Best solar panels for homes in India

Are you looking for the right solar panels for your home in India?

Naming any one brand for you would be wrong on my part.

Because it depends on many factors and India is a vast country with having 3.287 million square km area.

A solar panel working efficiently in North India may not perform that well in the southern part of the country. Let us figure out the best solar panels for your home in India.

Understanding the location of India

India is strategically located where we see 300 sunshine days in a year.

Making it a great solar destination.

Coordinates of India:

• Latitude: 8ᵒ4’ North to 37ᵒ6’ North
• Longitude: 68ᵒ7’ East to 97ᵒ25’ East

Concept of Peak Sun Hours

India receives over 5 PSH in a day (Till the time sun is in the sky).

When I talk about Peak Sun Hours, I mean the average sunlight falling over 1 m² area in a day over a region.

It is measured in kW/m²/day.

1 PSH = 1000 W/m²

You don’t get 1000 W/ m² every hour.

It varies throughout the day.

It is the sum of the total value of sunshine intensity every hour from sunrise to sunset.

Thereafter, dividing this value by 1000, we get the PSH for the day.

Let us understand this way, on a particular day a place in India receives sunlight in the following manner (from sunrise to sunset):

You can see that the sunlight intensity is increasing from sunrise till noon.

It is the maximum at noon.

Thereafter, it starts decreasing and reaches a minimum when the sun is setting.

Upon adding the sunlight intensity values from sunrise to sunset. We get the total sunlight on that day.

The total value on this particular day is 7596 W/m²

When I divide this value of 7596 W/m²/day by 1000 W/m²/day

I get the PSH for the day.

That are 7596/1000 = 7.596 PSH.

Finding average PSH in India

India is a big country with different sunlight intensities over this large area.

Therefore, we will try to figure out the average sunlight by taking different locations in the country in all the directions such as:

North: New Delhi PSH: 5.35 and J&K: 5.09

East: Assam PSH: 5.07 and West Bengal PSH: 5.31

West: Gujrat: PSH: 6.18

Central: Madhya Pradesh PSH: 5.94

South: Kerala PSH: 5.64

When I take the average:

(5.35 + 5.09 + 5.07 + 5.31 + 6.18 + 5.94 + 5.64)/7 = 28.18/7 = 5.51

I can say India receives an average PSH of 5.51.

That is a very good value, making solar financially attractive.

The different sunlight values mean different output from the same solar panels.

Before diving into the best solar panels for home/domestic use in India.

Let us understand its climate.

Climate of India

India is surrounded by different geographies.

• Himalayan ranges from North to East
• Bay of Bengal in the East
• The Indian Ocean in the South
• The Arabian Sea in the South-west
• The Thar Desert in the West

This creates different climatic conditions throughout the year.

South, South-west, and the eastern region of the country is humid due to their proximity to the water bodies.

The Northern region witnesses a temperate climate due to its proximity to the Himalayas.

Western India is dry and hot due to the presence of the vast Thar desert.

The Himalayas, Thar desert, Bay of Bengal, Arabian Sea, and the Indian ocean together create the monsoonal changes in the country.

And

We see mainly 4 different climates in the country namely:

• Winter: December to February
• Summer (Pre-monsoon): March to May
• Monsoon: June to September
• Autumn (Post monsoon): October to November

Now, we will figure out the best solar panels in different climates.

Solar panels for homes in snow falling regions

Regions that are close to Himalayan ranges and are above 3000 meters from the sea level, receive snowfall.

These regions are:

Jammu Kashmir, Upper parts of Himachal Pradesh, Ladakh, upper parts of Uttarakhand, Sikkim and Arunachal Pradesh, Manipur, Meghalaya,

Manipur and Nagaland though do not lie in the Himalayan ranges receive occasional snowfall.

In addition, these states do witness heavy rainfall in July and August.

Therefore, we need solar panels that can withstand heavy snowfall and work efficiently in the rainy season.

For this, we look at the snow load (top load rating) of the solar panels.

This metric shows the ability of the solar panel to withstand the snow weight and perform well.

It is shown in Pascals.

A high value of snow load rating is preferred for these regions.

The average top-load rating in the solar industry is 2400 Pascals.

How much snow weight a solar panel can withstand?

Let us see how much snow weight 2400 Pa can withstand.

Fresh, dry snow has an average density of 100 kg/m³.

Snow load rating (Pascals) = height x Snow density x g (acceleration due to gravity)

2400 = h x 100 x 10

Height = 2.4 meters.

A 2400 Pascals snow load rating solar panel will withstand snow up to a height of 2.4 meters on its surface.

People living in snow-falling regions look for solar panels having snow load ratings above 2400 Pascals.

These regions also receive heavy rainfall during monsoon.

That makes the atmosphere humid.

There are fair chances that the water layer may rust the solar panel and affects its useful life.

Therefore, we should look for corrosion-resistant solar panels.

IEC 61701 certified solar panels protect them from corrosion.

Summary for snow falling regions:

• Snow Load rating> 2400 Pa
• IEC 61701 and IEC 61215 certifications.
• Highly efficient

Solar panels for homes in the Indo-Gangetic plain

Punjab, Haryana, Delhi, UP, Bihar, Bengal.

And

MP and Gujarat (don’t lie in the Indo-Gangetic plain)

Don’t receive snowfall.

These states experience great temperature variations.

As low as near to the freezing point in winters usually for 1 or 2 days.

And

Summer temperature can be as high as 45ᵒC.

This is a big temperature variation.

The solar panels must perform in this temperature difference.

Look for solar panels with a wide operating temperature range.

In addition, in high temperatures the solar panel output reduces.

When the cell temperature goes beyond 25ᵒC, its output starts decreasing.

It is due to the increase in the internal resistance of the solar cells.

And they produce less current.

The temperature coefficient of power tells the amount or % of Pmax any solar panel will lose.

It is measured in %/ᵒC.

Formula:

Power loss (%) = (Cell temperature – 25ᵒC) x Temperature coefficient of power

Where

Cell temperature is the operating temperature of the solar cells.

Higher is the temperature coefficient of power, more is the power loss.

For regions with high temperatures, a lower value of temperature coefficient of power is preferred.

Read: Best solar panels for hot climate

The average value of the temperature coefficient of power in the solar industry is -0.4%/ᵒC.

Example

Assuming you have 200 watts solar panel with a temperature coefficient of power of -0.4%/ᵒC.

Further assuming, the ambient temperature of 30ᵒC

Cell temperature 50ᵒC (the solar cells operate at 20ᵒC to 30ᵒC higher than the ambient temperature).

The power loss would be:

(50 ᵒC – 25ᵒC) x -0.40%/ᵒC

= 25ᵒCx -0.40%ᵒC

= -10%

Your solar panel will be 10% of 200 watts = 20 watts.

It will produce 180 watts.

Therefore, look for solar panels that have a lower value than this average.

Also, the dry months of April and May experience dust storms with an average speed up to 60 km/hr.

The layer of dust can deposit on the panel surface.

This affects its output.

The efficient solar panels work better under these conditions.

Therefore, look for highly efficient solar panels.

Summary for solar panels for Indo-Gangetic plains

People living in these regions look for solar panels that have:

• Wide range of operating temperatures.
• Low-temperature coefficient of power
• Efficient so that they can perform with dust on their surface.
• Also, IEC 61701 certified for corrosion

Solar panels for homes in coastal areas with high humidity

India is a peninsula.

It is surrounded by water from three sides.

States like:

• Maharashtra
• Tamil Nadu
• Kerala
• Telangana
• Karnataka
• Goa
• Orissa
• West Bengal
• Daman and Diu
• Puducherry
• Andaman and Nicobar Islands (Bay of Bengal)
• Lakshadweep Islands (Arabian Sea)

Lie near the water bodies

• Bay of Bengal
• Arabian Sea
• Indian Ocean

These states have many regions with average humidity levels > 65%.

These places have higher water and salt content in their atmosphere.

The salt in the atmosphere facilitates the corrosion process.

People here generally find that their items corrode or degrade faster than usual.

The same would be the case with normal solar panels.

Therefore, people should look for corrosion-resistant solar panels for these regions.

IEC 61701 certifications for corrosion-resistant.

It determines the strength of the solar panel towards salt and humidity.

Wind speed and Solar panel strength

Also, tropical cyclones are common in these regions.

These cyclones are more prone in the months between May and November.

This results in heavy rains, storms, and winds.

Their high wind speed can break the solar panels.

Therefore, the solar panels must be strong enough to withstand the wind pressure.

Their ability to face the wind pressure is represented by wind load rating or rear load rating.

A high rating is preferred.

The solar industry average is 2400 Pascals.

It means that the solar panels can withstand:

Pressure = 0.613xV²

Pressure in Pascals

Velocity in m/sec

2400 Pascals = 0.613 x V²

V² = 2400/0.613

V = √3915.2

V = 62.6 m/secs or 225 km/hr

A 2400 pascals wind load rating solar panel can withstand wind speed up to 63 m/sec

Let us see whether this value of wind load rating can withstand the recent cyclones in India.

Let us talk about recent cyclones and their wind speeds.

1. Cyclone Tauktae (May 2021 in Kerala, Maldives, and Lakshadweep): Highest wind speed of 220 km/hr
2. Yaas Cyclone (May 2021 in (Odisha and West Bengal): 140 km/hr (Highest wind speed)
3. Nisarga (June 2020) (Maharashtra): Highest wind speed of 140 km/hr
4. Cyclone Amphan (May 2020 in West Bengal, Orissa): Highest wind speed: 260 km/hr

A 2400 Pascals wind load rating solar panel can withstand most the cyclones in India.

1) IEC 61701 certified solar panels (corrosion resistant)
2) Wind load rating >= 2400 Pascals
3) Highly efficient solar panels

Solar Panels for homes in rural areas in India

Over 65% of the Indian population lives in rural areas.

These places are open and have more green areas.

A gust of wind can deposit a layer of dust on the panel surface.

People are engaged in farming and keeping livestock.

The excreta of animals release ammonia gas.

This gas is corrosive in nature and corrodes the solar panels installed near livestock.

Also, some crops such as Paddy require a lot of standing water to grow. A system’s output installed near these crops may get affected due to the moisture content in the surroundings.

Summary

Therefore, the right solar panel for rural areas should be:

• Ammonia Resistant: IEC 62716
• Salt and mist resistant: IEC 61701
• Highly efficient

Common features

We discussed so far, the unique features that a solar panel must-have for each location.

Let us look at some features that should be common to all solar panels irrespective of their installation location.

• Reliable Brand: Choose the solar panel from a company that is reliable and a renowned brand in the market. The company must be operating for at least 10 years in the market.

• Great warranties: Look for solar brands that offer great warranties on their solar panels. Solar panels come with 2 warranties: A product warranty and a performance warranty.

• Excellent service: Look for a solar panel company that has an office or service center near to your place. This will help it to serve you better and fast.

Best solar panels brands for Indian climate

Waaree Solar Panel

• Waaree is a renowned manufacturer in India with a module capacity of over 2 GW.
• Wide power range with different technologies.
• The latest technology with 21.43% efficient solar panels in its Arka Series.
• They perform well in high temperatures with a temperature coefficient of power values of -0.34%/ᵒC to -0.3859%/ᵒC.
• Wide temperature operating ranges from -40 to 85ᵒC.
• Snow load rating 5400 Pa and wind load rating of 2400 Pa.
• Product warranty 10-12 years and Performance warranty of 25 years to 27 years.
• Price of Waaree solar panels (Rs. 26 to Rs. 32 per watt)

Adani Solar Panel

• It has a manufacturing facility of 1.5 GW at its Mundra plant in Gujarat.
• A top performer in reliability, tier-I bankable modules
• It has solar panels with a maximum power rating of 650 watts
• It has the latest technology such as half-cut solar cell technology, Mono PERC, MBB, and Bi-facial technology.
• Adani solar panels have a maximum efficiency of 21.19%
• Good temperature coefficient of power -0.34%/ᵒC, -0.35%/ᵒC, and -0.40%/ᵒC.
• Snow load: 5400 Pa and wind load rating of 2400 Pascals
• Product warranty: 12 years and performance warranty of 25 years
• (2% degradation in the first year and 0.55% from 2^nd year to 30^th year for its Eternal and Elan series.
• Suitable for long-term operations, dust and sand resistant, certified for safety qualification, dynamic mechanical load, performs well in different values of temperature and sunlight.
• Adani solar panels are resistant to heat and reduce heat losses.

Vikram Solar Panel

• It offers polycrystalline, monocrystalline, half-cut solar cell technology, and bifacial solar panels to its customers.
• Maximum efficiency of 21.02%
• Temperature coefficient of power -0.34%/ᵒC
• Strength 5400 Pa (snow load) and 2400 pascals (wind load)
• Product warranty:
• Long Product (10 years) and Performance warranties: 27 years (2.5% in the first year and 0.65% from 2^nd to 27^th year in Eldora Series
• Affordable price

Financial feasibility of solar in India

Solar is attractive in India that offers great returns.

Let us know the factors that affect the financial feasibility of solar in India:

Factors that affect the units produced by the system:

Sunlight

The sunlight intensity of over 5 kW/m²/day makes India a great solar destination.

The efficiency of the system

There is a number of losses in the system that affect its efficiency. These are:

• Shading loss: loss in the power due to shade of the nearby building or a tree on the panel’s surface.
• Temperature loss: The solar panels produce less current as the cell temperature exceeds above 25ᵒC.
• Dirt loss: The dirt accumulated over the surface of the solar panels reduces the power output.
• Conversion loss: Energy is lost when it is converted from one form to another. A solar power system absorbs sunlight and converts it into direct current. Thereafter, this direct current is converted into alternating current and runs our electrical appliances.
• Transfer loss: When current is transferred from one point to another through wires. Some of it gets lost in this process.

All these losses cumulatively reduce the power output by 20% to 30% in any solar power system.

After considering all the factors, a 5-kW grid solar power system in India generates 20 units per day.

Making an around 1,61,00 solar units in its lifetime

(Taking 25 years as the life of the solar panels).

Factors affecting Payback of solar in India

• Cost of the system: The average cost of a 5 kW solar power system (without battery backup) in India is Rs. 3,10,000/-. A high prices system reduces the financial feasibility.
• Maintenance cost of the system: With time the system gets old and requires maintenance. The maintenance cost increase with time.
• Rising electricity prices: The average cost of electricity is increasing by 8% per year. It means switching to solar is getting attractive with every passing year. Because you save more money when you generate solar electricity.

These factors help us in finding the financial feasibility:

• Payback: 8 years (Time in which your system pays back the amount invested)

• IRR: 17% (It is the annual return that your solar power system offers for 25 years)
• NPV: over Rs. 5,00,000 (The Net present value of the system when the total future cash flows are discounted to the present value)
• Units produced over a lifetime: 160,707 in 25 years
• Net savings in 25 years: Rs. 20,00,000 in 25 years.

Solar Feasibility Spreadsheet: An amazing tool to size, design, and find the financial feasibility of the solar power system

FAQ in Solar

1. How do solar panels work?

A solar panel is made of solar cells that are made from silicon.

Silicon absorbs the sunlight and converts it into electricity.

2. What are the different types of solar panels?

We have 2 types of solar panels:

Poly-crystalline (affordable but less efficient) and Mono-crystalline (more efficient but costly).

3. How many units does a solar panel generate in India per day?

In India, a 1-kW solar power system produces an average of 4 units per day.

4. What is the payback period of solar in India?

The payback of the solar power systems in India is between 6 to 9 years.

Depending upon the configuration you choose.

5. What is the average life of a solar panel?

The average life of a solar panel is 25-30 years. The power output from the solar panels gradually reduces with every passing year.

6. Warranty of a solar panel

Solar panels come with 2 warranties:

Product warranty: It protects your solar panel from any defect related to premature wear and tear of the solar panels.

Performance warranty: It assures that your solar panel will produce a certain percentage of its Pmax even after 25 years.

7. Do solar panels work in cloudy weather?

The panel output decrease as the sunlight fades away. Yes, solar panels do work in cloudy weather but their output reduces drastically.

8. What is the efficiency of a solar panel?

Solar panels absorb sunlight and convert it into electricity. How much sunlight is converted into electricity shows the efficiency of the solar panel.

We have solar panels with an efficiency of over 22%.

Read: The most efficient solar panels in the world

9. What are the different losses in solar power systems?

There are many losses in the system such as:

• Shading loss
• Transfer loss
• Temperature related losses
• Age-related loss
• Dirt loss
• Conversion loss

10. What is the price of a 5 kW solar power system in India?

• A grid-tied system without battery backup: Rs. 3,10,000 or Rs. 62 per watt
• Hybrid system with 1-day battery backup: Rs. 4,20,000 or Rs. 84 per watt.
• An off-grid system with 2 days of battery backup: Rs. 4,75,000 or Rs. 95 per watt.

11. How many solar panels are required to power a refrigerator in India?

You need 2 x 150-watt solar panels to run your 150 watts refrigerator in India.

12. What is a half-cut solar cell technology?

In this technology, the traditional solar cells are cut into halves and joined.

It offers many benefits such as:

• This improves the structural strength of the cell.
• Reduces heat losses
• And make them more tolerant of shading loss

13. What is MBB in solar panels?

Multi Bus Bars are the thin wires of copper or aluminum. They connect the solar cells together and take current from one point to another.

MBB reduces the current path. Hence minimizes the heat-related losses and improves the efficiency of the solar cell.

14. What is bi-facial solar cell technology?

The conventional solar panels produce current from one side only which is from the front side of the solar panel.

In bi-facial solar panels, the solar panels produce current from both sides.

Front and rear.

Hence increases the overall efficiency of the solar panel.

15. What is Mono-PERC technology?

In PERC solar cell technology, an extra layer is pasted at the back of the solar cell. This helps in trapping sunlight more efficiently.

It results in increased performance of the solar panel.