High output from OPEC members and producers in the U.S. triggered oil prices to collapse last year. The price of Brent crude, a global benchmark, fell by more than half -- from $115 per barrel in June 2014 to $49 per barrel in January 2015.

Today, Brent sits at $64 and is forecast to remain around that mark into 2016.

The drop in oil prices had no impact on electricity prices. But it was a rough end to the year for publicly traded renewable energy companies in 2014. The Guggenheim Solar ETS, a global index that tracks companies in all segments of the solar energy industry, fell by 30 percent over the latter half of 2014. Large solar companies including SunEdison, SolarCity and SunPower saw their stocks fall between 20 percent and 40 percent over the period.

Solar companies weren’t the only ones affected. The WilderHill Clean Energy Index, which tracks dozens of different clean energy stocks worldwide, fell by 32 percent as oil prices tumbled. This poor stock performance comes as global investments in clean energy projects reach record highs.

So what’s going on here? Falling stock prices usually reflect a weak market. And yet the market fundamentals for technologies like solar, wind, battery storage and energy efficiency continue to improve. Why are investors so confused?

In this episode of Rewired, we untangle the relationship between oil and renewable electricity.