Best Solar Panels

As the debate on climate change is getting more and more attention across countries and many new targets and oaths are being taken, many homeowners are looking for solutions that can help them reduce the carbon footprint. Sustainability, environment protection, and net carbon zero have become the buzz words with COP26, (26th Conference of Parties being held at Glasgow) renewable resources of energy are being advocated for adoption. Solar energy, therefore, becomes one of the possible solutions that can help mitigate the carbon emissions in the best possible way. An interesting fact is that 1 KW solar panel in its entire lifespan can help reduce the CO2 emissions equivalent to 14 fully grown trees for the same period. So practically it’s the saving of money or we may say the investment of money and direct contribution to the ecosystem with green energy solutions.

How many types of Solar Panels exist, and which one is best?

There are various types of solar panels that exist – Polycrystalline solar panel, mono PERC solar panel, and Bifacial solar panel, however, it is important to choose the appropriate one for your needs. So practically, it is advised to follow a 5-point checklist to conclude which solar panel is most ideal. These 5 points are –

1. Technology
2. Efficiency
3. Durability
4. Temperature coefficient 
5. Customer Review

1. Technology

There has been a constant quest on improving the basic integration and technology which is for the betterment of solar energy users. There have been advancements in technology over a period. About 4 years back almost 90% of solar panels used to be polycrystalline that was deployed for most of the applications and about 10% were monocrystalline panels. As we are progressing, more awareness amongst customers is helping them identify the right solution and monocrystalline and bifacial solar panels are being adopted with bifacial being the latest technology in India, today. It is projected that in India, in the coming 10 years over 50% of homes (i.e., around 15 crore households) will be powered by solar energy and rooftop solar panels will play a vital role in this. In India, the homes come in various sizes averaging in between 50 sq yards to 1000 sq yards and the solar rooftop installation varies from 500 Watt to 10 KW or 10,000 Watt.

2. Efficiency

Efficiency is more like the mileage that we understand for our vehicles. The better the mileage the preferred is the vehicle for long-term use and cost of ownership. In the case of solar panels, it's more to do with solar power generated per sq. ft.  (or area). So with the same area, the panel that gives more efficiency is considered better. Here is the reference table to describe the efficiency of the panels based on the technology they belong to.

Efficiency = {P_max/ (Area in m² x 1000W/ m²)} x 100

 Where P_max is the maximum panel power, 1000W/ m² is the solar irradiance and area is in m²  

Bifacial Solar Panel efficiency calculation: (these panels have the capability to produce power from both front and back of the solar panel)

Shark Bifacial Solar Panels are the most efficient solar panels in India with an efficiency of 24.09%

Solar Panel Capacity: 530W

Size of solar panel: 2.2 m²    

Efficiency: {530W/ (2.2 x 1000 W)} x 100 = 24.09%

3. Durability

Since the panels are expected to last a minimum of 25 years, which is a pretty long period for any product to face all weather conditions, including harsh summer sun to bitter cold and sub-zero temperatures to heavy coastal winds to corrosive saline moisture laden air to hailstorm, etc.  Hence the ability of the product to last long and withstand durability is very important.  Solar panel is made of 15 components including frame, glass, solar cells, solar wire, junction box, back sheet, etc.  Besides weather, solar panels are also exposed to external forces like monkeys, cricket balls, heavy equipment like a solar panel can withstand the human weight ranging from 100 Kg to 150 Kg.

Further, the other components lie wire i.e., 4mm DC wire can withstand fire and the junction box being waterproof and an anodized frame of 2mm.

4. Temperature Coefficient

There is a relationship between increasing module temperature and lower power resulting from this, therefore, temperature coefficient, during extremely hot summers is becoming important. The temperature coefficient is the rate at which the panel will underperform at each increase in degree Celsius (°C) e.g., in summers, a solar cell can get as hot as 65°C, leading to a direct impact on the efficiency that gets reduced and therefore it may produce less power.

Also in subzero conditions, the solar panels do produce electricity and that’s because solar panels produce electricity with the help of sunlight and not heat. The colder climates are usually optimal for solar panels. 

Like e.g.in northern parts of India – J&K, Ladakh, Himachal Pradesh, Uttarakhand, Punjab, Haryana, Delhi, many parts of UP doe experience foggy winters, and hill states face very low temperatures from November till February. 1 KW solar panel generates 3.75 units to 4.37 units however during the same period, southern and western states like Rajasthan, Tamil Nadu, Kerala, Karnataka, etc. the same panel produces 5.55 units – 6.31units. National Renewable Energy Laboratory (NREL) is the national laboratory of the U.S. Department of Energy is giving the solar radiation in KWh per sq meter per day.

5. Customer Review

 As India is adopting digital mode, online customer reviews help to give more clarity about the product and service. Solar panels being a one time investment product, it becomes most important to consider the reviews, ratings, benefits, how to install, right capacity, etc. before concluding the purchase. Any product with 4.5 ratings or above in the online platforms is more reliable and can be trusted.

Various companies and brands claim to have the best product, however, the latest bifacial technology, maximum efficiency, lower temperature coefficient, higher durability, and favorable customer review become the most important parameters in selecting the best solar panel, and considering these 5 points is highly recommended.