Study & Life Cycle Review of Solar PV Systems: an Example of a 25kwp Distributed Solar PV System in Bhopal

Study & Life Cycle Review of Solar PV Systems: an Example of a 25kwp Distributed Solar PV System in Bhopal

Manvendra Singh Thakur1, Miss Savita Vyas2 Anurag Gour3

1. M.Tech Scholar School of Energy Technology, UTD, RGPV Bhopal INDIA

2. Assistant Professor School of Energy Technology, UTD, RGPV Bhopal INDIA

3. Assistant Professor School of Energy Technology UTD, RGPV Bhopal INDIA

Abstract-In life cycle review (LCR) of solar PV systems, energy payback time (EPBT) is the normally used pointer to validate its primary energy use. However, EPBT is a utility of competing traditional energy sources with which electricity generation from solar PV system is compare, and amount of electricity produced from the solar PV system, which changes with solar irradiation and local ambient conditions. Consequently, it is more suitable to use location – specific EPBT for major decision-making in solar PV power generation planning and commissioning. LCR and life cycle cost benefit analysis are performed for a 25 kWp mono-crystalline solar PV system operating in RCVP Noronha Academy of Administration Bhopal Madhya Pradesh. Coordinates: 23°1224N 77°2537E

This paper evaluates different parameters from a life cycle perspective that affect climate change mitigation. The primary objectives are to quantify the different life cycle effects on resulting greenhouse gas (GHG) emissions for electricity produced by mc-Si panels for grid-connected systems in Bhopal Madhya Pradesh. The study considers the effects of energy efficiency measures, location of production, installation, building- integrated options, and climatic effects.

Keywords: life cycle, monocrystalline PV, climate change mitigation.

PV power plant, but it has some benefit also as per the global environment is concern.

Fig 1 The sharing of personified energy requirements for mc-Si PV array power plant

In this paper, we present major life cycle impact parameter (e.g., energy payback time and life cycle emissions) of solar PV technologies for which detailed data are available. This paper also includes the life cycle list data that were the building block of the reported LCR results. Fig 1 shows the distribution of embodied energy requirements for mc-Si PV power plant

1. INTRODUCTION

   This paper presents a review of life cycle assessment (LCA) of solar PV based electricity generation systems. Life cycle assessment of amorphous, mono-crystalline, poly-crystalline, thin film is most superior and secures technologies for the solar panel production has been studied. This paper includes various EPBT analysis of the PV system with reference to an oil fired power generation plant and greenhouse gas (GHG) emissions and their installation costs are compared. This paper proposes that however the cost of electricity generation is high in solar

   Fig: 2 Comparison of different PV cells

   1. Basics of PV solar Cell

   2. The PV cells are basic elements of PV generation system. Analysis of PV cells is basis for researching maximum power point tracking control algorithm. The

   electric generation principle of PV cells comes from PV effect, which of its physic structure is similar to PN junction in diodes. When the sun light shines on PV cells, PN junction can produce voltage. The power of one PV cell is very small. It is necessary for PV array to get greater power by connecting large number of PV cells in series. The equivalent circuit of PV cells is given in Fig.3

   Fig. 3PV Cell equivalent electrical circuit

   1.4. PVcell Performance Characteristics

   The PV Cell VI graph shows reveals that by incident of constant solar irradiance the generated output voltage of a cell falls, to provide more current.

   In an Ideal solar cell

   0

   =

   1 (1)

   Fig: 4 solar cell Array VI Charctestics curve

   The Fill Factor (FF) is defining as the ratio between the

   The open circuit voltage is

   power at the maximum power point and the product of the open circuit voltage and short circuit current. It is typically

   .. (2)

   better than 75% for good quality solar cells.

   = +1

   The short circuit is:

   = = . (4)

   = (3)

   1.3. PV Cell and Module Ratings

   • Standard Test Conditions (STC)

     In order to compare solar cells on a like for like basis a set of Standard Test Conditions (STC) has been defined. The conditions are normal irradiance of 1000w/m2, cell temperature 25 °C & Air Mass =1.5

   • Air Mass

   The receiving surface corresponding to AM 1.5 is defined as an inclined plane at 37° tilt (the average latitude in the USA) toward the equator, facing the sun. In this case, the surface normal points to the sun, at an elevation of 48.81°, its zenith angle, above the horizon.

   • Rated Power

   Rated Power is the maximum power generated measured in (Wp or kWp) by the solar cell or solar module under the Nominal Test Conditions.

2. LIFE CYCLE ASSESSMENT OVERVIEW

   The life-cycle for preparing photovoltaic cell starts from the extraction of raw materials from the material supplied and ends by disposing or recycling of the PV components (Figure 5)

   Fig: 5 Life cycle flow diagram of preparing PV Cell

   The Basic or raw material consist of those for balance-of- system and encapsulations components and the material required for mounting structures. The manufacture of a bulk silicon PV device is divided into several steps, that is, wafer, cell, and module. In the wafer stage, solar-grade polycrystalline or single-crystal silicon ingots are sliced into 0.2 mm thick wafers.

   During the cell stage, a p-n junction is formed by dopant diffusion and electric circuit is created by applying and sintering metallization pastes.

   Plant Specification for 25 kWp mono-crystalline solar PV system operating in RCVP Noronha Academy of Administration Bhopal Madhya Pradesh, shown in table 1

   Particulars	Solar Power Plant
   Capacity	25 KWp
   Type	Roof Top
   Units	1 Unit
   Uses	Battery backup system for existing electrical appliances
   Scope of Supply	Includes Solar PV module,Inverter,Battery
   Solar panel wattage	60 Wp X 90 Nos
   Battery Rating	12 V 1500Ah X 50
   Power Saving PM	1500 units
   Money saved PM	Rs ,9950/-
   Not in Scope	Civil work, conduit material ,wiring
   Technical Support	MPUVN Bhopal
   Cost	52.00 Lack Central subsidy 15.00L State subsidy 10.40L
   Area required	3750 sqft

   Table 1: Specification of solar PV plant

   1. Life Cycle Assessment Indicators and Interpretation

      2.1.1 Primary Energy Demand

      This s the cumulative primary energy demand throughout the life cycle of a PV system. Primary energy is defined as the energy personified in natural resources or that we get from nature of natural resources that has not undergone any anthropogenic conversion and needs to be converted and transported to become usable energy [1].

      1. Energy Payback Time

         Energy payback time is defined, as the period required by renewable energy power plant system to produce the equal quantity of energy (in terms of primary energy equivalent)

         that was used to generate by the system itself. Energy payback for roof top PV power plant or standalone system is shown in fig 6

         (EPBT)=(Emat+Emanuf+Etrans+Einst+EEOL)/((Eagen/n G)EO&)

         Where,

         Emat: Primary energy demand to produce materials comprising PV system

         Emanuf: Primary energy demand to manufacture PV system

         Etrans: Primary energy demand to transport materials used during the life cycle

         Etrans: Primary energy demand to transport materials used during the life cycle

         Einst: Primary energy demand to install the system

         EEOL: Primary energy demand for end-of-life management

         Eagen: Annual electricity generation

         EO&M: Annual primary energy demand for operation and maintenance

         nG: Grid efficiency, the average primary energy to electricity conversion efficiency at the demand side.

         Fig: 6 Payback of energy investment for Rooftop PV system

      2. Return on Energy Investment (ROEI)

         The conventional way of calculating the Return on Energy Investment of PV is as follows:

         EROI = lifetime / EPBT = T· ((Eagen/nG) EO&Mr)/ (Emat+Emanuf+Etrans+Einst+EEOL)

         We noted that sometimes the EROI is computed without the prior conversion of the generated electricity into its primary energy-equivalent, resulting to an EROI lower by a factor of 1/nG than the EROI calculated by the recommended equation above.

         Fig: 7 Cumulative Net Clean Energy Payoff for solar PV system

         It is mandatory to specify the approach on which the calculation is based (total or nonrenewable energy) and thus keep the transparency and traceability of the calculated EROI.Energy return payoff for a solar PV system is shown in fig 5.

         Parameter	Value
         2 Solar Irradiation (kWh/m /yr)	1,700 | 2,400
         System Lifetime	30 years
         Crystalline Silicon Module Efficiency
         Mono-crystalline	14.0%
         Multi-crystalline	13.2%
         Thin Film Module Efficiency
         Amorphous silicon (a-Si)	6.3 %
         Cadmium telluride (CdTe)	10.9%
         Copper indium gallium diselenide (CIGS)	11.5%
         Performance Ratio
         Ground-Mounted	0.80
         Rooftop	0.75

         Table 2: Different Solar PV Array Parameter for Calculation of Life Time

         Cell Type:	Mono-crystalline
         Cell Arrangement:	90 (9x 10)
         Dimensions:	64.5 x 38.7 x 1.57in (1638 x 982 x 40mm)
         Weight:	44.1 lbs (20kg)
         Front Cover:	Tempered glass
         Frame Material:	Anodized aluminum alloy
         Standard Packaging (Modules per Pallet):	24 pcs

         Table 3: Mechanical data for the specified solar PV power plant site

      3. Establishing Baseline emission

      One important consideration for life cycle assessments conducted in India is the verification and evaluation of baseline emissions. Often the studies that span a series of 10-30 years assume the electricity generation mix may remain constant. However, both the electricity mix and emissions will likely change over the next thirty years. Therefore, assessments should incorporate predictive modeling to estimate the future electricity generation mix. Another issue arises when studies assume that all electricity produced by solar electricity will replace electricity generated by a conventional source. However, with expected electricity demand to increase, it is unclear how much the electricity supply will increase and therefore whether solar will supplement the current electricity or displace the production of marginal electricity sources. These issues all affect the amount of GHG emissions offset by generating solar electricity and create different life cycle assessment results

3. SIMULATION RESULTS FOR DIFFERENT SOLAR PV TECHNOLOGIES

Fig: 8 Thin Film PV Array

Fig: 9 Standards Crystalline Array

REFRENCES

Fig: 10 High Efficiency Crystalline

Fig: 11 Electrical energy [production curve for different solar PV technologies

CONCLUSION

An assessment of renewable energy technologies for their potential to decrease GHG emissions requires careful analyses of all the stages in the life of the fuels and devices. Quantifying such emissions in both present-day and prospective contexts is dominant for comparing the environmental profiles of different electricity-generation options. GHG emissions in the lifecycles of solar electric and nuclear-fuel- technologies vary, depending on the efficiencies of upstream energy, local conditions, and other assumptions. Previous studies showing nuclear technology to have a clear GHG advantage over PV are greatly outdated; the emissions from the life cycles of the two cycles are comparable under todays average Asian country Conditions. In addition, GHG emissions during the life cycle of PV are lower than those from a biomass direct-firing cycle and an order of magnitude lower than those from coal, petroleum and natural gas burning. Established trends in the PV cycles of current PV technologies are expected to keep further reducing emissions in the solar-electric cycle.

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