How Efficient Are Solar Panels: Ultimate Guide [2026]

In recent years, the answer to the question of “how efficient are solar panels” has increased dramatically from an average of 15% to 20%. Some high-efficiency solar panels can reach up to 23% and generate greater electric bill savings than their less efficient counterparts, though they cost more upfront. Solar panels, combined with battery backups, can help you power various household appliances to lower your reliance on the utility grid and reduce bills. 

Jackery SolarSaga Solar Panels are built with high-quality monocrystalline silicon solar cells and have a high efficiency of around 23 - 25%. When combined with Jackery Portable Power Stations, you can lower your grid reliance and save money on high electricity bills. This comprehensive guide will help you understand the answer to “How efficient are solar panels,” along with factors affecting the efficiency and calculation methods. 

Takeaways 

• Solar panel efficiency refers to how well sunlight is converted into usable electricity and differs based on the type of solar panel.
• Some factors, like panel quality, angle, weather, and maintenance, can impact efficiency.
• Solar panels can generate some power on cloudy or cold days only if there is sunshine available.
• Jackery SolarSaga Solar Panels offer a high efficiency of around 23 - 25% and a portable design for home and outdoor use.

Understanding Solar Panel Efficiency 

Solar panel efficiency is the rate at which sunlight is converted into electricity, and it varies between 15% and 22% for typical home systems. For example, if the sun shines on a solar panel with a 15% efficiency, this means 15% of the sun's energy will be converted to solar energy in ideal conditions. 

Factors That Affect Solar Panel Efficiency 

There are multiple factors that can directly or indirectly affect solar panel efficiency. Let's check the common factors affecting how efficient are solar panels, as per the US Department of Energy: 

Wavelength: Light is made up of particles called photons. The larger the range of the photon a solar panel can absorb (infrared, ultraviolet, and visible range), the higher the efficiency and solar panel output will be.

Temperature: Solar cells become less efficient at high temperatures. Extreme temperatures can damage the solar cells and module materials, contributing to shorter lifetimes and reduced efficiency. 

Reflection: You can increase solar panel efficiency by reducing the amount of light reflected away from the PV cells. Solar panels with an anti-reflection coating and darker colors reduce light reflection and increase efficiency.

Other factors, such as the positioning and angle of the solar panels, shade, climate, and inverter efficiency, can affect the efficiency rate. 

How Efficient Are Solar Panels

Generally, monocrystalline and polycrystalline solar panels have an efficiency of 15 - 22%. On the other hand, thin film panels are less efficient, around 8 - 13%. Most manufacturers provide efficiency ratings based on the standard test conditions, which can act as a helpful reference. Let’s briefly explain how efficient are solar panels on cloudy days and in winter:

How Efficient Are Solar Panels on Cloudy Days

Solar panels don't perform well on cloudy days, but they still capture some energy if there is sunlight. However, if the sunlight reaching the PV panels drops to zero or very low levels because of clouds, solar panels won't be able to generate electricity. 

According to the US Department of Energy report, solar energy production can be affected by several factors, such as season, time of day, clouds, dust, haze, etc. That's why it is better to invest in a battery backup that stores the solar energy generated by the panels during peak sunlight hours. 

How Efficient Are Solar Panels in Winter

Solar panels do not work in winter without sunlight, as they need sunshine to work. Even in the winter, when there are fewer hours of daylight, the solar panels can still produce a sufficient amount of power. According to a report by the US Department of Energy, PV modules operate efficiently in cold weather. This is because temperatures above 77°F (25°C) can cause a decrease in voltage.

However, if the winter months are too cold with little to no sunshine, the solar panels won't be able to generate electricity. To ensure the solar system generates enough power during cloudy weather or winter, the best strategy is to pair the solar panels with power stations or battery backups. Such systems ensure that solar panels can convert sunlight into electricity, and power stations can store excess energy for later use. 

How to Calculate Solar Panel Efficiency 

The simple formula to calculate how efficient are solar panels: 

Efficiency = [Power Output (in kW) ÷ Panel Surface Area (in square meters)] * 100

The panel's wattage is typically printed on the panel itself or in the user manual. You can convert the wattage to kilowatts by dividing by 1000. In addition, the width and length of the solar panel are measured in meters and multiplied to calculate the area in square meters.

Let's take an example to understand better: 

Let's say you have a solar panel with a power rating of 200W (0.2 kW) and a surface area of 1.5 m2. 

Efficiency = [0.2 kW ÷ 1.5 m2] * 100 = 13.3%

Note: Solar panel efficiency can vary under real-world conditions, depending on temperature, shade, and weather.

Best Highly Efficient Jackery Solar Panels for Home and Outdoors

The Jackery SolarSaga Solar Panels are portable, foldable, and highly efficient panels suitable for outdoor adventures and home backup. They convert the maximum sunlight that falls on the cells into solar energy, which can be stored in the Jackery Portable Power Stations. The Jackery Solar Generators are suitable for powering essential indoor or outdoor appliances, such as refrigerators, lights, speakers, TVs, electric stoves, etc. Here are popular Jackery SolarSaga Solar Panels and how efficient are solar panels: 

Jackery SolarSaga 40W Mini Solar Panels 

The Jackery SolarSaga 40W Mini Solar Panel is an ultra-lightweight solar panel with an efficiency of 23%. It weighs only 2.6 lbs (lighter than a laptop) and has a four-fold design, making it ideal for on-the-go adventures such as hiking, camping, etc. It also has two output ports to power small appliances, such as cameras, laptops, phones, etc., directly. 

Customer Review 

I have used the USB-C and the USB-A ports to charge several devices. Of course, the time required depends on the intensity of the sunlight, but the panel works well. I plan to use this panel while camping and possibly backpacking.

— William Crane.

Jackery SolarSaga 100W Solar Panels 

The Jackery SolarSaga 100W Solar Panel has a high-efficiency rating of 24.3%, which makes it suitable for outdoor activities and emergency power outages. It is portable and lightweight, so you can carry the solar panel anywhere you go. It can be paired with the Jackery Explorer 1000 Plus Portable Power Station or another compatible battery backup to build a solar generator ideal for brief power outages or outdoor adventures like RV trips. 

Customer Review 

I love these solar panels! There are two USB ports that can be used while charging the Jackery. A zipper pocket on the back holds the charging cable and any adapters right where you need them.

— Caroline Castle.

Jackery SolarSaga 100 Prime Solar Panels 

The Jackery SolarSaga 100 Prime Solar Panel has an unshaded front to improve optimal sunlight absorption and increase efficiency to 24.3%. It is flexible and can easily be installed on RVs, campers, or balconies. You can pair the panel with the compatible Jackery Explorer 1000 Plus Portable Power Station to power most indoor or outdoor appliances for hours. 

Customer Review 

I mounted two of these SolarSage 100 Prime solar panels on the shed in my backyard. They work very well. I was impressed with the build quality (frankly, the best solar panel I've ever touched) and the ease of installation.

— Lief Larson.

Jackery SolarSaga 200W Solar Panels 

The Jackery SolarSaga 200W Solar Panel has a solar conversion efficiency of 24.3%. It converts maximum sunlight into electricity and charges the compatible power station faster. It can be carried anywhere to charge the compatible Jackery Portable Power Station to build a home battery backup for long-term outages or extended outdoor trips. 

Customer Review 

Absolutely love solar panels and generators. I camp in the trees, so it took a bit more solar capacity than someone who camps in full sun, but it's so worth it.

— Tab Barnard.

Jackery SolarSaga 500X Solar Panels 

One Jackery SolarSaga 500X Solar Panel combines six SolarSaga 85 Solar Panels, each of which can be used individually. It has a higher efficiency rate of around 25% and a 500W output to recharge the power station faster. The dual-sided solar panel for the home can be paired with the Jackery Explorer 5000 Plus Portable Power Station to build an essential home backup power solution for outages. 

Customer Review 

We were building a pergola, and instead of dragging all of the extension cords around, I just set the Jackery up and set the solar out. Used it to run battery chargers and work lights, even to power the sauna for use at the end of the day. When we finished for the day, I still had 65% left. SolarSaga 500X was money well spent and an excellent add-on.

— Robert H.

How to Maximize Your Solar Panel's Efficiency 

Maximizing solar panel efficiency involves following some simple tips. 

Clean Solar Panels: An NIH report reveals that dust and high temperatures can reduce solar panel efficiency over time. Hence, you need to clean the solar panels to remove dust that might affect efficiency.

Ensure Optimal Sunlight Exposure: Solar panels should directly face the sunlight and capture maximum sunlight. You must also ensure that no trees, buildings, or other objects might cast shadows on the panels, reducing their efficiency. 

Install Solar Battery Backups to Store Energy: Solar panels are entirely dependent on sunlight and do not produce electricity at night or on cloudy days without sunlight. Therefore, you should invest in a power station that stores the solar energy generated during the day. 

FAQs

How to measure the efficiency of solar panels?

Solar panel efficiency measures how effectively a panel converts the sun's energy into usable electrical energy. How efficient are solar panels can be calculated by dividing the panel's power rating (in kilowatts) by its total area (length x width in square meters) and multiplying by 100. This efficiency is typically assessed under Standard Test Conditions (STC).

What is the formula for solar energy efficiency? 

The general formula for solar panel efficiency is: Efficiency = [Usable Power Output (in kW) / Total Surface Area (in square meters)] x 100. This formula calculates the percentage of the sun's energy that a panel successfully converts into electricity.

What does 20% solar panel efficiency mean? 

A 20% solar panel efficiency means that, in ideal conditions, the panel will convert 20% of the sun's light that strikes it into usable electricity. 

How to calculate solar panel output? 

The simple formula to estimate the output of a solar panel: Daily Output (kWh) = Wattage (W) x Hours of Sunlight x Efficiency. For example, a 200W panel with 5 hours of sunlight and 20% efficiency would produce 0.2 kWh of energy per day (200W x 5H x 0.20 = 0.2 kWh).

Conclusion 

Solar panel efficiency is the rate at which sunlight converts into electricity and varies between 15% and 22%. Monocrystalline panels have the highest efficiency, while polycrystalline panels have a slightly lower efficiency rate. Understanding how efficient solar panels are helps you build a solar system that can reduce your electricity bills.

Jackery SolarSaga Solar Panels are portable and have a higher efficiency rate between 23% and 25%, so the maximum sunlight is converted into electricity. When paired with compatible Jackery Portable Power Stations, it helps you power household appliances at night, on cloudy days, or when the electricity grid is down.