Which Solar Panel Cleaning Methods Work Best | Tools, Solutions, Maintenance

Soft brush + deionized water cleaning effect is best, cleaning efficiency can increase about 15%–25%; when dust is heavy, use neutral cleaning agent (1:50 dilution) cooperate with low pressure water flush, every quarter 1 time, avoid hard objects scratching module surface.

Tools

Pick a good long pole

Carbon fiber material's long pole density is 1.5 grams per cubic centimeter, one piece length is 8 meters's retractable carbon fiber pole total weight is strictly controlled at 1.2 kilograms to 1.5 kilograms. By contrast, the same 8 meters length's 6,061 standard aluminum alloy pole weighs will exceed 3.5 kilograms. Operating personnel on inclination angle is 15 degrees to 30 degrees's roof continuously lift pole work 4 hours, using carbon fiber material can let shoulder neck part's muscle load decrease 30%.

Retractable pole usually by 4 to 6 sections pipe material nesting compose, single section pipe wall thickness needs to reach 1.2 millimeters, guarantee at completely stretch to 10 meters's longest working radius time, terminal's natural sagging deformation error is lower than 5 centimeters. Pipe sections between's cam locking device provides 30 kilograms's vertical locking force, applying 0.5 megapascal thrust will not happen shrink pipe slip off. Through one piece 10 meters long's retractable pole, a single person can safely cover up to 40 pieces of standard size, which is 1.6 meters multiplied by 1 meter's photovoltaic modules.

Look brush bristle parameters

Brush head's material data has strict standards, nylon 612 brush bristles are the current test data's most optimal choice, single root brush bristles' diameter precisely controlled at 0.05 millimeters to 0.15 millimeters between. Photovoltaic panel surface's tempered glass Mohs hardness is 5.5, nylon brush bristle's Mohs hardness set at 2 to 3's interval, at surface produce 1.5 kilograms physical friction force's same time, surface thickness is 120 nanometers's anti-reflection coating at passing 200 times back-and-forth brushing after, thickness wear amount not exceed 0.1 nanometers.

Brush head overall width configures at 35 centimeters to 60 centimeters between, inside embeds 2 to 4 pieces of brass material's fan-shaped nozzles. Nozzles under 0.27 megapascal's pipe water pressure, per minute output 2 liters to 3 liters's water volume. Sprayed out's water flow included angle fixed at 60 degrees, on panel form one layer thickness is 1 millimeter's continuous water film, will peeled out's diameter larger than 10 micrometers's dust particles rapidly wash down edge. Brush head and long pole's connection place installs with gear adjustment's rotating shaft, angle adjustment range from 0 degrees extends to 90 degrees, precisely fits 20 degrees, 30 degrees, or 45 degrees's installation bracket inclination angle.

Choose the right squeegee board

Clean surface's residual water drops need to use high purity silicone material's squeegee board, rubber material's Shore A hardness index needs to keep at 50 to 60's specific interval. Hardness exceeding 60 will increase 50% coating scratch probability, hardness lower than 50 then will at applying 0.5 kilograms's downward pressure load time happen excessive deformation, causing contact surface to produce 0.5 millimeters's gap leaking water.

One piece standard width is 45 centimeters's squeegee board, operating time with panel surface keeps 45 degrees's precise included angle, will surface residual's water film thickness forcefully press low to 0.01 millimeters below. At sunshine intensity is 500 watts per square meter, environmental temperature 25 degrees Celsius, meteorological conditions under, a 0.01 millimeters thick thin layer of water film will within 30 seconds completely evaporate exhaustively.

Squeegee board's silicone strip belongs to high frequency consumption accessories, bearing total 200,000 times, each time sliding length is 1.5 meters's friction attenuation after, edge flatness's physical error will expand to 0.2 millimeters, single root replacement glue strip's purchasing budget needs to control at 5 to 8 units currency within.

Hardware parameters comparison:

· Carbon fiber retractable pole: tensile strength 3000 MPa, elastic modulus 130 GPa, thermal expansion coefficient -0.5×10^-6/℃.

· Nylon 612 brush bristle: water absorption rate less than 1.5%, melting point 210℃, breaking elongation rate 40%.

· Brass nozzle: thread specification 1/4 NPT, spray hole diameter 1.2 millimeters, pressure resistance upper limit 1.5 MPa.

· Silicone squeegee strip: tear resistance strength 25 KN/m, temperature resistance range -40℃ to 200℃, rebound rate 60%.

Test water small instrument

TDS digital testing pen volume is 15 cubic centimeters, contains button cell's weight only is 50 grams, relies on measuring two poles probes between water body's electrical conductivity to display dissolved solid total amount. Entering cleaning system water supply pipe's TDS numerical value must be filtered through equipment and be pressed at 10 ppm below. When the input water quality's TDS numerical value rises to 50 ppm, per square meter's panel at water moisture natural evaporation after will leave over about 200 pieces diameter is 0.5 millimeters's calcium carbonate deposition spots, making light transmittance rate drop 1.2%, affecting 3 watts' peak power output.

Connected to water pump downstream's mixed bed deionization resin tank, inside fills capacity is 11 liters's polishing resin. When originating from tap water pipe's source water TDS is 100 ppm, 11 liters of resin through ion exchange reaction produces 4000 liters of purity is 0 ppm deionized water. According to the system, the total area is 500 square meters, and the single time cleaning water consumption is 150 liters's quantified standard. One tank fully loaded resin provides 26 pieces complete cleaning cycles's pure water supply. Water conveying pipeline uniformly adopts inner diameter is 8 millimeters, outer diameter is 12 millimeters's polyurethane soft pipe, pipe wall can bear 0.8 megapascal's hydrostatic pressure, maintains per minute 3 liters's stable liquid flow rate.

Automatic small machine

Targeting installed capacity exceeds 50 kilowatts' large-scale array, crawler type cleaning robot's work amount output far exceeds manual labor. Robot's whole machine weight parameters distribute between 15 kilograms and 25 kilograms, inside carries an output voltage of 24 volts, and capacity is 40 ampere hours's ternary lithium cell pack. Full charge state under continuous work time stabilizes at 180 minutes to 240 minutes. The chassis motor's traveling speed is set at 15 meters per minute, and the front end equips a width of 1.2 meters's nylon high-speed rotating roller brush, and the motor rotation speed reaches 400 revolutions per minute.

Every 60 minutes' effective cleaning coverage area is as high as 1,200 square meters. Bottom's trackless silicone crawler and glass surface's friction coefficient reaches 0.6, cooperates with internal impeller produced's 50 pascals negative pressure vacuum degree, on an inclination angle as high as 20 degrees's wet slippery glass panel keeps straight line climbing, every travel 100 meters's trajectory lateral offset amount is forcefully corrected and controlled at 5 centimeters's error range.

Solutions

Make good pure water

Reverse osmosis equipment under 0.6 megapascal's inlet water pressure, can source water's TDS concentration from 300 ppm decrease pressure to 15 ppm below. Water flow passes through pore diameter is 0.0001 micrometers's RO membrane time, desalination rate stably reaches 99.2%. Single branch specification is 4040's RO membrane module, per hour produces pure water 250 liters, waste water discharge ratio is 30%. Mixed bed resin tank connects at RO system back end, outlet water's electrical resistivity soars to 15 megaohm·centimeters, TDS numerical value thoroughly returns to zero.

1000 liters of absolute pure water's preparation cost keeps at 1.5 to 2 pieces of currency units between. At room temperature 30 degrees Celsius, pure water's evaporation speed on a glass surface is per minute 0.8 millimeters, surface residual solid micro particles mass approaches 0 milligrams. The pipeline inside maintains 0.4 megapascal's conveying pressure, can ensure single branch nozzle per minute outputs 2.5 liters of deionized water.

Mix a little cleaning essence

Encountering industrial oil pollution deposition, needs 10 liters of pure water to add 15 milliliters to 20 milliliters of non-ionic type surface active agent. Mixed solution's pH value strictly keeps at 6.5 to 7.5's neutral interval, surface tension from pure water's 72 dynes/centimeter suddenly drops to 30 dynes/centimeter. Mixed solution at spraying after with oil pollution contact reaction 45 seconds, dirt's physical adhesion force drops 80%. According to 1 to 500's blending proportion, single piece 2 square meters's photovoltaic panel each time cleaning consumes solution total volume not exceeds 200 milliliters.

Liquid parameters proportion:

· Surface tension: drops to 30 mN/m, lifts 150% of liquid spreading area.

· Foam thickness: keeps at 3 mm within, at 20℃ under stand still 2 minutes natural defoaming 60%.

· Rinse water volume: uses 0.3 MPa water pressure continuously sprays 15 seconds, consumes water 1.2 liters.

· Light transmission error: flushing after's glass light transmittance rate fluctuation value keeps at 0.1%'s tolerance within.

Dissolve away bird poop marks

Bird poop and tree branch secretions contain uric acid modules, acidity alkalinity test shows pH value between 3.0 and 4.5, attaching exceeds 72 hours will erode thickness is 200 nanometers's anti-reflection coating. Handling stubborn substances needs to blend volume accounts for 70% isopropyl alcohol solution (IPA), loaded into capacity is 500 milliliters's polyethylene spray kettle inside locally point spray.

Single time spray amount controls at 5 milliliters to 8 milliliters, covers a pollution area about 10 centimeters in diameter. Isopropyl alcohol solution on glass surface's best stay time is 90 seconds to 120 seconds, dissolving fat and protein's rate is ordinary natural water's 15 times. At an air temperature of 35 degrees Celsius, the high temperature environment under, 70% concentration's isopropyl alcohol will completely volatilize within 60 seconds, the volatilization residual object weight is 0 grams. Using pure water to proceed secondary flushing's flow rate needs to reach per minute 2 liters, takes away dissolved after diameter shrinks to 0.1 millimeters's solid granular objects.

Clear away white water scale

Targeting hard water left over's calcium carbonate and magnesium hydroxide spots, uses a 5% white vinegar solution to proceed with acidic neutralization. Will 100 milliliters of white vinegar and 900 milliliters of deionized water mix, blend out a pH value of 5.5's weak acidic cleaning liquid. Put configured good's liquid spray on thickness reaching 0.5 millimeters's calcified white spots on, chemical reaction produces carbon dioxide bubbles's cycle lasts about 3 minutes. Dissolving every 1 gram of calcium carbonate water scale needs to consume 8 milliliters according to the proportion of white vinegar solution.

Operating time must avoid aluminum alloy frame seam place 10 millimeters's range, solution and anodic oxidation aluminum layer contact exceeding 10 minutes will make oxidation layer thickness lose 0.5 micrometers. Per square meter glass area spraying 50 milliliters of acidic liquid after, must within 5 minutes introduce 1.5 gallons of pure water to proceed with comprehensive neutralization rinse. Flushed after water body pH value rises back to 6.8, will not towards system downstream's 15 millimeters drainage pipe fittings cause acidic corrosion.

Apply layer nano film

At thoroughly cleaning finished and panel temperature drops to 25 degrees Celsius time, towards glass surface spray coat titanium dioxide nano hydrophilic paint. Coating curing time is 12 hours, at surface form one layer thickness is 50 nanometers to 80 nanometers's dense protection film.

Nano film will water drop and glass's contact angle from original's 60 degrees press low to 10 degrees below, water drops spread into a thickness of only 0.1 millimeters's thin film form. At rainfall reaches per hour 5 millimeters's situation under, hydrophilic film makes dust be rainwater naturally washed's efficiency lift 40%. Using spectrometer to test coated after's panel, wavelength range from 380 nanometers to 1100 nanometers between's light transmittance rate increases 1.5%.

Single time coating's effective lifespan maintains at 18 months to 24 months, can bear 800 times friction coefficient is 0.3's physical wiping. 1 liter pack's nano paint liquid capacity can cover 150 square meters's panel area, converted per square meter's material cost is 3.5 pieces unit currency. Panel every running 1,000 hours, power generation revenue compared to not coated before increases 2.2%.

Maintenance

Check junction box

The photovoltaic panel's back face's junction box size is usually 150 millimeters long, 150 millimeters wide, and the thickness is about 25 millimeters. Inside encapsulates has 3 pieces playing bypass protection role's Schottky diodes. Every quarter's daily maintenance tasks require using infrared thermal imaging equipment at noon, 12 o'clock, when the sunshine intensity reaches 800 watts per square meter, time to proceed scanning.

Normal operating state under, junction box outer shell's physical temperature should maintain at 45 degrees Celsius to 55 degrees Celsius's interval. When the thermal imager screen displays local temperature soars to 85 degrees Celsius, it indicates an internal diode's resistance parameter has undergone a morbid change, and the forward voltage drop data from normal's 0.4 volts abnormally rises high to 1.2 volts. Junction box edge's black silicone sealing ring thickness is 3 millimeters, and as long as 36 months' ultraviolet light irradiation, silicone material's elastic modulus will drop 20%.

Once the sealing ring produces a width exceeding 1 millimeter's dry crack gap, the outer shell's protection level index will suddenly drop from IP68 to IP54. At relative humidity reaches 85% early morning, air condensed water moisture will along the gap seep in, making system's insulation resistance test value from healthy's 50 megaohms cliff style fall down to 2 megaohms below, triggering leakage protection switch within 50 milliseconds cut off output circuit.

Using a multimeter to test string's open circuit voltage time, if by 10 pieces panels series connected's system nominal voltage is 380 volts, actual measurement value only displays 340 volts, voltage deviation rate exceeds 10%'s allowed threshold, indicates at least has 1 piece junction box inside's bypass diode already been broken through and is situated in a permanent conduction state, every day will cause about 1.5 kilowatt hours's power quantity loss.

Test inverter

Wall-mounted type inverter's weight distributes between 15 kilograms and 20 kilograms, bottom's aluminum made heat dissipation fins spacing is 8 millimeters, bears equipment internal IGBT module sends out's heat amount. Every 180 days, the heat dissipation fins surface will accumulate a thickness of about 0.5 millimeters's dust resistance layer, making the heat exchange rate drop 15%. When the inverter's internal temperature sensing probe's numerical value climbs to 50 degrees Celsius above, the equipment will automatically start a derating operation program. If the temperature rises one degree Celsius, the AC output power will then forcefully cut down 0.5%.

Using a high-pressure fan provides per second 5 meters wind speed's air flow, from bottom to top, blow sweep heat dissipation channel 3 minutes, can let equipment's highest conversion efficiency newly stabilize at 98.5% peak value. Every separating 12 months, needs to spend 15 pieces of unit currency to purchase thickness is 5 millimeters's new type polyurethane filter cotton, replace away air inlet place intercepted 50 grams inhalable particulate matter's old filter net, guarantee chassis inside per minute maintains 50 cubic feet's air circulation amount.

Tighten screws

Panel and C type steel bracket mutually connected's hardware mainly is M8 specification's 304 stainless steel inner hexagon bolts. The system installed on the roof bears the day-night temperature difference, which brings thermal expansion and cold contraction, physical deformation. Every year, for as long as 8,760 hours, wind load and vibration will let nut's bite force produce tiny loosening. Maintenance operation requires using carries have digital display's torque wrench, will torque parameters precisely set at 15 Newton meters to 18 Newton meters between, towards array in all's fixing parts proceed one by one tightening.

When torque is lower than 10 Newton meters, the array encounters wind speed reaching per second 25 meters's gust environment time, panel edge frame will produce amplitude is 3 millimeters's high frequency resonance, extremely easily shake shatter thickness is 3.2 millimeters's surface glass. Fixing pressure block bottom's ethylene propylene diene monomer rubber (EPDM) gasket thickness is 2 millimeters, main role is to isolate aluminum alloy and stainless steel between's potential difference, prevent chemical corrosion.

Grounding wire's wire diameter parameter needs to reach 4 square millimeters, using a megaohmmeter measured obtained's system grounding resistance numerical value must be strictly pressed at 4 ohms within, ensure lightning strike produced's 10 kiloamperes surge current can within 10 milliseconds be led into underground.

Cut big tree branches

Surrounding growing broadleaf trees or coniferous trees, the top end branches' annual average growing speed can reach 0.5 meters to 0.8 meters. At the winter season, the 12th month's sun altitude angle drops to extremely low's 22 degrees, and the distance panel edge 5 meters away's tree crown will project out as long as 12 meters's physical shadow.

At string type system architecture, even if only has a single piece panel, 10% of the area is tree leaves shadow covered, series circuit's MPPT (maximum power point tracking) current parameter will then be limited, whole strip by 12 pieces panels constituted's circuit within 3 seconds's output power will sharply shrink 30% above.

Every year, budgets 50 to 80 pieces of currency, in the spring season, all things recover before hiring personnel use a length of 3 meters's high branch saw, will distance panel horizontal spacing smaller than 4 meters's tree crown proceed pruning. The cut-off diameter exceeds 5 centimeters's side branches, guarantee at every day morning 9 o'clock to afternoon 3 o'clock totaling 6 hours' golden sunshine cycle within, photovoltaic module surface 100%'s area received's light radiation intensity not lower than 600 watts per square meter.

Panel surface's bird poop cleaning cannot delay exceeds 72 hours, diameter only is 3 centimeters's white uric acid deposition object, due to completely blocking local cell cell towards spectrum in 400 nanometers to 700 nanometers visible light's absorption, will force cell cell from power source to transform to consume power load, produce as high as 85 degrees Celsius's destructive hot spot effect.

Stare power generation amount

One set newly installed's system PR value is usually situated at 78% to 82% interval. If continuous 7 days's PR monitoring data falls below 70% trigger line, and the same period local meteorological station published's rainfall amount is lower than 5 millimeters, the system algorithm will judge panel surface light transmittance rate has already substantially dropped. According to monocrystalline silicon module every year 0.5% linear attenuation rate calculation, running to the 5th year's system standard PR value should be 75.5%. When the actual data and the theoretical model's deviation amplitude exceed 3 percentage points, then needs to start a cleaning or physical overhaul program.