According to Dow Jones' World Solar Energy index, solar stocks rallied this month, up 17 percent on indications of rising demand for solar panels, particularly in China, and price stabilization.

Chinese solar companies surged to the highest level in at least five months, led by Yingli Green Energy Holding Co. (YGE) and Trina Solar Ltd. (TSL), after Deutsche Bank AG said major Asian manufacturers are running at full capacity.

Demand is expected to jump in the U.S., Europe and Asia this year. China is poised to double its solar capacity for the second year in a row, 4 to 5 gigawatts. The U.K. Energy Minister, Greg Barker, has stated that it is targeting solar capacity of 22 gigawatts in the nation by 2020, more than 20 times the current level.

Berkshire Hathaway-owned MidAmerican Energy Holdings announced in December it purchased a solar farm in Southern California for $2 billion. Google reported it invested over $450 million last year as well in solar projects. GE announced in 2011 that it's going to build the largest solar plant in America, capable of powering 80,000 homes each year. Billions of dollars more is expected to flood this market over the coming months.

The solar industry is set to grow immensely over the coming years. But tariffs, expected consolidation, and the steady removal of government subsidies make it hard to tell who is and isn't set to profit.

One way to invest in solar today is simply looking to an ETF like the Global Solar Index ETF. This fund is currently comprised of 33 securities. About a third of its holdings are in the U.S, a third is in China and the rest is spread out between Europe and Canada.