Sizing and roof space
Roughly 80 to 100 square feet of clear, shade-free roof is needed per kW with standard mounting. A 10 kW system therefore wants around 900 square feet, or less with elevated structures over an existing slab.
Sizing follows consumption, not roof size. We read twelve months of bills, find the expensive slab units, and design to remove those first.
Batteries, backup and load-shedding
An on-grid system alone shuts down during an outage; that surprises many first-time buyers. If you want power during load-shedding you need a hybrid inverter and a battery.
Lithium LFP costs more upfront than lead-acid and delivers far more usable cycles, which is why almost every serious Karachi backup design now uses it.
- On-grid: cheapest, best bill savings, no backup
- Hybrid: bill savings plus backup for selected loads
- Off-grid: full independence, largest battery, highest cost
Weather, dust and monsoon
Karachi's dust is the biggest silent loss; unwashed panels can lose a noticeable share of output within a month. Scheduled cleaning restores it.
Monsoon weeks reduce generation but net metering carries your exported units forward, so annual maths still works.
Money and payback
Payback depends on your slab. Heavy users in the top slabs typically recover their investment far faster than light users, because solar removes the most expensive units first.
Frequently asked questions
- How many units does 1 kW of solar produce in Karachi?
- Around 4 to 4.5 units per day on average across the year for a well-oriented, clean array.
- Can I run air conditioners on solar?
- Yes, with correct sizing. Inverter ACs on a hybrid system with adequate battery capacity run comfortably.
- Do solar panels work in Karachi's heat?
- They work, but output falls slightly as cell temperature rises; good mounting with airflow underneath limits the loss.
- How often should panels be cleaned in Karachi?
- Usually every four to six weeks, more often near construction or main roads.