Key takeaways
- Use 5.2 to 5.6 kWh/m²/day of local insolation and roughly 1,400 to 1,600 units per kW yearly as planning estimates, subject to your roof.
- APSPDCL net-metering has five main stages, and the proposed grid-connected capacity must fit your sanctioned load.
- A 3 kWp to 5 kWp home system needs about 240 to 500 sq ft of suitable, shade-free roof.
- PM Surya Ghar assistance reaches ₹78,000 for eligible homes with 3 kW or more; verify the scheme rules before applying.
Homes in Tirupati, Srikalahasti, Renigunta and Puttur often have enough sun for rooftop solar, with the area commonly described as having more than 300 sunny days a year. Sun alone does not determine your output. Roof shade, available area, panel angle and grid interruptions need a site check.
The Tirumala hills influence local weather. October and November bring Northeast Monsoon rain, while red soil and quarry dust settle on glass during dry periods. Your installer also has to take the proposed design through APSPDCL's approval and net-metering steps.
Use the estimates below to frame questions for a house in Tirupati or Srikalahasti, or a business roof in Renigunta. The monthly figures are illustrative. Ask for a shade survey and bill-based design before treating any unit or savings figure as a forecast for your property.
Sunlight and roof area in Tirupati district
The sunlight reaching a horizontal surface is measured as Global Horizontal Irradiance (GHI). The National Institute of Solar Energy (NISE) data cited for this district gives an indicative average of 5.2 to 5.6 kilowatt-hours per square metre per day (kWh/m²/day). A shaded or poorly oriented roof will collect less than that resource suggests.
For an initial estimate, use 4.0 to 4.5 units (kWh) per kW per day as an annual average. That is about 1,400 to 1,600 units per kW per year. Allow roughly 80 to 100 sq ft of shade-free roof for each kilowatt, then check actual dimensions, setbacks and shadow patterns on site.
Check the direction: Tirupati sits near 13.6° North. A true south-facing array tilted about 13° to 15° is a useful starting layout for annual generation. Let the shade survey and roof geometry decide the final angle.
How monthly generation changes with the seasons
Read the month-by-month table as a planning example. Tirupati's dry summer, two monsoon periods and winter skies shift the output across the year:
- Summer, February to May: The example gives 4.6 to 5.0 units per kW per day, often when air-conditioning demand rises.
- Southwest Monsoon and transition, June to September: Cloudier days bring the estimate to 3.8 to 4.2 units per kW daily; rain may rinse loose dust.
- Northeast Monsoon and winter, October to January: Rain in October and November brings about 3.2 to 3.6 units per kW daily. Clearer December skies can lift that to 4.2 to 4.6.
| Month | Typical weather | Sun each day | Units per kWp | Units at 3 kWp | Units at 5 kWp |
|---|---|---|---|---|---|
| Jan | Clear winter skies | 5.3 hrs | 132 u | 396 u | 660 u |
| Feb | Bright, dry days | 5.6 hrs | 128 u | 384 u | 640 u |
| Mar | Stronger pre-summer sun | 5.8 hrs | 148 u | 444 u | 740 u |
| Apr | Hot and mostly clear | 5.7 hrs | 142 u | 426 u | 710 u |
| May | Summer sun stays strong | 5.6 hrs | 145 u | 435 u | 725 u |
| Jun | Monsoon begins | 4.8 hrs | 122 u | 366 u | 610 u |
| Jul | Rain between sunny spells | 4.5 hrs | 118 u | 354 u | 590 u |
| Aug | Clouds on some days | 4.6 hrs | 122 u | 366 u | 610 u |
| Sep | Sun between seasons | 4.9 hrs | 124 u | 372 u | 620 u |
| Oct | Northeast Monsoon rain | 4.1 hrs | 105 u | 315 u | 525 u |
| Nov | Frequent heavy rain | 3.8 hrs | 98 u | 294 u | 490 u |
| Dec | Clearer winter sun | 4.8 hrs | 124 u | 372 u | 620 u |
| Annual | Estimated annual total | 5.0 hrs | ~1,475 u | ~4,425 u | ~7,375 u |
Compare 3 kWp, 5 kWp and 10 kWp layouts
Start with your recent bills and measured clear roof area. The three sizes below show how space and estimated monthly units rise together; final capacity should come from an audit of your load and shade.
A 3 kWp system for a smaller home load
A 3 kWp layout needs about 240 to 300 sq ft and may produce 360 to 420 units a month in this example. It can suit a 2BHK or 3BHK home with a fridge, washing machine and one AC used at night, depending on the bill. Eligible homes reach the ₹78,000 PM Surya Ghar subsidy cap at this size.
A 5 kWp system for higher household use
A house using two or three ACs may need around 5 kWp, provided the roof offers 400 to 500 sq ft without shade. The monthly estimate here is 600 to 720 units. If power cuts are common, ask about a battery and hybrid home system, then size the backup loads separately.
A 10 kWp system for larger roofs
A large family home, nursing clinic or shop-house with a three-phase connection might consider 10 kWp. Allow about 800 to 1,000 sq ft and use 1,200 to 1,450 monthly units as an illustration, not a bill-saving guarantee. Business owners can compare the design options in our commercial solar guide.
The APSPDCL net-metering steps
With an approved net meter, daytime surplus can be exported and accounted for against later use under the applicable billing rules. Ask your installer to manage these five steps and give you copies of each approval:
- Register the application: For a subsidy-eligible home, enter your service number on pmsuryaghar.gov.in and choose a registered vendor such as Ray2Volt.
- Obtain feasibility: APSPDCL checks available transformer capacity against the cited APERC 80% limit. Allow 3 to 5 days as an indicative approval period, then confirm current timing locally.
- Install and report: The vendor fits certified DCR modules and sends the Work Completion Report (WCR) with test results.
- Test the meter and sign: The bi-directional meter goes for MRT lab calibration, followed by the cited 25-year Interconnection Agreement.
- Complete commissioning: APSPDCL officers review safety, install the approved meter and energise the connection.
Check the bill first: Your proposed grid-connected solar capacity cannot exceed the sanctioned load under the rule cited here. For a 2 kW connection and a 3 kW proposal, ask APSPDCL for a load extension before seeking feasibility clearance.
Plan for dust, wind and animals
Use the site visit to check more than sunlight. In this district, dust, seasonal wind and animals each affect where panels and cables should go:
1. Dust from roads and quarries
Red soil and granite quarry activity around Renigunta, Chandragiri and Srikalahasti can leave a film on glass. The 8% to 15% output loss used here is an illustrative range after weeks without cleaning. Start with a 10 to 14 day wash interval in dusty weather, using clean water and a microfibre mop before the panels heat up, then adjust from your readings.
2. Wind-rated roof supports
The district is within about 70 km of the Bay of Bengal and can face squalls in the October to November Northeast Monsoon. Ask for a mounting design rated for 150 km/h winds, with hot-dip galvanised iron frames and chemical fasteners into sound RCC slabs where that roof design is used. The engineer should confirm the actual roof condition.
3. Protected cable routes
Monkeys use some roofs near Tirumala and Srikalahasti as a route between buildings. Have the installer enclose DC cable in heavy-duty galvanised iron conduit or rigid PVC pipe, with no loose wire available to pull or chew. Check the route again after any roof repairs.
Subsidy eligibility and indicative payback
The PM Surya Ghar scheme currently offers ₹30,000 at 1 kW, ₹60,000 at 2 kW and a capped ₹78,000 at 3 kW or more for eligible residential systems. The implementation period runs to 31 March 2027. Check the official portal for the rules that apply when you file.
Home subsidy applications need eligible DCR modules under the applicable ALMM listing and a registered vendor. Commercial sites do not receive this residential subsidy. Businesses may be able to claim 40% accelerated depreciation on written down value under section 33 of the Income-tax Act, 2025; confirm the current rate and your eligibility with your chartered accountant.
At the illustrative domestic tariff of ₹7.00 to ₹9.50 per unit used here, a 3 kW system has an estimated annual bill offset of ₹30,000 to ₹38,000. A typical home payback after the subsidy is 4 to 5 years, subject to a site audit, final price, use pattern and tariff. Ongoing bills and maintenance still matter; do not treat this as a guaranteed saving.
Choose a team that can service your roof
A rooftop array is planned for decades of use, so ask who will respond after commissioning. An online seller may use local subcontractors, while another firm may keep its own technicians nearby. Check the office address, service contact and fault process in either case.
Ray2Volt Solar Private Limited has its registered office in Srikalahasti and branches in Tirupati, Nagari and Puttur. We visit the site for a power audit, coordinate APSPDCL paperwork and provide local service for the components we install. Ask for the handover contacts and written service terms with the proposal.
For a visit, see our Tirupati installation service. Before comparing bids, use the solar installer questions and review our home rooftop options. Bring a recent bill and photographs of the roof so the first discussion can address both load and available area.
Confirm your case: Generation, subsidy and payback figures here are indicative. Schemes and tariffs can change, and your eligibility depends on the current rules and a site audit. Ray2Volt does not give tax or investment advice; ask your chartered accountant about depreciation.
Questions about local solar installation
What daily output can a 3 kW Tirupati roof produce?
Use about 12 to 13.5 units per day, or roughly 4,300 to 4,800 units a year, as an annual planning range. The example rises to 14 to 15 daily units in clear March to May weather and falls to 9.5 to 11 during the October to November Northeast Monsoon. Your roof needs its own shade and layout assessment.
What stages affect APSPDCL net-metering time?
An indicative local estimate is 3 to 4 weeks for the full cycle with a registered vendor. It includes feasibility, often estimated at 3 to 5 days, installation at 2 to 3 days, the work completion report, meter testing and field inspection. Ask APSPDCL or your installer for the current queue and requirements.
What if your sanctioned load is below the proposed solar size?
Under the rule described here, grid-connected capacity cannot be larger than your sanctioned load. For a 2 kW connection and a planned 3 kW or 5 kW system, apply to APSPDCL for a load extension before the solar feasibility step. Check the new sanction before assuming subsidy eligibility.
How should you deal with local red soil and quarry dust?
Several weeks of buildup may cut output by an illustrative 8% to 15%, depending on the site. Try a 10 to 14 day cleaning interval in dry weather, using clean water on cool panels. Compare your inverter readings to see whether that interval suits your roof.
How much PM Surya Ghar assistance can an eligible home receive?
The current central amounts are ₹30,000 for 1 kW, ₹60,000 for 2 kW and up to ₹78,000 for 3 kW or more. A registered vendor and eligible DCR modules are required. The scheme implementation period runs to 31 March 2027, but confirm the current rules and your eligibility before paying.
Ray2Volt Solar Private Limited
We design, install, and service rooftop solar for homes and businesses across Tirupati district and Andhra Pradesh, from PM Surya Ghar residential systems to commercial and industrial plants. Every enquiry starts with a free power audit.
Get a site-based solar plan for your Tirupati roof
Ray2Volt can visit your site for a free power audit and 3D shade review, then prepare a proposal that includes APSPDCL net-metering coordination.
