3 kW is the most frequently installed residential rooftop capacity in India, and for good reason: it suits a typical family home consuming 300 to 400 units a month, and it is the smallest capacity at which the maximum PM Surya Ghar central assistance band applies for eligible residential consumers.
What a 3 kW system typically costs
Residential rooftop systems are generally quoted in the region of ₹55,000 to ₹70,000 per kW before any subsidy, which puts a 3 kW system broadly between ₹1.65 lakh and ₹2.10 lakh. That is a range, not a price — where a specific project falls inside it depends on several real variables.
What moves the price within that range
- Module technology. Higher-efficiency modules cost more per watt but need less roof area — which matters when space is tight.
- Inverter selection. String inverter brand, warranty terms and monitoring capability all affect cost.
- Mounting structure. A standard low-height structure on a flat terrace costs far less than an elevated structure designed to keep the terrace usable underneath.
- Roof type and access. Sloped roofs, tin sheets and multi-level terraces need different structures and more labour.
- Cable runs and electrical work. Distance from the array to the inverter and from the inverter to your meter adds cable, conduit and labour.
- Safety and protection. Earthing, lightning arrestor and DC/AC protection are not optional — but they do appear in the price.
The effect of subsidy on net cost
For eligible residential consumers, PM Surya Ghar: Muft Bijli Yojana provides Central Financial Assistance of up to ₹78,000 for systems of 3 kW and above. Where that assistance is approved and received, the effective out-of-pocket cost of a 3 kW system falls substantially. Note that eligibility, vendor requirements and DISCOM approvals are governed by scheme rules that can change, and no installer can guarantee approval. Verify current details on the official portal.
What a 3 kW system generates
An unshaded, well-oriented 3 kW system in average Indian conditions typically produces around 11 to 13 units a day — roughly 340 to 380 units a month, or about 4,000 to 4,500 units a year. Actual output varies with your location's irradiation, panel tilt and orientation, shading through the day, ambient temperature, dust and seasonal weather.
What you need on the roof
Budget roughly 300 sq ft of genuinely shadow-free roof area. "Shadow-free" is the operative word: a water tank, parapet wall, adjacent building or tree that shades the array for part of the day will cut generation by more than most people expect, because shading on one module can affect the whole string.
Is 3 kW right for you?
Work backwards from consumption, not from the capacity you have heard about. Take your average monthly units across a full year — not one summer month — and divide by roughly 120 to get an indicative kW figure. If that lands near 3, a 3 kW system is a sensible starting point, subject to your sanctioned load, roof area and DISCOM's rules on permitted capacity.
This guide is general information, not technical or financial advice for a specific property. Figures are indicative and vary by location, tariff, site conditions and current policy. For a decision, get a site assessment. Talk to RIJARA ENERGY →