5 kW solar system — size, output and cost

What this size typically covers

A 5 kW array suits a site consuming in the region of 600 units a month. That figure comes from a planning assumption of roughly four peak-sun-hours a day in Punjab, derated for temperature, soiling and inverter losses — about 120 units per kW per month.

It is a planning figure, not a guarantee. Real output varies with orientation, tilt, shading, module and inverter selection, ambient temperature, and how well the system is maintained.

Roof area

Approximately 500 square feet of usable, unshaded area. Assess area honestly: parapet shadows, water tanks, stairwell blocks, and buildings to the south all reduce what is genuinely usable, and a layout that ignores them underperforms from day one.

How many modules is that

Roughly nine or ten modules at around 500-550 W each. Module wattage changes with every product cycle, so the count is for planning the roof layout — the design fixes the actual module, the tilt and the string arrangement.

What a 5 kW system typically runs

The most common domestic size in this market, and the smallest one that meaningfully changes a summer bill rather than shaving it.

Through a sunny day it carries the standing load of a family home — lighting, fans, refrigeration, pumps, electronics — alongside one to two inverter air conditioners, depending on how they are used and how much else is running at the same time. Evening consumption still comes from the grid unless net metering is banking the daytime surplus, or a battery is carrying it.

Supply and phase

Usually a single-phase connection. Where the site already has three-phase supply, the inverter choice changes and the array may be arranged differently, but 5 kW sits comfortably on either.

What matters more at this size is the condition of the existing distribution board. Domestic boards are frequently full, poorly labelled, or protected in a way that predates half the loads now connected — and generation should not be added to that without correcting it first.

With or without a battery

Grid-tied with net metering is the default, because it is the cheapest way to use every unit the array produces. A hybrid arrangement makes sense when outages genuinely stop the household — a home office, medical equipment, or a shop below the residence.

The array size does not change the backup question. Battery capacity is driven by which circuits must stay live and for how long, which is why hybrid and off-grid starts from a backup load schedule rather than from a number of hours.

Summer, winter and the shape of the year

Output is not constant across the year, and neither is consumption. Generation is highest in the long, clear days before and after the monsoon, and lowest in the short days of winter and under the dust and cloud of the wettest weeks. In this region the summer months combine the highest consumption with strong generation — which is why solar addresses a summer bill more directly than a winter one.

Two consequences worth planning around: a system sized against a summer bill alone will be larger than the year needs, and one sized against a winter bill will disappoint in June. We size against twelve months where the data exists, and say which way we are erring where it does not.

What determines the cost

We do not publish a price for this size, because a credible number depends on things that are only known after a site visit:

• Roof type and the mounting structure it requires
• Distance and route from array to inverter to distribution board
• Condition of the existing electrical installation
• Module and inverter selection
• Whether net metering is included
• Whether battery backup is part of the scope

Market-indicative ranges circulate widely online. They are not our prices, and repeating them here would imply a quotation we cannot stand behind.

If this size is not right

• Under roughly 450 units a month: 3 kW may be the honest size.
• Over roughly 900 units a month, or with several air conditioners running through the afternoon: look at 10 kW.
• Not sure: the sizing estimator will give you an indicative figure from your own bill in about a minute.

Next step

Use the sizing estimator to get an indicative size from your own bill or consumption. An engineer verifies the load and the site before any proposal.