Installation of solar panels has seen a significant increase in the last few years. Currently, around 40% of the UK’s energy is derived from a renewable source, out of which 6% is from solar energy. Solar energy makes you more energy independent, decreases electricity bills, and reduces your carbon footprint.

Since it is a renewable energy source, you do not have to worry about getting exhausted someday. If you wish to install solar panels in your house, you need to know if they are efficient. Efficient solar panels ensure that the usable electricity generated is high and save money in the long run.

To check if your solar panel system is efficient or not, you need to use a metric system. Solar cell efficiency is one such metric system that helps you determine the efficiency of your solar panels.

The guide covers different aspects of solar panel efficiency. Before installing solar panels, it is better to check for their high efficiency and decide which are the best panels on the market.

What Is Solar Panel Efficiency?

Solar panel efficiency is the metric used to measure the conversion of sunlight into electricity. The solar panels need to be directly exposed to a large amount of sunlight for conversion. You can measure solar panel efficiency under Standard Test Conditions STC, a very strict controlled test condition.

Solar Panels on RoofWhen conducting STC, the solar panel will be exposed to constant sunlight and temperature. It helps measure the voltage and current produced for multiple load resistances.

Solar panel efficiency can be determined by the maximum power rating of the solar panel at STC divided by the area of the panel in meters. The formula is –

Efficiency = ([Pmax / Area] / 1000) x 100%

Since solar panel efficiency is measured under standard test conditions STC, the real-world efficiency might be different. Several other factors come into consideration when considering the high efficiency of solar panels. These factors are –

  • Reflection
  • Panel age
  • Shade
  • Bushing and wiring
  • Protective backsheeting and roof color
  • The potential solar output of the region
  • Panel Installation and panel placement
  • Weather

The average solar panel efficiency is measured between 15% and 20%. However, depending on the solar panel quality, the efficiency may sometimes exceed 20%. The more the efficiency of a solar panel system, the more the homeowner can save on the amount of electricity generated.

Different Type of Solar Panel System

Before you think about installing a solar panel system in your home, you must conduct extensive research. You need to choose a panel that can fulfil your energy requirements. Currently, there are three main solar panel types in the market that you choose from.

Below are the types of solar panels and their features.

Monocrystalline Silicon Solar Panels

Monocrystalline solar panels are also called single-crystalline cells and are made of pure silicon. The solar cells are made from long rods made into wafers. Monocrystalline cells have the highest efficiency rate at 177% to 22%.

The monocrystalline cells have more space for the flow of electrons that makes the panel very efficient. They have square-shaped wafers that seem to be pitch-black and are very eye-pleasing. However, monocrystalline solar panels are very expensive.

Polycrystalline Silicon Solar Panels

Types of Solar PanelsPolycrystalline solar panel systems are also called multi-crystalline panels. They are a budget-friendly choice for homeowners but have less efficiency than monocrystalline panels. The efficiency rating of polycrystalline panels is 15% to 17%.

Polycrystalline solar is made from silicon crystals which are then cut into the shape of wafers. These wafers are blue and help in producing PV cells. Even though they are less efficient than monocrystalline panels, their low price range makes them a favourite of homeowners.

Thin Film Solar Cell Technology

The last type of solar panel is thin-film solar cell technology which is nothing like monocrystalline or polycrystalline panels. This solar cell technology does not have any outlines of the silicon cell. Thin-film technology uses substrate of glass, plastic, or metal.

They are very flexible, which makes them perfect for portable or small-scale applications. Thin-film solar cell technology is also very lightweight, and its efficiency rating is around 10% to 13%.

You will find them in blue or black colours.

Solar Cells and Their Efficiency – At a Glance

You can configure solar cells to increase the efficiency of solar panels. Below are some solar cells and their efficiency ratings.

  • Polycrystalline PERC – 16% to 17%
  • Monocrystalline PERC – 17% to 19%
  • Shingled Monocrystalline – 18 % to 20%
  • Half-Cut Monocrystalline PERC – 18% to 20%
  • Half-Cut Monocrystalline PERC MBB – 19% to 20.5%
  • Shingled Monocrystalline PERC – 19% to 20.5%
  • Half-Cut MBB Heterojunction – 20% to 22%
  • N-Type IBC – 20% to 23%

The above solar cell types have certain abbreviations that we have explained below for better understanding.

PERC – Passivated Emitter and Rear Cells

PERC reduces the electrons’ tendency to recombine by reflecting the solar power into the solar cells. They also absorb high wavelengths from the sunlight and offer a higher efficiency rating than traditional ones.

MBB – Multiple Busbars

MBB offers a reduction in loss of current by reducing the current flow rate through the cell wafer.

IBC – Interdigitated Back Contact

The cell’s front absorbs the sunlight whereas, the conversion takes place at the back. MBB is highly reliable and has great efficiency and yield.

What Are The Factors That Affect The Solar Panel Efficiency?

Solar panels are a crucial energy source and have several factors that affect their efficiency in the real world. Below are some of those factors –


Solar Panel Close UpThe panel material makes a huge impact on the efficiency of solar panels. These are the materials that are used to form the solar cells inside the solar panel system. It focuses on the solar cells, cable thickness, and wiring that occurs during the production of solar panels.

Reflectance Efficiency

Another factor that impacts solar panel efficiency is reflectance efficiency. The sunlight that falls on the solar panel is not completely absorbed and generates electricity. Most of the sunlight is not absorbed and reflects off of the surface.

If the sunlight reflects less from the surface, the energy output would be high.

Thermodynamic Efficiency

Thermodynamic efficiency refers to the solar panel’s optimal efficiency. It is the sunlight’s height that is converted into electric current. The approximate thermodynamic efficiency will is about 86%.

How Can You Increase Your Solar System Efficiency?

Solar panels have multiple solar PV systems that will collect energy from sunlight. Hence, you need to be able to increase the solar system efficiency after installing the system. Below are some of the ways you can maximize solar panel efficiency in the real world.

Reduce Drivers by Understanding Your Requirements

You need to determine the number of devices that you will be running on solar power. It will help you decide the number of drivers that you require. It is the best way to decide the right solar panel efficiency you require for your house.

Choose High-Quality Solar Panels

High-quality solar panels will have higher efficiency. Check for solar panel manufacturers that offer high-efficiency panels. However, going for expensive solar panels is not always the option. It would be best if you looked for options that are high in quality but not in price.

The Pitch and Angle

You can maximize the solar panel efficiency with the right angle and pitch. A solar panel will be able to produce electricity efficiently if they receive abundant sunlight. It would only be possible when the corner and pitch of the solar panels are correct.

Getting direct sunlight might be a problem during cloudy days, so you must keep this in mind. Ensure that the angle is right enough to get proper sunlight during cloudy days.

Clean Solar Panels

Roof Solar PanelsTo maximize the efficiency of the solar panels, you need always to keep them clean. You should ensure there is no dirt or dust on them. If the solar panels are not clean, it could hinder the efficiency of the panels.

Since the solar panels are glass, it would not be too hard to clean them. Apart from dust, it would be best to clean the solar panels of snow during winter. If snow accumulates on the solar panels, it will create a hindrance to direct exposure to sunlight.

Why Do You Need Efficient Solar Panels?

It is already established that solar panel efficiency is crucial for an efficient solar PV system. Having an efficient solar system means the carbon footprint is smaller, less space for energy output, and lesser use of raw materials.

You will need high solar panel efficiency for a certain application to generate electricity. In limited spaces, efficiency is also required to ensure that the panels can harness the perfect amount of energy. It is for smaller houses that do not have abundant roof or ground space.

However, you cannot always depend on the efficiency of the solar panels when you are looking for an ideal solar PV system. If the space is moderate to large, you can look for solar panels even with less efficiency. It means you can increase as many solar panels that you want to install.

Hence, depending on the roof space, the importance of solar panel efficiency will differ. Moreover, if the efficiency is high, the overall cost will reduce and vice versa. There will also be a reduction in the impact that the production of solar panels will have on the environment.

What Should Solar Shoppers Look For When Choosing Solar Panels?

Before installing solar panels, you need to ensure you choose solar panels from the right solar manufacturers. Solar shoppers will need to look into certain factors when they make a choice. Below are the said factors –

Look For Multiple Solar Panel Manufacturers

It would be best if you never finalized the first solar manufacturer that you find. Since installing the solar panel system is a huge purchase, you need to be very cautious about the decision. You need to ensure you conduct thorough research and review different solar panel manufacturers.

Go For Budget-Friendly Companies

Home Solar PanelsMost homeowners go for large companies thinking they would offer the best solar panel systems. However, that is not always the case since many local companies may also offer the same options. Moreover, large companies offer very expensive options which many homeowners might not be able to afford.

Along with looking for large companies, you also need to check out the smaller companies present in your locality. It will also help you understand whether or not you are making the right choice concerning the solar panel system.

With the right solar panel company, you can save a lot of money on panel installation.

Compare the Products

Along with comparing the companies, you need to compare the solar module offered by the companies. You need to know about the equipment that you will be installed on the roof. It is no secret that products from large companies will be of high quality and more expensive.

Sometimes, large companies can offer products that are unfavourable to the clients at a high price.

Hence, you can check the local companies for their product quality and price. If you find that the companies offer a quality product reasonably, you can go for local companies. It will prevent you from buying products at inflated rates.

Check Company Reviews

The solar industry is gradually growing, which means every day, there are new companies. Due to this increase in new companies, homeowners can become confused. It makes it hard to choose which company might be the best for them.

If you want to know about the company, it might be hard to get real insights. The representatives of the company will only tell you good things.

To know about the true condition of the company, you need to check for third-party reviews. If you are opting for local installers, you can ask your neighbours or local people who may have used the equipment of the same company.

It would also be better to check if the company has any social media presence and reviews on Google, Yelp, etc.

Calculate Price Per Watt (PPW)

The price of a solar system depends on the price per watt (PPW). When you contact solar companies, you will be given quotes. However, there may be variations in the real system size depending on the solar panels you use.

To calculate the price per watt (PPW), you need to use the formula –

Total System Cost / System Size in Watt

The metric KW measures the size of the solar system. You can find this by multiplying the system size of the panel by 1000.

Summing Up

Choosing the best solar panel system is not an easy task since there are multiple options in the market. You need to ensure that you choose the right solar panel manufacturer that offers solar panels with the efficiency rating you require.

The solar panel efficiency will also vary based on the roof space available to you. Apart from this, you also need to ensure that the solar panels are of high quality.

It would be best to look into your budget, solar cell lifespan, efficiency rating, and aesthetics of the panels when choosing solar panels. It would help you in the process of choosing efficient solar panels that are perfect for your house. With the right, efficient solar panels, you can save a good amount of money on your electricity bills.