What industrial solar actually pays back in Pakistan — with real generation data

Every solar company in Pakistan quotes a payback period. Almost none of them publish the generation data behind it. The number is usually produced by a simulation, run on optimistic irradiance assumptions, with no downtime and no soiling — and then presented as though it were a measurement.

So here is a measurement. The figures below are the recorded output of a 1 MW plant I designed and commissioned at Simta Foods in Vehari Industrial Estate, taken from the plant monitoring system between 9 May and 21 July 2026. The full daily record is on that project page.

Note what those numbers do not do. July has the highest single day in the whole period — 1,884 kWh on the 20th — and the lowest monthly average, because the inverters were off for the last ten days of the month. I could have reported July as a 710 kWh/day month and left it there, or reported the first 21 days only and claimed a much better average. Both would have been true statements and both would have been misleading.

Turning generation into money

Generation is not saving. What a unit is worth to you depends on whether you consume it or export it, and under net billing those are very different numbers — a self-consumed unit is worth your full industrial tariff, an exported one roughly a third of the old buyback rate.

Simta Foods runs a continuous-process food plant, so the great majority of what the array produces is consumed on site as it is produced. That is the reason the economics work there, and it is the first thing I check on any industrial site. Their own figure for the saving is PKR 1.9 million a month, which puts the payback under eight months against total project cost.

I want to be precise about the provenance of those last two numbers, because it differs from the generation data. The 68,317 kWh is mine — it comes from the monitoring system and I can show you the export. The PKR 1.9M/month is the client's figure, calculated against their own pre-solar tariff and their own bills. The payback follows arithmetically from it. I report it as theirs rather than presenting it as an independent measurement.

What actually shortens payback

• A load that runs during daylight. This is worth more than any equipment decision.
• Buying equipment at wholesale rather than through a margin. On a megawatt, the difference between wholesale and retail procurement is a large fraction of a year of payback.
• Correct sizing. Capacity that generates units you export at the buyback rate pays back roughly three times slower than capacity covering your own load.
• Uptime. Twelve days off in a 77-day window is around 15% of the period. Monitoring that someone actually watches is not a luxury on a plant this size.

What to ask anyone quoting you a payback

1. Is this figure simulated or measured? If simulated, on what irradiance assumption?
2. Does it assume I consume all of it, or does some of it assume export at the buyback rate?
3. What downtime and soiling losses are in the model?
4. Can you show me the monitoring data from a comparable plant you commissioned?
5. What is your margin on the equipment in this quotation?

The last question is the one that changes the answer most, and the one least often answered directly. My own answer is that there is no margin on the equipment at all — I am paid 4% of project cost on commissioning, and you receive every original supplier invoice.