Recently, the Citizen Times in Asheville, North Carolina, carried an encouraging article about the rapid spread of solar power among Western North Carolina's many beer brewers. Six of the region's local brewers have gone solar, installing rooftop solar arrays to power part or all of their operations. Those companies include Highland Brewing, Appalachian Mountain Brewery, Innovation Brewing, French Broad, Sierra Nevada and New Belgium (the last two have just recently opened East Coast operations in North Carolina).

I was, of course, already aware there were breweries running on solar, including the gigantic MillerCoors operation. In fact, being the selfless treehugger that I am, drinking beer is one of my favorite ways to support renewable energy. What I hadn't realized was how widespread a practice this is.

I started to wonder why.

solar panels photoSolar panels provide all of the electricity for Highland Brewing's operations in North Carolina, and they're by no means the only local brewer going solar. (Photo: WLOS News)

One potential reason, I suspect, is that beer brewing attracts science-minded types, and science-minded types tend to both understand the grave threat posed by climate change and get excited about new innovations that can improve our lives. But there may be another influence going on, and it's that solar power appears to be contagious.

As I've written previously over at TreeHugger, I've seen firsthand examples of this contagion in the U.K. When I moved from England to the United States in 2006, solar panels were an extremely rare sight on British rooftops. Somewhere around the beginning of this decade, however, the government introduced generous feed-in tariffs to support solar uptake, and the panels started proliferating. My parents installed an array. Then my brother. Then four or five of my parents' neighbors also got on the solar-powered bandwagon. It turns out there's even research to back up my questionable anecdotal evidence, with NYU/Yale researchers showing a direct correlation between the installation of solar panels in a neighborhood or street and the installation of more solar.

In fact, under the banner of "Solarize Salem," there are grassroots movements (now supported by the government) across the United States aiming to kickstart such contagions — working with group purchasing among neighbors to jumpstart a solar economy with a critical mass of installations that lead to more neighbors getting on board.

What I hadn't considered was that this contagion doesn't require a geographical focus to work. It can spread by industry, or from city to city; as private and public entities see their peers going solar, they start to understand the benefits and feel the pressure of keeping up with competitors. The phenomenon may explain, for example, why tech giants like Apple and Google are increasingly competing against each other to see who can pour the most money into clean tech the fastest. Similarly, as a growing number of cities move toward clean energy economies, I fully expect us to reach a point where it becomes hard not to get on board.

So it looks like solar power may indeed be contagious — and this is a contagion I would love to see spread.