Assessment of the feasibility of hybrid renewable power for supply pumping system for irrigation

: Crop identification is vital to make an inventory of the crops grown in a given area and their cultivation period. The Remote sensing (RS) techniques can provide information on the distribution of cultivated land, crop types, and areas for the agricultural sector's effective management. In remote sensing, various vegetation indices (VI) can analyze and evaluate multiple phenomena and themes. The Normalized Difference Vegetation Index (NDVI) is an essential and highly significant remote measurement widely used in agriculture for phenological monitoring and crop health (Ray and Dadhwal, 2001). In this work, we present a methodology for the contribution of NDVI from Landsat 7 (TM) and (ETM+) images to crop mapping in the Gharb region using a classification based on the pixel approach and estimating rice crop coefficient from NDVI. The classification results concern six main types of crops planted in this region (beet, maize, sugar cane, market gardening, cereals, and rice). The classification map showed differences in agricultural practices adopted by farmers in crop spatial distribution. The classification results showed the ability of this methodology to discriminate between crops. Crop coefficients were deduced from the NDVI extracted from the images. Due to meteorological data collected from the meteorological station TCSC of SK Tlet, the estimation of the reference evapotranspiration was made and subsequently the potential evapotranspiration of each crop during the agricultural season 2019-2020. The highest values for ETC were obtained when the crop was in its full development when water was mainly lost through transpiration after a slight decrease in the ratio values observed during the phase of the vegetative cycle (maturity). The water requirements (daily, monthly and annual) for the crops were determined and their electrical energy consumption. Renewable energy can be an effective solution to meet the energy needs of plots , greenhouses and large farms. A technical-economic study of different combinations of autonomous hybrid renewable energy systems (HRES) in order to meet the power supply needs of the above mentioned crops in the Gharb region. The renewable energy sources considered are solar, wind and biomass. The results show that for an average energy requirement of 92 kWh/day and a peak load of 6.5 kW, the unit energy cost of the optimal configuration scenario A (PV-wind-biomass-battery) is 0.19 $/kWh. Therefore, the design, development and implementation of the proposed system is a promising solution for the security of energy supply. For a 100% integration of renewable energy, the HRES produces electricity according to the following distribution: 11% from wind, 41% from solar and 48% from biomass.


Introduction
Agriculture is a vital and crucial element in the economy of the Gharb region. To ensure efficient management of agriculture, geospatial data and statistics are indispensable. However, traditional data collection techniques are expensive and unsuitable for monitoring seasonal crop development. The RS allows the mapping of crop types by monitoring their seasonal development using multidate images covering the crop growing cycle. The use of RS for crop identification in semi-arid areas is significant and useful [5]. Several  Research has shown a good simulation of crop coefficients derived from VI from multispectral images (Hunsaker et al., 2003). [15] Several researchers (Allen and al.. (2011)), , Gonzalez-Dugo and al.. (2009) have studied and defined the correlation and the best possible relationship between the crop coefficients of multispectral NDVI images based on the vegetation surface's reflectance. The VI allows bio-physical parameters to emerge from multispectral images using empirical equations. The VI can be used to define and monitor different crop parameters. [20] Different formulae were developed to estimate evapotranspiration; there are formulae based on energy balance (Penman, 1948; Allen and al.., 1998b; Nouri and al.., 2013) [18], formulas referring to the air temperature (Thornthwaite, 1948;Blaney, 1952) [19].
The FAO-56 PM equation is more accurate in ETO estimation because it uses many parameters and is the most widely used formula for estimating evapotranspiration in agriculture (Allen and al.., 1998b;Allen, 2000).
Many research studies have been carried out on estimating Kc values for vegetable crops (peas, onions, and tomatoes) [26,22].
Researchers have revealed that VI extracted from satellite images can be used to estimate crop coefficients. [24-25-29].

Figure 1 : The region of Gharb
The region of Gharb constitutes one of Morocco's most important agricultural perimeters, with a surface area of 116 000 ha. The perimeter is experiencing a real dynamic concerning the transition to drip irrigation.

Meteorological data
All meteorological data were collected from the TCSC weather station located in SA TAZI. The data are temperature (Tmax, Tmin, Taverage ), wind speed, net radiation, relative humidity, and reference evapotranspiration during the season 2019-2020. The rice crop evapotranspiration was estimated by in situ lysimetric measurements per decade for the growing season 2019-2020.
The FAO-56 PM equation requires standard climatological data of solar radiation, humidity, air temperature, and wind speed. [16]. All the meteorological data were recorded at the 2 m elevation point.

Estimation of crop evapotranspiration :
The following formula expresses crop evapotranspiration:  Table ) = ( P NIR − P red ) ( P NIR + P red ) The NDVI is the parameter that allows monitoring the evolution of the spectral response of the crop to applied irrigation rates while giving the different quality statuses of the crop (Bell and al.., 2009) [10]. The NDVI is an indicator of the chlorophyll activity in vegetation. [4] Researches were made by ( Doorenbos and Pruitt, 1977;Allen and al.., 1998) to elaborate the Kc values of different crops during their growing cycles. [11] Kc is estimated from NDVI due to the strong relationship between the NDVI and the Kc (Ray and Dadhwal, 2001) [12].Due to the relationship between NDVI and KC, NDVI has always been considered as a parameter for monitoring and control of vegetation during its growth cycle (Justice and Townshend, 2002) [13]. High photosynthetic activity leads to high NDVI values; in contrast, high temperatures lead to low NDVI values (Boegh et al. 1999). [14] Efficient and rational management of irrigation water requires a reliable quantitative estimate of evapotranspiration. In situ measurement of rice crop using a lysimeter is necessary for a reliable estimation of the crop coefficient's evolution over the entire period of its growth.

Data collection
The data used to validate classification results are the field data of the types of crops existing in the region of Gharb at the date of 14/04/2019. The data distinguishes six types of crops in addition to 3 land uses. The data presenting the crop types in plots have been divided to distinguish the data to validate the results and the characterization during the classification.
The crop identification based on phenology requires temporal monitoring during the stages of crop evolution. Crop mapping in our study was carried out for the agricultural season 2019-2020 according to field data availability.

Methodology
The adopted methodology in this work is shown in the methodology flowchart. The proposed system is an autonomous hybrid system containing biomass generator, solar PV field and wind turbines as power generation options. A data collection and preliminary assessment of the irrigation characteristics in terms of energy demand, available energy infrastructure, current and future renewable projects underway in the region have been conducted. System configuration is determined and optimum size of each power generation technology is achieved based on the local economic and energy requirement inputs.for irrigation. ETC is defined as the process by which water is lost by evapotranspiration.

Load assessment
The proposed system seems to be a promising option to supply the pumping station electricity need for irrigation purposes. The case study consists of six man crops supplied by irrigation water by pumping station connected to the electricity grid. However, the main purpose of this manuscript is to analyse the possibility of implementing centralized stand-alone HRES in similar rural area with irrigation is done traditionally due to not access to electricity network. Fig. 13 shows the distribution of the monthly electricity consumption throughout the year 2019-2020 for the six man crops on the Gharb region . A maximum of monthly consumption is seen over the months of July and August with an average value of 1891.2 kWh and the minimum in January with the average of 1140.12 kWh. The distribution of the average electric load per hour for the year 2019-2020 is depicted in Fig 14. A maximum load of 6.44 kW (at 23:00 h) is identified in the summer season.

Resources assessment
The Gharb region possesses a high potential of renewable energy resources notably biomass, wind and solar. The details of these resources are covered in the following paragraphs.

Solar irradiation data
Solar energy data for the region under examination is collected from meteorological station TSGC in SK Tlet. Fig. 10 and Fig.11 displays the daily irradiation for two typically days. The annual average solar global horizontal irradiance is 5.07 kWh/m2/ day with maximum of 7.18 kWh/m2/day observed in June and a minimum of 2.74 kWh/m2/day in December.

Wind data
The monthly mean wind speed is obtained from the meteorological station TCSG in SK tlet in Fig 5 .

Biomass resource
Biomass is among the oldest power sources in the world and through which methane (CH4) and carbon dioxide (CO2) gases are produced in the absence of oxygen by microorganisms. It is obtained from agricultural residues, animal waste, wood, and human waste etc (Zafar and Owais, 2006).  Electric load ( kw)

Hours
Electric load ( kw) Figure 14 : Typical summer day load demand

HRES detail and equipment
The autonomous Hybrid Renewable Energy System proposed in this manuscript is illustrated in Fig. 15, which contains five major components: biomass generator, PV Modules, wind turbines, converter, and batteries for storage. 4.1. Solar photovoltaic system The photovoltaic modules are polycrystalline silicon connected to each other, oriented towards the south and tilted at 33 , which is the optimum inclination in the studied region. Photovoltaic panels do not have a tracking system. The generating power by the PV modules is dependent on the upcoming solar radiation as well as ambient temperature. The initial price in the Moroccan market is approximately 1600 $/kW and considering that the module lifespan equals to the project life and the replacement price is taken to be zero. The operating and maintenance costs are estimated at 15 $/yr which is a reasonable value in the Moroccan scenario. The project lifespan is considered as 25 years. Power generated by PV modules is calculated as follows: [27] P PV = Y PV * f PV * ( G PV G refa ) * (1 + K T (T C − T ref ) Figure 15 : Configuration of the proposed hybrid power system where Uanem represents the wind velocity at anemometer height, respectively. Zhub is the wind turbine hub height, Zanem is the anemometer height, and a is the power law exponent.
= * * * * * ᶯ * ᶯ [29] where r is the air density, A is the rotor area in m2, V is wind velocity in m/s, Cp is performance density of air coefficient of the turbine and ht and hg are the efficiencies of wind turbine and the generator, respectively. The initial cost according to the Moroccan market of the wind turbine unit is considered as $10,775 with the replacement cost of $0 considering the equality between the project life and the wind turbine lifespan and the operation and maintenance cost of 20 $/year.

Biogas generator
The gasification reaction takes place under very high temperature conditions (>1000 C) (Heydari and Askarzadeh, 2016). Syngas is used as a source of electricity production from gas turbines. In this case, the cost of fuel is not considered because the fuel is the animal waste, which can be found abundantly. The initial price of biomass generator is taken as 1600 $/kW, the replacement and operating costs are assumed as 1250 $/kW and 0.1 $/h, respectively. The life of the biogas generator is taken as 20,000 h so as the lower heating value of 5.5 MJ/kg, and the percentage carbon content as 5%.

Converter
The converters are among the most important components of the hybrid system utilized to convert alternating current (AC) to direct current (DC) or the opposite way. To do this, it is placed between the AC and DC segments. The efficiency of the latter relies on the other devices of the hybrid system (Eroglu et al., 2011). In the present case, the initial, replacement, and maintenance costs per kW capacity are taken as $400, $400, and $0 per year, respectively. The lifetime of the converter is taken as 15 years. Efficiency of the inverter and rectifier are considered as 90% and 95%, respectively.

Battery
In hybrid systems, which are not usually connected to the electricity network, batteries play an important role as they ensure the continuous power supply during the periods when there is no or inadequate electricity production and maintain constant voltage during the peak demanding of irrigation . The storage capacityof the battery, Bc, is calculated using equation (8) (Malheiro et al., 2015). In equation (8), Dele is the daily electrical demand in [kWh/day].the daily electrical demand in [kWh/day], Dd is the depth of discharge of the battery, Na is the daily range Na is the daily autonomy, and hb and hinv are the efficiencies of the battery and converter, respectively. In this work, the battery employed has a capacity of 167 Ah with a nominal voltage of 6V. The capital cost and the replacement cost in Moroccan market of this battery is $330, the maintenance cost is equal to 10 $/year, with the expected lifetime of 15 years. Table 1 summarizes the specifications of the selected battery.

Simulation process and economic considerations
For the economic analysis, the life of the project is equal to 25 years; the discount rate and inflation rate are considered as 5% and 2.5%, respectively (Allouhi et al., 2016). Table3 summarizes the capital, replacement, and operating and maintenance (O&M) fees for each component of the hybrid system.

Net present cost
The hybrid power system optimization tool, HOMER, is exploited to optimize the system rested on the minimum net present cost (NPC) that can be evaluated as follows.
where Cann tot and CNPC represent total annualized cost ($/year) and total net cost ($), CRF is the capital recovery factor, Rproj is the project life time in years and i is the interest rate (%).

Levelized cost of electricity
The levelized COE is a very important indicator for economic analysis of any hybrid system. The COE means the cost of a kWh electricity generated by the system. The COE is calculated by Homer by dividing total annualized cost (TAC) with respect to the total annualized primary served load (kWh/yr) Eprim, as following: = NPC × CRT(i, N) [32] C NPC = E Prim [33] Table 3. Information regarding Hybrid power system components.

Compared to a scenario of diesel power generation.
The second approach quantifies the amount of avoided CO2 emissions comparing with the scenario of diesel-based power generation. Homer calculates CO2 emissions caused by a diesel EM AV,DG = (3.667 * m f * HV f * X f * CEF f ) − EM HRES [34] where mf represents the fuel volume (liter), HVf refers to the calorific number of the fuel (MJ/L), Xf means fraction of the oxidized carbon and CEFf means the carbon emission factor (tonne of car-bon/TJ), EMHRES and means the emissions emitted by the system. In this work, a hybrid system is designed and its performance characteristics are carefully examined to successfully fulfil the energy demand of the studied area. The proposed hybrid power system is optimized using HOMER, which delivers outcomes regarding the system optimization, performance and sensitivity analysis. HOMER identifies the optimum configuration of the off-grid taking into account the solar, wind and biomass renewable energy sources. HOMER performs simulations to describe the operation of each possible configuration by considering energy balance computations in each time step. At each time, HOMER predicts the energy demand to the corresponding energy from the proposed system, and evaluates the flows of energy between whether to charge/discharge the batteries. According to the computations, HOMER indicates whether a configuration is viable first in terms of satisfying the electric load under the given conditions. Then, it gives a detailed financial evaluation of costs during the whole project lifetime. As such, for each possible configuration, HOMER sorts by net present cost of the investigated options and indicates optimum scenarios inducing lowest life cycle expenditures. Table 5 describes the different scenarios examined by the simulation process. Table 4 shows the possible configurations of supplying the electric load to the studied zone based on the available energy sources. It also indicates design options and installed capacities with respect to each configuration. The most cost-effective system (Scenario A), as described in for unmet load with an excess production of the order of 253 kWh/yr. Following, scenario A has unmet load and excess production 21.4 kWh/yr and 2071 kWh/yr,respectively. The last scenario engenders the higher annual electricity production that surplus is estimated to be 52,605 kWh/year. In the rest of the discussion, the scenario A consisting of the Solar-Wind-Bio sources will be analysed, forming the optimum HRES configuration. Such a configuration is of a particular interest, particularly for guiding strategic policies for diversifying energy mixes.

Analysis of the optimum scenario (A)
The capital cost, the NPC, and operations costs of the suggested system (scenario A) which contains PV-Wind-Biomass-Battery are found to be $49,524, $123,887, and $4,008, respectively. The levelized (COE) is considered to be 0.2 $/kWh . The scenario A consists of a wind turbine with 5.1 kW capacity, 9.11 kW of PV panel, 3 kW of biomass generator, 53 167 Ah of accumulator, 4.7 kW converter with the strategy of cycle charging load. This optimal configuration emits about 9.58 kg/year of CO2. Table 6 shows the pollutants and their concentrations for the optimal configuration. The very low quantity of CO2 emissions can be attributed to the fact that the proposed system does not contain non-renewable energy sources.   Figure 16 : Configuration of the proposed hybrid power system Nitrogen oxides (NO2) 0.0664

Electricity production and economic
analysis for system A Fig. 17 illustrates the monthly average energy generation produced by scenario A. It is observed that the average monthly electricity generation is nearly constant for the biogas generator and solar panels throughout the year. Solar energy generation experiences a slight decrease in October, November, December and January (rainy season with low radiation values, rain and overcast conditions) and the maximum generation is reached in June and July (peak of the summer season ). For the production of electricity generated by biomass decreases in June/July and its maximum is predicted in December. The relative contribution of each component is as 11% of wind power, 41% of solar power and 48% of biomass power, respectively . The biomass generates more power with annual pro-duction of 17,701.00 kWh than other components in the proposed system. PV panels have annual energy contribution of 15,106.00 kWh. The lowest amount of energy is derived from the WT, which is envisaged to be 4167.00 kWh. Table 5 shows that there is energy surplus totalling of 2071 kWh, that is to say 5.6% of overall production. This excess energy can be used to support the increasing energy needs of the farmers (household appliances , greenhouses , …). Unmet load electric for this scenario is around 21.4 kWh/yr, (equivalent to 0.0642%) which is insignificant value proving the effectiveness of the proposed architecture.

Turkish Journal of Computer and Mathematics Education
Vol. 12 No.4 (2021),  Research  Table 7 provides the capital, replacement, O&M, and salvage costs for each element of the hybrid energy system which are found to be $49,524.40, $32,779.54, and $46,142.01, respectively.

Sensitivity analysis
In this study, for a complete technical-economic evaluation of the proposed HRES (scenario A), it is critical to carry out sensitivity analyses on key operating/financial parameters. The first sensitivity deals with the impact of the variation of the discount rate and the inflation rate on the cost of energy and the net present cost of the system. Both parameters were varied from 0% to 10% with an increment of 0.5%.
The cost of electricity (COE) generated by the system hybrid (PV/ Wind/Biomass/Battery) is illustrated in a surface plot as shown in Fig.19. The discount rate (%) is taken along x-axis and the inflation rate (%) along y-axis. According to this figure, the inflation rate and discount rate have an influential effect on the economic performance of the HRES. In other words, by increasing the inflation rate and decreasing the discount rate decreases the unit cost of the energy produced (Nyeche and Diemuodeke, 2020). The second sensitivity study is to evidence the effect of capital cost reduction on the HRES financial performance. The initial cost

Environmental and carbon market analysis
Morocco was committed to COP21 to reduce its GHG emissions in 2030 by 40% compared to projected emissions by 2030. This goal corresponds to a cumulative reduction of 523.5 Mt CO2-eq over the period between 2020 and 2030. The integration of systems based on renewable sources to produce electricity is vital to reduce greenhouse gas emissions and fossil fuel based resources (Anvari et al., 2018). Quantification of CO2 emissions avoided by the proposed system is introduced and compared to the different power generation modes.

Scenario based on grid extension
The avoided CO2 emissions that can arise from replacing grid electrification by the PV-wind-biomass system arecalculated based on Eq. (34). The quantity of CO2 emissions in this case was esti-mated to be around 26.48 tonnes of CO2 per year.

Scenario based on diesel power generation
An additional simulation was carried out considering the same electric demand at the same region. The proposed system contains a non-renewable energy source consisting of the DG-battery to assess the CO2 emissions avoided due to the utilization of The hybrid system based on renewable energy resources. The capital cost and the replacement cost of the diesel generator are consid-ered as 300 $/kW while the maintenance cost is taken equal to 0.03 $/hours. The simulation results are illustrated in Table 7 (Scenario 1). It is an interesting configuration since it allows assessing the amount of CO2 avoided by the PV-Wind-Biomass Battery system discussed above. That is to say, the production of electricity in this case will only be ensured by the diesel generator.In addition to the environmental damage that will be caused by this system, the price of the electricity produced is equal to 0.354. Table 7. Annual electricity production of hybrid system and consumption.    Table 9. Summary of DG-Battery system.

Conclusion :
The monitoring of agricultural fields in terms of production and irrigation water management efficiency at the regional level can be based on the extraction of information from satellite images through the temporal dynamics of biophysical variables that affect crop photosynthesis. The annual NDVI LANDSAT series has been processed according to the classification based on the pixel approach.
The results showed the ability of this methodology to discriminate between cultures. converting to renewable energy in the world in general and in Morocco in particular via several projects such as the Moroccan green plan and green generation in irrigation has become an essential solution, it is in this perspective that we have made a technical study to evaluate first the need for electricity to ensure an irrigation demand and without interruption of six crops in the region of GHarb as shown on the map, and a technical-economic study to evaluate the different variants available. Simulation and analysis results showed that with an average daily energy demand of 92 kWh and a peak load of 6.5 kW, the energy cost of the optimal configuration (scenario A) is $0.19/kWh. This cost increases from scenario A to scenario F. Therefore, option A is the most cost-effective and is chosen as the optimal configuration. For the biomasswind-PV-battery option A, it was shown that the initial investment cost, maintenance cost, NPC and electricity cost are $49,524.40, $4,008, $123,887 and $0.2/kWh respectively. These are competitive figures that outperform the other alternatives studied.