Data checked 24 September 2026
How this estimate works
The calculator is an energy-sizing aid for an initial conversation. It does not size protection, cables, structures, inverter surge output, or an off-grid system. Your actual design needs a site survey and load assessment.
Electricity use
Use the average monthly kWh shown on 12 electricity bills. In amount mode, monthly units = the entered bill amount ÷ your own effective cost per unit. We do not apply one universal Pakistan tariff. IESCO’s published February 2026 tariff guide distinguishes protected, unprotected, and time-of-use categories and fixed charges. Taxes, adjustments, arrears, and different utilities can change a bill. Amount mode is only a rough alternative.
Pakistan solar-production data
We retrieved city-centre estimates from the European Commission’s JRC PVGIS 5.3 API on 24 September 2026. These use ERA5 historical weather from 2005–2023, crystalline silicon, 1 kWp, 30° tilt, south orientation, ventilated mounting, and 14% system losses. They are historical model averages, not live forecasts or measured performance at your roof. Nearby obstructions need separate assessment.
| City | kWh per kWp / year | Model data |
|---|---|---|
| Islamabad / Rawalpindi | 1,592.68 | Source JSON |
| Lahore | 1,603.48 | Source JSON |
| Karachi | 1,718.45 | Source JSON |
| Peshawar | 1,576.18 | Source JSON |
| Multan | 1,685.44 | Source JSON |
| Faisalabad | 1,638.91 | Source JSON |
| Quetta | 1,880.51 | Source JSON |
Solar capacity = monthly units × 12 ÷ adjusted annual output. The displayed ±15% range is an illustrative sizing sensitivity, not a measured error bound or a performance guarantee. Seasonal bars show the model’s monthly distribution. The tool does not model hourly self-consumption, grid outages affecting PV production, export limits, battery recharge losses, or future load changes.
Backup calculation
Nominal battery kWh = average backup load in kW × continuous outage hours ÷ usable-capacity fraction ÷ battery-to-load efficiency. We round up to 0.5 kWh for discussion. The default 90% usable capacity and 90% efficiency are explicit planning assumptions, not manufacturer specifications. This assumes a fully charged battery and no solar contribution during the outage. Battery energy and power limits are separate; motors, pumps, and air conditioners need individual starting-load checks. For separate outages, recharge time must be assessed.
Pakistan connection and billing policy
Under regulation 14 of the NEPRA Prosumer Regulations, 2026, new arrangements bill imported energy at the applicable tariff and value exported energy at the national average energy purchase price. Rates may change. The rules and subsequent amendments must be read together; existing agreements can have different treatment. We do not calculate export income or promise bill elimination.
Regulation 3 links proposed DG capacity to sanctioned load and includes network eligibility conditions. The 6 August 2026 amendment removes the requirement for NEPRA concurrence for facilities of 25 kW or below; the distribution licensee’s approval is still required. An estimator result is not a connection approval. Confirm the current rules with your utility before installation.
What happens to your figures?
The website keeps recent calculations in your session for up to one hour so you can request a review. Submitting the review form stores your contact details and the estimate in the RENS admin inbox. Nothing is sent to WhatsApp until you choose to share it. See our privacy policy and website disclaimer.