Why clean solar panels without water?

By 2030, it is expected that 10% of global energy requirements will be met by solar power. However, one of the major problems faced after the installation of the panel is the accumulation of dust. 

Cleaning these panels requires approximately. 10 billion gallons of water per year. This amount of clean water could quench the thirst of 2 million people. The largest solar power installations, like the ones in China, India, the UAE, and the US, are in desert regions. The water needed to clean these panels via pressurized water jets must be trucked in from a long distance. This water must be pristine to ensure no deposits are left behind on the surface of the panels. Employing the dry scrubbing method is less effective as it can scratch the panel, reducing the amount of light transmitted to the PV cells.

Apart from this, the use of water for cleaning makes up to 10% of the operational costs of panel installation. 

Therefore, there is a dire need to look for ways to clean solar panels without water. 

How to Clean Solar Panels without Water

Since cleaning the panels with water has been a cost-effective and efficient way, it might be challenging to think of ways to clean panels without water.  Here are a few alternative ways to clean the panels.

1. Dry Cleaning Tools: 

• Soft Bristle Brush or a broom: A soft-bristle brush or a broom can gently sweep away dust and debris. Ensure the brush is clean and does not contain any abrasive materials that could potentially damage the panels by scratching them. 
• Microfiber cloth or Mop: A Microfiber cloth or mop to gently wipe the surface of the panels could be used. As the Microfiber is non-abrasive, it can help to remove the dust and any light debris. 

2. Compressed Air or Blower: 

• Compressed Air: A can of compressed air can be used to blow away dust and litter. Before using compressed air, make sure the air pressure is not too high to avoid any damage to the panels. 
• Blower: A blower, like a leaf blower, could be used with adjustable settings to blow away any buildup of leaves, dust, and grime from the surface of solar panels. 

Check this video on cleaning solar panels with a leaf blower https://www.youtube.com/watch?v=MmkCMWzhCLs&ab_channel=TheRealMartian

3. Solar Panel Cleaning Gel or Foam: 

• Along with the evolution in the technology of solar panels over the years, cleaning solutions have made significant advancements as well. Some companies, like International Products Corporation, provide efficient cleaning solutions in the form of gel or foam formulated specifically for solar panels. After applying the gel or foam, allow it to sit for a couple of minutes. Then, wipe away gently with a clean cloth to get rid of loosened dirt from the surface. 

1. Commercial Cleaning Tools:

• Several companies are offering automated robots to clean the panels in a hassle-free fashion without water. Companies like Helios CleanTech offer self-charging, full-automated robots for dry cleaning the panels specifically. There are also cleaning kits available that include specialized cleaning solutions, brushes, and wipes designed to be used without water. 

4. Dust Repellent Coatings: 

• A UK-based company, Solar Sharc, has come up with a dust-repellent coating to be applied on the surface of panels. This coating is composed of nanoparticles, only a few microns thick, which makes it transparent. As per the website of the company, the coating is self-cleaning and allows water droplet formation on its surface that can roll off the solar panels. 
• Such a dust-repellent coating can help prevent any buildup of dirt and grime, thereby making it easy to use a broom or brush to wipe for dry cleaning

Check this video on Nanocoating https://www.youtube.com/watch?v=sKyBQf3yOi8&ab_channel=SustainableEveryDay

5. Electrostatic Repulsion: 

• The coating of nanostructures can erode over time after withstanding the harsh weather conditions. There must be a better alternative solution to cope with the problem. 
• The Engineers at MIT have developed a waterless cleaning method for the removal of dust on the panel. The no-contact system makes use of electrostatic repulsion to repel the dust particles, thus causing the dust particles to detach and virtually leap off the surface of the panel. 

To activate this system, a simple electrode (which could be a simple metal bar) passes above the panel’s surface. This imparts an electrical charge to the dust particles. The opposite charge is applied to the transparent conductive layer, a few nanometers thick, which is deposited on the toughened glass of the panel. These particles are then repelled by a charge applied to the panel. 

This system operates automatically using a simple electric motor and guide rails running along the sides of the panel. 

A permanent arrangement of thin strips of conductive transparent material above the panel could be an alternative option to eliminate the installation of moving parts. 

Check this video on this technology https://www.youtube.com/watch?v=epX9kUuDmgY&ab_channel=MassachusettsInstituteofTechnology%28MIT%29

• Other research groups have put efforts into developing electrostatic force-based solutions that rely on electrodynamic screens. This requires the use of interdigitated electrodes. The screens can have defects that permit the moisture to enter, leading to their failure. Such screens can be useful at sites where moisture is not a point of concern, like Mars. On Earth, even in the arid regions, moisture can be a major trouble. 

However, before adopting any method for cleaning the panel, it is recommended to check with the panel manufacturer. This can prevent the implementation of any inappropriate cleaning method that can void warranties or end up ruining the panel. 

In case the panels are installed at a height difficult to reach, consulting a professional for help could be the best way to ensure safety. 

 

 

Advantages of Cleaning Solar Panels without Water

The inclusion of water is generally referred to as the most effective method to clean the solar panel. However, in times when people are finding alternative ways to meet the demands for clean drinking water, the use of water for cleaning panels may not receive appreciation. Here are several benefits of cleaning the panels without water. 

1. Conserving water: 

Conserving water in every possible manner could be crucial in regions experiencing water scarcity. This shall help people rely on green energy in areas with limited water resources and strict water use regulations. 

2. Reducing Environmental Impact: 

Deploying waterless methods for cleaning reduces the environmental impact in comparison to the traditional water-based methods. Avoiding water usage helps reduce the energy and resources associated with water treatment and transportation. 

3. Time saving: 

When panels are cleaned with water, care must be taken that the panels are dry before starting the system. This means it is labor-intensive work and consumes a lot of time. As opposed to this, the dry-cleaning methods are much quicker as they require less preparation and clean-up time. Thus, saving the precious time of your busy schedules.

4. Ease of use in harsh environmental conditions: 

Cleaning the panels with water in freezing temperatures may not be feasible. However, dry-cleaning methods can be implemented in such harsh weather conditions. The automated systems can handle these Herculean tasks for you. 

5. Avoids water streaks and residues: 

The quality of water available depends on the water resources nearby. Some areas may be supplied with hard water, having high amounts of mineral content. Using such water can leave streaks or residue on the panels after cleaning. These problems can be easily avoided by using dry-cleaning methods instead. 

6. Lowers the risk of Water Damage: 

Even if it is safe to be used for cleaning the panels, an excess amount of water or inappropriate cleaning techniques can lead to water ingression or cause a shock circuit. The waterless method eliminates this kind of risk to the panel as well as personnel.

Conclusion

The Earth has successfully transitioned from the state of global warming to global boiling, as per the UN chief. Climate change is evidence of the dire need to not only conserve valuable water resources but also adopt alternative methods to reduce water dependency. 

There are various ways to clean solar panels without water, including a soft bristle brush or broom, a blower, solar cleaning gels or foams, commercially available kits, dust-repellent coating, or electrostatic repulsion systems. 

Despite the advantages discussed by relying on dry-cleaning methods, the fact cannot be overlooked that these methods lack the effectiveness of cleaning panels as well as water-based methods. Dry cleaning may fail to remove stubborn dirt, bird droppings, or any oil residues. It is always advised to seek guidance from the manufacturer for cleaning the panels. 

A combination of dry and wet cleaning could work the best way to ensure the water is conserved along with maintaining and cleaning the panels as well.