![• 4. Battery sizing
Total appliances use = (18 W x 4 hours) + (60 W x 2 hours) + (75 W x 12 hours)
Nominal battery voltage = 12 V
Days of autonomy = 3 days
Battery capacity = [(18 W x 4 hours) + (60 W x 2 hours) + (75 W x 12 hours)] x 3
(0.85 x 0.6 x 12)
Total Ampere-hours required 535.29 Ah
So the battery should be rated 12 V 600 Ah for 3 day autonomy.
References for solar sizing :
http://www.leonics.com/support/article2_12j/articles2_12j_en.php
http://www.firstgreen.co/2014/08/solar-pv-system-sizing-step-by-step-
approach-to-design-a-roof-top-system-and-software-analysis/](https://image.slidesharecdn.com/splarpv-181215030100/85/Splar-pv-38-320.jpg)
Splar pv
- 1. Solar Photovoltaic system Alternative energy sources
- 2. What is a Photovoltaic Cell? • also called solar cell, is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect. Solar Cell (PV) Light Electricity
- 3. Photovoltaic effect • Sunlight is composed of photons, that contain various amounts of energy corresponding to the different wavelengths of the solar spectrum. • The electrons present in the valence band absorb energy and, being excited, jump to the conduction band and become free. • These highly excited electrons are accelerated into a different material by a built-in potential. • This generates an electromotive force(emf), and thus some of the light energy is converted into electric energy.
- 4. Materials of Solar Cell • Semiconductors ➢Germanium, Silicon ➢Gallium arsenide, Indium arsenide, cadmium sulphide, Cadmium telluride ➢Aluminium gallium arsenide ➢Indium aluminium gallium arsenide
- 5. History of Solar Cells Discovered by French physicist , Alexandre-Edmond Becquerel. A description of the first solar cells made from selenium wafer were made by Charles Fritts and operated at 1% effeciency . Charles Fritts constructed what was probably the first true solar cell. He coated a semiconductor material (selenium) with an extremely thin layer of gold. A cadmium sulphide p-n junction was produced with an efficiency of 6% Audobert and Stora discover the photovoltaic effect in cadmium sulphide (CdS). The Fraunhofer Institute for Solar Energy achieve a 44.7% efficiency in solar cell technology. The University of South Wales breaks the 20% efficiency barrier for silicon solar cells under one sun conditions.
- 6. Solar photovoltaic cell current electron
- 7. Solar cell – Working Principle ⚫ Operating diode in fourth quadrant generates power
- 8. • The solar cell is composed of a P-type semiconductor and an N-type semiconductor. • Solar light hitting the cell produces two types of charge carrier, negatively charged electrons and positively charged holes in the semiconductors. • Negatively charged (-) electrons gather around the N-type semiconductor while positively charged (+) holes gather around the P-type semiconductor. • .
- 9. • When sun light falls on silicon metal cell, the photon energy allows the electrons from the P- layer to move to the N-layer, creating an electric potential difference on the semiconductor borders. • If these borders are connected to a load by conductive wires, there will be a flow of electric current, getting back the electrons to the P-layer and starting the process again. • A photovoltaic cell generally has low current and voltage levels, of about 3 A and 0.7 V, respectively.
- 11. Types of PV cells Silicon Crystalline Cells Thin Film Cells made by using crystalline silicon solar cells, developed from the microelectronics technology industry. made by depositing one or more thin layers (thin film) of photovoltaic material on a substrate. Mono Crystalline PV Cells Multi Crystalline PV Cells Amorphous Silicon PV Cells Poly Crystalline PV Cells (Non-Silicon based)
- 12. Silicon Crystalline Technology Currently makes up 86% of PV market Very stable with module efficiencies 10-16% Mono crystalline PV Cells Made using saw-cut from single cylindrical crystal of Si Operating efficiency up to 15% Multi Crystalline PV Cells Caste from ingot of melted and recrystallized silicon Cell efficiency ~12% Accounts for 90% of crystalline Si market
- 13. Thin Film Technology • Silicon deposited in a continuous on a base material such as glass, metal or polymers. • Thin-film crystalline solar cell consists of layers about 10μm thick compared with 200-300μm layers for crystalline silicon cells. • Low cost substrate and fabrication process. • Not very stable .
- 14. Amorphous Silicon PV Cells The most advanced of thin film technologies . Manufactured by applying thin-layer manufacturing technology for semiconductor Operating efficiency ~6% . Makes up about 13% of PV market . • Mature manufacturing technologies available • Very flexible. Easy to fit on any shape of substrate. • Initial 20-40% loss in efficiency . Glass substrate type Film substrate type
- 17. Solar PV Module • Interconnected smaller solar cells • Two ways 1 Thin film technology 2 Wafer based technology • Solar cell 0.25𝑊𝑃 − 3.37𝑊𝑃 • Solar PV Module 3𝑊𝑃 − 300𝑊𝑃 (𝑊𝑃 =Pick power)
- 19. Series and Parallel connection of cell • Series connection for increase o/p voltage • Parallel connection for increase o/p current
- 21. Mismatch in Module • Difference in the cell processing • Same rating but different manufacturer • Partial shading of cells or modules • Damage caused by UV light on semi- transparent cell • Breaking of glass cover
- 22. Hot spots & Bypass diode in PV Module • Under series short circuit condition of the string cell will become reverse biased. • Due to cell breakdown lot of heat generate and generate extra power Hot spot • Bypass diode is used to avoid the destructive effect of hot spots or local heating. • In parallel connection blocking diodes use for avoid hot spots.
- 24. Components of Si wafer-based PV module
- 25. PV systems • Three categories 1. Stand-alone PV systems 2. Grid-connected PV systems 3. Hybrid PV systems
- 26. Stand-Alone PV system Dependence • Load requirements • Resource availability • Performance of the system • Reliability of the system • Cost of the system
- 27. Type of load in stand-alone PV system ➢Type-a Unregulated with DC load Load varies according sunshine condition No arrangement for energy storage
- 28. Type-b Regulated with DC Load • For power regulator maximum power point tracker(MPPT) circuit inserted. • MPPT circuit gives smooth operation
- 29. Type-c Regulated with Battery and DC Load • Used when non-sunshine hour or night-time operation • Use charge controller circuit to prevent the overcharging and deep discharging
- 30. Type-d Regulated with battery & AC &DC loads
- 31. Type-e Regulated hybrid system with AC and DC loads
- 32. Solar PV System
- 33. Major system components 1) PV Module : converts sunlight into DC electricity. 2) Solar charge controller : Regulates the voltage and current coming from the PV panels going to battery and prevents battery overcharging and prolongs the battery life. 3) Inverter : Convert DC into AC 4) Auxiliary energy sources : diesel generator or other renewable energy sources. 5) Battery 6) Loads
- 34. Solar PV system Sizing 1.Determine power consumption demands: Find out the total power and energy consumption of all loads. 1.1 Calculate total Watt-hours per day for each appliance used and add all. 1.2 Calculate total Watt-hours per day needed from the PV module by multiplying by 1.3 because of system losses. 2. Size the PV modules : To find out the sizing of PV module, the total peak watt produced needs. The peak watt (Wp) produced depends on size of the PV module and climate of site location. We have to consider “panel generation factor”. For India PGF is 4.32.
- 35. 2.1 Calculate the total Watt-peak rating needed for PV modules by dividing total watt hour per day by PGF. 2.2 Calculate the number of PV panels for the system by dividing total watt peak power by rated out put of solar module. 3. Invertor capacity : the inverter must be large enough to handle the total amount of Watts you will be using at one time. The inverter size should be 25-30% bigger than total Watts of appliances. 4. Battery capacity : Total Watt-hours per day used by appliances x Days of autonomy (0.85 x 0.6 x nominal battery voltage) 0.85 because of battery loss 0.6 depth of discharge
- 36. • Example: A house has the following electrical appliance usage: • One 18 Watt fluorescent lamp with electronic ballast used 4 hours per day. • One 60 Watt fan used for 2 hours per day. • One 75 Watt refrigerator that runs 24 hours per day with compressor run 12 hours and off 12 hours. • The system will be powered by 12 Vdc, 110 Wp PV module 1. Determine power consumption demands Total appliance use = (18 W x 4 hours) + (60 W x 2 hours) + (75 W x 24 x 0.5 hours) = 1,092 Wh/day Total PV panels energy needed = 1,092 x 1.3 = 1,419.6 Wh/day.
- 37. 2. Size the PV panel Actual requirement = 4 modules So this system should be powered by at least 4 modules of 110 Wp PV module. 3. Inverter sizing Total Watt of all appliances = 18 + 60 + 75 = 153 W For safety, the inverter should be considered 25-30% bigger size. The inverter size should be about 190 W or greater. 2.1 Total Wp of PV panel capacity needed = 1,419.6 / 3.4 = 413.9 Wp 2.2 Number of PV panels needed = 413.9 / 110 = 3.76 modules
- 38. • 4. Battery sizing Total appliances use = (18 W x 4 hours) + (60 W x 2 hours) + (75 W x 12 hours) Nominal battery voltage = 12 V Days of autonomy = 3 days Battery capacity = [(18 W x 4 hours) + (60 W x 2 hours) + (75 W x 12 hours)] x 3 (0.85 x 0.6 x 12) Total Ampere-hours required 535.29 Ah So the battery should be rated 12 V 600 Ah for 3 day autonomy. References for solar sizing : http://www.leonics.com/support/article2_12j/articles2_12j_en.php http://www.firstgreen.co/2014/08/solar-pv-system-sizing-step-by-step- approach-to-design-a-roof-top-system-and-software-analysis/