Water-based cleaning agent for photovoltaic panel and preparation method of water-based cleaning agent

Abstract

The invention provides a water-based cleaning agent for a photovoltaic panel and a preparation method of the water-based cleaning agent. The water-based cleaning agent comprises 12-17% of a coordination agent, 0.5-5% of a semiconductor photocatalyst, 0.5-5% of strong acid and weak base salt, 1-5% of a surfactant, 1-10% of alcohol and the balance of deionized water. By the adoption of the technical scheme, multi-stage and multi-target cleaning of complex dirt on the surface of the photovoltaic panel can be achieved through the synergistic effect of all the components, and the surfactant and the alcohol are responsible for wetting and removing oil dirt; the coordination agent and the strong acid and weak base salt are responsible for decomposing inorganic scale; the core component semiconductor photocatalyst generates free radicals with strong oxidizing property under the irradiation of sunlight and is used for degrading stubborn organic pollutants such as bird droppings, pollen and the like, a cleaning solution which is efficient, environment-friendly, economical and safe and non-corrosive to panel materials is provided, and the power generation efficiency of the photovoltaic panel can be effectively recovered and maintained.

Description

Technical Field

[0001] This invention relates to the field of photovoltaic panel cleaning technology, and in particular to a water-based cleaning agent for photovoltaic panels and its preparation method. Background Technology

[0002] Solar energy, with its abundant resources and environmentally friendly characteristics, has become a core force in the transition from fossil fuels to renewable energy. Currently, the global cumulative installed capacity of photovoltaics (PV) has exceeded 1 terawatt (TW) and is still in a period of rapid growth. This huge installed capacity implies a massive market for post-installation operation and maintenance (O&M). Among these, cleaning PV panels is a crucial aspect. PV panels are often exposed to the natural environment during actual operation, inevitably accumulating various pollutants on their surfaces, including dust, organic impurities, and oil. These accumulated pollutants can obstruct light transmission, reducing power generation efficiency. Severe contamination can lead to a 15%-35% decrease in power generation efficiency, and in some cases, even more than 50%. Furthermore, accumulated pollutants can form localized hot spots on the PV panel surface, accelerating the aging of cells and encapsulation materials, and shortening the panel's lifespan. Therefore, regularly cleaning the PV panel surface is essential for maintaining stable and high photoelectric conversion efficiency.

[0003] The main sources of contaminants on photovoltaic (PV) panel surfaces are organic residues, such as feces, pollen, leaf sap, and bacterial deposits. These types of contaminants are highly adhesive and difficult to remove. Furthermore, the types of contaminants on PV panel surfaces are also geographically specific. For example, dust / sand distribution is particularly severe on panel surfaces in arid and semi-arid regions, while oil, carbon particles, and metal particles are common on panels near industrial areas. Moreover, in areas with low rainfall, residual scale and calcium deposits after rainfall can also contribute to surface contamination. Therefore, PV panel surface cleaning agents must not only consider their green and efficient cleaning capabilities but also the impact of the environment in which the PV panels are used.

[0004] Currently, photovoltaic panel cleaning technologies are mainly divided into two categories: physical cleaning and chemical cleaning. Physical cleaning methods include high-pressure water jet rinsing, manual wiping, and the use of automated cleaning robots. While these methods are effective to some extent, they have many limitations: high water consumption, high energy consumption, and the potential to cause microscopic scratches to the anti-reflective coating on the panel surface, affecting long-term power generation performance. The application of large-scale machinery is particularly limited for inaccessible scenarios such as rooftop distributed photovoltaic systems.

[0005] Chemical cleaning methods typically use cleaning agents containing specific chemical components. However, most cleaning agents on the market are single-function products. For example, some formulations are mainly based on solvents and surfactants, primarily targeting oil stains; others are mainly based on acidic or alkaline substances, used to remove inorganic scale. These products are ineffective against the multi-layered, complex dirt composed of inorganic matter, organic matter, and oil stains found in the real world. They often only remove one type of contaminant while remaining ineffective against other components, resulting in incomplete cleaning.

[0006] Therefore, there is an urgent need in this field for a new cleaning solution that can efficiently and safely remove complex contaminants, while being environmentally friendly, non-damaging to panel materials, and cost-effective, to fill the gap in existing technologies. Summary of the Invention

[0007] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a water-based cleaning agent for photovoltaic panels and its preparation method, so as to solve the problem that the single cleaning method in the prior art is difficult to effectively remove complex pollutants.

[0008] To achieve the above and other related objectives, the present invention provides a water-based cleaning agent for photovoltaic panels, the water-based cleaning agent comprising: 12-17% of a ligand, 0.5-5% of a semiconductor photocatalyst, 0.5-5% of a strong acid-weak base salt, 1-5% of a surfactant, 1-10% of an alcohol, and the balance being deionized water.

[0009] By adopting the above technical solution, the synergistic effect between the components can be utilized to achieve multi-stage, multi-target cleaning of complex dirt on the surface of photovoltaic panels: surfactants and alcohols are responsible for wetting and removing oil stains; ligands and strong acid-weak base salts are responsible for decomposing inorganic scale; the core component, semiconductor photocatalyst, generates strong oxidizing free radicals under sunlight irradiation, which are used to degrade stubborn organic pollutants such as bird droppings and pollen. This provides an efficient, environmentally friendly, economical, and safe cleaning solution that is non-corrosive to panel materials, and can effectively restore and maintain the power generation efficiency of photovoltaic panels.

[0010] In one embodiment of the present invention, the ligand is selected from at least one of sodium citrate, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, nitric acid triacetic acid, sodium gluconate, sodium tartrate, polyaspartic acid, or polyepoxysuccinic acid.

[0011] In one embodiment of the present invention, the semiconductor photocatalyst is selected from at least one of titanium dioxide, zinc oxide, bismuth oxide, bismuth oxychloride, or titanium zinc layered double hydroxide (LDH).

[0012] In one embodiment of the present invention, the strong acid-weak base salt is selected from at least one of ammonium chloride, aluminum sulfate, zinc chloride, ferric chloride, or copper sulfate.

[0013] In one embodiment of the present invention, the surfactant is selected from at least one of cocamidopropyl betaine, alkyl glycoside or rhamnolipid.

[0014] In one embodiment of the present invention, the alcohol is selected from at least one of methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, glycerol, or diethylene glycol.

[0015] In one embodiment of the present invention, the cleaning agent comprises the following components by mass percentage: 16% sodium citrate, 1% titanium zinc LDH, 1% ammonium chloride, 2% alkyl glycoside, 4% isopropanol, and 76% deionized water.

[0016] A method for preparing a water-based cleaning agent for photovoltaic panels as described above includes the following steps: S1, providing deionized water in a reaction vessel under stirring; S2, adding each component to the deionized water in the order of ligand, semiconductor photocatalyst, strong acid-weak base salt, surfactant, and alcohol; S3, continuing stirring after each component is added until a homogeneous and stable solution is formed.

[0017] In one embodiment of the present invention, the stirring speed is 100-500 rpm.

[0018] The use of a cleaning agent as described above in cleaning contaminants on the surface of a photovoltaic panel.

[0019] As described above, the water-based cleaning agent for photovoltaic panels and its preparation method of the present invention have the following beneficial effects: 1. Highly efficient and broad-spectrum cleaning: Through the synergistic effect of multiple components, it can effectively remove complex dirt including oil, dust, scale and stubborn organic matter in one go, with extremely high cleaning efficiency; 2. Unique photocatalytic self-cleaning function: Introducing a semiconductor photocatalyst to drive the deep degradation of stubborn organic pollutants using solar energy; 3. Green and environmentally friendly: It adopts a water-based formula, and the main components are highly biodegradable, non-toxic and harmless, and do not contain harmful substances such as chlorofluorocarbons, phenols or heavy metals, which meet the environmental protection requirements of modern industry. 4. Safe and non-corrosive: It uses mild surfactants and a near-neutral pH system to ensure that the cleaning agent does not corrode or damage the glass, anti-reflective coating, aluminum alloy frame and sealant of the photovoltaic panel; 5. Simple preparation and economical cost: The preparation process of this invention is only physical mixing at room temperature. The process is simple, and the raw materials used are all common chemical products that are easy to obtain. It has significant cost advantages and prospects for industrial application. Attached Figure Description

[0020] Figure 1The diagram shows a comparison of the components and performance of the various embodiments and comparative examples in this invention. Detailed Implementation

[0021] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0022] Please see Figure 1 It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding and reading. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and purpose of the invention, should still fall within the scope of the technical content disclosed in this invention. Furthermore, the terms such as "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation. Example 1:

[0023] This invention provides a water-based cleaning agent for photovoltaic panels. The water-based cleaning agent comprises: 12-17% of a ligand, 0.5-5% of a semiconductor photocatalyst, 0.5-5% of a strong acid-weak base salt, 1-5% of a surfactant, 1-10% of an alcohol, and the balance being deionized water.

[0024] The ligand is selected from at least one of sodium citrate, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, aziridine triacetic acid, sodium gluconate, sodium tartrate, polyaspartic acid, or polyepoxysuccinic acid, preferably sodium citrate; The complexing agent (sodium citrate) mainly functions to chelate divalent metal ions such as calcium and magnesium in water, as well as metal salts in dirt. By forming stable water-soluble complexes with these ions, it can effectively decompose inorganic mineral deposits such as scale and calcium spots, and prevent them from re-adhering to the panel surface during the cleaning process.

[0025] The semiconductor photocatalyst is selected from at least one of titanium dioxide, zinc oxide, bismuth oxide, bismuth oxychloride, or titanium zinc layered double hydroxide (LDH), preferably titanium zinc LDH.

[0026] Semiconductor photocatalysts (titanium zinc LDH) can generate highly active electron-hole pairs by transitioning valence band electrons to conduction bands when excited by light (especially ultraviolet rays in sunlight). These electron-hole pairs react with oxygen in water and air to generate reactive oxygen species (ROS) with extremely strong oxidizing capabilities, such as hydroxyl radicals. These radicals can indiscriminately attack and degrade large-molecule stubborn organic pollutants such as bird droppings, pollen, and bacterial plaque, breaking them down into harmless small molecules such as carbon dioxide and water. This achieves deep chemical cleaning of pollutants that are difficult to remove with traditional cleaning agents.

[0027] The strong acid-weak base salt is selected from at least one of ammonium chloride, aluminum sulfate, zinc chloride, ferric chloride, or copper sulfate, preferably ammonium chloride.

[0028] A strong acid-weak base salt (ammonium chloride) hydrolyzes in water, creating a slightly acidic environment. This mild acidity helps break down carbonate scale and disrupts the chemical structure of certain organic pollutants, while providing a stable pH buffer for the entire system.

[0029] The surfactant is selected from at least one of cocamidopropyl betaine, alkyl glycoside or rhamnolipid, preferably cocamidopropyl betaine.

[0030] Surfactant (cocamidopropyl betaine), as a mild amphoteric surfactant, primarily functions to significantly reduce the surface tension of water, allowing the cleaning solution to fully wet and penetrate the hydrophobic oil layer. Its lipophilic groups in its molecular structure encapsulate oil particles, while the hydrophilic groups suspend them in water. Through emulsification and dispersion, it removes oil, dust, and carbon particles from the panel surface. Its mild nature avoids damage to the anti-reflective coating on the panel surface.

[0031] The alcohol is selected from at least one of methanol, ethanol, isopropanol, ethylene glycol, propylene glycol, glycerol, or diethylene glycol, preferably isopropanol.

[0032] Isopropanol is a highly efficient organic solvent and degreaser. It works synergistically with surfactants to enhance the solubility of stubborn oily substances and organic residues (such as gums and greases), thus compensating for the deficiency of water-based systems in dissolving non-polar pollutants.

[0033] After the cleaning agent comes into contact with the photovoltaic panel, the surfactant and alcohol react rapidly to wet the entire contaminated surface and dissolve and emulsify the outermost layer of oil and soot. Then, as the oil layer breaks down, the cleaning solution can penetrate to the lower layer. The ligand and strong acid-weak base salts begin to react with the inorganic scale and mineral salts, dissolving them. At the same time, the semiconductor photocatalyst exposed to sunlight is activated and continuously generates strong oxidizing free radicals, which chemically decompose the most stubborn organic matter that adheres the most firmly, removing it from the root. Example 2:

[0034] This embodiment provides a method for preparing a water-based cleaning agent for photovoltaic panels as described in Embodiment 1, comprising the following steps: S1. Deionized water is provided in the reaction vessel under stirring. The reaction vessel can be a beaker. S2. The components are added to the deionized water in the following order: ligand, semiconductor photocatalyst, strong acid-weak base salt, surfactant, and alcohol. S3. Continue stirring after each component is added until a homogeneous and stable solution is formed. Example 3:

[0035] The total mass of the cleaning agent is 100%. Add 76% deionized water to a beaker and set the stirring speed to 300 rpm. Add 16% sodium citrate and stir for 5 minutes, then add 1% titanium zinc LDH and continue stirring for 10 minutes. Next, add 1% ammonium chloride and stir for 5 minutes, then add 2% cocamidopropyl betaine and stir for 8 minutes. Finally, add 4% isopropanol and stir for 10 minutes to obtain the cleaning agent. Place the prepared cleaning agent in a beaker and immerse the de-dusted photovoltaic panel in the cleaning agent for 10 minutes. The cleanliness of the photovoltaic panel can reach 99.11%. Example 4:

[0036] The total mass of the cleaning agent is 100%. Add 76% deionized water to a beaker and set the rotation speed to 300 rpm. Add 16% sodium citrate and stir for 5 minutes, then add 1% zinc oxide and continue stirring for 10 minutes. Next, add 1% ammonium chloride and stir for 5 minutes. Then add 1.5% rhamnolipid and stir for 8 minutes. Finally, add 4% isopropanol and stir for 10 minutes to obtain the cleaning agent. Place the prepared cleaning agent in a beaker and immerse the de-dusted photovoltaic panel in the cleaning agent for 10 minutes. The cleanliness of the photovoltaic panel can reach 96.95%. Example 5:

[0037] The total mass of the cleaning agent is 100%. Add 70% deionized water to a beaker and set the rotation speed to 300 rpm. Add 15% sodium citrate and stir for 5-10 minutes, then add 5% titanium zinc LDH and continue stirring for 5-10 minutes. Next, add 2% ammonium chloride and stir for 5 minutes, then add 3% cocamidopropyl betaine and stir for 8 minutes. Finally, add 5% isopropanol and stir for 10 minutes to obtain the cleaning agent. Place the prepared cleaning agent in a beaker and immerse the dust-removed photovoltaic panel in the cleaning agent for 10 minutes. The cleanliness of the photovoltaic panel can reach 96.23%. Example 6:

[0038] The total mass of the cleaning agent is 100%. Add 76% deionized water to a beaker and set the rotation speed to 300 rpm. Add 16% sodium citrate and stir for 5 minutes, then add 1% titanium zinc LDH and continue stirring for 10 minutes. Next, add 1% ammonium chloride and stir for 5 minutes. Then add 2% alkyl glycoside and stir for 8 minutes. Finally, add 4% isopropanol and stir for 10 minutes to obtain the cleaning agent. Place the prepared cleaning agent in a beaker, and immerse the de-dusted photovoltaic panel in the cleaning agent for 10 minutes. The cleanliness of the photovoltaic panel can reach 100%. Example 7:

[0039] The total mass of the cleaning agent is 100%. Add 75% deionized water to a beaker and set the rotation speed to 300 rpm. Add 16% sodium citrate and stir for 5-10 minutes, then add 1% titanium zinc LDH and continue stirring for 5-10 minutes. Next, add 1% ammonium chloride and stir for 5 minutes, then add 2% cocamidopropyl betaine and stir for 8 minutes. Finally, add 5% isopropanol and stir for 10 minutes to obtain the cleaning agent. Place the prepared cleaning agent in a beaker and immerse the de-dusted photovoltaic panel in the cleaning agent for 10 minutes. The cleanliness of the photovoltaic panel can reach 97.86%.

[0040] Comparative Example 1: To verify the key role of the semiconductor photocatalyst in this invention, a comparative example was set up. Its formulation was basically the same as in Example 1, except that no semiconductor photocatalyst was added, and its mass was replaced by deionized water; the specific formulation was: 77% deionized water, 16% sodium citrate, 1% ammonium chloride, 2% cocamidopropyl betaine, and 4% isopropanol. Using the exact same preparation and cleaning methods as in Example 1, especially when cleaning panels containing a large amount of stubborn organic contaminants, the final cleanliness was measured to be only 82.50%.

[0041] like Figure 1 As shown in the data, all embodiments of the present invention exhibit excellent cleaning effects, with cleanliness levels exceeding 96%. In particular, by comparing Example 3 (cleanliness level 99.11%) and Comparative Example 1 (cleanliness level 82.50%), it is clearly evident that in the absence of a semiconductor photocatalyst, the cleaning agent's ability to treat complex contaminants (especially organic contaminants) is significantly reduced. This directly proves that the introduction of a semiconductor photocatalyst is key to the outstanding technical effects of the present invention; its role is indispensable and not self-evident.

[0042] In summary, this invention utilizes the synergistic effect between its components to achieve multi-stage, multi-target cleaning of complex contaminants on photovoltaic panel surfaces: surfactants and alcohols are responsible for wetting and removing oil stains; ligands and strong acid-weak base salts are responsible for decomposing inorganic scale; and the core component, a semiconductor photocatalyst, generates highly oxidizing free radicals under sunlight irradiation to degrade stubborn organic pollutants such as bird droppings and pollen. This provides an efficient, environmentally friendly, economical, and safe cleaning solution that is non-corrosive to panel materials, effectively restoring and maintaining the power generation efficiency of photovoltaic panels.

[0043] Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial application value.

[0044] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A water-based cleaning agent for photovoltaic panels, characterized by, The water-based cleaning agent comprises: 12-17% of a complexing agent, 0.5-5% of a semiconductor photocatalyst, 0.5-5% of a strong acid weak base salt, 1-5% of a surfactant, 1-10% of an alcohol, and the balance being deionized water, the semiconductor photocatalyst.

2. The water-based cleaning agent for photovoltaic panels according to claim 1, characterized by the fact that: The complexing agent is selected from at least one of sodium citrate, ethylenediaminetetraacetic acid, diethylenetriaminepentaacetic acid, nitrilotriacetic acid, sodium gluconate, sodium tartrate, polyaspartic acid, or polyepoxysuccinic acid.

3. The water-based cleaning agent for photovoltaic panels according to claim 1, characterized by the fact that: The semiconductor photocatalyst is selected from at least one of titanium dioxide, zinc oxide, bismuth oxide, bismuth oxychloride, or titanium zinc LDH.

4. The water-based cleaning agent for photovoltaic panels according to claim 1, characterized by the fact that: The strong acid weak base salt is selected from at least one of ammonium chloride, aluminum sulfate, zinc chloride, iron chloride, or copper sulfate.

5. The water-based cleaning agent for photovoltaic panels according to claim 1, characterized by the fact that: The surfactant is selected from at least one of cocamidopropyl betaine, alkyl glycoside, or rhamnolipid.

6. The water-based cleaning agent for photovoltaic panels according to claim 1, characterized by the fact that: The alcohol is selected from at least one of methanol, ethanol, isopropyl alcohol, ethylene glycol, propylene glycol, glycerol, or diethylene glycol.

7. The water-based cleaning agent for photovoltaic panels according to claim 1, characterized by the fact that: The cleaning agent consists of the following components by mass percentage: 16% of sodium citrate, 1% of titanium zinc LDH, 1% of ammonium chloride, 2% of alkyl glycoside, 4% of isopropyl alcohol, and 76% of deionized water.

8. A process for the preparation of a water-based cleaning agent for photovoltaic panels as claimed in any one of claims 1-7, characterized by, The method comprises the following steps: S1, providing deionized water in a reaction container under stirring; S2, sequentially adding each component into the deionized water in the order of complexing agent, semiconductor photocatalyst, strong acid weak base salt, surfactant, and alcohol; S3, continuing to stir after each component is added until a uniform and stable solution is formed.

9. The method for preparing a water-based cleaning agent for photovoltaic panels according to claim 8, characterized by the fact that: The stirring speed is 100-500 rpm.

10. Use of the cleaning agent of any one of claims 1 to 7 in cleaning photovoltaic panel surface contaminants.

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