Page 91 - GRIHA Manual Volume III - Introduction to National Rating System
P. 91
84 GRIHA Manual: Volume 3
2. Demand estimation: Detailed load analysis should be conducted to calculate the total power
requirement of the building. Depending on the load (wattage) of the equipments to be
powered by the PV system, total power requirement can be determined; and based on the
usage patterns of all these equipments (daily, hourly usage, and number of days annually),
electricity demand can be calculated.
3. Identification of appropriate technology: Review the site specifications and building
requirements to decide whether a stand-alone, grid-interactive or hybrid PV system would
be suitable for the location. Once the type of PV system to be installed has been finalized,
evaluate the PV technologies available in the Indian market and select the technology that is
technically and financially most suitable. Depending on the size and type of solar PV system,
a technical analysis of the proposed system should be conducted. This analysis will take into
account the system losses that occur due to the use of battery, charge controller, and inverter.
Technical analysis of the proposed system will provide (a) annual electrical output/generation
and (b) required PV array area to be installed.
4. Design the PV system as per the requirement: PV system sizing should be done keeping in
mind the annual average solar insolation value for the selected location. In systems where
battery bank is used for storage, the minimum battery capacity is specified by the daily
load. Battery capacity is designed considering days of autonomy (duration for which the
system should work when there is no sunshine i.e. continuous cloudy days during monsoons
or winter months).
Correct assessment of system specifications including all possible losses, connected loads
and time variation, likely degradation of system components due to ageing, and so on over
the designed life time should be conducted while designing the PV system.
It should be ensured that the electrical energy generated by the PV array matches the
energy consumed by the equipments powered by the designed PV system. If the PV capacity
is less than the minimum requirement, it may result in system failure after some time.
Installation guidelines
1. Determine the total area requirement for installation of PV power system and identify
a suitable building location where the PV can be mounted or integrated into the
building envelope.
2. The average solar PV modules and framing will add a load of about 7–8 kg per square foot.
So, ensure that the roof or any other structure below the PV installation is capable of handling
such loads.
3. Ensure that the PV installation is done in a manner such that it will not cause any hindrance to
any future construction/extension work.
4. In the northern hemisphere, solar panels should be installed such that they are facing south.
For maximum annual energy collection, the tilt of the solar panel should be equal to that of
0
the latitude of the area. Latitude +15 tilt provides maximum collection during winters, while
0
latitude -15 tilt provides maximum collection during summers.
5. Ensure that the solar panels are located in a shadow-free area.
6. Wiring and electrical load distribution should be planned to have optimum utilization of solar
energy.
7. To speed up the installation process and limit errors in wiring connections, devices that simplify
connections like plug connectors, polarized caps, and push tabs should be used.
2. Demand estimation: Detailed load analysis should be conducted to calculate the total power
requirement of the building. Depending on the load (wattage) of the equipments to be
powered by the PV system, total power requirement can be determined; and based on the
usage patterns of all these equipments (daily, hourly usage, and number of days annually),
electricity demand can be calculated.
3. Identification of appropriate technology: Review the site specifications and building
requirements to decide whether a stand-alone, grid-interactive or hybrid PV system would
be suitable for the location. Once the type of PV system to be installed has been finalized,
evaluate the PV technologies available in the Indian market and select the technology that is
technically and financially most suitable. Depending on the size and type of solar PV system,
a technical analysis of the proposed system should be conducted. This analysis will take into
account the system losses that occur due to the use of battery, charge controller, and inverter.
Technical analysis of the proposed system will provide (a) annual electrical output/generation
and (b) required PV array area to be installed.
4. Design the PV system as per the requirement: PV system sizing should be done keeping in
mind the annual average solar insolation value for the selected location. In systems where
battery bank is used for storage, the minimum battery capacity is specified by the daily
load. Battery capacity is designed considering days of autonomy (duration for which the
system should work when there is no sunshine i.e. continuous cloudy days during monsoons
or winter months).
Correct assessment of system specifications including all possible losses, connected loads
and time variation, likely degradation of system components due to ageing, and so on over
the designed life time should be conducted while designing the PV system.
It should be ensured that the electrical energy generated by the PV array matches the
energy consumed by the equipments powered by the designed PV system. If the PV capacity
is less than the minimum requirement, it may result in system failure after some time.
Installation guidelines
1. Determine the total area requirement for installation of PV power system and identify
a suitable building location where the PV can be mounted or integrated into the
building envelope.
2. The average solar PV modules and framing will add a load of about 7–8 kg per square foot.
So, ensure that the roof or any other structure below the PV installation is capable of handling
such loads.
3. Ensure that the PV installation is done in a manner such that it will not cause any hindrance to
any future construction/extension work.
4. In the northern hemisphere, solar panels should be installed such that they are facing south.
For maximum annual energy collection, the tilt of the solar panel should be equal to that of
0
the latitude of the area. Latitude +15 tilt provides maximum collection during winters, while
0
latitude -15 tilt provides maximum collection during summers.
5. Ensure that the solar panels are located in a shadow-free area.
6. Wiring and electrical load distribution should be planned to have optimum utilization of solar
energy.
7. To speed up the installation process and limit errors in wiring connections, devices that simplify
connections like plug connectors, polarized caps, and push tabs should be used.
