Although we don't believe in timing the market or panicking over market movements, we do like to keep an eye on big changes -- just in case they're material to our investing thesis.

What: Shares of Chinese solar manufacturer Yingli Green Energy (NYSE: YGE) have fallen 12% today after Germany said it would change its feed-in tariff system.

So what: The semiannual cut of Germany's solar feed-in tariff is apparently being scrapped for a monthly cut, according to Environment Minister Norbert Roettgen. A flood of solar installed before the most recent cut, at the end of 2011, has the country fearing that falling solar costs will outpace the country's feed-in tariff reductions.

Now what: Since more than twice the goal of 3.5 GW of solar was installed last year, there have been changes rumored for weeks. A cap was thought to be a solution, but apparently more frequent cuts are the solution they've come up with. The strong start to the year for solar stocks isn't lost with this news; it just adds a bit of uncertainty in the German market. Germany has provided most of the world's demand for years, but that is changing quickly, and the country still figures to have a prominent role in solar during 2012.

Interested in more info on Yingli Green Energy? Add it to your watchlist.