A rooftop solar power plant has several key electrical, civil/mechanical, and monitoring components. The electrical components include PV modules, a power conditioning unit/inverter, junction boxes, DC and AC cables, and connectors. Civil/mechanical components are module mounting structures, foundations, and cable/equipment mounting structures. Monitoring components include a weather station, SCADA system, energy meter, and other instruments to track performance.

1. Introduction To Rooftop Solar Power Plant
Components

2. Components Involved In RSPP
Components
of Solar
Power Plant
Electrical
Civil &
Mechanical
Monitoring

3. Electrical Components Of RSPP
PV Module
• Electronic device converting sunlight into electricity
• Available as Crystalline, thin film and Concentrated PV cells
• Wide range between 10 – 400 Wp
Power Conditioning Unit / Inverter
• A combined unit of DC to AC power conversion and storage
of DC power
• Available for Single as well as for Three phase power
supply
Junction Box
• A device for combining all strings/arrays at single point
giving 2 outputs of DC
• Available as Array Junction Boxes and Main Junction Boxes
• Available with inbuilt Surge Protection Devices

4. Electrical Components Of RSPP
DC Cables
• DC cables are the Solar cables that will be used between PV modules, from
modules to Junction Boxes and from Array Junction Boxes to Inverter
• These cables are UV protected cables as these are exposed directly or
indirectly to day light
• These cables are available in size from 1.5 to 400 sqmm
AC Cables
• AC cables are used form Inverter to Transformer primary and from
Transformer secondary to RMU or to Switchyard and .
• These cables are armored 3 or 3.5 or 4 core Cu or Al XLPE insulated GI
armored cables.
• These are available in LT (650/1100V) and HT (3.3/6.6/11/22/33kV) cables
forms
MC4, Branch and Fuse Connectors
• MC4 and MC 3 connectors are used to accommodate different insulation
diameter solar cables and used to interconnect two modules
• The branch connectors are used to connect different strings

5. Electrical And Monitoring Components Of
RSPP
Earth Pit
• For protection of all electrical as well as mechanical structures
against earth faults earth pits are provided.
• It has an electrode, an earthing strip and chemical compound
generally.
Distribution Panel
• These are enclosed panels which are used to distribute the
generated power from solar to different loads
• It consist of MCB/fuses, SPDs of different rating as per requirement
of system
Lightning Arrestor
• These are used to protect the electrical instruments against
lightning.
• Based on application these are available as sub station and spike
type ( to be used on buildings)

6. Electrical And Monitoring Components Of
RSPP
Weather Monitoring Station
• Irradiation, wind, temperature, humidity and precipitation are some
of the measures which are monitored to check the performance of
Solar PV plant
• For measuring solar radiations pyranometers are used and for wind
speed measurement anemometers are used
SCADA system
In small scale plant control can be done using MCBs but for large
scale power plants for automatic opening and closing of system in
case of fault SCADA monitoring is used
Energy Meter
• These are basic energy meters which can be used as per consumer
connection i.e 1-phase or 3-phase, domestic or industrial.
• These energy meters monitor different parameters of system like
line current, phase voltage, frequency, power factor, active energy ,
maximum demand, etc

7. Civil And Mechanical Components Of
RSPP
Module Mounting Structure
• MMS are designed based on type of base, for flat roof or ground mount
system foundation based structures are mounted , nowadays ballasted roof
mounting is most common and for sloped or pitched roof rail structure is
implemented
• MMs material are generally aluminium alloys or stainless steel for ground
mount mostly hot dip galvanized steel is used
Mounting Structure Foundations
• Combined or Isolated footing are done on flat roofs
• PCC foundations are most common
• M-20 or M-25 grade material is used as per strength requirement
Inverter or Junction Box Mounting / Wall Support Structure
• Small Inverters or Array Junction Boxes can be wall mounted
• These can be supported on rails or on rear panels or mount brackets

8. Miscellaneous Components Of RSPP
Cable glands
• It is a device designed to attach and secure the end
of a cable to the equipment
• These are available in brass , aluminium, stainless
steel or plastic form
Cable Lugs
• Used to connect cables to electrical appliances,
other cables, surfaces, and mechanisms
• These are available in different types as copper ring
type, tubular type, pin type, aluminium lug , battery
lugs, etc.

9. Miscellaneous Components Of RSPP
Cable ties, ferrules
• Cable ties are used to avoid hanging of cables
and also give aesthetic look to system
• Ferrules can be used in marking or labeling
cables
• Ferrules can be sleeve type or universal T type
Cable Trays
• Used to support insulated electric cables used
for power distribution and communication.
• Available in GI, galvanized steel, stainless steel
aluminum, or glass-fiber reinforced plastic
• These are either Ladder type or perforated type