After years of underperforming the broader markets, alternative energy related exchange traded funds are making a turnaround.

The Guggenheim Solar ETF (NYSEArca: TAN) is up 8.3% over the past week and 55.5% higher year-to-date. [Solar ETF Rallies Over 50% in a Month]

The fledgling solar energy industry has gone through some growth pains as it witnessed high volatility on prospects of high supply and low demand. However, growing global is improving and companies are finding better financing, reports Claudia Assis for MarketWatch.

Recently Goldman Sachs announced a financial deal with SolarCity (NasdaqGS: SCTY) for $500 million, and the investment manager plans to invest $10 billion into alternative energy over the next decade, according to the Motley Fool.

However, Mahesh Sanganeria, an analyst with RBC Capital, warns that a correction in the next few months is “a good possibility.”

“The question is what would trigger it?” Sanganeria asked in the MarketWatch article.

The United States Natural Gas Fund (NYSEArca: UNG) gained 7.7% over the past week and is up 21.4% year-to0date.