PV Savvy - Panel Selection

How to Choose the Best Panel? From PV Savvy

How to Choose the Best Panel?

Know More About Solar Panels
There are over 1500 panel brands in the market

How do you choose the best from these?

Here is a list of critical parameters to look into

Go through sections to know more
Panel Grades
GRADE - Make sure you do not end up with Grade C or lower
Click on each to know its specific characterstics

Grade A

Grade B

Grade C
Grade A

Highest quality

No cosmetic imperfections

Could be costlier than others

Overall Performance
High
Grade B

Slightly lower quality than Grade A

Has minor cosmetic imperfections like color deviations and slight bends

Could be more economical than Grade A

Overall Performance
Good
Grade C

Low quality

Has visible defects like major cracks and bends

Could be really cheap but is a poor choice overall

Overall Performance
Poor
Grade A offers highest quality. Grade B panels usually have acceptable quality and could be much less costly than Grade A panels. Avoid grades lower than B.Check with your EPC if you are unsure of the panel grades.
Efficiency

EFFICIENCY - Higher the efficiency, you require less area for same output

Efficiency: 11%
Area: 2.5m²
or
25.0 sq.ft

#For a 250W panel

#As efficiency changes, electricity generation from panels of same rated output does not

Drag Slider

11% 20%

Go for very high efficiencies only if you have significant space constraints

Look for module efficiency in the range 15-16%. Modules with efficiencies much higher could be quite expensive, and might not be needed unless you have significant space limitations
Warranty

Warranty- Manufacturers offer two type of warranties; linear and standard. Guaranteed output is higher with linear than standard.This can result in generation increase of up to 7%

Click to compare both

Additional Value

1. Guaranteed units for 25 years with Linear: 3.37 Million*

2. Guaranteed units for 25 years with Standard: 3.15 Million*

3. Overall % increase with Linear: 6.5 %

*For a 100kW System

Going for Linear Warranty will cost you a bit more, but guarantees much higher yield than that for Standard Warranty. Go for it
Temperature Coefficient

TEMPERATURE COEFFICIENT - Panel performance decreases in high temperatures. Consider panels with low temperature coefficient, else you can lose up to 2.5% of generation

The temperature coefficient of a solar panel represents the extent to which the panel’s efficiency decreases for every degree increase in temperature beyond the standard temperature (25° C). The temperature coefficient could range from -0.4%/° C for a good panel to -0.55%/° C for a not-so-good solar panel

High Temperature Coefficient

Yearly Generation*

Low Temperature Coefficient

Yearly Generation*

*For a 100kW System

Generation loss with high temp. coefficient = 0%
(compared to low temp. coefficient)

Drag Slider

(to vary panel temperature)

25°C 50°C

Go for low temperature coefficients so that panels perform well even at high temperatures
Anti-PID Feature

Anti-PID Feature - Panels without anti-PID(Potential Induced Degradation) may degrade easily and may need replacement within a few years

Potential Induced Degradation (PID) is a degradation of the solar panel caused by voltage, heat and humidity. It is possible to minimize or prevent PID through incorporation of effective anti-PID elements in the panels.

Click to compare generation difference

Compared with panel having Anti-PID feature

1. Generation loss without Anti-PID feature(if you are lucky) after 25 years: 40%

2. Generation loss without Anti-PID feature(if you are not lucky) after 25 years: 75%

With Anti-PID feature, your panels are likely to last longer. Just make sure chosen panels have this feature.
High Performance at Low Sunlight

LOW LIGHT PERFORMANCE - Good performance at low irradiance(sunlight) makes panels perform better in low light conditions.

Can result in a generation increase of up to 7%

Some solar panels generate higher electricity than other panels of similar wattage under low light conditions, even though at higher levels of solar radiation, both panels might generate the same amount of electricity. Solar panels with this positive characteristic could thus generate more during early morning and late evening hours, resulting in a higher output overall over solar panels without this feature.

Click to compare generation difference

Additional Value

Additional Value

Overall increase per day= 7%

If your region has low sunshine, ensure your panels have this feature
Summary
Poor panel selection could result in significant generation loss

Ensure the following at the very least in your panels:
- Grades A or B
- A good warranty
- Anti-PID feature
And do these too:
- Show the details in this page to your installer and ask relevant questions
- Bookmark this page and refer to it when needed

Solar Made Simple

How to Choose the Best Panel? From PV Savvy

How to Choose the Best Panel?

Know More About Solar Panels

Panel Grades

Click on each to know its specific characterstics

Grade A

Grade B

Grade C

Efficiency

Warranty

Temperature Coefficient

High Temperature Coefficient

Low Temperature Coefficient

Anti-PID Feature

High Performance at Low Sunlight

Summary