Trends in Photovoltaic Roofing

installing solar panels
While solar panels have reigned supreme for decades, they are not the only way to add solar power options to a building. Solar shingles are coming of age. (Image credit: elenathewise / 123RF Stock Photo)

By Eric Kirberg

Current market trends show the roofing industry is staying up-to-date with green technology. One such technology is photovoltaic roofing. It is as appealing to home owners as it is to larger commercial businesses for its environmental and economic benefits.

When photovoltaic (PV) roofing debuted on the commercial market in 2005, adoption was slow as the “solar shingles” – aka photovoltaic cells – were much more costly than traditional solar panels. Almost a decade later, things have changed and solar shingles are more affordable and in much wider use and demand.

1. Materials – Updates and new market offerings  

Solar shingles are still considered a fringe market and pricing remains largely uncompetitive. But they are being explored by more companies who have hopes of becoming low cost leaders. The good news is the attachment of the standard panels has improved dramatically and has less of an impact on roofing systems and existing warranties.

In 2014, some customers may want PV shingles for the aesthetics offered, as they are often more appealing as a roofing option than other solar materials. Here are some of the best products on offer:

Certainteed is considered a leader in this market due the levels of service guarantees it offers.

Arizona-based Global Solar Energy’s main focus is its flexible thin-film CIGS embedded solar shingles developed with Dow Chemical Company. PowerFLEX delivers very high efficiency, and due to its lightweight properties can be applied directly to multiple surfaces without penetrations. It also doesn’t create any additional wind load.

Dow Chemical Co.’s Powerhouse Solar Shingles have been designed with the homeowner in mind. They are visually appealing and come backed by a serious amount of data outlining cost benefits and service.

Germany-based Solarwatt has launched its new Solarwatt Easy-In roof solar tile system, which was specifically designed for replacing conventional roofing tiles on pitched roofs.

Florida-based EternaTile is marketing a polyurethane, foam molded, interlocking solar tile that is geared to blend with a variety of roofing styles. What makes its tiles appealing is that they were developed in four styles of tiles to replace existing roofs with flat asphalt, slate, cedar shake or clay roll tiles. So the consumer has some aesthetic choice here.

2. Environmental Considerations

A great incentive to go solar is, of course, that it’s a clean, renewable and an accessible source of power for consumers and businesses alike. Residents of solar powered buildings benefit from harnessing the sun’s thermal energy to reduce their reliance on the electrical grid, carbon emissions, and their electric bills. In some areas, solar users are even able to sell back unused electricity to the power grid.

And the pressure to comply is on. In States like California, the Energy Commission requires all new residential and commercial buildings to have solar ready roofs as of January 1, 2014.

Obviously, California is known for it’s sunshine. But populations in the Midwest and East coast might be surprised to learn that it’s not only a location’s “sun hours” that contribute to solar power outputs.

In St. Louis, Missouri, for example, the average daily sun hours is just over 4, which is comparable to places like Miami. But the sun’s rays are an interesting topic to consider when you factor in more than warmth. In colder climates, we use a lot of electricity in winter months – when there are no leaves on trees. So an average house or business might receive more sunny days in January when it’s using more energy than in the summer months. The reason is this: many well planned properties are arranged so they have shade trees on the north side for protection in the summer – so less solar energy capacity – but also a reduction in energy consumption due to the shading. You really have to consider a whole year to understand the reality of energy usage and the advantages of solar power.

3. Best Construction Practices, Maintenance and Monitoring

Starting off, make sure you have a good engineer who knows how to evaluate the load your building can absorb. Panels and shingles will add a lot of weight to your roof and the structure must be analyzed. If you are building or buying a building, make sure you source the original planning documents, as well as any additions to the structure. Seek out the “structural” drawings along with the “architectural” and verify the actual structure was built according to those plans.

Check the local ordinances to make sure you have the green light to add a PV system. And look to the utility service provider to show historical energy usage stats, and to see if they offer any incentives for going solar. A state by state guide is also provided by the Department of Energy: http://dsireusa.org/.

Once you’re set up, look for “low hanging fruit” for energy conservation. Things like old appliances, retro-fitting lights with LED, and heat pumps all contribute to the solar equation.

Monitoring your energy usage has also been made faster and easier. The Helios system is all new and you can now see not only generation statistics, but also a variety of data points that tell how you “helped the world” by offsetting barrels of oil, or the equivalent number of trees you may have saved.

4. Benefits (Economic + Environmental) 

A report from Scientific America claims “that a typical residential cluster of 350 solar shingles on a roof could slash one’s household electric bill by 40-60 percent.” These installations can be costly on the front end but after tax incentives and long term savings on energy bills, the investment pays off quickly.

And according to Swanson’s Law, costs will only continue to decline. The solar industry is growing at great speeds as the world searches for better and more sustainable power sources. According to Swanson’s law, the cost of the photovoltaic cells needed to generate solar power will fall by 20% with each doubling of global manufacturing capacity. And there are many more technological developments coming out of the lab every day.

Solar roofing shingles and tiles offer benefits beyond the energy bill, too. They are far less bulky than their panel counterparts and smaller pieces and parts can often mean that replacing damaged workings is much easier and cheaper.

The benefits to going solar only increase over time as the industry develops technology and as consumers grow to understand the fiscal and global advantages. Keep up with the trends and your business will keep making the sun shine on the bottom line.

About the Author

Eric Kirberg is the President of Kirberg Company in St. Louis, Missouri, leaders in roofing since 1920. He serves on the Board of Directors of the National Roofing Contractors Association (NRCA), the Associated Roofing Contractors of St. Louis, and the Associated General Contractors (AGC). http://kirberg.com/

3 thoughts on “Trends in Photovoltaic Roofing”

What Do YOU Think?