3kW vs 5kW vs 10kW Solar System — Which Size Do You Need?
Updated March 2026 | By Sri Ishaan Solar Team
Choosing the wrong solar system size is one of the most common (and costly) mistakes homeowners make. Go too small and you don't offset your bill. Go too large and you're over-investing — and may even face TSSPDCL approval issues. This guide helps you find the sweet spot for your home in Hyderabad or anywhere in Telangana.
The Simple Rule: Your Monthly Bill Tells You the Size
In Hyderabad's climate, 1 kW of solar produces roughly 120–140 units (kWh) per month on average (accounting for cloudy days, monsoon season, and panel degradation). Use this to map your bill to the right system size:
| Monthly Bill | Units Used | Recommended Size | Roof Space Needed |
|---|---|---|---|
| ₹500 – ₹1,000 | ~100–150 units | 1–2 kW | 100–200 sq ft |
| ₹1,500 – ₹2,500 | ~200–350 units | 2–3 kW | 200–300 sq ft |
| ₹2,500 – ₹4,000 | ~350–550 units | 3–5 kW | 300–500 sq ft |
| ₹4,000 – ₹7,000 | ~550–900 units | 5–7 kW | 500–700 sq ft |
| ₹7,000 and above | 900+ units | 8–10 kW | 800–1,000 sq ft |
Thumb rule: 100 sq ft of shade-free roof = 1 kW of solar capacity.
PM Surya Ghar Subsidy by System Size
Bigger isn't always better when it comes to subsidy — the PM Surya Ghar scheme caps at ₹78,000 for systems of 3 kW and above:
| System Size | Total Cost (Sri Ishaan Solar) | Subsidy | Your Net Cost |
|---|---|---|---|
| 1 kW | ₹50,000 | ₹30,000 | ₹20,000 |
| 2 kW | ₹1,00,000 | ₹60,000 | ₹40,000 |
| 3 kW | ₹1,50,000 | ₹78,000 | ₹72,000 |
| 5 kW | ₹2,50,000 | ₹78,000 | ₹1,72,000 |
| 10 kW | ₹5,00,000 | ₹78,000 | ₹4,22,000 |
Note: Our pricing is Rs 50,000 per kW all-inclusive — panels, inverter, structure, wiring, installation, and DISCOM paperwork. No hidden charges.
3 kW System — Best For
A 3 kW system is the most popular choice for Hyderabad households. Here's why it makes sense:
- Monthly bill of ₹2,000–₹3,000 (2–3 AC rooms + basic appliances)
- Roof space available: 300 sq ft shade-free area
- Gets the maximum PM Surya Ghar subsidy of ₹78,000
- Generates ~360–420 units/month on average
- Typical payback: 4–5 years, 25-year savings of ₹6–8 lakhs
Ideal for: 2BHK / 3BHK independent house or villa, family of 4–5, moderate AC usage.
5 kW System — Best For
- Monthly bill of ₹3,500–₹6,000
- 3+ ACs running simultaneously, or home office setup
- Roof space: 500 sq ft shade-free area
- Generates ~600–700 units/month
- Also eligible for ₹78,000 subsidy
- Typical payback: 4–5 years for high-bill households
Ideal for: Large 3BHK or 4BHK independent house, G+1 home with separate floors in use, families with 3+ ACs.
10 kW System — Best For
- Monthly bill above ₹7,000–₹10,000
- Large bungalows, farmhouses, or combined residential + commercial use
- Roof space: 800–1,000 sq ft unshaded
- Generates ~1,200–1,400 units/month
- Excellent for net metering — export surplus to grid and earn credits
Ideal for: Double-storey independent houses with large roofs, gated community villas, or homes that want to zero out the electricity bill completely.
Special Cases: When Standard Sizing Doesn't Apply
AC-heavy homes (3+ ACs): In summer months (April–June), Hyderabad ACs run 8–10 hours daily. One 1.5-ton AC consumes about 1.5 kWh/hour. If you're running 3 ACs simultaneously, you may need a 5–6 kW system even if your current bill suggests a 3 kW is enough. Why? Solar offsets daytime usage — which is exactly when ACs are busiest. It's a perfect match.
EV charging at home: An electric two-wheeler (Ather, Ola) adds about 1–1.5 kWh/day. An electric four-wheeler (Tata Nexon EV) adds 8–15 kWh/day depending on usage. If you're planning an EV purchase, size up by 1–2 kW to cover future charging needs. EV + solar is one of the smartest combinations for Hyderabad homeowners right now.
Small roof, high bill: If your shaded roof limits you to 3 kW but your bill demands 5 kW, consider higher-efficiency panels (400W+ monocrystalline) which generate more per square foot. We can advise on the best panel type during the site survey.
Rented home: Not ideal for large systems — landlord agreement, subsidy eligibility, and payback period considerations complicate things. A 1–2 kW system with a portable structure may work in some cases. Call us to discuss.
Quick Self-Check: Which Size Is Right for You?
- Look at your last electricity bill — what's the units consumed (kWh)?
- Divide by 130 — that's the rough kW you need
- Check your roof: count the shade-free area in sq ft and divide by 100
- Take the smaller of the two numbers as your starting point
- Add 1 kW if you're planning an EV or have 3+ ACs
Get a Free Load Analysis — We'll Size It Right for You
At Sri Ishaan Solar, we don't guess. Our engineer does a proper load analysis — looking at your actual bills, appliance list, and roof — before recommending a system size. No upselling, no pressure. Just the right size for your home and budget.
Get Free Load Analysis on WhatsApp →
Or call: +91 83099 65527