Understand Solar PV Panel and roof top project

3. What is a photovoltaic (PV) system?
• PV technology produces electricity directly from electrons freed by the interaction
of sunlight with a solar panel made of semiconductor material. The power
provided is direct current (DC) electricity. The basic building block is known as a
Solar cell. Many cells put together are known as a module, and many modules
assembled together form an array. A PV system will consist of an array of modules
generating DC electricity, an inverter and can be stored in battery storage banks.

4. Photovoltaic (PV) Hierarchy
• Cell < Module < Panel < Array

5. Available Cell Technologies
• Single-crystal or Mono-crystalline Silicon
• Polycrystalline or Multi-crystalline Silicon
• Thin film
• Ex. Amorphous silicon or Cadmium Telluride

6. Monocrystalline Silicon Modules
• Most efficient
commercially available
module (17% - 21%)
• Most expensive to produce
• Circular (square-round) cell
creates wasted space on
module

7. Polycrystalline Silicon Modules
• Less expensive to make
than single crystalline
modules
• Cells slightly less efficient
than a MONO crystalline
(15% - 19%)
• Square shape cells fit into
module efficiently using the
entire space

8. Amorphous Thin Film
• Most inexpensive technology
to produce
• Metal grid replaced with
transparent oxides
• Efficiency = 8 – 12 %
• Can be deposited on flexible
substrates
• Less susceptible to shading
problems
• Better performance in low
light conditions that with
crystalline modules

9. Selecting the Correct Module
• Practical Criteria
• Size
• Voltage
• Availability
• Warranty
• Mounting Characteristics
• Cost (per watt)

10. Current-Voltage (I-V) Curve

11. Effects of Temperature
• As the PV cell
temperature increases
above 25º C, the
module Vmp decreases
by approximately 0.5%
per degree C

12. Effects of Shading/Low Insolation
• As insolation
decreases
amperage
decreases while
voltage remains
roughly constant

13. Shading on Modules
• Depends on orientation of internal module circuitry relative to the
orientation of the shading.
• SHADING can half
or even completely
eliminate the output
of a solar array!

14. Series Connections
• Loads/sources wired in series
• VOLTAGES ARE ADDITIVE
• CURRENT IS EQUAL

15. • Loads/sources wired in parallel:
• VOLTAGE REMAINS CONSTANT
• CURRENTS ARE ADDITIVE
Parallel Connections

16. What are the different types of rooftop solar PV
systems?
• Grid Connected - These systems have no storage other than the grid itself. Any
excess electricity generated from solar system is fed back into the grid. At night or
during times of intense cloud cover, the installation draws power from the grid.
• Hybrid (Grid tied with Storage) - These systems are grid connected, but also
have some storage capacity by way of a small battery bank. They provide some
measure of continuity when the grid goes down at the same time as there is not
sufficient solar input.

17. What are the components of a photovoltaic (PV) system?
• A PV system or a stand-alone system made up of different components. These
include PV modules (groups of PV cells), which are commonly called PV panels;
one or more batteries; a charge regulator or controller fasten; an inverter for a
utility-grid-connected system and when alternating current (ac) rather than direct
current (dc) is required; wiring; and mounting hardware or a framework.

18. Electricity Terminology
• Voltage
• Measured in Volts
• Electrical potential
• Current
• Measured in Amps
• Rate of electron flow
• Resistance
• The opposition of a material to the flow of an electrical current
• Depends on
• Material
• Cross sectional area
• Length
• Temperature
• Watt
• Measure of Power
• Rate of electrical energy
• Not to be confused with Current!
• Watt-hour (Wh) is a measure of energy
• Unit quantity of electrical energy (consumption and production)
• Watts x hours = Watt-hours
• 1 Kilowatt-hour (kWh) = 1000 Wh

19. Types of Current
• DC = Direct Current
• PV panels produce DC
• Batteries store DC
• AC = Alternating Current
• Utility power
• Most consumer appliances
use AC
• Electric charge changes
direction

20. Symbols and Units
Voltage: E or V (Volts)
Current: I or A (Amps)
Resistance: R or Ω (Ohms)
Watt: W (Watt)

21. Typical Wattage Requirements
Appliance Wattage
Blender 350
TV (25 inch) 130
Washer 1450
Sunfrost Refrigerator (7 hours a
day)
refrigerator/freezer (13 hours a
day)
112
475
Hair Dryer 1000
Microwave (.5 sq-ft)
Microwave (.8 – 1 sq-ft)
750
1400

22. Grid-Tied System Overview

23. Grid-Tied System
• Advantages
• Easy to install
(less components)
• Grid can supply power
• Disadvantages
• No power if grid goes
down

24. Wire Components
• Conductor material = copper (most common)
• Insulation material = thermoplastic (most common)
• Wire exposed to sunlight must be classed as sunlight resistant

25. Color Coding of Wires & Conduit
• Electrical wire insulation is color coded to designate its
function and use
Alternating Current (AC) Wiring Direct Current (DC) Wiring
Color Application Color Application
Black Ungrounded Hot Red (not NEC req.) Positive
White Grounded
Conductor
White Negative or
Grounded
Conductor
Green or Bare Equipment
Ground
Green or Bare Equipment
Ground
Red or any
other color
Ungrounded Hot
• Cable: two or more insulated conductors having an overall
covering
• Conduit: metal or plastic pipe that contains wires

26. Wire Size
• Wire size selection based on two criteria:
• Ampacity
• Voltage drop
• Ampacity - Current carrying ability of a wire
• Voltage drop: the loss of voltage due to a wire’s resistance and
length

27. Safety Considerations
• Unsafe Wiring
• Splices outside the box
• Currents in grounding conductors
• Indoor rated cable used outdoors
• Single conductor cable exposed
• “Hot” fuses

28. Safety Equipment
• Disconnects • Overcurrent Protection

29. Grounding
• Provides a current path for surplus
electricity to travel too (earth)

30. Solar Site & Mounting
• Understand azimuth and altitude
• Describe proper orientation and tilt angle for solar collection
• Evaluate structural considerations
• Pros and cons of different mounting techniques

31. Site Selection – Panel Direction
• Face true
south
• Correct for
magnetic
declination

32. Altitude and Azimuth

33. Solar Pathfinder
• An essential tool in finding a good site for solar
energy is the Solar Pathfinder
• Provides daily, monthly, and yearly solar hours
estimates

34. Site Selection – Tilt Angle
Year round tilt = latitude
Winter + 15 lat.
Summer – 15 lat.
Max performance is
achieved when panels
are perpendicular to the
sun’s rays

35. Solar Access
• Optimum Solar Window 9 am – 3 pm
• Array should have NO SHADING in this window (or longer if possible)

36. General Considerations
• Weather characteristics
• Wind intensity
• Estimated snowfall
• Site characteristics
• Corrosive salt water
• Animal interference
• Human factors
• Vandalism
• Theft protection
• Aesthetics
• Loads and time of use
• Distance from power conditioning equipment
• Accessibility for maintenance

37. Basic Mounting Options
• Fixed
• Roof, ground, pole
• Integrated
• Tracking
• Pole (active & passive)

38. Pole Mount Considerations
• Ask manufacturer for wind loading specification
for your array
• Pole size
• Amount of concrete
• Array can be in close proximity to the house, but
doesn’t require roof penetrations

39. Tracking Considerations
• Can increase system performance by:
• 15% in winter months
• 30% in summer months
• Adds additional costs to the array
• Require regular maintenance

40. Passive Vs. Active
Active:
• Linear actuator motors controlled
by sensors follow the sun
throughout the day
Passive:
Have no motors, controls, or gears
Use the changing weight of a gaseous
refrigerant within a sealed frame member
to track the sun

41. Roof Mount Considerations
• simple and cheap to install
• offer no flexibility in the orientation of your solar
panel.
• can only support small photovoltaic units.
• Penetrate the roof as little as possible
• Weather proof all holes to prevent leaks
• May require the aid of a professional roofer
• Re-roof before putting modules up
• Leave 4-6” airspace between roof and modules
• On sloped roofs, fasten mounts to rafters not
decking

42. Building Integrated PV

43. Solar Energy Incentives
• Tax credits and deductions
• 30% tax credit
• Local & state grant and loan programs

44. Hybrid System
(With Batteries)
• Complexity
• High: Due to the addition
of batteries
• Grid Interaction
• Grid still supplements
power
• When grid goes down
batteries supply power to
loads

45. Battery Basics
 Battery
 A device that stores electrical energy (chemical energy to electrical
energy and vice-versa)
 Capacity
 Amount of electrical energy the battery will contain
 State of Charge (SOC)
 Available battery capacity
 Depth of Discharge (DOD)
 Energy taken out of the battery
 Efficiency
 Energy out/Energy in (typically 80-85%)
The Terms:

46. Batteries in Series and Parallel
• Series connections
• Builds voltage
• Parallel connections
• Builds amp-hour capacity

47. Functions of a Battery
Storage for the night
Storage during cloudy weather
Portable power
Surge for starting motors
**Due to the expense and inherit inefficiencies of batteries it is
recommended that they only be used when absolutely necessary (i.e.
in remote locations or as battery backup for grid-tied applications if
power failures are common/lengthy)

48. Batteries: The Details
Primary (single use)
Secondary (recharged)
Shallow Cycle (20% DOD)
Deep Cycle (50-80% DOD)
Types:
 Unless lead-acid batteries are charged up to 100%, they will loose
capacity over time
 Batteries should be equalized on a regular basis
Charging/Discharging:

49. Battery Capacity
 Amps x Hours = Amp-hours (Ah)
Capacity:
100 amps for 1 hour
1 amp for 100 hours
20 amps for 5 hours
 Capacity changes with Discharge Rate
 The higher the discharge rate the lower the capacity and vice versa
 The higher the temperature the higher the percent of rated capacity
100 Amp-hours =

50. Rate of Charge or Discharge
Rate = C/T
C = Battery’s rated capacity (Amp-hours)
T = The cycle time period (hours)
Maximum recommend charge/discharge rate = C/10

51. Battery Safety
• Batteries are EXTREMELY DANGEROUS; handle with care!
• Keep batteries out of living space, and vent battery box to
the outside
• Use a spill containment vessel
• Don’t mix batteries (different types or old with new)
• Always disconnect batteries, and make sure tools have
insulated handles to prevent short circuiting

52. Controller Considerations
• When specifying a controller you must consider:
• DC input and output voltage
• Input and output current
• Any optional features you need
• Controller redundancy: On a stand-alone system it might be desirable to have more then
one controller per array in the event of a failure

53. Inverter Basics
• An electronic device used to convert direct current (DC)
electricity into alternating current (AC) electricity
Function:
 Efficiency penalty
 Complexity (read: a component which can fail)
 Cost!!
Drawbacks:

54. Specifying an Inverter
• What type of system are you designing?
• Stand-alone
• Stand-alone with back-up source (generator)
• Grid-Tied (without batteries)
• Grid-Tied (with battery back-up)
• Specifics:
• AC Output (watts)
• Input voltage (based on modules and wiring)
• Output voltage (120V/240V residential)
• Input current (based on modules and wiring)
• Surge Capacity
• Efficiency
• Weather protection
• Metering/programming

55. What is net-metering?
• Net-meter (bi-directional meter) is having provision to record energy imported
from the grid to meet the load and energy exported to the grid after self-
consumption. Both energy import and export records in the net-meter. The
difference between Export and Import readings is the actual energy
consumed/delivered.
• The net meter records surplus energy exported to DISCOM grid. When your
system generates less energy than your consuming load, the meter records
energy imported from DISCOM grid.

56. How the billing and payments are made?
i. The consumer shall receive monthly a net import/export bill indicating
either net export to the grid or net import from the grid.
ii. In case of net import bill, the consumer shall settle the same as per existing
norms. If it is a net export bill (after self-consumption), net credit amount
payable will be deposited by DISCOM into consumer’s bank account,
provided by consumer at the stage of submission of application.
iii. The amount payable for net export of energy shall be as per APPC prevailing
tariff of GERC.
iv. The credit if any shall be settled within 30 days from the date of meter
reading and credited to the bank account through NEFT or settle in next
billing cycle.

57. What is the annual energy generated from a 1 KW Solar Power
plant?
• The usual benchmark for energy generated from a 1 KW Solar Power plant is
considered as 1500 units. This is only a benchmark and should not be considered as
the actual output for a given location. The amount of actual energy generated from a
Solar Power Plant in a year depends on both internal and external factors. External
factors which are beyond the control of a solar developer can include the following:
• Number of sunny days
• Solar Irradiation
• Day Temperatures
• Air Mass
• The output also depends on the following internal factors all of which are within the
control of a Solar Developer:
• Plant Location
• Usage of Solar Tracking systems
• Quality of equipment used
• Workmanship of the EPC contractor
• O&M activities

58. What permissions/clearances are required to setup a Solar PV
Plant?
• A certain set of permissions need to be obtained and documents need to be submitted
in order to setup a Solar PV plant. While these may vary from state-to-state, in order
to get a Solar PV Project Accredited by Gujarat State Load Dispatch Center (Gujarat
SLDC) for REC mechanism, the following are the statutory clearances and
environmental clearances to be furnished:
• Industrial Clearance
• Land conversion (Agricultural to Non-Agricultural)
• Environmental Clearance Certificate from GPCB, Gujarat
• Contract labour license from Gujarat Labour Department
• Fire Safety certificate from Gujarat Fire Department
• Latest tax receipt from the Municipal/Gram Panchayat for the factory land.
• Auditor compliance certificate regarding fossil fuel utilization
• Approval from Chief Electrical Inspector
• Clearance from Forest department

59. Continued…
• Also, all necessary approvals/agreements before start of Solar PV
project construction are to be furnished as and when necessary.
These include the following:
• Land purchase
• Power Evacuation arrangement permission letter from DISCOM
• Confirmation of Metering Arrangement and location
• ABT meter type, Manufacture, Model, Serial No. details for Energy Metering.
• Copy of PPA (important as Preferential PPA projects are not eligible for REC mechanism)
• Proposed Model and make of plant equipment
• Undertaking for compliance with the usage of fossil fuel criteria as specified by MNRE
• Details of Connectivity with DISCOM
• Connectivity Diagram and Single Line Diagram of Plant
• Any other documents requested by GEDA

60. 125 KWp Solar PV Plant @WAGH-BAKRI
by
TOPSUN ENERGY LIMITED
Gujarat Tea Processors &
Packers Ltd
(Wagh Bakri Tea Group)
Site Address: Dholka, Ahmedabad

61. The benefits from a 1 MWp Grid-parallel Solar PV Plant are as
follows:
• A Solar PV Plant is the greatest insurance against rising power tariff.
• It produces power over its life at less than Rs. 4/unit (Considered -25 years)
• PV Plants can reduce power bills by up to 70% (for day-based units).
• A Solar PV Plant produces stable power throughout the day.
• Accelerated Depreciation benefit available under Section 80 IA sub-section 4
(Income Tax) for projects executed & commissioned.
• Good IRR’s = between 15% - 23% (factor dependent).
• Solar PV Plants are virtually maintenance free.
• Solar Plant can generate electricity for around 25 years.
• Gujarat Govt.declared Solar Rooftop Policy in that you can feed your extra power to
Discom & Discom will pay you money as per APPC Rate.
• Additional REC (Renewable Energy Certificate) Rs.3.5/unit will sell to those customer who
need the REC.

62. Power generated by the system over a period of 25 years 3.35 Cr kwh
Initial investment by the beneficiary Rs. 6 Cr
Interest @ 12.5% till the payback has been achieved Rs. 2.5 Cr
Guaranteed Generation 13,72,500 kWh per year
Cost of inverter replacement in 8th / 16th year Approx. Rs. 60 lakhs to Rs. 80 lakhs
Lifetime Savings Approx. Rs. 45-50 Cr
Accumulated cost for O & M for 25 yrs Rs.2.55 Cr
(Considered 5 % escalation Y-O-Y)
Levelized Cost Of Energy Less than Rs. 4 /unit
IRR 16 % IRR
IRR & LCOE : 1 MWp Solar PV Plant

63. Solar Capacity 1 MWp
Area Required 10000-15000 Sq.m
Roof Type & Orientation PEB Structure, G.I Sheet– East West direction & South direction
Power Tariff per KWh Rs. 7 & above KWh
Guaranteed Generation 13,72,500 kWh per year
Annual Savings Rs. 96,07,500 per annum
Lifetime Savings (25 year life of Solar PV system ) Approx. Rs. 45-50 Cr
Guarantee 5 years guarantee of entire system.
Components MNRE Certified

64. Thank you…
Contact Us:
Jigar Patel
+91-9978955773
marketing.exe2@topsunenergy.com
Topsun Energy Limited