What You Need To Know About Solar Panel Efficiency?

Importance of Solar Panel Efficiency

Importance of Solar Panel Efficiency

I think you will agree with me when I say:

Purchasing Solar panels can be quite a tedious process.

There are lots of things to consider when purchasing a solar panel.

Things that come to mind are:

  • What brand to buy?
  • What type of Solar PV system to go for?
  • Where to install the system and so on..

What we tend to forget is how important Solar panel efficiency is when purchasing a Solar panel. We are not well informed regarding the efficiency of Solar panels.

Solar Panel Efficiency can make a huge difference to your savings. Do your research well on the Solar panel efficiency before you buy solar to reap rich dividends.

This blog will help you in this regard to better understand Solar Efficiency. In this post we look at the importance, factors to consider and ways to improve Solar efficiency.

Are you ready?

Let’s start.

Solar Panel Efficiency

Efficiency of a system refers to delivering greatest output from limited inputs for a system.

In relation to Solar Efficiency, it’s about how much power the Solar panels generate. The power generated has a direct correlation to the sunlight incident on it.

Consider two panels with different solar efficiency:

The one with higher efficiency produces more electricity with other conditions being ideal.

Most efficient solar panels in the world record efficiencies in the range of 18-22% as of date. Thin Film PV modules produce around 8% Solar efficiency. Recently Sunpower, a Solar PV manufacturer broke the record on Solar efficiency with 24.1% efficiency.

Solar Cell Efficiency is one of the key factors leading to higher Solar Panel efficiency. But it doesn’t mean that higher Solar cell efficiency leads to higher Solar panel efficiency. This is  due to interspacing issues of the cells that affect panel efficiency.

Note that solar panel efficiency doesn’t equate to actual power production. It is still an important metric and do consider it with other measures like Solar PV capacity. (This is the most power that the solar panels can generate based on the design.)

Also Watt hours is an important metric to consider in deciding the produced by the Solar Panels. Watt hours is the energy generated by the Solar Panels over time. This helps to compare with the watt hours produced using traditional fossil fuels.

Why High efficiency is important for Solar Panels?

  • More power with efficient utilization of space
  • There is lesser need for Solar panels
  • More savings
  • Produces lesser electricity bills.
  • Sustainable – use of lesser materials which is good for the environment

Benefits of Efficient Solar Panels

Onsite Factors to consider for Solar Efficiency

Solar Efficiency as marked on the Solar Panels may not match with that of the onsite location. This is because tests conducted to mark the solar panel efficiency are carried out in controlled environments. These tests do not take into account the Onsite factors.

Key Onsite factors to consider

There are a lot of onsite factors that contribute to the Solar Panel efficiency. These can have a significant impact on the Panel efficiency. Some of the important ones to consider are:

  • Irradiance and Shading
  • Location/Orientation
  • Time and day of solar irradiance
  • Heat

Let’s look at each of the factors individually:

Irradiance and Shading:

Irradiance is the power received by the Solar Panels with the incident solar energy.

The amount of electricity generated is in direct correlation with the Solar exposure. Hence the location of the Solar panels play a crucial role and reduce shading of the solar panels.

Shading of the Solar Panels affects the Solar panel efficiency of due to less irradiance. Also shading of a part of the Solar panel can affect the other solar panels connected. Hence the efficiency of the entire system drops.

Location / Orientation:

The Solar Panel orientation affects the irradiation levels. Not choosing the right orientation can reduce the output of the Solar panels.

Install the Solar PV system in the direction of true south to get most solar exposure in India. This is due to the fact that India is located in the Northern hemisphere.

Time and day :

The time and day also determines how much power the Solar panels generate. The system generates less power on a cloudy day compared to a sunny day as there is less light incidence.

Heat :

One may think that too much of sunlight can be good for the amount of power generated by the Solar panels. But too much of sunlight can generate a lot of heat which can reduce the efficiency of the Solar Panels.

Other tools used for more solar irradiance like Solar Trackers –

Solar Trackers attached to the Solar panels direct them for easy movement. This enables the solar panels to track the path of the sun for most solar exposure.

These factors are discussed in detail in this article related to PV system.

Solar Soiling and its impact on Solar panels

Solar Soiling refers to the things that may fall on the solar panels that reduces its efficiency. These may be things like dust, bird droppings, leaves and others.

Solar Soiling can decrease efficiency(degradation) of the Solar panels by 1.5-6% over the year.

One of the other effects of Solar soiling is PID (Potential Induced Degradation). This reduces the Solar efficiency in a big way.

PID(Potential Induced Degradation)

Due to Solar soiling, electric fields are formed around the Solar panels. These are created from the interactions between the internal and external fields of the solar panels. These electric fields can bring down the Solar system efficiency.

Solar Panel Maintenance

Hence it’s important to clean the Solar Panels periodically to reduce Solar panel inefficiency.
Cleaning the Solar panels is not a difficult job since there are no moving parts to the system. But be careful about cleaning the solar panels on the solar rooftop.
Hence one should buy Solar Panels with high efficiency and reduced degradation levels.


In this article we looked at the importance of Solar Panel Efficiency and the onsite factors that affect it. Also looked at were the topics on Solar Soiling and its effects on Solar Panels. We also looked at ways to improve efficiency through proper maintenance of Solar panels.

Lavancha provide high quality Solar panels with maximum efficiency with low degradation levels. This provides maximum benefit to you as a solar user.

If you are interested in purchasing the Solar panels for your building, please contact us


Leave a reply