Montreal, Canada

Is solar energy a fad? Is the bull market in alternative energy over? George Soros, Warren Buffet and T. Boone Pickens certainly don't think so as all three currently maintain stakes in solar energy. But could these investors – probably the greatest collection of investment minds of the 20th century -- be wrong about solar power?

Prior to the collapse of global financial markets in late 2008, solar stocks ranked among the hottest investments. Initial public offerings (IPOs) in New York were dominated by solar companies in 2007. And then the party ended.

Since hitting an all-time high in the summer of 2008 a benchmark measuring solar stocks' performance has tanked a cumulative 72% heading into this morning's trading. By every measure, that's a first-class bear market.

Solar companies' profitability is falling because of competition from China and cuts to state support in Germany and Spain; approximately 72% of power-producing photovoltaic panels were installed in 2008 in these two important markets. But over the last 18 months the Germans and the Spanish have markedly cut state subsidies.

The failure of the Copenhagen Summit in December didn't help alternative energy. The United Nations (UN) failed to extend limits on carbon dioxide emissions; UN-led talks failed to extend the 1997 Kyoto treaty's carbon limits beyond 2012 for 37 regulated countries, undermining confidence at companies that they'll need to own carbon-emission permits in future decades.

One of the leading solar companies in the world, First Solar of Phoenix, Arizona, has seen its stock price crash since peaking almost two years ago. First Solar – a benchmark holding in every alternative energy index – has plunged 63% since May 2008.

Another source of alternative energy – wind power – has also seen its sails curl over the last 18 months.

Wind-based energy is viewed as more economical than solar power but many towns across the United States have petitioned against wind farms because they occupy too much land.

Vestas Wind Systems A/S of Denmark, a world leader, has seen its stock price crash 61% since peaking in August 2008.

Amid skyrocketing oil prices over the last ten years many investors and analysts alike believed alternative energy would command a greater share of government subsidies. And initially, that's how it played out with the Germans and other European countries deeply cutting the cost to finance solar and wind power. But despite the bull market in crude oil and its resultant high price, the shine has come off alternative energy since 2008; not even a big boost from China vis-à-vis subsidies starting in 2009 is helping the sector.

At some point the leading solar and wind companies will be worth a hard look. Peak Oil has arrived and that means over the longer term we're going to have to supplement expensive sources of energy like crude oil. Also, clean energy isn't the rage it was a few years ago prior to the credit crisis. The shine is off alternative energy.

Solar and wind are down but not out. All bear markets draw to an end.