1. Partnership To Advance Clean Energy-Deployment (PACE-D)
Technical Assistance Program
Presented by
USAID PACE-D TA Program
Apr-18
Solar PV Rooftop Training Program For Entrepreneurs
Session:
Solar PV Rooftop Technology Overview

2. Contents
Solar energy technologies
Solar PV technology – applications
How the solar PV system works
Movement of sun across the sky
Solar radiation

3. Contents
Introduction to grid connected Solar PV Rooftop system
Components of grid connected Solar PV Rooftop system
Different configurations of Solar PV Rooftop system
Energy generation estimation from Solar PV Rooftop
system

4. Renewable Energy Technologies
Renewable Energy
Technologies
Hydro Energy
Biomass Energy
Geothermal Energy
Solar Energy Wind Energy
Wave Energy

5. Renewable Energy Technologies - Potential

6. Solar Energy Technologies
There are many different ways of harnessing solar energy. The most commonly
available solar energy technologies are:
Solar
Photovoltaic (PV)
Systems
Solar Hot Water
Systems
Concentrated
Solar Power
(CSP)
Passive Solar
Design

7. Solar PV Technology – Off-Grid Applications

8. Solar PV Technology – Off-Grid Rural Applications

9. Solar PV Technology – Off-Grid Industrial
Applications

10. Solar PV Technology – Off-Grid Mobility
Applications

11. Solar PV Technology – Small Distributed
Applications
 Installed in building roofs
(Residential, industrial or commercial)
 Generated power is typically
consumed by the loads within the
building and excess power can be
exported to the electricity grid
 Typical system size : 1kWp to 20kWp
or more

12. Solar PV Technology – Large Distributed
Applications
 Installed in large building roofs
(warehouse, industrial or commercial)
 Power may be consumed by the
loads within the building / exported
to the electricity grid or open access
 Typical system size: 50kWp to 5 MWp

13. Solar PV Technology – Utility Scale Grid Connected
Applications
 Directly connected to the
transmission/distribution system
 Typical Capacity: MW scale

14. Solar PV Technology – Micro Grid Applications
PV Array
Battery Bank &
Control Room

15. Solar Thermal Technology –
Concentrating Solar Power Applications
Concentrating Solar Power Technologies
Parabolic Dishes Parabolic Troughs
Central Receiver
Tower
Linear Fresnel

16. How the Solar PV System Works
When exposed to light a voltage difference occurs between the side of the cell
exposed to the light and its underside. If a circuit is completed, electrical current will
flow.

17. Movement of the Sun across the Sky
SOLAR ELECTRIC INSTALLATION COURSE – OFF-GRID APPLICATIONS
21 December
21 September 21 June
21 March

18. Movement of the Sun across the Sky – The Sun Path
Diagram
Solar radiation available
at a particular location
keeps changing during
the day and also during
the year. The amount of
solar radiation received
by a solar array is not
same during all the
time of the day and it is
also not the same in
different months of a
year.

19. Solar Radiation
The radiation from sun is
received by earth in form
of Direct Irradiance and
Diffused Irradiance.
Combining direct and
diffuse irradiance is called
global irradiance

20. Solar Radiation - Global Annual Solar Radiation in kWh/m2

21. Solar Radiation – Indian Scenario
India being a tropical country receives
adequate solar radiation for 300 days,
amounting to 3,000 hours of sunshine
equivalent to over 5,000 trillion kWh

22. Grid Connected Solar PV Rooftop System
Solar PV array generate DC power. This DC power is converted to AC power via the
inverter and the AC power is supplied (or fed) into the electricity grid.
PV Modules
Mounting
frame
Junction Box
DC Cabling
Solar Array Isolator
Inverter AC Cabling
Main Switch
Solar Supply
Meter
Switchboard
Power Grid

23. Grid Connected Solar PV Rooftop System
 Installed in building roofs (Residential, industrial or commercial)
 Generated power is typically consumed by the loads within the building and
excess power can be exported to the electricity grid

24. Components of Solar PV Rooftop System
The major components of Solar PV Rooftop system are:
 PV Array (a group of Solar PV modules combined in series / parallel)
 Grid-connected Inverter
 Balance of System (BoS) Components
 Transformer (required for large rooftop system)
 Multimode (Hybrid) Inverter (for grid-connected PV system with battery)
 Storage Battery (for grid-connected PV system with battery)

25. Components of Solar PV Rooftop System – PV
Arrays
The solar photovoltaic technology is evolving and different technologies have been
emerged in recent years. The key features of the following types of PV modules
which are commercially available at present global market will be discussed.
 Mono-crystalline PV module
 Polycrystalline modules
 Amorphous thin film module
 Multi junction amorphous thin film module
 CdTe thin film module
 CIGS thin film module

26. Components of Solar PV System - Grid Connected
Inverter
 A grid-connected inverter is directly
connected to the PV array. The
inverter will convert the solar DC
power to an AC sine wave that
matches the AC supply in voltage and
frequency to which it is connected
 If the AC grid is not present, the
inverter will simply not function

27. Components of Solar PV System – Multi-mode (Hybrid)
Inverter
 Connects to battery bank as a charger
 Produce a sine wave in
synchronisation with the grid
 Produce a sine wave independent
from the grid
 Export to Grid and power specified
loads

28. Components of Solar PV System – Storage Battery
 Secondary batteries are used
 There are many battery types with
their own operating principles
 How a battery is charged, discharged
and handled will determine the life of
the system
 Lead Acid – Sealed or Unsealed

29. The Key Balance of System (BoS) Components
 DC cables and AC cables
 Array junction box/ DC combiner box
 Over current protection device/ circuit breakers
 Disconnection devices
 Plugs, Sockets and connectors
 Lightning protection system
 Earthing and bonding arrangement
 Energy meters
 System Monitoring
 Marking and Signage

30. Different Components of Solar PV Systems
General functional configuration:
PV arrays are used to supply power to an
application circuit which can be of two
types:
 PV array is connected to AC system
via conversion equipment which
includes at least simple separation
 PV array is connected to AC system
via conversion equipment which does
not include simple separation

31. Different Components of Solar PV Systems
Grid connected Solar PV Rooftop
system with no battery or DG backup
 Normally the solar PV rooftop system
is connected with the grid
 When the grid fails, inverter
controlled switch S1 will open
 On grid restoration, S1 will close
Utility AC BUS
Main Consumer
Panel
Solar
AC Loads
GM
CM SM
GE GI
GW
S1
CI SI SE
-
± SM – Solar Meter
GM – Grid Meter
CM – Consumer Meter
Courtesy: CEA
Inverter

32. Different Components of Solar PV Systems
Grid connected Solar PV Rooftop system
with charger cum inverter as load
 Normally the solar PV rooftop system is
connected with the grid
 When the grid fails, inverter controlled
switch S1 will open
 On grid restoration, S1 will close
 Battery storage can be provided for full
load or selected load
Utility AC BUS
Main Consumer Panel
Solar
AC Loads
GM
CM SM
GE GI
SW
S1
CI SI SE
-
±SM – Solar Meter
GM – Grid Meter
CM – Consumer Meter
Courtesy: CEA
InverterCharger
cum
Inverter
Battery

33. Different Components of Solar PV Systems
Utility AC BUS
Main Consumer Panel
Solar
AC Loads
GM
CM SM
GE GI
SW
S1
CI SI SE
-
±
SM – Solar Meter
GM – Grid Meter
CM – Consumer Meter
Courtesy: CEA
InverterDM DE
S1
DG BUS
DG
Grid connected Solar PV Rooftop with
DG set as backup
 Normally the solar PV rooftop system is
connected with the grid
 When the grid fails, inverter controlled
switch S1 will open
 On grid restoration, S1 will close
 DG set can be connected to full load or
selected load

34. Different Components of Solar PV Systems
Grid connected Solar PV Rooftop
with multimode inverter and battery storage
Source: GSES
handbook on Grid
connected PV
systems with
battery storage

35. Energy Generation Estimation from a Solar PV Rooftop System
The amount of energy delivered by the solar PV rooftop system depends on a number of
factors, but the primary factors are:
 Rated capacity or size of the solar PV rooftop array (Wp or kWp)
 Amount of solar irradiation it receives (expressed as peak sun hour)
 The total efficiency of the system after considering all the losses
 Performance degradation over life cycle
Energy Yield
Peak Sun
Hour
Array Rated
Power
System
Efficiency
Degradation
Factors

36. Peak Sun Hours (PSH)
 Solar energy available in a given
location is expressed as kWh/m2/day.
This is commonly referred as Peak
Sun Hours (PSH)
 For example, if solar radiation for a
particular location is 5 kWh/m2/day
then PSH for that location will be 5
hours
Source: GSES handbook on Grid connected PV systems
design and installation

37. Losses in PV Array and Systems
Cause Estimated Loss* (%) Efficiency Factor
Temperature 10% 0.90
Dirt 3% 0.97
Manufacturer’s Tolerance 3% 0.97
Shading 2% 0.98
Orientation 0% 1.00
Tilt Angle 1% 0.99
Voltage Drop 2% 0.98
Inverter 3% 0.97
Loss due to irradiance level 3% 0.97
Transformer & AC transmission 1% 0.99
Total De-rating Factor (multiplying all de-rating factors) 0.72
* Example only. Actual value will be based on design and site condition

38. Energy Generation Estimation – Working Example
On a clear and a sunny day, a 10kWp PV array received 5 Peak Sun Hours (hours).
Total loss (de-rating factor) in the system is estimated as 0.73 (73%)
Expected output can be determined as follows:
Expected Output = Peak Sun Hours x Peak Power Output x Total derating factor
= 10kWp x 5 hour/day x 0.73
= 36.50kWh per day (1st year)

39. Energy Generation Estimation – Working Example
Energy generation from PV modules degrades over its life cycle @ 0.7% to 1% per
year

40. Energy Generation Estimation – Working Example
On a clear and a sunny day, a 10kWp PV array received 5 Peak Sun Hours (hours). Total
loss (de-rating factor) in the system is estimated as 0.73 (73%)
Expected output can be determined as follows:
Expected Output = Peak Sun Hours x Peak Power Output x Total derating factor
= 10kWp x 5 hour/day x 0.73
= 36.50kWh per day (1st year)
= 32.85kWh per day (on 10th year)
= 29.56kWh per day (on 25th year)

41. 41
Anurag Mishra
Senior Clean Energy Specialist
USAID/India
Email: amishra@usaid.gov
Disclaimer:
This training material is made possible by the support of the American
People through the United States Agency for International
Development (USAID). The contents of this material are the sole
responsibility of Nexant, Inc. and do not necessarily reflect the views of
USAID or the United States Government. This material was prepared
under Contract Number AID-386-C-12-00001.