Everything you need to know about Net Metering, solar hardware quality, financial returns, and maintenance cycles in Pakistan.
What is the NEPRA Net Metering application process?
Net metering is a billing mechanism that credits you for excess solar power sent back to the national grid. The process involves:
System feasibility & loading inspection
Preparation of the technical file & electrical structural maps
Submission of application forms to LESCO/IESCO
Physical inspection of the wiring and solar site by DISCO officials
Installation of the green bidirectional meter
This process takes 3-6 weeks, and is handled end-to-end by Fast Traders & Solar Solutions.
What is a green bidirectional meter?
A bidirectional meter records energy flow in two directions:
Import: The units of electricity consumed from LESCO/IESCO when solar generation is low (e.g., at night).
Export: The excess units of electricity generated by your panels and fed back into LESCO/IESCO grid during peak sun hours.
Your monthly bill is computed on the "Net Balance" of these two units.
Do I get paid in cash for exported units?
Utility companies (like LESCO) do not issue checks or cash payouts monthly. Instead, they maintain a running credit balance in your account in units.
If you export more than you import, your credit units roll over to subsequent months to offset your bills during winters or rainy cycles.
If a large positive credit balance remains in your account at the end of the quarterly/annual cycle, the utility DISCO adjusts the credit amount based on national export tariff rates defined by NEPRA.
How do I size my solar system?
Sizing depends on your historical average electricity bills and your daytime load usage:
5kW System: Suitable for monthly usage of 400-500 units. Supports 1 inverter AC, refrigerators, fans, and LED lights.
10kW System: Best for 800-1100 units. Supports 2-3 inverter ACs, water pumps, and normal household loads.
15kW/20kW System: For 1200+ units. Supports 4+ ACs, electrical appliances, and large double-story residences.
What is the difference between N-type and P-type panels?
N-type solar cells (TOPCon technology) offer several advantages over traditional P-type cells:
Higher Efficiency: Converts a higher percentage of sunlight to usable electricity.
Lower Degradation: N-type panels degrade at a rate of less than 0.4% per year, retaining over 87% capacity at year 30.
Superior Temperature Coefficient: Performance does not drop as drastically during hot Lahore summers (40°C+).
How long do lithium LFP batteries last compared to tubular lead-acid?
LFP (Lithium Iron Phosphate) batteries are premium storage systems:
Life Expectancy: Lithium LFP cells provide over 6000 cycles (10-15 years). Lead-acid tubular batteries last 1-2 years max.
Depth of Discharge (DoD): Lithium LFP can be safely discharged to 90% capacity, while tubular batteries should not go below 50%.
Maintenance: Lithium is completely maintenance-free, while tubular batteries require continuous monitoring of distilled acid levels.
What is the average payback period for solar in Lahore?
With rising utility tariffs and peak-hour adjustments, residential solar in Pakistan delivers an outstanding return on investment:
Payback Horizon: The typical system pays for itself in 3 to 4 years.
Financial Return: After the payback threshold, the system provides 100% free electricity for the remaining 20+ years of active panel warranty life.
Will my solar system work during power outages/load-shedding?
This depends entirely on the system type you install:
On-Grid Systems: These shut down automatically during grid power outages. This is a safety regulation to prevent backfeeding power into utility lines, which could harm electricians working on local transformers.
Hybrid Systems: These switch seamlessly within 10 milliseconds to battery storage when the utility grid drops, keeping your essential loads running without interruption.
How often should solar panels be cleaned in Pakistan?
Due to high dust levels, smog, and carbon soot in cities like Lahore, panels should be cleaned every 10 to 14 days:
Impact of Dirt: A thick layer of dust can degrade energy yields by 15% to 30%.
Best Practice: Always wash panels during early mornings or late evenings. Washing them under high noon sun causes extreme thermal shock, which can result in micro-cracks in the PV glass cells.
What is the active lifespan of panels and inverters?
Modern Tier-1 solar equipment is built to last:
Solar Panels: Panels have a 25-year performance warranty. They can generate power for up to 30+ years, degrading slowly to about 80-85% of their original capacity by year 25.
Inverters: Hybrid and on-grid solar inverters have an expected operating lifespan of 8 to 12 years. They typically carry a 5-year replacement warranty, which can be expanded to 10 years.
