solution of three-dimensional shallow water flows [14]. Several numerical methods with solution of shallow water equations are used in practical applications [15], [16], [17]. Due to its geographical position, Morocco has a great renewable energy resources potential as sun, wind, water and more precisely of that coming from the sea (two maritime facades view: The Atlantic and Mediterranean Sea). The development of a hydrokinetic sector in Morocco will complete the diversification of energy strategy applied by the government, but, up to now, it is in the R & D. Generally, the greatest potential for marine current energy is located where there are powerful winds and high waves. Some studies are shown that the Atlantic coast has an important annual potential [18], as for the Mediterranean Sea especially in the strait of Gibraltar [19]. The present work considers the assessment of the current marine on specific zones of the Moroccan littoral (three zones: Tarfaya, El-Jadida and Tangier) by modeling its velocities using a numerical model for simulating marine’s characteristic’s with a high accuracy. The objective of these studies is to get an Atlas marine current(map) for determine the most adequate zone for the development of stream energy (tidal energy) in Morocco, evaluate its potential, and for design the most suitable hydrokinetic turbines adapted to Moroccan potential. 2. Studies area: 2.1. Area of study: Located between Africa and Europe, Morocco has an interesting geographical position in the Maghreb region (32 ° 00'N 5 ° 00'W) (Figure 1). It’s bordered by the Mediterranean and the Atlantic seas, Moroccan coast has a total length equivalent to 3500 km, which makes it a country with an important potential of renewable marine energy source. The Moroccan coast can be divided geographically in 3 zones as show in the table 1. Table 1. Geographical position of Moroccan coast. Coast Region
North Atlantic
South Atlantic
Mediterranean sea
Sites
El-jadida
Tarfaya
Tangier
Geographical coordinates 27° 54’ 48” N 12° 55’ 44” W 33.2316° N, 8.5007° W 35.7595° N, 5.8340° W
Three sites are in studies for determining their MCE potential. The choice of these 3 sites is based on their localization on the Moroccan coast (Mediterranean, south Atlantic and north Atlantic). The first sector studied in this work is Tangier, located in the north of Morocco on the Mediterranean Sea with geographical position is 35.7595° N, 5.8340° W. it’s characterized by the Mediterranean climate, the summers are relatively hot and sunny and the winters are wet and mild, and also by the winds speed and the wavelengths having very high values. The second one is EL-Jadida, located in the middle of Morocco on the south Atlantic coast, the geographical position is 33.2316° N, 8.5007° W (Figure 2), with a local Mediterranean climate. The last one is Tarfaya characterized by its marine
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resources, located in the south of Morocco on the north Atlantic coast (southwestern Morocco), the geographical position is 27° 54’ 48” N and 12° 55’ 44” E (Figure 2) with a middle desert climate.
Fig. 1. Geographical position of Morocco. Source: www.mapsdumaroc.com
Fig. 2 Moroccan coast subdivision
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2.2. Numerical model SWAN: Numerical modeling is a widely applied technique to solve complex problems through computational simulation. it uses mathematical models (equations) to describe the physical conditions, which could help to contribute to the development of releasing current marine atlas and also define the most important websites in various ways [21] such as waves and hydrodynamic models. With the purpose of determining the marine current velocity in the study areas in the Moroccan coast, a numerical model based on the recommendations for wave resource characterization in the nearshore with high accuracy was used. SWAN model “Simulating Waves Nearshore”, is a third-generation wave model was developed, implemented, and validated at Delft University [22] [23]. It can calculate, short-crested waves in coastal regions with shallow water and ambient currents. SWAN The model is based on a Eulerian formulation of the discrete spectral balance of action density that accounts for refractive propagation over arbitrary bathymetry and current fields. The process presented in SWAN for wave generation and dissipation are: dissipation by bottom friction, wave-wave interaction, white-capping, etc... The model SWAN solves the evolution of the wave spectrum by the spectral action balance equation (equation 1):
N cx N cy N c N c Sw t x y
(1)
2.3. Resource assessment: a.
Current marine:
Marine current, also named tidal stream, tides and tidal currents are generated by gravitational forces of the sun and moon on the earth's waters. Due to its proximity to the earth, the moon exerts roughly twice the tide raising force of the sun. The gravitational forces of the sun and the moon create two "bulges" in the earth’s oceans: one closest to the moon, and other on the opposite side of the globe. These "bulges" result in the two tides (high water to low water sequence) a day - the dominant tidal pattern in most of the world's oceans [24]. The kinetic energy contained in in marine currents can be harnessed using a hydrokinetic turbine technology [25], that is similar to wind energy, but there are many differences in the operating conditions. The density of water is 832 greater than that of wind, and the water flow speed is much smaller [1]. The marine current energy resources have a major advantage over the other renewables energy resources because it’s predictable over the time scales and it has no impact on the environment [26]. b.
Theoretical background:
The evaluation of the energy resources of the tidal stream will be completed by first identifying the theoretical resource. the kinetic energy passing from a vertical cross section perpendicular to the direction of flow per unit time, or the instantaneous tidal power density available in the given tidal current by:
P 0.5 AV 3
(2)
Therefore, the average power density per unit area of cross flow (per meter of depth) and averaged over a defined tide period can be expressed as:
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P 0.5V 3
(3)
It is important to note that the extractable power will strongly depend on the physical characteristics of the site and the performance of the individual energy converter intercepting the resource. Also, according to the Betz theory only 59.25% of the fluid energy can be extracted [23]. The dependence of the power produced on a predictable model of tidal forces makes this type of energy converter very attractive for the energy supply market [25]. c.
Methodology:
The contribution proposed in this work consists in the computation of an existing and validated model for SWAN the velocity of marine current, using specific characteristics of the studied zones (Tarfaya, EL Jadida and Tangier). the working methodology is based on recognizing and defining the specific data characteristics of each site in terms of its: bathymetry, wind velocity, and waves. the description of the methodology is described in Figure 3.
Ressources investigation for marine curent turbine
Modelling the marine current velocity using the bathymetry
Bathymetry data
Tidal Data
Map and profil sites
calculate the tidale parameters
Numerical Modeling: SWAN Model Calculate the Velocity distribution and determine the potential for a particular site
Fig. 3. Working methodology In order to simulate the calculation with SWAN model, it’s necessary to prepare:
Bathymetry data:
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The bathymetry data interpolated into the SWAN model are derived directly from EMODNET/bathymetry with high resolution (The European Marine Observation and Data Network (EMODnet consists of more than 150 organizations assembling marine data, products and metadata to make these fragmented resources more available) [28]. The data are scanned with a spatial resolution of 0.02 Km (as an ASCII file). The inclusion of the higher resolution bathymetry in our sites of study improve current velocity validation compared to the other results with a medium resolution of bathymetry data. To ensure compatibility between SWAN and bathymetry data, data processing was carried out using an IDL program. This sampling is done before all simulations and is provided to SWAN as input file. The bathymetry map was made using surfer software (Figure 4,5,6).
Mediterranean Sea: Tangier site
a
b
Fig. 4. (a) Bathymetry map of tangier; (b)Tangier bathymetry Profile
South Atlantic coast: Tarfaya site:
a
b
Fig. 5. (a) Bathymetry map of Tarfaya; (b) A 3D map of bathymetry Profile
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North Atlantic coast: El-Jadida site:
a
b
Fig. 6. (a) Bathymetry map of El-Jadida; (b) El-Jadida bathymetry Profile
Input data:
The forcing factors taken into account by the model are the wave elevation and the wind velocity. At the ocean boundary, the wave elevation is computed as each time by using the in-situ measurement or with satellite. For this work, the input data are obtained from CMEMS database [29]. In most times, it’s used to identify tidal stream energy potential in different regions by several researches. A treatment applied to CMEMS data in order to be compatible with the input file of model SWAN. At each node of the SWAN model, the current characteristics are calculated according to the applied forcing (waves /wind). 3. Results and discussion: In order to properly calculate the speed of currents marine in the three chosen sites, a good analysis and data preparation of was made before starting the calculus of the SWAN model. The bathymetry of the study area is treated with IDL code, in order to be compatible with this model. The bathymetry is modeled using Surfer as shown in Figure 4,5,6. After, being validated, the currents velocities were calculated after 30h of computation, the results of simulation obtained by SWAN are generated in a .dat (or .nc) extension form file with the outputs as shown in table 2. Table 2. example: An extract from SWAN output file (case Tangier) Xp[degr]
Yp[degr]
Depth[m]
Hsig[m]
Tm01[sec]
RTpeak[sec]
Ubot[m/s]
-7.767
33.5993
16.4954
2.11875
4.7750
6.4826
0.217451
-7.756
33.5993
263.7953
2.17687
4.8035
6.4826
0.3914
-7.745
33.5993
1137.3041
2.28109
4.8752
6.7488
0.2863
-7.734
33.5993
1080.4418
2.28583
4.8249
6.4826
0.5163
-7.724
33.5993
182.6679
2.51642
4.9620
6.7488
0.8026
-7.713
33.5993
11.3492
2.53106
4.9952
6.7488
0.455568
-7.702
33.5993
78.3720
2.58495
4.9847
6.4826
0.453455
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Mediterranean Sea: Tangier Site
Fig. 7. Current Velocity Distribution in (m/s) in Tangier coast
The obtained results in figure 7 show that the speed velocity of marine current in Tangier site varying between 0.2m/s et 1.9m/s. The nearest area to the coast has a current marine velocity that varies between 0.2 and 0.5 m/s, however, the further area there are excellent current velocities specially in dipper water (~ 450m), it is between 1.5 and 1.9m/s.
South Atlantic coast: Tarfaya site
Fig. 8. Current Velocity Distribution in (m/s) in Tarfaya coast
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The map shown in Figure 8 is obtained using a IDLcode. It describes the distribution of the current velocity in the Tarfaya site which is varying between varying between 0.01 m/s et 2.3m/s. The nearest area to the coast has a current marine velocity that varies between 0.9 and 2.3 m/s, however, the further area their current speed is considered mediocre. It is between 0.08 and 0.5m/s.
North Atlantic coast: El-Jadida site
Fig. 9. Current Velocity Distribution in (m/s) in El-Jadida site
The results shown in Figure 9 describe the distribution of the current velocity in the El-Jadida site. The variation of the velocity distribution is very high in this study area; it varies between 0.4m/s et 4m/s especially in the nearshore. Once the velocity distribution in the region of concern has been evaluated, it can be practiced to the HAMCT power curve to calculate the power output. The Horizontal Axis Marine Current Turbine (HAMCT) is the most advanced tidal stream technology available that can be employed to calculate the quantity of energy required [1]. In this study the rotor diameter is 10 m, so the swept area A, is 314 m2. Table 3. example: Estimation of the theoretical puissance site Coast Region North Atlantic South Atlantic
Sites El-Jadida Tarfaya
Theoretical Potential ~ 22 Kw ~ 19 Kw
Mediterranean sea
Tangier
~ 11 Kw
Marine current energy potential in the Mediterranean Sea (Tangier site) is very quiet with a view to other regions of the world, where MCE energy field is previously existing [2][3]. A few Mediterranean sites could be exploitable as the street of Gibraltar [4] (hydrokinetic turbine require a current velocity of at least 1.5- 2 m/s to work effectively), which justifies the absence of the industrial development community until now. the Mediterranean current marine energy potential can be characterized as medium potential.
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In the Moroccan Atlantic coastline has a large potential for tidal energy production. It may contribute meaningful profits with less cost and fewer ecological influences as compared to others sources. The current speed in the North Atlantic (varying between 0.5m/s and 4m/s) offers to this region a high potential of MCE, also for the South Atlantic the potential value is very important (~40 KW). A MCE converters mounted in this area could suitably produce an important quantity of power. In order to validate the results obtained with the SWAN model, a comparison with satellite data (satellite images) and the results obtained with our model of computation for the Tarfaya site, in the same period, was carried out for very precise points (4 points A, B, C and D). According to the site of NOAA [30] and that of the Mercator [31] as shown in the following table.4. The choice of these points is made according to the distance to the coast. one point ready for the odds(A) and one in the middle of the study area(B) and the last is far from the coast (C). The sea surface height (SSH) measurement is essential for deriving and monitoring the ocean currents and eddies, the ocean wave height and wind velocity and the ocean geodesy and geophysics. During the past 40 years, satellite radar altimetry has played an important role in determining the SSH from space with a high-level accuracy, which can cover the shortages of irregular and sparse sampling by shipboard and air board measurements. Table 4: Three points data velocity comparison between SWAN, NOAA and MERCATOR Xp (deg)
POINT
Yp (deg)
SWAN
Depth(m)
NOAA
MERCATOR
A
28
-13.25
30
0.98
Naan
0.6
B
27.6
-134
30
0.5
0.3
0.3
C
27
-14.3
30
0.2
0.24
0.25
This difference in speed can be justified by the choice of the model since the SWAN model is a model dedicated to the calculation of the nearshore zones, which leads to say that the margin of error is a little large in the zones farthest. Considering the altimetry data given by the satellite images, it is found that the current velocities of the furthest sites are almost identical. however, at nearshore, it is difficult to make this comparison since there is a lack of data, due to the satellite trajectory which does not cover these areas. Also, this differences can be made in the influence of the bathymetry. 4. Conclusion: In order to produce electricity without having any impact on the environment, Marine Renewable Energy (MRE/EMR) is considered, this paper treats the marine current's energy (that from ocean currents precisely) assessment. The study has given a preliminary assessment of the potential sites around Morocco in order to implement the energy diversification strategy and reduce the electricity bill. A 3D numerical model SWAN has been employed to simulate tidal flows (marine current) across the 3 Moroccan coast sites chosen (Mediterranean Sea, South Atlantic, and North Atlantic). The ability of the model to calculate the features of the marine current using CMEMS database has been shown to be reasonable. The results of the model have been mapped to determine the most potential zone. it was remarked that there are some difficulties especially with the collection and the treatment of bathymetry data and CMEMS data (winds, waves, ....) so that they will be compatible with SWAN. The results obtained approved that Morocco has a great potential of MCE resource for the development of renewable marine energy production. A comparison was made on Tarfaya zone between SWAN results and altimetry data given by NOAA. The maximal current velocity is greater than 2.5 m/s calculated in the North Atlantic (0.5 m/s ~ 4m/s) with the corresponding theoretical power 2514W/m².
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This assessment has provided an overall order to estimate the available potential of tidal stream resource in Morocco coast. It will provide a basis for more detailed analysis to guide the selection of the suitable site for marine current energy extraction and also for designed the perfect HKT adapted in this region. Acknowledgements This work is ostensibly supported by the GREEN ENERGY PARK RESEARCH PLATFORM, IRESEN (Research Institute in Solar Energy and Renewable Energy) BENGUERIR, MOROCCO. The authors acknowledge Mr. Aissa Benazzouz Geostatistics, Geoinformatics (GIS), Oceanography and professor in ISEM institute; for the support and the assistance in order to accomplish this work. References [1] [2] [3] [4] [5] [6]
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Indian Institute of Technology Bombay, Mumbai- 400076, India Received 27 January 2015; revised 06 May 2015. Casulli,V., and R.A. Walters, “An unstructured grid, three-dimensional model based on the shallow water equations,” International Journal for Numerical Methods in Fluids, vol.32, pp. 331-348, 2000.
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[24] http://www.esru.strath.ac.uk/EandE/Web_sites/0506/marine_renewables/background/marinecurrents.htm [25] Gu, Y., Lin, Y., Xu, Q., Liu, H., & Li, W. (2018). Blade-pitch system for tidal current turbines with reduced variation pitch control strategy based on tidal current velocity preview. Renewable Energy, 115, 149–158. doi:10.1016/j.renene.2017.07.034
[26] Ferro, B.D., Wave and Tidal Energy: Its Emergence and the Challenges it Faces. Refocus, 2006. 7(3): p. 46-48. [27] Hardisty, J., 2007. Estuaries: Monitoring and Modeling the Physical System. Blackwells, Oxford. [28] http://portal.emodnet-bathymetry.eu/depth-contours [29] http://marine.copernicus.eu/services-portfolio/access-to-products/ [30] https://podaac-tools.jpl.nasa.gov [31] http://bulletin.mercator-ocean.fr
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Energy Procedia 157 Energy Procedia 00(2019) (2017)1037–1049 000–000 Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, www.elsevier.com/locate/procedia 19–21 September 2018, Athens, Greece
Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18, Marine Currents Energy Resource for Morocco 19–21 September 2018,Characterization Athens, Greece Salma HAZIMa,b, Ahmed El Ouatouatia, Mourad Taha Janana, Abdellatif Ghenniouib
The 15th International Symposium on District Heating and Cooling Marine Currents Energy Resource Characterization for Morocco LM2PI, ENSET Mohammed V University of Rabat, Avenue des Forces Armées RabatGhennioui 10100, Morocco. Salma HAZIM , feasibility Ahmed El Ouatouati Mourad Taha Janan ,Royales, Abdellatif Assessing the of , using the demand-outdoor Research Institute for Solar Energy and New Energies (IRESEN), Greenheat Energy Park, Benguerir, Morocco. temperature function for a*[email protected] long-term district heat demand forecast LM2PI, ENSET Mohammed V University of Rabat, Avenue des Forces Armées Royales, Rabat 10100, Morocco. a,b
a
a
a
b
b
a
b
Abstract a
Research Institute for Solar Energy and New Energies (IRESEN), Green Energy Park, Benguerir, Morocco.
a I. Andrića,b,c*, A. Pinaa, P. Ferrão , J. Fournierb., B. Lacarrièrec, O. Le Correc *[email protected]
IN+ Center for Innovation, Technology and Policy Research - Instituto Superior Técnico, Av. Rovisco Pais 1, 1049-001 Lisbon, Portugal
b Over the last two decades, there has been a great interest in marine renewable energy exploitation Veolia Recherche & Innovation, 291 Avenue Dreyfous Daniel, 78520 Limay, France (70% of the globe are c ocean) due to the limitation of fossil resources and the effect of climate change. The marine current a huge Département Systèmes Énergétiques et Environnement IMT Atlantique, 4 rue Alfred Kastler, 44300energy Nantes,constitutes France Abstract potential of marine renewable resources for producing electricity using a Hydrokinetic turbine. the assessment of the potential resources thedecades, most necessaire adequate location for implementing and choosing Over of thesites last istwo there hasstep beento aselect great the interest in marine renewable energy exploitation (70%theofcorresponding the globe are conversion systems. The main objective of this work is to calculate and map with a high resolution (200 m) current velocity ocean) due to the limitation of fossil resources and the effect of climate change. The marine current energythe constitutes a huge of some Moroccan in orderresources to select for the producing items with electricity high resource potential. In this sense, the the current velocityofwas Abstract potential of marinesites renewable using a Hydrokinetic turbine. assessment thecalculated potential using the 3D dimensions’ hydrodynamic model addition,fortheimplementing accurate dataand of Copernicus center with have resources of sites is the most necessaire numerical step to select the SWAN. adequateInlocation choosing the corresponding been employed with the main SWAN parameters to work perform high potential. The obtained show the of the sites District heating networks are objective commonly the literature one of results the most effective solutions decreasing the conversion systems. The of addressed this isintothe calculate andasmap with a high resolution (200 m)potential theforcurrent velocity selected to facilitate the choice of the adequate technology which can be employed to extract the kinetic energy of the marine gas emissions from to theselect building sector.with These require highIn investments are returned the heat ofgreenhouse some Moroccan sites in order the items highsystems resource potential. this sense, which the current velocitythrough was calculated current. sales.the Due the changed climate conditions and building renovation policies, heat demand the futurecenter couldwith decrease, using 3D to dimensions’ hydrodynamic numerical model SWAN. In addition, the accurate data of in Copernicus have prolonging the with investment returnparameters period. been employed the SWAN to perform the high potential. The results obtained show the potential of the sites selected to scope facilitate the paper choiceis of adequate technology which employed to extract the kinetic energyfor of heat the marine The main of this to the assess the feasibility of using thecan heatbedemand – outdoor temperature function demand current. forecast. The district of Alvalade, located in Lisbon (Portugal), was used as a case study. The district is consisted of 665 ©buildings 2018 Thethat Authors. Published by Elsevierperiod Ltd. and typology. Three weather scenarios (low, medium, high) and three district vary in both construction © 2019 The Authors. by Elsevier Ltd. This is an open accessPublished article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) renovation scenarios were developed (shallow, intermediate, deep). To estimate the error, obtained heat demand values were This is an and openpeer-review access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, compared with results from a dynamic heat demand model, previously developed and validated by the authors. Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. © 2018 The Authors. Published by Elsevier Ltd. The results showed that when only weather change is considered, the margin of error could be acceptable for some applications Environment and Sustainability, TMREES18. This an open accessdemand article under the CCthan BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) (theiserror in annual was lower 20% for all weather scenarios considered). However, after introducing renovation Keywords: Marine renewable energy, Potential, current velocity, kinetic powercombination density, Morocco Selection peer-review under responsibility of the scientificmarine committee of Technologies andscenarios Materials for Renewable Energy, scenarios,and the error value increased up toSWAN, 59.5% (depending on the weather and renovation considered). Environment Sustainability, The value ofand slope coefficient TMREES18. increased on average within the range of 3.8% up to 8% per decade, that corresponds to the decrease in the number of heating hours of 22-139h during the heating season (depending on the combination of weather and Keywords: Marine renewable energy, Potential, marine current velocity, kinetic power density, Moroccoon the renovation scenarios considered). On theSWAN, other hand, function intercept increased for 7.8-12.7% per decade (depending 1.coupled Introduction: scenarios). The values suggested could be used to modify the function parameters for the scenarios considered, and improve the accuracy of heat demand estimations.
2017 The Authors. Published by Elsevier Ltd. 1.©Introduction:
Peer-review under of thebyScientific Committee of The 15th International Symposium on District Heating and 1876-6102 © 2018 Theresponsibility Authors. Published Elsevier Ltd. Cooling. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment Keywords: Heat demand; Forecast; Climate change and Sustainability, TMREES18. 1876-6102 © 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18.
1876-6102 © 2017 The Authors. Published by Elsevier Ltd. 1876-6102 © 2019 The Authors. Published by Elsevier Ltd. Peer-review under responsibility of the Scientific Committee of The 15th International Symposium on District Heating and Cooling. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/) Selection and peer-review under responsibility of the scientific committee of Technologies and Materials for Renewable Energy, Environment and Sustainability, TMREES18. 10.1016/j.egypro.2018.11.271
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Salma Hazim et al. / Energy Procedia 157 (2019) 1037–1049 Author name / Energy Procedia 00 (2018) 000–000
Nomenclature MRE MCE MCED R&D SWAN CMEMS N Cx, Cy σ Ө S P V A ρ
marine renewable energy marine current energy marine current energy devices research and development simulating wave nearshore copernicus marine environment monitoring service local rate of change of action density in time. propagation of action in geographical space (with propagation velocities Cx and Cy in x and y space, respectively) the relative frequency due to variations in depths and currents wave propagation directions source/sink term for: wind-wave generation, wave breaking, bottom dissipation, nonlinear wavewave interactions theoretical power cross-section density currents velocity (m/s) cross section area (m²) sea water density (~ 1025 Kg/m²/m)
The depletion of fossil resources and the acceleration of greenhouse gas emissions indicate a growing threat of climate change that makes the energy issue a global problem. The research of other kinds of energy sources becomes a great interest of all scientific and industrial communities in the world concerned with energy production, consumption and management. This research is not only limited to find new sources but also gives an important interest to get sources that have a weak impact on the environment, such as renewable energies [1]. Many kind of renewable energy resources are in use like wind, water, solar, water dams, etc… In the last two decades, a big interest has been given to marine renewable energy (MRE) (70% of the earth are covered by ocean), especially marine current energy (MCE), by several communities like UK [2][3], Iran [4], France [5,6], Mexico [7], Canada [8]. Marine currents are generated from tidal movements and ocean circulation. Tides are the result of the interaction of the gravitational fields of the Earth, Moon, and Sun. The kinetic energy contained in marine currents can be harnessed using hydrokinetic turbine similar to that used to extract wind energy. The MCE resources has many advantages than the other renewable energy resources, it’s characterized by its predictability over long time [10], the density of seawater is greater than the density of air [9], no impact on the environment [10]. MCEDs provide an important source of energy without any effect of climate change, radioactivity and global contamination which associated with conventional systems. The potential of marine currents is very important in many sites around the world. The knowledge of this sites containing a very high potential is a preliminary task for the implementation of the infrastructure allowing the extraction of the energy contained in the marine currents. To do this, many methods are used among them we find numerical modeling. Due to advances in computer technology and hydrodynamic numerical modeling, it became possible to consider the direct calculation of the currents characteristics from the marine hydrodynamic equations. Nowadays, the ability of a numerical model to describe the currents of a marine area is practically constrained only by the computing power of computers and the knowledge of bathymetry [11]. Numerical modeling tools are mostly used for the site selection process across the continental shelves [12] [13]. Some of interesting approaches have used for this purpose. Benoit et al., 1996[32] use TOMAWAC numerical model for the construction of a database of marine currents and
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waves for the Atlantic region. Thiebota an al. [13] use the TELEMAC 2D for modeling tidal stream on Alderney Race (Raz Blanchard). A numerical model of marine currents in Bangka strait used a semi-implicit finite difference method for the numerical solution of three-dimensional shallow water flows [14]. Several numerical methods with solution of shallow water equations are used in practical applications [15], [16], [17]. Due to its geographical position, Morocco has a great renewable energy resources potential as sun, wind, water and more precisely of that coming from the sea (two maritime facades view: The Atlantic and Mediterranean Sea). The development of a hydrokinetic sector in Morocco will complete the diversification of energy strategy applied by the government, but, up to now, it is in the R & D. Generally, the greatest potential for marine current energy is located where there are powerful winds and high waves. Some studies are shown that the Atlantic coast has an important annual potential [18], as for the Mediterranean Sea especially in the strait of Gibraltar [19]. The present work considers the assessment of the current marine on specific zones of the Moroccan littoral (three zones: Tarfaya, El-Jadida and Tangier) by modeling its velocities using a numerical model for simulating marine’s characteristic’s with a high accuracy. The objective of these studies is to get an Atlas marine current(map) for determine the most adequate zone for the development of stream energy (tidal energy) in Morocco, evaluate its potential, and for design the most suitable hydrokinetic turbines adapted to Moroccan potential. 2. Studies area: 2.1. Area of study: Located between Africa and Europe, Morocco has an interesting geographical position in the Maghreb region (32 ° 00'N 5 ° 00'W) (Figure 1). It’s bordered by the Mediterranean and the Atlantic seas, Moroccan coast has a total length equivalent to 3500 km, which makes it a country with an important potential of renewable marine energy source. The Moroccan coast can be divided geographically in 3 zones as show in the table 1. Table 1. Geographical position of Moroccan coast. Coast Region
North Atlantic
South Atlantic
Mediterranean sea
Sites
El-jadida
Tarfaya
Tangier
Geographical coordinates 27° 54’ 48” N 12° 55’ 44” W 33.2316° N, 8.5007° W 35.7595° N, 5.8340° W
Three sites are in studies for determining their MCE potential. The choice of these 3 sites is based on their localization on the Moroccan coast (Mediterranean, south Atlantic and north Atlantic). The first sector studied in this work is Tangier, located in the north of Morocco on the Mediterranean Sea with geographical position is 35.7595° N, 5.8340° W. it’s characterized by the Mediterranean climate, the summers are relatively hot and sunny and the winters are wet and mild, and also by the winds speed and the wavelengths having very high values. The second one is EL-Jadida, located in the middle of Morocco on the south Atlantic coast, the geographical position is 33.2316° N, 8.5007° W (Figure 2), with a local Mediterranean climate. The last one is Tarfaya characterized by its marine
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resources, located in the south of Morocco on the north Atlantic coast (southwestern Morocco), the geographical position is 27° 54’ 48” N and 12° 55’ 44” E (Figure 2) with a middle desert climate.
Fig. 1. Geographical position of Morocco. Source: www.mapsdumaroc.com
Fig. 2 Moroccan coast subdivision
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2.2. Numerical model SWAN: Numerical modeling is a widely applied technique to solve complex problems through computational simulation. it uses mathematical models (equations) to describe the physical conditions, which could help to contribute to the development of releasing current marine atlas and also define the most important websites in various ways [21] such as waves and hydrodynamic models. With the purpose of determining the marine current velocity in the study areas in the Moroccan coast, a numerical model based on the recommendations for wave resource characterization in the nearshore with high accuracy was used. SWAN model “Simulating Waves Nearshore”, is a third-generation wave model was developed, implemented, and validated at Delft University [22] [23]. It can calculate, short-crested waves in coastal regions with shallow water and ambient currents. SWAN The model is based on a Eulerian formulation of the discrete spectral balance of action density that accounts for refractive propagation over arbitrary bathymetry and current fields. The process presented in SWAN for wave generation and dissipation are: dissipation by bottom friction, wave-wave interaction, white-capping, etc... The model SWAN solves the evolution of the wave spectrum by the spectral action balance equation (equation 1):
N cx N cy N c N c Sw t x y
(1)
2.3. Resource assessment: a.
Current marine:
Marine current, also named tidal stream, tides and tidal currents are generated by gravitational forces of the sun and moon on the earth's waters. Due to its proximity to the earth, the moon exerts roughly twice the tide raising force of the sun. The gravitational forces of the sun and the moon create two "bulges" in the earth’s oceans: one closest to the moon, and other on the opposite side of the globe. These "bulges" result in the two tides (high water to low water sequence) a day - the dominant tidal pattern in most of the world's oceans [24]. The kinetic energy contained in in marine currents can be harnessed using a hydrokinetic turbine technology [25], that is similar to wind energy, but there are many differences in the operating conditions. The density of water is 832 greater than that of wind, and the water flow speed is much smaller [1]. The marine current energy resources have a major advantage over the other renewables energy resources because it’s predictable over the time scales and it has no impact on the environment [26]. b.
Theoretical background:
The evaluation of the energy resources of the tidal stream will be completed by first identifying the theoretical resource. the kinetic energy passing from a vertical cross section perpendicular to the direction of flow per unit time, or the instantaneous tidal power density available in the given tidal current by:
P 0.5 AV 3
(2)
Therefore, the average power density per unit area of cross flow (per meter of depth) and averaged over a defined tide period can be expressed as:
Salma Hazim et al. / Energy Procedia 157 (2019) 1037–1049 Author name / Energy Procedia 00 (2018) 000–000
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P 0.5V 3
(3)
It is important to note that the extractable power will strongly depend on the physical characteristics of the site and the performance of the individual energy converter intercepting the resource. Also, according to the Betz theory only 59.25% of the fluid energy can be extracted [23]. The dependence of the power produced on a predictable model of tidal forces makes this type of energy converter very attractive for the energy supply market [25]. c.
Methodology:
The contribution proposed in this work consists in the computation of an existing and validated model for SWAN the velocity of marine current, using specific characteristics of the studied zones (Tarfaya, EL Jadida and Tangier). the working methodology is based on recognizing and defining the specific data characteristics of each site in terms of its: bathymetry, wind velocity, and waves. the description of the methodology is described in Figure 3.
Ressources investigation for marine curent turbine
Modelling the marine current velocity using the bathymetry
Bathymetry data
Tidal Data
Map and profil sites
calculate the tidale parameters
Numerical Modeling: SWAN Model Calculate the Velocity distribution and determine the potential for a particular site
Fig. 3. Working methodology In order to simulate the calculation with SWAN model, it’s necessary to prepare:
Bathymetry data:
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The bathymetry data interpolated into the SWAN model are derived directly from EMODNET/bathymetry with high resolution (The European Marine Observation and Data Network (EMODnet consists of more than 150 organizations assembling marine data, products and metadata to make these fragmented resources more available) [28]. The data are scanned with a spatial resolution of 0.02 Km (as an ASCII file). The inclusion of the higher resolution bathymetry in our sites of study improve current velocity validation compared to the other results with a medium resolution of bathymetry data. To ensure compatibility between SWAN and bathymetry data, data processing was carried out using an IDL program. This sampling is done before all simulations and is provided to SWAN as input file. The bathymetry map was made using surfer software (Figure 4,5,6).
Mediterranean Sea: Tangier site
a
b
Fig. 4. (a) Bathymetry map of tangier; (b)Tangier bathymetry Profile
South Atlantic coast: Tarfaya site:
a
b
Fig. 5. (a) Bathymetry map of Tarfaya; (b) A 3D map of bathymetry Profile
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North Atlantic coast: El-Jadida site:
a
b
Fig. 6. (a) Bathymetry map of El-Jadida; (b) El-Jadida bathymetry Profile
Input data:
The forcing factors taken into account by the model are the wave elevation and the wind velocity. At the ocean boundary, the wave elevation is computed as each time by using the in-situ measurement or with satellite. For this work, the input data are obtained from CMEMS database [29]. In most times, it’s used to identify tidal stream energy potential in different regions by several researches. A treatment applied to CMEMS data in order to be compatible with the input file of model SWAN. At each node of the SWAN model, the current characteristics are calculated according to the applied forcing (waves /wind). 3. Results and discussion: In order to properly calculate the speed of currents marine in the three chosen sites, a good analysis and data preparation of was made before starting the calculus of the SWAN model. The bathymetry of the study area is treated with IDL code, in order to be compatible with this model. The bathymetry is modeled using Surfer as shown in Figure 4,5,6. After, being validated, the currents velocities were calculated after 30h of computation, the results of simulation obtained by SWAN are generated in a .dat (or .nc) extension form file with the outputs as shown in table 2. Table 2. example: An extract from SWAN output file (case Tangier) Xp[degr]
Yp[degr]
Depth[m]
Hsig[m]
Tm01[sec]
RTpeak[sec]
Ubot[m/s]
-7.767
33.5993
16.4954
2.11875
4.7750
6.4826
0.217451
-7.756
33.5993
263.7953
2.17687
4.8035
6.4826
0.3914
-7.745
33.5993
1137.3041
2.28109
4.8752
6.7488
0.2863
-7.734
33.5993
1080.4418
2.28583
4.8249
6.4826
0.5163
-7.724
33.5993
182.6679
2.51642
4.9620
6.7488
0.8026
-7.713
33.5993
11.3492
2.53106
4.9952
6.7488
0.455568
-7.702
33.5993
78.3720
2.58495
4.9847
6.4826
0.453455
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Mediterranean Sea: Tangier Site
Fig. 7. Current Velocity Distribution in (m/s) in Tangier coast
The obtained results in figure 7 show that the speed velocity of marine current in Tangier site varying between 0.2m/s et 1.9m/s. The nearest area to the coast has a current marine velocity that varies between 0.2 and 0.5 m/s, however, the further area there are excellent current velocities specially in dipper water (~ 450m), it is between 1.5 and 1.9m/s.
South Atlantic coast: Tarfaya site
Fig. 8. Current Velocity Distribution in (m/s) in Tarfaya coast
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The map shown in Figure 8 is obtained using a IDLcode. It describes the distribution of the current velocity in the Tarfaya site which is varying between varying between 0.01 m/s et 2.3m/s. The nearest area to the coast has a current marine velocity that varies between 0.9 and 2.3 m/s, however, the further area their current speed is considered mediocre. It is between 0.08 and 0.5m/s.
North Atlantic coast: El-Jadida site
Fig. 9. Current Velocity Distribution in (m/s) in El-Jadida site
The results shown in Figure 9 describe the distribution of the current velocity in the El-Jadida site. The variation of the velocity distribution is very high in this study area; it varies between 0.4m/s et 4m/s especially in the nearshore. Once the velocity distribution in the region of concern has been evaluated, it can be practiced to the HAMCT power curve to calculate the power output. The Horizontal Axis Marine Current Turbine (HAMCT) is the most advanced tidal stream technology available that can be employed to calculate the quantity of energy required [1]. In this study the rotor diameter is 10 m, so the swept area A, is 314 m2. Table 3. example: Estimation of the theoretical puissance site Coast Region North Atlantic South Atlantic
Sites El-Jadida Tarfaya
Theoretical Potential ~ 22 Kw ~ 19 Kw
Mediterranean sea
Tangier
~ 11 Kw
Marine current energy potential in the Mediterranean Sea (Tangier site) is very quiet with a view to other regions of the world, where MCE energy field is previously existing [2][3]. A few Mediterranean sites could be exploitable as the street of Gibraltar [4] (hydrokinetic turbine require a current velocity of at least 1.5- 2 m/s to work effectively), which justifies the absence of the industrial development community until now. the Mediterranean current marine energy potential can be characterized as medium potential.
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In the Moroccan Atlantic coastline has a large potential for tidal energy production. It may contribute meaningful profits with less cost and fewer ecological influences as compared to others sources. The current speed in the North Atlantic (varying between 0.5m/s and 4m/s) offers to this region a high potential of MCE, also for the South Atlantic the potential value is very important (~40 KW). A MCE converters mounted in this area could suitably produce an important quantity of power. In order to validate the results obtained with the SWAN model, a comparison with satellite data (satellite images) and the results obtained with our model of computation for the Tarfaya site, in the same period, was carried out for very precise points (4 points A, B, C and D). According to the site of NOAA [30] and that of the Mercator [31] as shown in the following table.4. The choice of these points is made according to the distance to the coast. one point ready for the odds(A) and one in the middle of the study area(B) and the last is far from the coast (C). The sea surface height (SSH) measurement is essential for deriving and monitoring the ocean currents and eddies, the ocean wave height and wind velocity and the ocean geodesy and geophysics. During the past 40 years, satellite radar altimetry has played an important role in determining the SSH from space with a high-level accuracy, which can cover the shortages of irregular and sparse sampling by shipboard and air board measurements. Table 4: Three points data velocity comparison between SWAN, NOAA and MERCATOR Xp (deg)
POINT
Yp (deg)
SWAN
Depth(m)
NOAA
MERCATOR
A
28
-13.25
30
0.98
Naan
0.6
B
27.6
-134
30
0.5
0.3
0.3
C
27
-14.3
30
0.2
0.24
0.25
This difference in speed can be justified by the choice of the model since the SWAN model is a model dedicated to the calculation of the nearshore zones, which leads to say that the margin of error is a little large in the zones farthest. Considering the altimetry data given by the satellite images, it is found that the current velocities of the furthest sites are almost identical. however, at nearshore, it is difficult to make this comparison since there is a lack of data, due to the satellite trajectory which does not cover these areas. Also, this differences can be made in the influence of the bathymetry. 4. Conclusion: In order to produce electricity without having any impact on the environment, Marine Renewable Energy (MRE/EMR) is considered, this paper treats the marine current's energy (that from ocean currents precisely) assessment. The study has given a preliminary assessment of the potential sites around Morocco in order to implement the energy diversification strategy and reduce the electricity bill. A 3D numerical model SWAN has been employed to simulate tidal flows (marine current) across the 3 Moroccan coast sites chosen (Mediterranean Sea, South Atlantic, and North Atlantic). The ability of the model to calculate the features of the marine current using CMEMS database has been shown to be reasonable. The results of the model have been mapped to determine the most potential zone. it was remarked that there are some difficulties especially with the collection and the treatment of bathymetry data and CMEMS data (winds, waves, ....) so that they will be compatible with SWAN. The results obtained approved that Morocco has a great potential of MCE resource for the development of renewable marine energy production. A comparison was made on Tarfaya zone between SWAN results and altimetry data given by NOAA. The maximal current velocity is greater than 2.5 m/s calculated in the North Atlantic (0.5 m/s ~ 4m/s) with the corresponding theoretical power 2514W/m².
Salma Hazim et al. / Energy Procedia 157 (2019) 1037–1049 Author name / Energy Procedia 00 (2018) 000–000
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This assessment has provided an overall order to estimate the available potential of tidal stream resource in Morocco coast. It will provide a basis for more detailed analysis to guide the selection of the suitable site for marine current energy extraction and also for designed the perfect HKT adapted in this region. Acknowledgements This work is ostensibly supported by the GREEN ENERGY PARK RESEARCH PLATFORM, IRESEN (Research Institute in Solar Energy and Renewable Energy) BENGUERIR, MOROCCO. The authors acknowledge Mr. Aissa Benazzouz Geostatistics, Geoinformatics (GIS), Oceanography and professor in ISEM institute; for the support and the assistance in order to accomplish this work. References [1] [2] [3] [4] [5] [6]
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