All solar forecasts ... are probably wrong

But they are not without value. And despite their differences, most point upwards.

"[Solar market] forecasts tend to be wildly different from source to source and from quarter to quarter," says Patrick Barnds, market segment director, Energy, Guardian Industries. "After studying it for a few years now, the one thing that we can say with a high degree of certainty is that all the forecasts are probably wrong. There are just too many factors that have the potential to impact the growth rates over time. These include technical developments, government policy and incentives, industry capacity, the cost of power generation from existing sources (i.e. oil, gas, coal, nuclear, hydro-electric), etc."

That doesn't mean the glass industry shouldn't prepare for growth in the solar market, however. We still need to develop a forecast, Barnds says. "In fact, it's critical for our [Guardian] plant and asset planning purposes if we are going to invest ahead of demand and market needs."

Guardian, for example, expects the North American photovoltaic market to grow at a compound annual growth rate of between 23-31 percent from 2010 to 2015, according to Barnds. "From 2015 to 2020, we expect the CAGR to be closer to 33-35 percent. There will be some bumps along the way, and we don't expect the growth curve to be smooth. However, we believe that the averages are reasonable in any three to five-year period."

At PPG, Wayne Boor, manager, solar technology transfer, for the company's performance glazings business, said solar glazings could account for 10 to 20 percent of flat glass sales, if not more, by 2015.

And at GlassBuild America, Richard Voreis, CEO, Consulting Collaborative, reported PV worldwide installations could double by year-end 2012.

These are big numbers. As to how accurate they are, only time will tell. As Barnds points out, there are a lot of factors in play. Here in Colorado—where solar panels are becoming a more common sight—it's easy to see a future in which residential and commercial buildings are powered by the sun. But what are you seeing in your market? Are these forecasts in line with your expectations? 

The author is editor of Glass Magazine. Write her at jchase@glass.org.