Cost & ROI7 min read
3kW vs 5kW Solar System: Which Size Is Right for Your Home?
Both attract the same ₹78,000 subsidy. The deciding factor is your annual consumption, not the price difference.
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Key takeaways
- Both sizes receive the same ₹78,000 PM Surya Ghar subsidy — the extra 2 kW in a 5 kW system is bought entirely at full price.
- 3 kW generates about 4,800 units a year in Jaipur; 5 kW generates about 8,000.
- Choose 3 kW if your annual consumption is under about 5,000 units, 5 kW if it is closer to 8,000.
- 3 kW needs roughly 220 sq ft of shade-free roof; 5 kW needs around 350 sq ft.
- Oversizing hurts returns: exported units are credited at less than the retail tariff you avoid by self-consuming.
This is the most common question we are asked by homeowners in Jaipur, and it usually arrives framed as a budget question. It is not. Both sizes attract the same ₹78,000 central subsidy, both are straightforward to install, and both are sound investments. The difference between them is whether the capacity matches your consumption.
Get that right and either system pays back in three to five years. Get it wrong in the direction of too large and you have bought generation you will export at a discount for twenty-five years.
The numbers side by side
A 3 kW system in Jaipur generates roughly 4,800 units a year — about 12 to 13 units a day — needs around 220 sq ft of shade-free roof, and costs an indicative ₹1,70,000 to ₹2,15,000 before subsidy. Net of the ₹78,000 subsidy, that is roughly ₹92,000 to ₹1,37,000.
A 5 kW system generates roughly 8,000 units a year — about 21 to 22 units a day — needs around 350 sq ft, and costs an indicative ₹2,70,000 to ₹3,40,000 before subsidy. Net of the same ₹78,000, that is roughly ₹1,92,000 to ₹2,62,000.
So the extra 2 kW costs about ₹1,00,000 to ₹1,25,000 net and delivers about 3,200 extra units a year. At a ₹7 residential tariff that increment saves around ₹22,000 annually, paying for itself in four to five years. That is a good investment — if you use the units.
The rule that actually decides it
Take your annual consumption from your electricity bill and divide by 1,600, which is roughly what each installed kilowatt generates in a year in the Jaipur region. That gives the capacity that would fully offset your usage.
A household using 5,000 units a year lands at about 3 kW. One using 8,000 units lands at about 5 kW. If your answer comes out at 4 kW, install 4 kW — the market talks in round numbers, but systems do not have to be.
- Under 5,000 units a year → 3 kW
- 5,000 to 6,500 units a year → 4 kW
- 7,000 to 8,500 units a year → 5 kW
- Above 9,000 units a year → look at 6 kW and above, subject to sanctioned load
The air conditioning question
Most households ask this question because of cooling load, so it is worth being specific. A 1.5-ton air conditioner consumes roughly 8 to 12 units on a hot Jaipur day when run for six to eight hours.
One air conditioner used seasonally sits comfortably within 3 kW alongside normal household load. Two used regularly through the summer pushes you towards the top of 3 kW. Three or more, or any air conditioning running through the working day, is a 5 kW conversation.
When roof area, not consumption, decides
On many Jaipur plots the terrace is smaller than it looks once the mumty, water tanks, and the winter shadow of a neighbouring building are excluded. If a proper shadow analysis leaves you with 250 sq ft of genuinely clear roof, 5 kW is not available regardless of your consumption — unless you elevate the array, which is often the right answer and keeps the terrace usable underneath.
Frequently asked questions
Does a 5kW system get more subsidy than a 3kW system?
No. Both receive ₹78,000, because PM Surya Ghar caps central assistance at that figure for any residential system of 3 kW or above. The additional two kilowatts in a 5 kW system are bought entirely at full price and have to be justified by your consumption.
Can I start with 3kW and expand to 5kW later?
Technically yes, but it is usually more expensive than installing 5 kW at the outset. Expansion means a fresh DISCOM application, possibly a different inverter, additional mounting and labour, and a second mobilisation. If your consumption clearly justifies 5 kW, install it once. If you genuinely expect consumption to rise — a growing family, or an EV — say so at design stage so the inverter and cabling are specified with headroom.
What happens if my solar system is too big for my consumption?
You export the surplus, and under net metering exported units are credited at less than the retail tariff you would have avoided by consuming them yourself. Returns fall as the system outgrows the load. There is also a regulatory limit: permitted capacity is tied to your sanctioned load, so an oversized application can simply be refused.
Why clients choose Dvaitam Solar
Engineering-first approach
Structural survey, seasonal shadow analysis and yield modelling before a capacity is quoted — never a catalogue picked off a price list.
Premium Tier-1 equipment
ALMM-listed modules and BIS-certified balance of system, specified against the engineering and not substituted after contract.
PM Surya Ghar assistance
Portal registration, DISCOM feasibility, net metering and inspection filed and chased until the subsidy is credited.
End-to-end EPC execution
Design, supply, civil, electrical, testing and commissioning under one scope and one accountable team.
Professional installation
Method statements, quality records captured as work proceeds, and measured commissioning tests rather than a switch-on.
Long-term support
Monitoring configured at handover, a documented O&M pack and a performance baseline you can hold the plant to in year five.
Next steps
Related reading
- Cost & ROI5kW Solar System Cost in Jaipur: A Full Price BreakdownWhere the money actually goes in a 5kW installation, and why two quotes for the same capacity can differ by ₹70,000.
- SubsidyPM Surya Ghar: Who Qualifies and How Much You Actually GetEligibility rules, the exact slab arithmetic, housing-society rates and the document checklist — everything to settle before you touch the portal.
- Cost & ROIHow to Calculate Solar ROI Properly (and Spot a Padded Projection)The four-line calculation that gives you a real payback figure, and the five assumptions vendors quietly adjust to improve it.
Browse every guide in the Dvaitam solar knowledge base.
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