What is Solar Panel Efficiency?

With the worldwide rising solar energy adoption, solar panel efficiency has become an important aspect of energy production. This blog helps us understand what solar panel efficiency is and the factors affecting and improving it. 

Solar panel installation is a smart investment, as it’s a sustainable energy source that reduces both the carbon footprint and electricity bills.

In order to determine the performance of a solar unit, you need to understand the efficiency of a solar power plant.

In simple terms, solar panel efficiency is the rate/percentage at which sunlight is converted into usable energy.

Example: if a panel has a 20% solar efficiency, it converts 20% 20% of the absorbed sunlight into electrical energy. Meanwhile, the unused sunlight is either lost or reflected from the panel’s surface.

In cases where a rooftop or area has restricted installation space, a high-efficiency panel is an ideal choice, as it generates more energy in a limited space.

Importance of efficiency in solar energy:

• Better ROI: For every penny spent, you get more electricity.
• No space restrictions: it’s even more beneficial for small houses & businesses with less roof space.
• Cost-effective: Efficient solar panels generate more power in their lifespan, providing long-term savings.
• Lower resource requirements: We can produce a large amount of energy with the help of limited materials & resources.

Understanding Solar Efficiency

The conversion rate is the most important measure of solar panel efficiency.

The overall energy input calculates the solar panel efficiency compared to the overall energy absorbed from the sun. 

Efficiency Percentage = (Electricity Output / Solar Energy Input) x 100

So, if the solar panel absorbs 1000 watts of solar energy and produces around 300 watts of electricity, then the solar efficiency of the panel is 30%.

This conversion rate plays a major role in calculating the amount of energy generated by your solar plant on a daily, monthly or annual basis.

Example: a 300W solar panel with 20% efficiency will produce more energy as compared to one with 15% efficiency, under the same sunlight conditions.

This difference will help in understanding your panel requirements to achieve the specific energy goals.

Factors Influencing Solar Efficiency

• Panel Design

The amount of sunlight a solar panel absorbs depends on its shape and structure. Monocrystalline panels are more efficient as compared to polycrystalline panels, due to their pure silicon-based structure. On the other hand, thin film panels are flexible and lightweight, but operate at a lower efficiency rate.

• Cell Technology

PERC (Passivated Emitter Rear Cell), N-type silicon cells, and bifacial panels are some new advancements improving the panel efficiency in the last few years. These latest innovations focus on better sunlight absorption, reducing energy loss and enhancing solar efficiency.

• Intensity of Sunlight 

The energy output of a solar panel is mainly dependent on the amount of sunlight received. Locations with sunny conditions showcase better solar efficiency. Climate changes and cloud shade can also fluctuate the overall efficiency.

• Installation & Angle

While installing the solar panels, ensure that the angle & orientation of the panels are towards the right direction. Ideally, a solar panel should face the opposite direction of their hemisphere (Facing north in the southern hemisphere and south in the northern hemisphere)

• Effects of Shading

Shades caused by trees, buildings, or other obstacles can significantly reduce the overall solar panel efficiency. A short shadow can affect the plant’s performance altogether. Although some advanced solar panels have the feature to minimise this effect, careful planning to avoid shading effects is still vital.

• Temperature Impact

Higher temperatures do not mean higher solar efficiency. Mostly, solar panels operate best at 25 degrees Celsius. The energy production decreases with rising temperatures, making the temperature coefficient an important factor to consider during hotter climatic conditions.

Enhancing Efficiency Through Maintenance

Regular cleaning of solar panels is the most essential aspect of maintaining the efficiency of solar panels.

A solar panel is 24/7 exposed to nature and comes in contact with dirt, pollen, bird droppings, and several such elements that block the direct impact of sunlight.

Even a small leaf can affect the solar panel’s efficiency.

Dry or dusty conditions accumulate dust & debris over the panel’s surface.

According to studies, this can affect the solar efficiency by 20% to 30%.

Best ways for Solar Panel Cleaning

• Make sure you clean the panels during early morning or evening (cooler parts of the day), as rapid temperature changes might leave cracks in the panel.
• While hand cleaning, use soft sponges, water and non-abrasive detergents. Strictly avoid high-pressure water flow as it may lead to damage to the panel’s surface.
• Hire professionals or a solar panel cleaning service for hard-to-reach panel installations.
• Try to figure out damage, corrosion, loose wiring or any such issue while cleaning.

TAYPRO’s automated solar panel cleaning system uses advanced technology to clean your solar panels gently, increasing the panel’s efficiency and energy production.

Efficiency Levels

Typically, commercially available solar panels have an average efficiency of 15% to 25%, which is enough for homes & small businesses.

This efficiency range may vary depending on the product, brand, model, and environmental conditions. 

High-end efficiency technologies

Let’s discuss the technologies present in premium solar panels below:

• N-type silicon cells

These cells have low breakdown rates and generate better efficiency with time.

• PERC Technology

This technology helps the panel absorb more sunlight by adding an extra reflective layer.

• Bifacial Panels

These types of panels absorb sunlight from both front and back, and are mostly used in places with reflective ground surfaces.

These panels often achieve a 25% to 30% efficiency rate, making them an ideal option for limited space and highly demanding environments.

Ongoing Research and Achievements in Laboratories

Several innovations are pushing the general efficiency range of solar panels in laboratories.

Multi-junction cells & Concentrated PV systems have already achieved over 40% efficiency during lab tests.

Many renowned institutions are working on the next chapter of solar energy, such as the Perovskite solar cells, promising higher efficiency at lower costs in the future.

Conclusion

Solar panel efficiency is the key aspect to determine the performance of your solar plant and the amount of usable energy generated. 

High efficiency of a solar power plant means maximum energy production, lower space requirements, and more long-term savings.

Points to remember:

• The efficiency percentage is the amount of sunlight converted into electricity
• Solar efficiency depends on panel design, cell technology, sunlight, temperature, and proper maintenance.
• Regular cleaning and proper installation angles can help in achieving peak performance.
• Mostly, commercial panels have a solar efficiency of 15% to 25%, and premium panels up to 30%.
• Latest technology and innovations are pushing the boundaries to achieve greater solar cell efficiency in the future.

With the current trends in solar evolution, all the new technologies and premium panels will be easily accessible in the next few years.

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