On-grid system is consists of two major components solar panel and an on-grid/grid tied inverter.
Solar Panels in Pakistan
in Pakistan almost five tier-1 grade-A solar modules are available i.e Trina, Jinko, JA, Canadian and Longi.
However, some other brands which are not tier-1 but A-grade i.e. CSUN can be used without any doubt.
All these solar panels are offered with 12 years replacement/workmanship warranty and 25/30 years of 80% leaner output warranty.
On-Grid/Grid-Tied inverters in Pakistan
on-grid inverters available brands in Pakistan are (Huawei, Solis, Goodwe, Growatt, Solis, Knox, SMA, SunGrow, Aotai and Sofar) are most popular for commercial and domestic solar system application
PV Mounting System
L2 / L3 / L4 type PV mounting structure made with import G.I Sheet 30 micron galvanized available in 12, 14 and 16 Gauge. The most poplar usage is 14 gauge PV mounting. However, due to rooftop layout and design, limited space availability or due to shading problems customized PV mounting structure is being used. Customized PV mounting structure cost is based on how much material is used as well as quality of PV mounting
Flexible DC Wire – from Solar panel to inverter
The most useable application is 6mm wire but few installers use 4mm dc flexible wire with is not recommended if length is increased between solar panel array and on-grid inverter. up to 17 ampere per array 6mm dc flexible wire is the best choice
Earthing, Surge protection
Earthing is the most imported part also required by NEPRA and AEDB authorities to give approval/License for net metering (Green Meter). The ideal earthing should be up to water level depth. A pure cooper rope wire (without insulation) should be used. Wire thickness can be determined as per solar system size in Kilowatts. However, some installer only use 10 feet long copper rod only.
DC and AC earthing should be separate and minimum 10 feet distance should be maintained between both earth pits.
Earth pits should remain live by keeping it wet and resistance value must not increase >5 Ohms.
A surge arrestor should be installed on rooftop with higher altitude in comparison to PV module height.
Installation Related material (IRM a, b, c)
Installation related material should be A Class quality. Since, customer like to get best available inverter in the market or best solar panel, installation materials such as pipe, duct, cable ties, MC4 connectors, DC fuses, SPD (Surge protection device) should be made by renowned brand.
a. Cable Ties
Cable ties should be made of pure nylon not ordinary plastic material and must be UV resistant. in other case cable ties will not last more than few months and all cable will be observed hanging in the air or lied down on the rooftop surface.
White cable ties are rated for indoor use only. for outdoor use only black nylon UV resistant cable ties are recommended
Duct and pipe should be thick UPVC plastic material. As we assume solar system minimum life as 25 years.
c. MC4 Connectors
MC4 Pairs must be good quality and should not be remain loose while connecting male and female pairs. in other case they can caught fire, heating and energy loss. in some scenario loose connection can cause serious damage to the property.
Installation of Solar panels
Solar panels should be installed in shade free area of rooftop
Solar panel should be fixed properly, each nut, bolt fasted enough using torque wrench
solar panel should be 180 degree facing sought-ward, inclination of solar panel can vary from 5 degree to 40 degree depending on sun horizon as per area/terrain situation.
Installation of on-grid inverter
Mostly on-grid inverter are IP67/IP68 dust and splash resistant but direct UV rays of sun can fade and weaken the outer case of on-grid inverter. inverter must be installed in shady area where is proper air circulation available. If inverter is installed in air tight premises it can effect inverter performance and efficiency.
Online monitoring of solar system
Almost every on-grid inverter manufacture is offer built-in WIFI dongle and monitoring app for cloud based online mentoring . Monitoring is available for Windows OS, Android and Apple IOS all platforms.
Net Metering / Green Meter / Feed Back to Grid License (up to 25KW domestic Solar system)
If you want to replace a Green Meter with conventional meter. It is a lengthy and tiring process. It take about 1.5 to 2.5 months.
as per New NEPRA policy a domestic user can apply for green meter once solar system is already installed.
Required documentation for green meter
- Applicant CNIC Copy
- Recent paid electricity bill Copy
- Inverter Serial No.
- Inverter Datasheet
- Solar Panel Datasheet
- Affidavit (Stamp Paper) PKR 50 or PKR 100
- System layout diagram
- Installer company invoice (company must have AEBD authorization)
important note: customer can install solar system @ 1.5 times factor of sanction load mentioned on his electricity bill. If sanction load is less than required demand, customer can write application to local division to increase it against a very nominal fee. estimated 1000 PKR/KW.
for example: if sanction load is 9KW customer can apply for 13.5KW solar system to feed back to grid.
Civil work is necessary if rooftop is old or there is chance of seepage. concrete based pads should be at the point of anchor bolts on the rooftop. Also on open sided rooftops with no wall and in windy area concrete pad are very necessary.
Solar system Abnormal / Standby / Not Working
Check all three phases are live
Check Natural is not break
Check Solar panel array is connected to inverter
Check Phase sequence is proper (R-S-T) applicable to few inverter brands like infini 10KW design
Check AC Breaker is OK
Check DC Breaker or fuse is OK
Check inverter screen or inverter app if it is showing warning or error code
Contact system installer
Maintenance of solar system
The only major maintenance of solar system is to keep your solar panels clean from dust layer.
Only water is required to wash the solar panel surface at least two time a week if there is not rain.
if solar panels are dusty, up to 30 percent energy production will be reduced.
Useful video links related to installation