SolarQna Solar FAQs & Engineering Knowledge Hub

Question 1

What is solar energy?

Accepted Answer

Solar energy is sunlight converted into electricity or heat. Rooftop solar panels use photovoltaic cells to generate electricity for homes and businesses.

Question 2

How does a rooftop solar system work?

Accepted Answer

Solar panels generate DC electricity, and an inverter converts it into AC electricity for appliances. Grid-connected systems may export surplus power.

Question 3

What are the main components of a solar system?

Accepted Answer

A typical system includes solar panels, an inverter, mounting structures, DC/AC protection devices and wiring. Batteries are optional.

Question 4

How much electricity does a 1 kW solar system generate?

Accepted Answer

A 1 kW rooftop system may generate approximately 4–5 units per sunny day under favourable Indian conditions. Location, season and shading affect output.

Question 5

Does solar power work on cloudy days?

Accepted Answer

Yes. Panels still generate electricity from daylight, but output is lower than on clear, sunny days.

Question 6

Can solar panels generate electricity at night?

Accepted Answer

No. Solar panels need light to generate electricity. Night-time power comes from the grid or a charged battery.

Question 7

How long do solar panels last?

Accepted Answer

Many modern panels are designed to operate for 25–30 years or longer, although electricity output gradually declines. Check model-specific warranty terms.

Question 8

Does a rooftop solar system include a battery?

Accepted Answer

Not always. Standard on-grid systems usually operate without batteries. Battery backup requires a suitable hybrid or off-grid configuration.

Question 9

How do I choose between on-grid, off-grid and hybrid solar?

Accepted Answer

Choose on-grid to reduce grid electricity use, off-grid where grid supply is unavailable, and hybrid where grid-connected solar with compatible backup is required.

Question 10

Which solar system is best for a home?

Accepted Answer

On-grid systems generally suit homes focused on bill savings; off-grid and hybrid systems suit homes needing battery backup. The right choice depends on your needs.

Question 11

How do I decide the solar system size for my house?

Accepted Answer

Review 12 months of electricity bills, daytime consumption, usable roof area, local sunlight and your DISCOM’s rules.

Question 12

Can I run an air conditioner on solar power?

Accepted Answer

Yes, if the solar array and inverter are appropriately sized. Battery capacity is also needed if you want backup operation.

Question 13

Is 3 kW solar enough for a house?

Accepted Answer

A 3 kW system can suit many moderate-consumption households, but actual suitability depends on appliance loads and daily units consumed.

Question 14

Can I install solar on a small roof?

Accepted Answer

Often yes. High-efficiency panels can improve output from limited space, but a shade-free layout and safe mounting clearances matter.

Question 15

Can commercial buildings install rooftop solar?

Accepted Answer

Yes. Offices, shops, factories and warehouses can install rooftop solar after checking roof strength, electricity demand and applicable approvals.

Question 16

How is commercial solar system size calculated?

Accepted Answer

Sizing considers sanctioned load, interval electricity use, daytime demand, roof area, tariffs and any export restrictions.

Question 17

Can solar help reduce business electricity bills?

Accepted Answer

Yes. Solar generation can offset grid electricity purchases, especially when business operations consume power during the day.

Question 18

Are commercial solar systems eligible for PM Surya Ghar subsidy?

Accepted Answer

The central household subsidy under PM Surya Ghar is for eligible residential consumers, not ordinary commercial installations.

Question 19

What is an on-grid solar system?

Accepted Answer

An on-grid system uses solar panels and a grid-connected inverter to supply power and, where permitted, export surplus electricity.

Question 20

Does an on-grid solar system require batteries?

Accepted Answer

No. Conventional on-grid solar systems operate without batteries.

Question 21

Will my on-grid solar inverter work during a power cut?

Accepted Answer

Normally no. Standard grid-tied inverters shut down when grid power fails to protect utility workers and equipment.

Question 22

What is net metering in solar?

Accepted Answer

Net metering is a billing arrangement that accounts for solar electricity exported to and imported from the grid, subject to state/DISCOM regulations.

Question 23

What is the difference between on-grid and off-grid solar?

Accepted Answer

On-grid systems work with the utility grid; off-grid systems use batteries or another standalone energy source to supply power independently.

Question 24

What is an off-grid solar system?

Accepted Answer

An off-grid solar system supplies electricity independently of the utility grid, typically through solar panels, a battery and an inverter.

Question 25

Is a battery necessary for off-grid solar?

Accepted Answer

A battery is normally required to power loads when solar generation is insufficient or unavailable, unless another backup source is provided.

Question 26

Can an off-grid solar inverter run a refrigerator?

Accepted Answer

Yes, provided the inverter supports the refrigerator’s starting surge and running load and the battery supplies enough energy.

Question 27

How long can an off-grid system provide backup?

Accepted Answer

Backup depends on usable battery capacity, appliance load, inverter losses and the battery’s state of charge.

Question 28

Does an off-grid solar system qualify for the central rooftop subsidy?

Accepted Answer

PM Surya Ghar support is focused on eligible grid-connected residential rooftop installations. Verify the latest scheme conditions before choosing a system.

Question 29

What is a hybrid solar system?

Accepted Answer

A hybrid system combines solar generation with grid interaction and battery storage, subject to the inverter’s design and configuration.

Question 30

What is the difference between hybrid and on-grid solar?

Accepted Answer

A conventional on-grid system has no battery backup; a compatible hybrid inverter can manage battery storage and selected backup loads.

Question 31

Can a hybrid solar system export excess power to the grid?

Accepted Answer

Some hybrid inverters support grid export, provided the installation is approved and configured according to local regulations.

Question 32

Can a hybrid solar system work during a power cut?

Accepted Answer

Yes, if the inverter offers backup output and a suitable battery is installed. Backup power and loads depend on the model.

Question 33

Can I add batteries to an existing on-grid system?

Accepted Answer

Sometimes. You may need an AC-coupled battery system, compatible hybrid inverter or other design changes.

Question 34

Does a hybrid solar inverter work with lithium batteries?

Accepted Answer

Compatible models can use lithium batteries, but voltage, BMS communications and inverter specifications must match.

Question 35

What is PM Surya Ghar: Muft Bijli Yojana?

Accepted Answer

It is a Government of India programme supporting eligible households installing residential rooftop solar systems through the national portal.

Question 36

How much central rooftop solar subsidy can I get?

Accepted Answer

Under the standard central schedule, eligible households may receive ₹30,000 for 1 kW, ₹60,000 for 2 kW and ₹78,000 for 3 kW or more. Special-category provisions may differ.

Question 37

Can I get a ₹78,000 subsidy for a 3 kW solar system?

Accepted Answer

Yes, eligible residential consumers can receive up to ₹78,000 in central assistance for an approved 3 kW rooftop solar system under standard rates.

Question 38

How do I apply for rooftop solar subsidy?

Accepted Answer

Apply through the official PM Surya Ghar portal, follow DISCOM approval and registered-vendor procedures, and complete the required inspection and documentation.

Question 39

Can I claim PM Surya Ghar subsidy with a non-DCR solar panel?

Accepted Answer

No. PM Surya Ghar projects must meet applicable domestic-content requirements. Choose a qualifying DCR module and follow the scheme process.

Question 40

Does buying a rooftop solar kit automatically qualify me for subsidy?

Accepted Answer

No. Subsidy eligibility requires the scheme's applicant, equipment, vendor, installation and inspection conditions to be met.

Question 41

Is solar financing or EMI available?

Accepted Answer

Solar loans and EMI options may be available through banks or financing partners, depending on eligibility and current lending terms.

Question 42

Is solar subsidy available for a rented house?

Accepted Answer

Eligibility depends on the electricity connection, roof permissions and scheme rules. Seek consent from the property owner and confirm with the DISCOM.

Question 43

What is a solar panel?

Accepted Answer

A solar panel is a module made of photovoltaic cells that convert sunlight into direct-current electricity.

Question 44

What is a TOPCon solar panel?

Accepted Answer

TOPCon is a solar-cell technology using tunnel oxide passivated contacts to help improve efficiency and reduce electrical losses.

Question 45

What is a bifacial solar panel?

Accepted Answer

A bifacial panel generates electricity from both the front and rear surfaces. Rear-side output depends on reflected light and mounting conditions.

Question 46

What is the difference between Mono PERC and TOPCon panels?

Accepted Answer

Both use monocrystalline cells; TOPCon generally offers improved passivation and efficiency potential compared with conventional PERC designs.

Question 47

What does DCR mean in solar panels?

Accepted Answer

DCR stands for Domestic Content Requirement. Applicable Indian programmes require specified solar cells and modules to meet domestic sourcing rules.

Question 48

What is the difference between DCR and non-DCR solar panels?

Accepted Answer

DCR modules meet prescribed domestic-content criteria; non-DCR modules may use cells or components that do not meet those criteria.

Question 49

What does solar panel wattage mean?

Accepted Answer

A rating such as 600 Wp represents the module’s maximum output under standard test conditions, not continuous real-world generation.

Question 50

What is solar panel efficiency?

Accepted Answer

Panel efficiency measures how much incoming sunlight a module converts to electricity under standard test conditions.

Question 51

Are dual-glass solar panels better?

Accepted Answer

Dual-glass panels can improve environmental protection and durability, but performance depends on cell technology, construction and installation.

Question 52

Do solar panels need regular cleaning?

Accepted Answer

Yes, when dust, bird droppings or other deposits reduce light reaching the cells. Cleaning frequency depends on local conditions.

Question 53

What is the difference between product and performance warranty?

Accepted Answer

A product warranty covers specified manufacturing defects; a performance warranty covers minimum power output over the stated period.

Question 54

What is the efficiency of the UTL 630W G12R TOPCon panel?

Accepted Answer

Our 630Wp G12R N-Type TOPCon bifacial panel offers up to 23.32% module efficiency.

Question 55

Is the UTL 630W G12R panel DCR-compliant?

Accepted Answer

No. Our listed 630Wp G12R TOPCon panel is a non-DCR module. For schemes requiring DCR modules, choose an eligible DCR model.

Question 56

What is a solar inverter?

Accepted Answer

A solar inverter converts electricity generated by solar panels into usable AC power and may also manage charging and power flow.

Question 57

What is an MPPT solar inverter?

Accepted Answer

An MPPT inverter or controller continuously adjusts the solar operating point to harvest more available power as conditions change.

Question 58

What is the difference between PWM and MPPT?

Accepted Answer

PWM is a simpler charging method; MPPT can adapt panel voltage and generally harvest more energy when operating conditions vary.

Question 59

How do I select a solar inverter?

Accepted Answer

Check system type, AC load, PV capacity, MPPT voltage range, battery compatibility, grid requirements and warranty.

Question 60

What is the difference between kW and kVA?

Accepted Answer

kW measures real power; kVA measures apparent power. Their relationship depends on the electrical power factor.

Question 61

Can a solar inverter work without a battery?

Accepted Answer

Yes, conventional on-grid inverters work without batteries. Many off-grid inverters require a battery, depending on model.

Question 62

What does inverter efficiency mean?

Accepted Answer

Inverter efficiency is the proportion of input electrical power delivered as useful output after conversion losses.

Question 63

Can I connect more panels than the inverter’s rated AC power?

Accepted Answer

Some inverters allow a higher DC solar array capacity, within their stated input-voltage, current and power limits.

Question 64

What is a hybrid solar inverter?

Accepted Answer

A hybrid inverter coordinates electricity from solar panels, batteries and the grid, with features varying by model.

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