The Dirt On Solar Panels

Solar panels have been the topic of thousands of articles over the past couple of years. It seems like everyone is going pro-solar, but there is one thing that few people have addressed: Dirt. Solar panels glisten in the sun after first being installed, and make any building look modern, shiny and new when viewed from above. But after a little while, these panels reflect a little less and don’t function as well. Tree branches hanging overhead drop sap onto anything below, flocks of birds leave behind a mess after spending the night overhead while dust, grime and mold adds to the layers of dirt already coloring the solar panels a splotchy brown.

Dirt is a major problem with solar panels, and letting it accumulate over a few months may reduce a solar panel’s efficacy by almost 25%. It is suggested that solar panels are cleaned on a regular basis, but this can be time consuming and even dangerous.

OCS Energy has developed a practical solution with the use of an automated cleaning system. In a recent press release, the company explains why they came up with the novel idea:

“After receiving numerous maintenance inquiries from clients over the years, and seeing no practical cleaning solutions, Rich O’Connell, CEO of OCS Energy, developed the SolarWash system. The patent pending SolarWash system provides a complete solar cleaning solution including maintenance free nozzles, a web?based interface, and a programmable logic controller (PLC). The end?to?end solution allows operators of large PV systems to effectively manage their resources, initiating the washing of panels without the need to schedule a maintenance crew.”

Panel performance declines without regular
cleaning – OCS Energy has an automated solution.
(Source: OCS Energy, Inc.)

Buyers of solar panels often assume that the work is over after the panels are installed.

Obviously this isn’t the case when cleaning crews need to be hired on a regular basis in order to keep the panels functioning properly.

SolarWash isn’t exactly cheap, but it will pay for itself in under five years by eliminating cleaning costs and increasing the amount of energy absorbed by the panels.

Solar panels will now really be maintenance-free with SolarWash’s fully automated fanning nozzles spraying the panels down whenever they get too dirty.

7 Responses to “The Dirt On Solar Panels”
  1. DJ says:

    Well, that’s all well and good to send a solution that costs more to maintain the Cells and get a decent return on the investment. But what about the dirt that is actually bonded to the surface?? The ONLY way to get that off is PHYSICAL MOTION. Example: Wash your car in a spray type car wash. Get out of the car and run your finger on the driverside door panel. You will be able to see where your finger went. True. a wash is better than nothing but still if you don’t keep them VERY clean, don’t expect a return in your time spent in the House. Oh, another thing to look at is you are paying TWICE on your investment!! Thru Government Subsidies and your contractor of whom you purchased the panels and installed them. Extended warranty, anyone???

  2. Tim says:

    The idea is that if you run one of these systems on a regular basis, you won’t have to get up there and clean as often. As far as things like sap from trees, I just hope your solar installer isn’t stupid enough to install a system right under a bunch of foliage. If that is the case, then you are never going to get the most out of your panels.

    Unless you plan on keeping your solar panels for less than 5 years I don’t see how this is such a bad idea for you DJ.

  3. C.A. White says:

    He’s right you must physically wash the panel to really clean it.

    That is why we devolped the KlearvieW System for cleaning of solar panels, windows and skylights.

    Solar Panel – From the beginning KlearvieW Systems has always been a green company. KlearvieW Systems has targeted solar panels as being a key component of the green future. KlearvieW is the perfect fit for the solar panel industry.

    Solar panel utilization / implementation are not without challenges. As a solar panel collects dust, leaves and bird droppings they become dramatically less efficient.

    The KlearvieW system is adaptable to numerous different applications, with quick and easy change of brushes and squeegee blades to perfectly fit the end-users needs.

    Utilizing the Green self sustaining system shown on page xii. The KlearvieW Systems uses the captured rain water that sheets off of the solar panel surface into a gutter system conveying the captured rain water into a storage tank. Inside of the storage tank is a simple line pump powered directly from the solar panels themselves.

    KlearvieW takes this one step further by recycling; utilizing the initial captured rain water as the power source to drive the mechanism. Once expelled from the unit we capture the water and recycle so it can be used again to drive the mechanism. It is safe to say, you can’t get any greener than that!

    i. Solar panels will sustain maximum efficiency with the KlearvieW System in place.

    ii. Return on investment will take place within the first year the KlearvieW System is installed and placed into operation on a solar panel array.

    iii. Dust buildup on Solar Panels can cause up to a 15% reduction in sun light conversion. With a typical 2000 kilowatt solar electric generating system the dust and dirt would cost: 15% x 2000 = 300 watt reduction per month. 300 watts x .15 cents utility cost equals a loss of $45 a month ($540.00 per year) due to DUST and DIRT.

  4. Optical Losses resulting from shadowing of the cell surface through contact with the glass surface or reflection of incoming rays on the cell surface. Shading can reduce output 40%. If even one full cell in series string is shaded, it will likely cause the module to reduce its power level to ½ of its full available value. If a row of cells at the he bottom of a module is fully shaded the power output may drop to zero. Soiling can reduce output 5-20%. Mismatch between panesl can reduce output by 15%. Due to the semi-conductive nature of silicon cells, small amounts of shade (fist sized) can completely disable the output of a module or even a string of modules (non-producing cells become non-conductive). PV systems with any shade will have production loss. Shade is quantified in terms of percent solar access. Shade measuring tools such as the Solar Pathfinder or Solmetric SunEye can be used to provide both monthly and annual solar access measurements.

    Remember, the other losses from Spectrum: Differing semiconductor materials or combinations are suited to specific spectral ranges because of this a portion of the radiant energy cannot be used because the photons have insufficient energy to activate electrons across band gap (charge carriers).
    Heat: An amount of surplus photon energy is transformed into heat rather than into electrical energy. Heat adversely affects solar cell performance. Resistance: Electricity traveling through wires encounters resistance. The lower the voltage and higher amperage and the longer the longer distance electricity runs the higher the electrical loss. Conversion: The array cannot be directly to the battery but usually we want an intermediary so to regulate battery charging. Battery charging electronics are ~70 to 90% efficient.Battery: Power is lost in putting the electricity into and extracting it out of the battery. This is ~75% to 80% efficient. Overlooking the loss due to wiring and electrical connections: the end-to-end efficiency of the system is therefore approximately 7% to 8% . Centralized optimization reduces overall performance to the weakest panel. The most important degradation process is relative to PV panels: account 1% per year (loss of efficiency). In 20 years (guaranteed lifespan) the efficiency will be 20% lower. The cause is a loss of properties in materials (glass transmitivity, PV cells efficiency). Inverter can also reduce its performance in the time.

    While a lot of factors are beyond our control, the new power optimization technologies to harvest more power from your PV system need more attention. These technological work needs more lab research like Genetic Engineering research of the entire PV system. Xandex Solar is extensively working on this power optimization technological research and develoment to offer a new product that harvests more power from the PV module. A few more to come in near future. These products will additionally benefit to our long term investment of PV system.

  5. Asher says:

    Hi all,

    to DJ, physical motion is NOT the only way to remove dust bonded to the surface of a solar cell. Who here has heard of Masuda? He was a professor at the University of Tokyo.

    He developed a simple design to remove dust from solar panels. It was used on the moon, and I think on Mars. I am making it for a third year uni project.

    You can make an electric field that pushes dust off a solar panel. its called an electric curtain. We’re making ours for less than $150 using simple parts you can buy at an electronics store or out of an old microwave…

  6. Danny Boy says:

    To Asher!!!
    Can you elaborate about the electric curtain. I couldn’t find any practical material on the matter.
    Thanks a lot

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