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

Is solar suitable for energy-intensive industries?

Accepted Answer

Yes. Continuous-process industries—such as textile spinning, steel rolling, cold storages, chemicals, and plastic injection moulding—experience the highest financial returns. Because industrial grid tariffs typically range between ₹8.50 and ₹14.00 per kWh, solar generated at a levelized cost (LCOE) of ₹2.50 to ₹3.80 per kWh yields immediate, substantial operating margin expansion.

Question 12

How much rooftop or land area is required?

Accepted Answer

For rooftop solar, approximately 80 to 100 square feet of shadow-free area is required per kWp of capacity (using 540Wp+ high-density mono PERC/TOPCon panels). For ground-mounted installations, standard engineering layouts require approximately 3.5 to 4.5 acres of land per MWp, accommodating inter-row shading distances, internal roadways, and transformer yards.

Question 13

Can an industrial facility use both rooftop and ground-mounted solar?

Accepted Answer

Yes. Many manufacturing complexes implement hybrid behind-the-meter setups combining industrial shed roofs (RCC and trapezoidal sheet metal) with adjacent ground space or parking canopies, synchronizing through common LT/HT distribution panels with unified SCADA monitoring.

Question 14

How is solar plant capacity determined?

Accepted Answer

Plant sizing is calculated through a granular review of: (1) 12-month DISCOM electricity bills and load curve data (15-minute TOD interval profiles); (2) Sanctioned contract demand (kVA/kW) and DISCOM ceiling regulations; (3) Usable shadow-free structural area; and (4) Day-shift vs night-shift consumption balance to maximize self-consumption.

Question 15

How much can an industrial consumer save with solar?

Accepted Answer

An optimized industrial captive system typically reduces daylight grid electricity expenditure by 40% to 75%. For an industrial facility consuming 100,000 units monthly at ₹11/unit, a 500 kWp rooftop installation generating ~60,000 units saves approximately ₹6.6 Lakhs monthly or ~₹79 Lakhs annually, delivering full payback within 2.8 to 3.6 years.

Question 16

What happens to excess solar generation?

Accepted Answer

Depending on state-specific DISCOM regulations (such as MERC in Maharashtra), surplus power generated on weekends or plant shutdowns is exported to the grid via net metering or gross metering, or injected under Open Access banking rules where credits offset billing in subsequent settlement cycles.

Question 17

What is Open Access Solar?

Accepted Answer

Open Access is a regulatory mechanism established under the Electricity Act 2003 that allows commercial and industrial consumers with high power demands to procure green electricity from an off-site utility-scale solar plant using state transmission and distribution (DISCOM) grid infrastructure.

Question 18

Who can use Open Access?

Accepted Answer

Under current Green Energy Open Access (GEOA) regulations, consumers with a contracted demand or sanctioned load of 100 kW or above (and traditionally 1 MW+ for standard Open Access) connected at 11 kV or higher can source off-site solar power.

Question 19

What is Captive Open Access?

Accepted Answer

In a 100% Captive model, the industrial consumer develops and owns the off-site solar plant (or holds 100% equity). The consumer consumes the generated electricity directly, rendering the project legally exempt from Cross-Subsidy Surcharge (CSS) and Additional Surcharge (AS).

Question 20

What is Group Captive?

Accepted Answer

Under Rule 3 of the Electricity Rules 2005, a Group Captive project requires participating power consumers to collectively hold at least 26% equity ownership in the Special Purpose Vehicle (SPV) power plant and consume at least 51% of generated energy in proportion to equity. This qualifies the consumers for statutory exemption from Cross-Subsidy Surcharge (CSS).

Question 21

What is Third-Party Open Access?

Accepted Answer

In Third-Party PPA Open Access, a private solar developer builds, owns, and operates the off-site plant and sells electricity directly to the consumer under a bilateral Power Purchase Agreement. The consumer incurs zero capital expenditure, but Cross-Subsidy Surcharge (CSS) and Additional Surcharge apply unless governed by special state exemption orders.

Question 22

What charges apply to Open Access?

Accepted Answer

Open access power bills incorporate: (1) PPA generation tariff; (2) Transmission charges (STU); (3) Wheeling charges (DISCOM); (4) State transmission/distribution losses; (5) SLDC scheduling charges; and (6) Cross-Subsidy Surcharge (CSS) and Additional Surcharge (where applicable). Group Captive structures eliminate CSS, optimizing landed unit costs.

Question 23

What is Cross-Subsidy Surcharge?

Accepted Answer

Cross-Subsidy Surcharge (CSS) is a regulatory compensatory tariff determined by State Electricity Regulatory Commissions (such as MERC) paid to the local DISCOM when a consumer purchases power from an alternate source. As established by the Electricity Act, genuine Captive and Group Captive power plants are strictly exempt from CSS.

Question 24

Can Open Access reduce industrial electricity costs?

Accepted Answer

Yes. High-tension industrial consumers currently paying ₹10.50–₹13.50/kWh can land Group Captive solar power at ₹5.50–₹7.20/kWh (inclusive of wheeling, transmission and banking charges). For a facility consuming 10 Million units annually, this generates ₹4 to ₹7 Crores in recurring annual cost savings.

Question 25

What does Chirayu's EPC service include?

Accepted Answer

Chirayu's turnkey EPC scope encompasses: geotechnical and structural wind analysis, 3D shadow simulations, electrical SLD and protective relay engineering, Tier-1 module & inverter procurement, hot-dip galvanized mounting structures, balance of plant (AC/DC combiner boxes, HT transformers, vacuum circuit breakers), statutory liaisoning (CEIG/DISCOM approvals), synchronized grid charging, and performance ratio (PR) testing.

Question 26

How does Chirayu evaluate a solar project?

Accepted Answer

Evaluation begins with drone-assisted 3D photogrammetry and topographical site audits to map azimuth, tilt, and obstacles. Structural engineers audit building load-bearing capacity, while electrical engineers log 15-minute power quality parameters to produce an investment-grade Detailed Project Report (DPR).

Question 27

What happens during project development?

Accepted Answer

Project development advances through 4 structured milestones: (1) Technical design & component finalization; (2) Statutory grid connectivity application & DISCOM sanction; (3) Civil foundations, module mounting structure (MMS) erection & electrical cabling; and (4) CEIG electrical inspector testing, net-metering commissioning, and plant handover.

Question 28

How long does a solar EPC project take?

Accepted Answer

Rooftop industrial systems (100 kW to 1 MW) typically reach commercial operation in 6 to 12 weeks. Ground-mount and utility-scale projects (2 MW to 25 MW) require 16 to 24 weeks depending on land development, dedicated bay construction at the substation, and transmission line right-of-way (ROW) clearance.

Question 29

What approvals are required?

Accepted Answer

Standard industrial solar installations require: (1) DISCOM grid feasibility and connectivity sanction; (2) Chief Electrical Inspector to Government (CEIG) electrical safety drawing approval & charging inspection; (3) State Pollution Control Board clearance (if applicable); and (4) Bi-directional / SEM meter testing and synchronization certificate.

Question 30

Is there any need to take permission from Electricity Supply Utility to install solar power plant?

Accepted Answer

For Grid Connected Solar Power Plants, there is a detailed process followed as per Electricity Supply Utility (DISCOM) Rules and Regulations for installation, technical feasibility, net metering, and commissioning. There is no permission required for installing an Off-Grid Solar System.

Question 31

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 32

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 33

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 34

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 35

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 36

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 37

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 38

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 39

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 40

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 41

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 42

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 43

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 44

What size solar plant does a factory need?

Accepted Answer

It depends on your daytime electricity consumption, not just your roof area. We size systems around your actual load profile from 12 months of electricity bills so maximum generated power is consumed on-site.

Question 45

Can I get solar without paying anything upfront?

Accepted Answer

Yes — under the RESCO/OPEX model, a developer builds and owns the plant on your site and you buy the generated power at a fixed lower per-unit rate.

Question 46

What's the difference between rooftop solar and Open Access?

Accepted Answer

Rooftop solar is on your premises. Open Access lets you buy solar power generated at an off-site plant delivered through the state grid when roof space is insufficient.

Question 47

Who qualifies for Open Access in Maharashtra?

Accepted Answer

Eligibility depends on your electricity connection, sanctioned load or contract demand, the type of Open Access arrangement, and the applicable regulations. Green Energy Open Access may be available to eligible consumers meeting a 100 kW threshold, while conventional Open Access can have different requirements.Chirayu Power can help assess your electricity bills and project requirements to determine whether Open Access may be suitable for your business.

Question 48

Do captive solar projects have to pay Cross-Subsidy Surcharge (CSS)?

Accepted Answer

Eligible captive projects may qualify for exemption from CSS, provided they meet the applicable ownership, consumption, and regulatory requirements.

Question 49

How long does the Open Access approval process take in Maharashtra?

Accepted Answer

The timeline depends on the project size, required approvals, grid availability, and the relevant authorities processes. The expected timeline can be assessed once the project details are reviewed.May vary from 40-60 Days

Question 50

What happens if a group captive member fails to consume their 51% ratio?

Accepted Answer

If the 51% consumption threshold is breached annually, captive status can be revoked by the regulator for that financial year, making CSS applicable retroactively. We structure buffers to prevent breach risks.

Question 51

Do captive consumers need to be physically adjacent to the solar park?

Accepted Answer

No. Captive and Group Captive power is wheeled through the state high-voltage transmission grid (MSETCL / MSEDCL) regardless of geographical distance within Maharashtra.

Question 52

Can a company migrate from a Third-Party PPA to a Group Captive structure later?

Accepted Answer

Yes, by restructuring the agreement and acquiring equity in the generating SPV. Chirayu Power advises and assists in corporate transitions to captive status.

Question 53

How much equity does each company need to invest?

Accepted Answer

The group collectively holds at least 26% equity in the generating SPV, proportional to their contracted power off-take ratio. Chirayu Power structures the equity schedules transparently.

Question 54

How many consumers can be part of one Group Captive solar plant?

Accepted Answer

There is no statutory cap in principle. Most practical SPVs involve 3 to 10 industrial consumers to ensure smooth governance and proportional compliance.

Question 55

What happens if one member consumption drops significantly?

Accepted Answer

Their captive status (and CSS exemption) can be scrutinized if consumption drops below the equity ratio. Our Shareholder Agreements include provisions to re-balance or re-allocate units safely.

Question 56

Why does landed cost differ between DISCOM zones in Maharashtra?

Accepted Answer

Wheeling charges, distribution losses, and local electricity duties vary by DISCOM operating region (e.g., MSEDCL vs TATA Power vs Adani Electricity). We model your specific DISCOM area.

Question 57

How does solar energy banking work in practice?

Accepted Answer

Banking lets you credit daytime solar power generated but not consumed against your grid draw at other times, within the monthly billing cycle and subject to regulatory settlement rules.

Question 58

What is the difference between transmission charges and wheeling charges?

Accepted Answer

Transmission charges pay for the state high-voltage grid (MSETCL), while wheeling charges pay for the local distribution network (MSEDCL) delivering power to your factory substation.

Question 59

Does behind-the-meter solar require grid synchronization?

Accepted Answer

Yes, standard grid-tied inverters require reference voltage to operate safely and shut down during outages to prevent islanding. For power during outages, we integrate DG sync controllers or BESS.

Question 60

Can BTM solar damage factory shed roofing or cause leakage?

Accepted Answer

No. We deploy specialized non-penetrative seam clamps on standing-seam roofs and leak-proof EPDM-gasketed fastenings that maintain 100% weather integrity.

Question 61

What happens to excess solar energy on non-working Sundays?

Accepted Answer

Surplus units are exported to the utility grid under net metering or net billing agreements, or managed using zero-export limiters to prevent uncredited grid backfeed.

Question 62

Can we buy back the solar system before the 25-year term ends?

Accepted Answer

Yes, standard RESCO PPA agreements include transparent buyout schedules after 5, 10, or 15 years, allowing you to acquire the asset at predefined depreciated prices.

Question 63

Who is responsible if solar panels degrade or break under RESCO?

Accepted Answer

Chirayu Power and the investor bear 100% of maintenance, cleaning, component replacement, and insurance costs throughout the entire PPA term.

Question 64

What is the minimum plant capacity required for a RESCO agreement?

Accepted Answer

Typically 200 kW or higher for rooftop systems, and 1 MW or higher for ground-mounted or open access configurations.

Parameter	RESCO / OPEX Model	Direct CAPEX Ownership	Standard Utility Supply
Initial Capital Required	₹0 (Zero capital expenditure)	Full system cost upfront or loan	₹0 (Monthly utility bills)
Operation & Maintenance	Borne 100% by developer	Managed by client / EPC O&M	Handled by DISCOM
Per-Unit Electricity Cost	Discounted fixed / indexed PPA rate	Free after 3-4 year payback	High escalating utility tariff
Tax Depreciation Benefit	Claimed by solar developer	Claimed 100% by your company	None available
Performance Guarantee	Guaranteed minimum generation	Guaranteed by EPC warranty	No uptime guarantee

RESCO / OPEX Solar:Pay For Solar Power Per Unit with Zero Capital Outlay

Pay only for generated units at a discounted solar tariff.

Preserve Core Capital

Zero Performance Risk

Pre-Agreed Asset Transfer

Frequently Asked Questions

RESCO / OPEX Solar:Pay For Solar Power Per Unit with Zero Capital Outlay

Zero-Capital Solar Power Purchase Agreement

CAPEX vs. RESCO / OPEX Model

Pay only for generated units at a discounted solar tariff.

Core Advantages of the RESCO Route

Preserve Core Capital

Zero Performance Risk

Pre-Agreed Asset Transfer

Frequently Asked Questions