These materials were meant to revolutionize the solar industry. Why hasn’t it happened?

But stability is still a challenge.

In a study published in Science in April, researchers discovered a new way to make solar cells with more efficiency and lifetime. The cells were in the lab for 1,500 hours.

The problem is getting the results into the real world. Silicon has set a high bar, with many manufacturers guaranteeing that their panels will maintain 80% of their performance for 30 or even 40 years.

After a few months, researchers found that perovskite-based cells performed at over 90% of their initial levels. It isn't going to cut it if you lose 10% of a cell's performance in that time span.

The tests have all been done using tiny cells. Making the larger cells that can be strung together into full-size solar panels can lead to setbacks in efficiency and lifetime.

These challenges mean the day when perovskites take over solar markets isn't as close to hand as some researchers make it out to be.

Adding stabilizers and materials that protect them from the elements could eventually enable these solar cells to last a couple of decades in normal operating conditions. He thinks it will be a decade or more before they make commercial progress.

There is a need for different types of solar cells despite the challenges. Jenny Chase is the head of solar analysis at New Energy Finance.

In tandem cells, where a perovskite layer is stacked on top of a Silicon cell, they wouldn't have to compete directly with Silicon. The two materials could complement each other.

None of that is likely to happen unless someone can make perovskite solar cells that are far more stable. But certainly, researchers are not giving up on the promise. As Green puts it, “There’s still a chance that someone will really nail it.”