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Roof Renew Pros

Solar Panel Cleaning

Some Factors That Determine Solar Panel Efficiency…

Solar panel efficiency, or conversion rate, refers to how much of the incoming solar energy is converted into electrical power. For example, the efficiency of commercial solar panels operates in the range 11-15%.


What are the most efficient solar panels?

The most efficient solar cell to this date is based on a multi-junction concentrator and converts 44.0% of incoming solar energy into electricity.


How Important is Solar Panel Efficiency?

Efficiency ratings of solar panels are only one of many different factors that have to be taken into account when considering going solar.


Consider this: Solar panels with conversion rates of 8% will need twice the area as solar panels with conversion rates of 16%. This is why most homeowners end up choosing mono- or poly-crystalline solar panels – these have great efficiency rates and are also space-efficient.


Is there anything I can do to make sure my solar panels perform the way they should?

This is where solar panel monitoring comes in. In order for solar panels to be effective these are influenced by a whole host of variables.


Here are some to guide you.


Solar Panel Types

  • Monocrystalline solar panels are based on the highest-purity silicon available. This makes them the most efficient solar panel type available for homeowners.

  • Solar panels based on polycrystalline silicon are usually not quite as efficient as monocrystalline, but there is not that much of a difference.

  • Today`s thin-film solar panels are relatively inefficient, but they also cost less. Thin-film solar panels take up a lot more space than mono- or polycrystalline solar panels, which is why they are unsuited for most households. The efficiency of individual solar cells (not entire solar panels/modules) is typically higher.

Some Elements That Affect Your Panels


Obviously shaded areas affect the output of solar panels. And Depending on your area of setup, a little shade could bring down an entire solar system. If you look into Micro-inverters they will over a possible solution to shade issues. Make sure that that professional solar panel installers will do a thorough analysis of shaded areas for proper placement. On average our clients spend $1,217.63 less per year on electricity. That's including the cost of solar panels.

Orientation Or Positioning

For best efficiency, solar panels should be positioned to maximize the input of sunlight. This means that solar panels should be faced south in the U.S.Solar trackers were invented in order to adjust the orientation of solar panels to followthe sun`s trajectory throughout the day. For most homeowners, solar trackers do not pass a cost-benefit analysis – they are simply too expensive.The pitch of your roof can be altered with racks. In many cases this will allow your solarpanels to stay longer in the sun.


Temperature is not something you have to consider unless you live in very hot areas (e.g. San Antonio and Phoenix in the U.S.).

As the temperatures increase, the efficiency of solar panels usually decreases a little bit. Professional installers will make sure that the solar panels are positioned to receivesufficient amounts of airflow. This induces natural cooling, which help keep theefficiency rates up.


Solar panels efficiency however does degrade a little bit over time. A general rule of thumb is that the power output drops by 0.5% every year. Don’t let this sway yourdecision of installing them, because the fact is solar panel manufacturers often offer awarranty that guarantees the power output stays above 80% after 25 years!


A solar system generally requires very little maintenance, especially if the system isgrid-tied. However, cleaning the solar panels on a regular basis is recommended. Dustand dirt will affect the efficiency of solar panels if not taken care. Some would have youbelieve that an occasional rain storm will effectively clean your solar panels. Many industry reports are noting that the lack of scheduled cleanings can cause sola rpanels to lose 15 - 25% of their efficiency and increase a solar cells payback time by 3 -5 years! Look, you installed solar panels to save money, be conscious of the environment and your children’s future, do you really want to wait years to actually have them work in your favor? Self-cleaning systems are one option but not only do they present a substantial investment. These deposits will not be removed with subsequent cleanings with soapand water. The deposits leave long lasting staining that will have to physically beremoved. 

How often should I clean my solar panels?

Unfortunately, there is no single answer for this question. Best practices would be to monitor the power output of the solar panels to get an idea of how often cleaning them is necessary some companies recommend four times a year, others twice a year. You need to choose what works for you and your

particular situation and location.


Roof Renew Pros Uses The Right Technique For Every Job!

Solar panels can lose anywhere from 10%-20% of their power generating capabilities after the first year.  From our observation a UV blocking film of dirt develops over the glass panels. Start adding pollen, bird droppings, road traffic, or salt if near the ocean, you can start to seriously diminish you return of your investment in the solar panels on your home or building. We at Roof Renew Pros have spent years of research testing the various methods. Pressure washing, although cheap, you get what you pay for, and water spots, are still left behind on the panel. Weren’t you trying to save money? And with pressure washing them I'd be more careful with panels that have micro-inverters mounted underneath as you don't want to put their

seals to the test. 


We at Roof Renew Pros have found that the safest and most thorough way to clean a solar panel is to use de-ionized water.  Using de-ionized water is the safest, most effective way to save you money, and protect your panels. This method is created by running water through a series of filters to remove all of it’s impurities.  This type of water will dry 99.9% spot free since all of its impurities have been removed. This water is free from salts and calcium that otherwise leave little ugly white spots on your panels when dried. There are DI systems that can run through a water fed pole with a soft brush on the end.  The DI water will run through the pole, out of the brush, and on to the panel.  With a gentle motion of the brush and a DI

water rinse, the panel will become perfectly clean. But other companies are saying this type of cleaning is expensive. DI cleaning is no more expensive than power washing them, the smalltime pressure washer companies want you to think that so that they can get the work. If they are not using a soap to clean it, and if they are using just water and some pressure? Then yes we will be higher, but again, you installed them because they were more economically sound for you and your family, so then you would want them cleaned correctly so that they last, and so does your money, and peace of mind by actually having a company that invests in the proper methods of cleaning such an expensive tool on your home.


Ok so I understand how I should have my panels cleaned, however having
someone clean my solar panels with water, isn’t that dangerous?

We all know that electricity and water doesn’t mix very well so questioning if it will be safe to spray electricity creating panel with a hose, or even any pressure washer is a valid one. And that is especially the case since it is a fact that power production from a solar panel technically can’t be

turned off. They will produce electricity for as long as there is sunlight. But the simple answer is: No you won’t get shocked when doing a solar panel cleaning.


Because you did hire a professional that did install your solar panels the right way didn’t you? And I’m assuming that the panels you purchased are at least standard panels with certifications and a guarantee to last for many years to come correct? And I’m assuming electrician used good isolated wiring when connecting your solar system together? Of course he did since he’s an electrician. And your solar panels don’t contain any cracks either because with the accompanying warranty you would already have all such problems fixed right?  A correctly installed solar panel can get sprayed with water everywhere without any effect at all. Meaning you can merrily shower the front side, back side, the conduit, the wiring or any of the junction boxes, without any risk of electric shock.


So to conclude this shocking rant you should be fine getting your panels cleaned providing your solar system doesn’t consist of a DIY kit of solar cells from eBay or Craigslist that you soldered together yourself. Oh and as long as you didn’t put up those homemade solar panels in your sparetime using clothes hanger and barbwire to make it work.

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