Techno-Economic Analysis of Hybrid Renewable Power Generation System Under Different Climatic Zones in India

10 This research focuses on the techno-economic analysis of hybrid renewable energy systems 11 (HRESs) for power generation under different climatic zones i.e., composite, temperate, cold, 12 warm and humid, and hot and dry. The system is modelled and simulated based on 13 meteorological data of New Delhi, Bangalore, Srinagar, Kolkata and Jodhpur. It consists of a 14 solar photovoltaic system (PV), a wind turbine, a fuel cell, a converter, an electrolyzer, and a 15 hydrogen tank. Srinagar has the highest total net present cost (NPC) of 57,44,105.53 US$ 16 whereas Bangalore has the lowest NPC i.e., 34,01,103.82 US$. Hydrogen production range is 17 between 1955 to 1963 kg/yr for all climatic zones. Solar PV power is reasonably good for all 18 climatic zones whereas wind power is not suitable for colder zones, but it is proven to be 19 quite good for hot and dry climatic conditions. Therefore, installing a HRES according to the 20 climatic conditions will provide a sustainable and dependable energy solution that solves 21 climate issues, improves energy security, and encourages ecological responsibility.


Introduction
In today's globalising world, the rising demand for energy due to population growth and industrialisation is largely satisfied by fossil fuels that release greenhouse gases like methane (CH4), nitrous oxide (N2O) and carbon dioxide (CO2) [1].Currently, interest in producing power via renewable energy sources (RESs) is growing in equally the public and private sectors, because of an enormous rise in the cost of fossil fuels and the threats to the environment produced by the usage of traditional fuels [2].As a result, RESs are viable options for generating power since they are dependable, environmentally friendly, and freely available.This technology provides safe, clean, and ecologically beneficial energy.Another significant advantage of this technology is its minimal maintenance and running expenses, as it contains no moving components.These characteristics make this technology suitable for producing energy for a wide variety of applications.Renewables, particularly solar PV and wind have gained the greatest ground of all forms of energy this decade, accounting for 43% of global power output in 2030, up from 28% currently [3].The aforementioned structure is intended to be an environmentally friendly solution since it seeks to increase the use of RESs.
PV generators are simple devices that convert sunlight into electrical energy [4].From an operational perspective, the production power of PV power generation varies greatly due to weather variability.Another disadvantage is that PV is sunlight-dependent, and its production does not meet load demand throughout the year [5].
An approach to overcoming this challenge is to combine the solar framework with additional power sources like fuel cell, wind power, electrolyzer, hydrogen tank and convertor, to ensure a continuous 24-hour power supply.Ram et al. presented an in-depth study of the capabilities and limits of various HRES software, claiming that HOMER can do a techno-economic analysis [6].Baghel et al. investigated the effect of tilt angle and albedo on the specific production of solar PV systems.Results indicate a linear relationship between albedo, tilt angle and specific production [7].Aykut et al. investigated grid-connected HRESs.The optimal system's NPC is determined to be US$ 5.612.501,while the LCOE is 0.067 $/kW and also reduces greenhouse gas emissions [8].Kumar et al. looked into the viability of a PV/diesel HPS from an economic standpoint in diverse climate zones of Tamil Nadu.Kanyakumari is the ideal climate zone in Tamil Nadu for setting up a PV/diesel HRES based on the NPC, renewable fraction (RF), carbon emission in tons/year, and diesel consumption in lit/year [9].Kallio et al. investigated the HRES using Matlab/Simulink to identify the individual COE of items.The charges vary greatly on a monthly and regional basis.The lowest yearly specific cost of electricity is 0.29 €/kWh in the southernmost region, while the lowest specific cost of heat products is 0.319 €/kWhex (0.034 €/kWh) and overall exergy efficiency is 13% to 16% [10].
Babatunde et al. investigated an off-grid hybrid PV, micro wind turbine, and RES with hydrogen and battery storage.In South Africa, the total NPC and LCOE of the ideal energy system were 8771 US$ and 0.701 US$/kWh, respectively, compared to 9421 US$ and 0.756 US$/kWh in Nigeria [11].Turkay et al. evaluated the economics of standalone and gridconnected HRES.Results reveal that grid-connected HRESs are more likely to adapt than independent (100% renewable system) designs [12].Nallolla et al. investigated an HRES by evaluating the lowest possible LCOE: 0.244 $/kWh, NPC: $7.01 M, and the high RF: 84.1%.This ideal HRES setup offers a consistent power supply with no unfulfilled loads [13].Lau et al. examined an HRES containing PV/BS (417 batteries, 1476 kW solar PV, hydrogen tank 20 kg, electrolyzer 200 kW, and 59.6 kW converter) by evaluating the lowest feasible LCOE: 0.244 $/kWh, NPC: $7.01 M, and the highest RF: 84.1%.It became clear that adopting a hybrid PV/diesel system with batteries could produce considerably cheaper NPC and COE than an independent diesel system with a 25-year projected horizon and a 6% annual interest rate [5].Ismail et al. examined a system that consists of solar panels, a battery bank, and a diesel generator; the COE is 0.239 US$/kWh with a contribution from the sun of 90% and a battery bank of 0.4 AD.When CO2 emissions were considered, it was observed that a diesel generator produces more CO2 when in operation, than a PV, battery, and diesel generator HRES [14].Koussa et el.analysed the design of a HRES that combines wind and solar energy with battery storage [15].Basu et al. found the hybrid structure is the most practicable, where electricity demand is moderate [16].Bhayo et al. investigated and optimised a standalone HRES for powering a 3.032 kWh/day dwelling unit [17].
According to the literature, no detailed techno-economic study based on meteorological data for different climatic zones in India utilising HOMER has been performed.The effect of climatic conditions on power generation using solar PV, wind energy, fuel cell and electrolyzer has been carried out for five different cities i.e., New Delhi, Bangalore, Srinagar, Kolkata and Jodhpur.The present investigation is completed using the National Renewable Energy Laboratory's (NREL) HOMER model.Wind power generation is highly appreciable for Jodhpur, Kolkata and Bangalore.However, it is not good for Srinagar i.e., cold climatic conditions.Additionally, it has been found that installing such a system as per the local climate can greatly reduce emissions, encourage environmental sustainability, and improve power generation.The study's findings will aid investors and policymakers in identifying climatic conditions based on expertise that will deliver the best return on investment for significant projects in the residential and industrial sectors.

2.
Material and Methods

Site Selection
India has five distinct stations, each with a wide range of climates.The following subsections provide a brief description of these zones, which have unique climates that are intended to be hot and dry, warm and humid, temperate, composite, and cold.The five stations that correlate to the five climatic regions of India are New Delhi, Bangalore, Srinagar, Kolkata and Jodhpur as given in Table 1 and the location of the selected site is shown in Figure 1(a).The primary goal of the system is to supply electricity and produce hydrogen to balance out the irregular nature of RESs. Figure 1(b) shows the layout of HRES and it consists of the solar PV system, a wind turbine, a fuel cell, a converter, an electrolyzer, and a hydrogen tank.The size and cost of the HRES must be optimised to achieve an optimal cost-performance ratio for different climatic zones of India.

Availability of resources at the selected stations
Table 2 depicts the vast potential of available annual average solar radiation and annual average wind speed of the selected stations.As per the NASA prediction data, Bangalore station has the highest potential for solar radiation and wind speed and Srinagar has the lowest potential for the same.Figure 2 and Figure 3 show the NASA prediction of the worldwide energy resource database for solar global horizontal irradiation resources and monthly average wind speed at 50m above the surface of the earth.multiplying the current and voltage as given by Eq. ( 1) [19].
The installation and replacement costs of a 1 kW solar PV energy system are estimated to be US$ 3000 for each and a 90% derating factor.The solar PV arrays are supposed to have a lifecycle of 25 years.

Hydrogen Fuel Cell
Hydrogen fuel cells (HFCs) are electrochemical devices that use an electrochemical reaction with oxygen to convert the chemical energy of hydrogen fuel into electrical energy.Water and heat are the by-products of this chemical process.Every HFC must connect electrodes, one positive and one negative, referred to as the cathode and anode, respectively.Hydrogen is the main fuel used in fuel cells, however, oxygen is also required.
Due to their high power density, precise power, low operating temperature, durability, efficiency, and ability to perform well in dynamic environments, proton exchange membrane (PEM) fuel cells are among the best options for distributed generation in HRES.Fuel cells use hydrogen as their main fuel, but they also need oxygen.Tanks filled with compressed gas are the standard method for storing hydrogen.Fuel cells use hydrogen as their main fuel, but they also need oxygen.In tanks filled with compressed gas, hydrogen is often stored.An HFC voltage is given by Eq. ( 2) [20].
UtH2 and UtO2 stand for utilisations of hydrogen and oxygen, Pffuel and Pfair for supply pressures of fuel and air, respectively, Vffuel and Vfair for flow rates of fuel and air, respectively, and x% and y% for the proportions of hydrogen and oxygen in the fuel oxidant, respectively.The UtH2 and UtO2 are given by Eq. ( 5) and Eq. ( 6) respectively [20].

Electrolyzer
An electrolyzer is an apparatus that electrolyzes water (H2O) to separate it into hydrogen (H2) and oxygen (O2), using electrical energy.Two electrodes are submerged in an electrolyte solution in an electrolyzer.The electrodes connected to the positive and negative terminals of a power source are referred to as anode and cathode, respectively.Water molecules at the cathode undergo reduction to produce hydrogen gas (H2) when an electric current is supplied, whereas water molecules at the anode experience oxidation to release oxygen gas (O2).
According to Eq. ( 7), modelling is done for the input electrical energy dependence on the hydrogen mass flow [20].

Wind Turbine
Wind turbine system having a rated capacity of 3 kW and a maximum output of 150 kW is modelled.The power output of a wind turbine is determined at each time step by HOMER using hourly wind speed and direction data for that particular region.Usually, a meteorological station provides this data.To predict the power output of the wind turbine under typical temperature and pressure circumstances, HOMER first determines the hub height and wind speed.The anticipated power value from the power curve is multiplied by the air density ratio by HOMER to take into consideration the actual environmental circumstances.If the wind speed at the hub height is greater than the range allowed by the power curve, the turbine is unable to produce any electricity.In this instance, it is presumed that wind turbines cannot generate power at wind speeds beyond the maximum cut-off or below the cut-in.By applying linear interpolation to locations where the power curve is recorded, HOMER calculates the wind turbine yield.A power curve illustrates the entire amount of power produced by the wind speed at the centre point height.The turbine's output is zero, outside of the power curve.When the required wind speed for operation is too low for producing energy, the turbine shuts off to prevent damage.In this investigation, A 3 kW G3 turbine with a 17 m hub height is employed.The capital cost is US$ 18000 and 20 years lifespan.The power output of a wind turbine is calculated as in Eq. ( 8), and the wind speed acting on the wind turbine is calculated as in Eq. ( 9) [1].

Converter
Power converters are the main components of HRESs.Power electronics devices are significant.Throughout the AC and DC segments, a power electronic converter is expected to maintain power upstream.A 60 kW capacity converter is used for this system.The capital cost of the converter is 300 US$, and the replacement cost is also 300 US$ for 1 kW.A unit's lifespan is estimated to be 15 years with a 95% efficiency.Converter efficiency is calculated by Eq. ( 10) [13].

Cost analysis of hybrid renewable energy system
In the cost-advancement approach, HOMER duplicates each framework design in the search space and displays the potentially viable ones in a diagram, arranged with NPC.Therefore, it only displays the least-cost configuration inside each system category or type, revealing only a portion of these overall optimisation findings.The cost of the HRES is the sum of the costs of each of its components.As an example, the cost of a fuel cell (CFC), hydrogen tank (CHtank), solar PV system (CSPV), wind turbine system (CWTS), electrolyzer (CElect), and system converter (CConv) is the total cost of an HRES is given by the Eq.(11).
The cost of each component of HRES is finding out by using Eq. ( 12), The first thing HOMER does is to assess the system's specific achievability and capacity to handle the load demand.Secondly, it evaluates the total NPC of the system, which represents the system's life-cycle costs, comprising of initial setup costs (IC), replacement part costs (RC), fuel costs (FC), operation and maintenance costs (OM), and the costs associated with obtaining power from the network.NPC of the HRESs is given by Eq. ( 13) [8] and capital recovery factor (CRF) is given by Eq. ( 14) [4].

Results and Discussions
With the help of the HOMER software, simulation has been done according to the input parameters and limitations mentioned above.According to the total NPC and the necessary power demands for a specific station under its existing energy resources, HOMER Pro simulates the available resources according to the different selected stations, and every system arrangement in search space and assesses the more feasible ones.Figure 4 shows the power output of the flat plate PV throughout the year with 100 kW to 200 kW rated capacity of solar PV panels.The total rated capacity of wind turbines varies from 150 kW to 300 kW for all the stations.The lowest wind penetration is found in Srinagar while the highest is in Kolkata as shown in Figure 5. Fuel cell generator capacity ranges from 0 kW to 60 kW.
Figure 6 shows the generator power output for each hour of the day throughout the year.
Electrolyzer input power capacity ranges from 0 kW to 60 kW as shown in Figure 7.As seen in Figure 8, the capacity factor for New Delhi is 21.2% whereas 18.9% for Kolkata.
The total production of Kolkata is get decreased by 10.84 % as compared to New Delhi.The wind turbine capacity factor is extremely low in Srinagar.However, the annual average wind speed is 2.41 m/s i.e., also very less as compared to all other stations.The LCOE of Srinagar is 6.14 US$/kWh and it is 94.95% more than the LCOE of Jodhpur.The capacity factor of Bangalore is 20.7% i.e., the highest capacity factor while Srinagar's capacity factor is 0.945.
Therefore wind power generation is not a good choice for cold climatic zones (Figure 9).The overall NPC, capital cost, and cost of energy (COE) of all the stations i.e., New Delhi, Bangalore, Srinagar, Kolkata and Delhi are evaluated through simulation.The Proposed HRES system for Srinagar is the highest total NPC i.e., 57,44,105.53US$ and the proposed system is very cost-effective for Bangalore.The capital cost is also very high for Srinagar whereas the capital cost is the same for the three stations i.e., New Delhi, Bangalore and Jodhpur as given in Table 3.    Figure 15 illustrates the monthly electricity generation for all the stations.Here, Srinagar is contributing 74% of the total electricity generated by solar PV, while Kolkata is contributing the least.All of the station's average electricity generation from fuel cells ranges from 11% to 21%.It is feasible to produce electricity using wind turbines in New Delhi, Bangalore, Jodhpur, and Kolkata and for the Srinagar station, wind power is not very ideal.

Conclusion
Techno-economic analysis has been carried out based on five different climatic zones i.e., hot and dry, warm and humid, composite, temperate and cold via meteorological data of five cities namely New Delhi, Bangalore, Srinagar, Kolkata and Jodhpur.A system made up of Solar PV, wind, fuel cell, electrolyzer and converter has been modelled, simulated and optimized using HOMER to find out the best suitable.The following conclusion has been drawn based on the analysis: • Srinagar has the highest LCOE i.e., 1.7 US$/kWh and whereas Jodhpur has the lowest LCOE i.e., 1.14 US$/kWh.The total NPC for Srinagar is 57,44,105.53US$ whereas Bangalore has the 40.78 % lowest NPC as compared to Srinagar.
• Wind power is not suitable for colder zones and it is found very suitable for hot and dry climatic conditions.LCOE of wind energy power generation in Srinagar is 6.14 US$/kWh whereas 0.31 US$/kWh for Jodhpur.
• Fuel consumption is highest in New Delhi i.e., 4,602 kg under composite climatic conditions whereas lowest for Bangalore i.e., 3689 kg.The capacity factor of the electrolyzer is 17.3 % and its value is the same under all climatic conditions, However, the hydrogen production is lowest in Srinagar i.e., 1955 kg/yr and highest for Bangalore and Kolkata i.e., 1963 kg/yr.
• Electricity production using solar PV is 44% and 74% in New Delhi and Srinagar respectively whereas 60%, 50% and 53% use wind power.Results show solar PV is a good choice for all climatic zones, however, wind power generation is restricted to warm and humid, temperate, hot and dry climatic zones.
As per the findings, the goal of climatically appropriate HRES design is to produce an effective and dependable energy generation system that maximises the use of available RESs while taking into account the region's unique climatic characteristics.This kind of technology

Figure 1 :
Figure 1: (a) Selected site locations in India and (b) Layout of HRES

Figure 4 :Figure 5 :
Figure 4: Power output of generic flat plate PV

Figure 8 :
Figure 8: Total production and capacity factor of solar PV for all the stations

Figure 9 :
Figure 9: Total production and capacity factor of wind turbine for all the stations

Figure 10 :Figure 11 :
Figure 10: Overall Total NPC, operating cost and Levelized COE of all stations

Figure 12 :
Figure 12: LCOE for PV, wind turbine and the overall system

Figure 13 :
Figure 13: Annual emissions produced from the HRES

Figure 14 :
Figure 14: Total NPC of all stations of HRES (a) Based on different types of cost (b) Based

Table 2 :
Potential of solar radiation and wind speed of different selected stations

Table 3 :
Total optimized NPC of HRES in 25 years of operation at different stations Results show that the capital cost of installing an HRES in Srinagar is 41.19% higher than New Delhi, Kolkata and Jodhpur stations.The replacement cost of Bangalore station is very feasible i.e., 8,90,039.26US$ whereas 17,90,376.28US$ for Srinagar.Overall total NPC for Srinagar station is 57,44,105.53US$ and Bangalore has the 40.78 % lowest NPC as compared to Srinagar.The detailed cost analysis based on the various components is shown in Figure 14(b).