Question 1

What is a Solar Rooftop System?

Accepted Answer

In a solar rooftop system, solar panels are installed on the roof of any residential, commercial, institutional, or industrial building. This can be of three primary types: (i) Grid Connected Solar Rooftop System (without battery storage), (ii) Solar Rooftop System with battery storage facility (Off-Grid), and (iii) Hybrid Solar Rooftop System (Grid Connected along with Battery Storage backup).

Question 2

What is a Grid Connected Solar Rooftop System?

Accepted Answer

In a Grid connected Solar Rooftop PV system, the DC power generated from SPV panels is converted to AC power using a power conditioning unit (inverter). Generated power during daytime is utilized fully for powering facility loads, and excess power is fed into the grid through net metering. A grid-connected system is operational as long as the grid is available. In cases where solar power is insufficient due to cloud cover or night time, loads are served seamlessly by drawing power from the grid, which acts as a virtual storage facility.

Question 3

How Do We Generate Electricity From The Sun?

Accepted Answer

Solar energy systems work when sunlight hits a solar photovoltaic module (solar panel or PV panel) and causes electric current to flow through semiconductor cells. The direct current (DC) produced by the PV panels is controlled and regulated by an inverter, which converts DC into alternating current (AC), needed for operating machinery, commercial equipment, and household appliances.

Question 4

What is a Solar Rooftop System with Storage facility?

Accepted Answer

Such rooftop systems incorporate a battery energy storage facility. The solar electricity generated during daytime sunshine hours is stored in the battery bank and can be utilized during the night or during power cuts when solar generation is not available.

Question 5

When do the batteries come into the picture while installing solar?

Accepted Answer

If you are going for an off-grid or hybrid solar solution, solar batteries are one of the crucial components as they allow you to store the electricity generated by the solar plant and use it in case of power outages or in case of no mains. A good battery provides long backup duration, high cyclic life, and requires minimal maintenance.

Question 6

Does solar power work at night?

Accepted Answer

Solar panels require direct or diffuse sunlight to produce power, so they do not generate electricity at night. However, you can seamlessly get the power you need at night through bidirectional grid net metering (importing grid power offset by daytime export credits) or by installing a battery energy storage system (BESS) charged during daytime hours.

Question 7

What is the lifespan of solar panels?

Accepted Answer

Most Tier-1 solar panels have a lifespan of 25 to 30 years. Their efficiency typically degrades at a very low rate (around 0.5% per year), and modern panels are designed with linear performance warranties guaranteeing 80% to 85% of original rated performance after 25 years.

Question 8

Do solar panels work on cloudy days?

Accepted Answer

Yes, solar panels work on cloudy days or when the sun is not shining as brightly. Power output can be slightly reduced, but the solar panels still produce clean electricity from ambient diffuse radiation to help meet your facility power needs.

Question 9

What is solar EPC?

Accepted Answer

Solar EPC stands for Engineering, Procurement, and Construction. It is a comprehensive, turnkey project delivery model where a single dedicated contractor handles the entire lifecycle of a solar installation: architectural layout, civil & structural engineering, electrical single-line diagrams (SLD), Tier-1 equipment procurement, DISCOM/CEIG statutory liaisoning, grid integration, and testing commissioning.

Question 10

How much electricity can a solar plant generate?

Accepted Answer

In India, a well-engineered solar power plant typically generates 1,300 to 1,550 kWh (units) per kWp annually, translating to approximately 3.6 to 4.2 units per kWp per day. Exact generation depends on geographic global horizontal irradiance (GHI), module tilt angle, shading profiles, inverter efficiency, and thermal degradation characteristics.

Question 11

How much rooftop area is required for a home?

Accepted Answer

A standard residential installation of 3 kW to 5 kW requires approximately 250 to 500 square feet of shadow-free rooftop space. For large villas or housing societies (common area lighting, water pumps, elevators), systems ranging from 10 kW to 100 kW require 1,000 to 10,000 sq.ft.

Question 12

How much can a residential solar system reduce electricity bills?

Accepted Answer

A residential on-grid net-metered solar system can slash monthly power bills by 70% to 90%. In higher residential consumption slabs (where utility tariffs exceed ₹9–₹12/unit), a 5 kW plant generating ~600 units monthly saves ₹4,500 to ₹6,500 every month.

Question 13

How much subsidy is available for home solar?

Accepted Answer

Under PM Surya Ghar, central subsidy provides ₹30,000 for 1 kW, ₹60,000 for 2 kW, and up to ₹78,000 for 3 kW+ installations.

Question 14

What maintenance does a rooftop solar system require?

Accepted Answer

Residential systems require minimal maintenance: periodic cleaning of the module glass surfaces with water every 10 to 15 days to remove ambient dust, plus an annual electrical inspection of circuit breakers, earthing pits, and surge protection devices (SPDs).

Question 15

How long does a residential solar system last?

Accepted Answer

Panels provide a 25-year performance warranty with an annual degradation rate under 0.55% to 0.7%. Grid-tied string inverters typically carry 5 to 10-year manufacturer warranties and are designed for a 12 to 15-year service life.

Question 16

What does solar O&M include?

Accepted Answer

Comprehensive Operations & Maintenance includes scheduled module cleaning, thermographic drone inspections to identify micro-cracks and hot spots, IV curve tracing, transformer oil dissolved gas analysis (DGA), switchgear contact resistance testing, vegetation control, and 24/7 SCADA cloud performance tracking.

Question 17

How frequently does a solar plant need maintenance?

Accepted Answer

Module soiling cleaning cycles are conducted every 10 to 14 days in industrial or dusty zones (or automated via robotic waterless systems). Inverter and electrical switchgear preventive maintenance is performed quarterly, with annual calibration of protection relays and pyranometers.

Question 18

How is plant performance monitored?

Accepted Answer

Chirayu implements IoT-enabled SCADA telemetry that streams string-level current, voltage, weather station irradiation, ambient temperature, and inverter output to a centralized dashboard, providing automated anomaly alerts and daily generation yield reports.

Question 19

What happens if generation drops?

Accepted Answer

Our remote telemetry detects underperforming strings within minutes. Rapid-response field technicians carry thermal imaging cameras and digital earth testers to isolate module hotspots, blown fuses, inverter fault codes, or grid curtailments, maintaining guaranteed 99%+ plant availability.

Question 20

How does Chirayu handle preventive maintenance?

Accepted Answer

Preventive maintenance follows a digital calendar covering: torquing checks on structural fasteners to withstand 150 km/h wind gusts, insulation resistance (megger) testing of DC cables, earthing pit resistance measurement (< 1 ohm target), and inverter air filter replacements before peak generation seasons.

Question 21

How much maintenance do solar panels require?

Accepted Answer

Solar panels are relatively low-maintenance as they are solid-state and have no moving parts. Regular cleaning to remove dirt and debris, as well as occasional checks on the system’s wiring, inverters, and electrical components, are usually sufficient.

Question 22

What is the typical payback period for solar?

Accepted Answer

For industrial and commercial consumers on high-tariff slabs (₹9.00 to ₹13.00/kWh), the simple payback period for a CAPEX rooftop solar project is typically 2.5 to 3.8 years. After payback, the plant delivers virtually free green electricity for the remaining 20+ years of its design life.

Question 23

What factors affect solar project ROI?

Accepted Answer

Key determinants of ROI include: (1) Current utility base tariff and future tariff escalation rates; (2) Local solar irradiation (GHI) and specific generation yield; (3) System sizing relative to daytime baseload; (4) Quality of Tier-1 equipment minimizing degradation; and (5) Tax depreciation benefits and financing interest rates.

Question 24

What costs should be considered before investing?

Accepted Answer

A holistic financial model accounts for: Initial EPC capital cost (modules, inverters, structures, BOS, grid integration), DISCOM statutory liaisoning and meter fees, annual O&M agreements (~1% to 1.5% of CAPEX), comprehensive insurance coverage, and inverter warranty extension reserves at Year 10–12.

Question 25

How does electricity tariff affect solar savings?

Accepted Answer

Every rupee increase in utility tariff directly magnifies your solar cash savings. While utility power tariffs have historically escalated at 4% to 7% compounded annually in major industrial states, your solar levelized cost of energy (LCOE) is locked at approximately ₹2.50 to ₹3.80/kWh, providing a permanent hedge against inflation.

Question 26

How do Open Access charges affect the economics of a project?

Accepted Answer

In off-site open access projects, state regulatory charges (transmission, wheeling, and loss adjustments) comprise a significant portion of landed costs. Structuring projects under Captive or Group Captive models legally eliminates Cross-Subsidy Surcharge (CSS) and Additional Surcharge (AS), preserving maximum tariff differential and ensuring healthy 18%+ project IRRs.

Question 27

How much do solar panels cost?

Accepted Answer

The price of solar power has dropped drastically over the past decade. Total cost depends on factors such as module brand, roof type, mounting structure, system size, and engineering specifications. Use our Solar Calculator to calculate your potential savings or contact our engineering team for an itemized turnkey quotation.

Question 28

Are there government incentives for installing solar panels?

Accepted Answer

Many governments offer incentives, tax credits, or rebates to encourage the installation of solar panels. In India, central subsidies under PM Surya Ghar Muft Bijli Yojana provide up to ₹78,000 for residential systems, while commercial and industrial enterprises benefit from 40% accelerated depreciation (AD) and green energy open access surcharge waivers, significantly reducing upfront costs.

Question 29

How long does net meter approval take from MSEDCL?

Accepted Answer

Net meter approval and physical meter installation typically takes 2 to 3 weeks following application submission.

Question 30

What maintenance is required for residential solar?

Accepted Answer

Only periodic washing with clean water every 10 to 15 days to remove dust and maintain peak energy generation efficiency.

Question 31

How long does subsidy disbursement take after commissioning?

Accepted Answer

Subsidy is credited directly into the consumer bank account via DBT within 30 days of DISCOM inspection and net meter installation.

Question 32

Can I claim PM Surya Ghar subsidy on an existing solar installation?

Accepted Answer

No, the scheme strictly applies to fresh installations registered through the national portal prior to commencement of works.

Question 33

What is the maximum subsidy amount for a residential villa?

Accepted Answer

The maximum subsidy for an individual household is capped at ₹78,000 (attained at 3 kW and higher system capacity).

Question 34

What happens to unused solar units at the end of the year?

Accepted Answer

Surplus credits remaining at the annual settlement date (typically March 31) are paid out by the DISCOM at the Average Power Purchase Cost (APPC) rate.

Question 35

Does the net meter work during a grid power outage?

Accepted Answer

For safety reasons, grid-tied inverters automatically shut off during a blackout (anti-islanding) to protect utility workers. A hybrid BESS is required for blackout backup.

Question 36

How long does DISCOM net meter installation take in Maharashtra?

Accepted Answer

Net meter sanction and installation typically takes 2 to 4 weeks following physical system commissioning and CEIG/DISCOM technical inspection.

Question 37

Is Virtual Net Metering approved in Maharashtra?

Accepted Answer

Yes, MERC regulations permit group and virtual net metering frameworks for residential housing societies and multi-consumer premises.

Question 38

How are billing credits divided among society members?

Accepted Answer

Credits are allocated according to a predefined ratio filed with the DISCOM, either pro-rata by apartment square footage or proportional to capital investment.

Question 39

Can tenants benefit from Virtual Net Metering?

Accepted Answer

Yes, tenants with utility connections in their name can receive virtual generation credits without modifying rented premises.

Question 40

Which industries gain the most from industrial solar thermal?

Accepted Answer

Textile processing, industrial laundries, dairies, chemical manufacturing, food processing plants, and hotels with high continuous hot-water consumption.

Question 41

Can solar thermal work alongside an existing boiler?

Accepted Answer

Yes, solar thermal is engineered to preheat feed-water entering existing oil, gas, or biomass boilers, drastically reducing burner fuel burn.

Question 42

What is the efficiency difference between solar thermal and solar PV?

Accepted Answer

Solar thermal converts 60% to 75% of solar radiation directly into heat energy, whereas solar PV operates at 20% to 22% electrical conversion efficiency.

Question 43

What inverter and module tech was deployed for Kirti Solapur?

Accepted Answer

Tier-1 Mono PERC bifacial solar modules paired with centralized high-efficiency inverters and SCADA monitoring.

Question 44

How is annual yield monitored at Latur site?

Accepted Answer

Real-time IoT cloud telemetry logs generation hourly with automated inverter status alerts.

Question 45

How does PM-KUSUM benefit agricultural feeders?

Accepted Answer

It provides reliable daytime electricity to farm pumps, reducing DISCOM distribution losses.

Question 46

What voltage level is used for grid interconnection?

Accepted Answer

Interconnection at 33 kV substation busbar with dedicated vacuum circuit breakers (VCB).

Question 47

Did Simplex Chemopack combine rooftop and ground mounted arrays?

Accepted Answer

Yes, utilizing factory shed roofs alongside contiguous ground space to maximize installed capacity.

Question 48

Can new industrial off-takers acquire capacity at Patur Solar Park?

Accepted Answer

Yes, expansion bays and ongoing project execution allow new off-takers to plug into existing park infrastructure.

Question 49

What payback period was achieved for Chanvim Plastics?

Accepted Answer

Project investment was fully recovered in under 3.2 years through high self-consumption and tax depreciation benefits.

Parameter	Residential Net Metering	Commercial Net Billing	Gross Metering
Consumer Eligibility	Residential & Societies (up to 10 kW+)	Commercial & Industrial (>10 kW)	Independent Solar Generators
Export Valuation	1:1 Unit Offset against retail tariff (₹6-₹12/u)	Weighted export rate or APPC (₹3.00-₹3.80/u)	PPA Feed-in tariff only
Banking Horizon	Monthly rollover until March 31 settlement	Monthly billing reconciliation	No banking (instant generation sale)
Battery Requirement	None (Grid functions as virtual storage)	Optional for peak rate optimization	Not required

Residential Net Metering:1-to-1 Energy Banking for Homeowners

Self-consumption first, automatic grid export second.

Certified Dual-Register Hardware

Grid Safety Disconnect

Connected Load Compliance

Frequently Asked Questions

Residential Net Metering:1-to-1 Energy Banking for Homeowners

How Bi-Directional Net Metering Works

Bi-Directional Power Flow Stages

Self-consumption first, automatic grid export second.

Core Net Metering Architecture

Certified Dual-Register Hardware

Grid Safety Disconnect

Connected Load Compliance

Frequently Asked Questions