How Much Revenue is a Soiled PV Array Losing?


How much revenue is a soiled PV array losing, and at what point does it make sense to wash the array?

Owners, developers, bankers and O&M providers all want to know when it makes sense to clean a PV array to recapture revenue that it would otherwise lose due to soiled modules. On the one hand, an overly soiled array represents a loss of money. On the other, a premature cleaning represents a waste of money. While you must consider many variables to reach a definitive washing decision, the economics of module washing are not complex: If having a clean array saves more money than it costs to wash the array, then washing it probably makes sense.

This article shares some of our analyses and observations on array soiling drawn from many years of operational experience. We have had successes and failures, which have led to interesting discoveries and some dead ends. We have based most of our research on utility-scale PV plants with high dc-to-ac ratios in sunny, arid locations. These plants are subject to a unique set of circumstances: They spend a lot of time at full power, have relatively steady soiling rates and are rarely exposed to enough rain to significantly clean the modules.

Click here to read the full article at Solar Pro Magazine.



Step One
A chemical fills in the microscopic ridges.

Step Two
This bonding substrate is then capped and sealed, enhancing surface smoothness.


  • Soiling inhibitor
  • Scratch resistance
  • Impact resistance
  • Resistance to leaching of calcium and sodium (etching caused by hard water)
  • At least 20% more brilliance - shine in glossy surfaces
  • Environmentally friendly
  • Improves cleaning with all systems - Manual, Automated, Mobile, Rainfall
  • Increased PV efficiency


  • 15 year limited warranty for commercial solar panel application
  • Residential (limited lifetime) warranty

Contact us to get started and stop losing money to soiling.

Kyle Domer
The Right Amount of Flashing to Use for Waterproof Solar Installs

Generations of builders have installed asphalt shingle roofing on homes with chimneys, side walls and other structures that introduce a vertical surface above the roof line. To preserve the integrity of the roof and prevent water leaks, roofers tend to install flashing next to these structures with at least a 4-in. overlap on the horizontal plane. As a manufacturer of roofing and solar photovoltaic systems, CertainTeed recommends that when installers affix modules to the roof, they treat the anchoring system like any other vertical rooftop structure and provide at least a 4-in. horizontal overlap.

Why 4 inches? The specification comes from the latest edition of the National Roofing Contractors Association Roofing Manual: Steep-slope Roof Systems, published in 2013. (NRCA will release a new version of the manual next year.) Though there isn’t necessarily empirical data showing the lateral distance that water can travel on a sloped roof, NRCA members have 45 years of accumulated knowledge and experience since the first publication of the manual. They know weatherproofing for shingle roof systems about as well as anyone.

Click here to read the full article at Solar Power World.


Kyle Domer
OSHA Issues Final Rules On Fall Hazards

Falls are a major danger in the glass, glazing and construction industries, and the U.S. Department of Labor’s Occupational Safety and Health Administration (OSHA) has put forth new efforts to reduce them.

Late last week, OSHA issued a final rule updating its general industry “Walking-Working Surfaces” standards specific to slip, trip and fall hazards. The rule also includes a new section under the general industry “Personal Protective Equipment” standards that establishes employer requirements for using personal fall protection systems.

“The final rule will increase workplace protection from those hazards, especially fall hazards, which are a leading cause of worker deaths and injuries,” David Michaels, OSHA assistant secretary of labor, said in a statement. “OSHA believes advances in technology and greater flexibility will reduce worker deaths and injuries from falls.”

Click here to read the rest of the article at US Glass magazine.

Kyle Domer
NEC 2017 Solar PV Labeling - What You Need to Know

In September, the new NEC 2017 was published and released, giving the industry a glimpse into many new changes and additions in Article 690. As PV systems grow and evolve, the required labeling must change with it to ensure safe and informative installations. Like any evolving process, input from many sources is required to gain a better understanding of what works and what does not, so the process of change can proceed in a way that makes sense for everyday use in real world applications.

Code making panel 4 of the NEC 2017 reviewed hundreds of public inputs. Each suggestion was weighed, reviewed and compared to other similar requests and then voted up or down based on all relevant data and substantiations. Many suggestions were for improved labeling. In the end, the panel addressed a number of inputs; some of the changes are outlined in this article... Read the rest of the article at Solar Power World.

HellermannTyton pre-printed Solar Installation labels are made with durable UV stable materials and adhesives that are designed to stick to both baked enamel and powder coat surfaces. Where applicable, labels are made using reflective materials for first responder safety.

  • Features and Benefits
  • Made with UV stable inks and materials for durability and weather resistance
  • Supplied with aggresive adhesive to ensure long life
  • Meets NEC & IFC standards for printed text, character height, color and outdoor UV stability to pass inspections
  • Pre-printed labels offer significant time and cost savings over high priced engraved and lead time purchased markers
  • Reflective properties to meet applicable NEC code requirements for reflective identification.

*Now available for only $83.50 per 50-pack at

Kyle Domer
Preventing Fires in Solar Installations with Cable Care

Cables and connectors are vital parts of a PV array. The selection of cables is an important procedure, but how the cables are managed thereafter also influences how the entire PV system will function. Poor cable management can ultimately lead to problems.

Cables were the culprits in two fires that happened in PV arrays, one in Bakersfield, California in 2008 and one in Mount Holly, North Carolina in 2011. Bill Brooks from Brooks Solar prepared a paper for the Solar America Board for Codes and Standards explaining the causes of the fires. In both cases, cable insulation damage was identified as the root cause. A significant amount of work goes into the complex process of designing and planning a PV power plant, whether on the rooftop of a building or ground-mounted on the field. This then translates into an efficient, working PV power plant in situ. With the rapid uptake of PV, it is also common to see homeowners who design and implement their own small PV rooftop projects. With so much already invested, it would be vexing if careless cable management after installation lead to losses. And dangling, untidy cables are simply unaesthetic.

Read the full story at PV Magazine


HellermannTyton stainless steel ties are designed with a ball bearing locking mechanism to assure high tensile strength and easy insertion when securing hoses, cables, pipes and more.

Features and Benefits

  • 304 grade stainless steel offers excellent resistance to corrosion, weather, chemical and fire resistance.
  • Ball bearing locking mechanism assures high tensile strength and easy insertion.

*Now available for only $51.15 per 100-pack at

Kyle Domer
2017 Construction Forecast - What Should You Expect?

Healthy Advances Forecast Through 2017

Mid-year update projects somewhat slower gains in construction activity for both this year and next.

The national economy seems to be on a slower growth path so far in 2016, in part due to the growing list of national and international vulnerabilities that continue to appear. This slower growth in the broader economy is beginning to put downward pressure on the construction industry. After a solid performance last year, where most commercial and industrial construction sectors grew by 20 percent or more, 2016 was viewed as a year where activity was expected to moderate.

The year has gotten off to a solid start, but the American Institute of Architects’ Consensus Construction Forecast Panel expects growth to begin to moderate as the year progresses. Overall building construction spending is expected to grow around 6 percent this year, and stay in that range for 2017. Commercial construction sectors are projected to be the strongest performers this year, with the institutional categories moving back a bit from their pace of last year. Next year, the commercial sectors are expected to see slower yet still healthy levels of growth, while most institutional sectors will see a somewhat accelerated pace of activity.

Read the entire report on the AIA website.

Kyle Domer
Solar Power International Special Offer from 3M

In celebration of our 8th consecutive year exhibiting at Solar Power International, Mudge Fasteners is pleased to present a special offer on 3M™ Extreme Sealing Tape.

Anyone who places an order for two cases of 3M™ Extreme Sealing Tape during SPI 2016 will receive a FREE 3M™ Application Toolkit.

Visit the 3M page to learn more about 3M Extreme Sealing Tape. If you're at SPI, stop by Booth #1172 or email to learn more!

Everything you need for applying tape successfully.

Everything you need for applying tape successfully.

Kyle Domer
Top 5 Reasons to Visit Us at Solar Power International 2016

We're the Expert in Solar Fasteners.
Have a question about what fastener would be best in your application? Need info on custom fasteners, job site direct delivery, material kitting and more? We're here to help, and no one knows solar fasteners like we do.


Test out some new products.
Like the 3M™ Extreme Sealing Tape, a highly conformable acrylic tape specifically designed to get results under exposure to direct sunlight.


Find resources for NEC 2014 requirements.
With California and other states moving to NEC 2014, products available from HellermannTyton can help you meet ANSI and NEC 2014 labeling requirements.


Save some money.
If you're installing solar panels, chances are pretty good that you're using some stainless steel lag bolts, washers, hex nuts & more. With 40+ years experience sourcing fasteners at the most competitive rates, we'll help you leave Vegas with some money-saving ideas, even if you lose your chips at the tables.


Solve a problem.
We all have them, don't we? Whether it's a price problem, engineering difficulty or logistics challenges, if it relates to solar fasteners, we'll help you solve it.

Kyle Domer
Harvesting Solar Power from Space?

In a new report, the viability of sending solar panels into space to collect a vast quantity of uninterrupted energy has been re-investigated. Although the idea has been around since the 1970’s, space solar power has always been viewed as prohibitively expensive. In the current energy climate down here on Earth with spiraling oil prices and a massive push toward green energy sources, sending massive solar arrays into geosynchronous orbit doesn’t seem like such a strange (or expensive) idea. There are many obstacles in the way of this plan, but the international community is becoming more interested, and whoever is first to set up an orbital array will have a flexible and unlimited energy resource.

It sounds like the perfect plan: build a vast array of solar panels in space. This avoids many of the practical problems we have when building them on Earth such as land availability, poor light conditions and night time, but sending a sunlight farm into space will be expensive to set up. In the 1970’s a plan was drawn up by NASA for the possibility of orbital sunlight “harvesting”, but it was deemed too expensive with a hefty price tag of at least $1 trillion.

Click here to read the rest of the article.

Kyle Domer
Solar Activity and Its Effects on the Earth

All aspects of life on this planet are affected by solar activity. The sun is constantly active and changing, and this solar variation has the ability to alter things on earth in a variety of ways. Solar variation is defined as disturbances on the sun’s surface, can include a number of things including solar storms and flares. By understanding solar activity, you can also maximize solar energy production by fine tuning your solar panels.

Understanding Solar Activity for Solar Energy Purposes
Solar variation has a great effect on solar energy generating systems. Large solar flares send out huge amounts of photons, which are the actual particles which stimulate the solar cells to generate electricity. This means that solar panels will generate more electricity in periods following large solar storms because of the increased amount of photons.

Click here to read the rest of the article.

Kyle Domer
The Importance of PV Array Wire Management


PV systems are expected to have a 25-year lifespan, and array wire management solutions should match this expectancy. However, designers and installers face persistent challenges to managing free-air conductors within the PV array.

Implementing a safe, reliable and Code-compliant wire management system for exposed PV conductors is not an easy task. PV module leads can be too long or sometimes too short, requiring site-specific solutions for supporting and interconnecting the cables. Equipment grounding, PV source-circuit and inverter-output conductors from microinverters and ac modules must also be managed to ensure protection from potential damage. Within the PV array, these various conductors are often secured to module frames, support rails and other racking system components. While securing array wiring seems like it should be a straightforward exercise, the reality is that integrators continue to face numerous challenges.

Click here to read the full article from Solar Pro Magazine.

Kyle Domer
Power Swap - How to Substitute Powers for Hilti

Powers Fasteners can provide a competitive advantage through price, availability and technology. 

Powers Fasteners has been a worldwide pioneer in the fastening industry since 1921, and today is the leading supplier of concrete and masonry anchors and fastening systems in North America. Powers has extensive engineering and manufacturing expertise in several product groups, including mechanical anchors, adhesive anchoring systems and powered forced-entry systems such as powder-actuated and gas fastening systems. 

Hilti products are often specified but can be easily substituted by an equivalent Powers product. Use the chart below to help you swap across a Hilti spec.

Kyle Domer
How to Select a Drill Point Size

Tek® screws, are also known as self drilling screws, but are not to be confused with self-tapping or sheet metal screws which do not pre-drill. A self-drilling screw has a very small carving at the end of its tip called a drill bit. These screws drill their own hole and then tap threads to combine two or more pieces of material together without pre-drilling. This is done with nothing more than a standard power drill motor. Depending on the thickness of the material you are drilling into, you have several drill points available, the longest being a Tek 5.

Click here to download a printable PDF version of the guide to use for reference when making decisions about which drill point size is right for which fasteners for your application.

If you have any questions about self drilling screws from Mudge Fasteners, please call us at (800) 634-0406.

Kyle Domer
Are All Zinc Coatings Created Equal?

Zinc is naturally found in elements such as air, water, and soil as well as in plants, animals, and humans. It is the 27th most abundant element in the Earth’s crust and is infinitely recyclable without the loss of its properties, making it a true renewable resource.

Zinc’s ability to protect iron and steel products from corrosion has been known for centuries as the material has been used in construction since the second century. More than 13 million tons of zinc is produced annually worldwide—70 percent of which is from mined ores and the remaining is from recycled sources. More than half of this annual production is used in zinc coatings to protect steel from corrosion.

Click here to read the rest of the article at Construction Specifier.


Characteristics of Platings, Coatings & Finishes Chart

While we're on the topic of platings (like zinc), we'd like to offer you our downloadable Characteristics of Platings, Coatings & Finishes chart.

Click the image to the right to download a printable PDF version of the chart to use for reference when making decisions about which plating, coating or finish you should use on fasteners for your application.

Kyle Domer
Fall Safety Training from FallTech

Ensuring that your employees are protected when working at heights is the business of FallTech Services Group. Fall Protection equipment will only protect a worker if they know when, where and how it is to be used. FallTech Services Group specializes in helping businesses identify fall safety hazards, write fall protection plans, engineer anchorage solutions and train employees in fall safety.

Offering a well equipped training facility with certified fall safety trainers, FSG provides a full range of in depth courses in fall protection. A balance of hands on training and classroom instruction provides the optimal fall protection training experience and course offerings ranging from entry level fall safety hazard awareness to the supervisory level competent person fall safety training. Additionally, custom fall safety courses and site specific fall protection training are available through our alternative curriculum program.

Regularly scheduled fall safety courses are available to attendees both at the FallTech Training Center in Compton, CA, a variety of regional venues throughout the United States, and at client facilities throughout North America.

FallTech Services Available

  • Fall Safety Hazard Analysis
  • Site Survey
  • Written Job Fall Safety Analysis
  • Building Plan Review
  • Written Fall Protection Plans
  • Jurisdictional Code Review
  • Fall Safety Structural Review
  • CAD Design
  • Customized Fall Protection Equipment Development
  • Fall Safety Anchor Point Design

Unlike most of their competitors, all FallTech products are proudly MADE IN USA.

Kyle Domer
Which Elco Fastener is Right for Your Application?

Elco Construction recently released their new product selection guide, which clarifies what fasteners from the Flex Technology family are best for which applications.

Click here to download the selection guide, or see below for which substrate materials work best for Elco Flex Technology products. 

Steel to


Steel / Aluminum Combinations

Aluminum to


Treated Wood to
Steel or Aluminum


Kyle Domer