Anything that blocks sunlight from your solar panels, such as tree branches, dirt and leaves can reduce your energy output. The Solar Electric Power Association (SEPA) states that energy output can be decreased by about 10% due to dirt and other residues. In areas with heavy bird droppings, pollution, dust or pollen, the efficiency can decrease as high as 15-20%. Sun City Solar recommends you clean your solar panels as part of your regular home maintenance. Clean panels will also maximize your investment and allow you to use all of the energy output available.

For convenience, hosing off the solar panels should get them clean enough to improve efficiency. However, if cleaning the solar panels requires more than a hose (for bird droppings and such), you will need to manually clean the solar panels with a brush and water.

To clean your solar panels manually, here are some factors to consider:

• It is recommended you NOT use soap and use SOFT water where possible. Hard water (with a high mineral content) can eventually build up heavy deposits.
• Never climb onto the array – use a soft brush with an extension pole. Boat cleaning brushes (around $30) are the best.  Boat cleaning brushes are designed not to scratch and offer flow-through handles which deliver water right to the bristles.
• If chemical cleaning is required, use a detergent that will not damage aluminum. Many domestic detergents can damage panel frames and clamps.
• For large arrays, a commercial window cleaning system is advised. These brushes can extend up to 30′ and will deliver deionized water directly to the glass surface to remove dirt and leave no deposits.
• Never power wash the solar panels.  The high pressure may dislodge wiring or damage the shingles around the roof mounts.

Solar panels benefit from natural cleaning from rain which usually removes most of the dirt and grime. How often you clean your panels is determined by the weather in your part of the country. For areas with less dirt, it is recommended to wash them around 1-2 times a year.

There is no set time to wash your solar panels, but you may want to include the maintenance with other seasonal chores, such as cleaning the gutters or washing windows.  Clean solar panels will definitely improve your energy output and put more money in your pocket. Call Sun City Solar Energy and, for a nominal fee, we will be happy to wash your panels for you.

Would you like to live completely off the grid? The Harris’ have decided to do just that! Building a beautiful new home with Off-Grid Solar Power designed and installed by Sun City Solar Energy. The Harris’s will moved in at the end of August and are very excited to be energy independent. 

In Tulsa, one of our many repeat customers, Mr. Russell, has asked Sun City Solar to install his fifth installation with our team. Starting last November with a solar power system with battery back up and Solar Hot Water, Mr. Russell has asked Sun City Solar to install another solar power system with battery back up and Solar Hot Water on another home.

Sun City recently designed and installed a solar lab for Oklahoma Gas and Electric so they can test several inverters.

Last week we finished a large Solar Hot Water system for Eureka Springs Transit Authority, a  Solar Power system for the City of Springdale, and a Solar Pool Heater for Eco Apartments.

Of course, we continue to install many residential grid tie systems and enjoy our customer’s smiles when they see their meter spin backwards!

Sunpower, an American company, sells the solar module with the highest efficiency of 19.6%.  Number three Sanyo  HIT technology combines a crystalline silicon cell with an additional amorphous silicon layer. The difference between the leader and the number 10 is 3.4%; Although a small difference, it could be relatively significant. The difference could mean you will use less space on your roof to achieve the same system power or energy yield. It also means you need less Balance Of System components such as mounting hardware. Does it  pay to use the higher efficient modules?

This ranking does not say anything about the module cost per Watt, nor about the most important concern, the cost per produced solar kWh. It could mean that a module of lower efficiency is so much cheaper that the extra cost for other system components (more frame, cables, installation work) can easily be covered by the money saved on the modules. Also, some modules perform better in real life conditions rather than in the standard test condition as mentioned on the their certified datasheet.

All but one of the  the top 10  modules are manufactured in Asia.  The number one, Sunpower, is from the US, but their cells and modules are manufactured in the Philipines.   Several well known brands did not make it into the Top-10 as most are  young and unknown brands.It will be interesting to see what market position these young companies obtain.   The future will tell as the top 10 listings  will continue to change.