First Solar is the first pure-play renewable energy company to join the S&P 500 Index.

"In the US, energy policy is made on the state level," CEO Mike Ahearn said. "Every state has a different approach." In contrast, Ahearn said China has designated a region within the country for renewable energy production and transmission.

A run of poor earnings has damped confidence in once-booming solar companies.

"During the boom, there were significant capacity increases. There were also, by the way, significant announcements of capacity that may or may not have happened..."

First Solar has announced 2Q09 profits that exceeded industry expectations, but its share price fell on news that it would offer rebates in Germany and maintain, rather than raise, its full-year outlook.

A wave of consolidation is sweeping the solar power industry.

First Solar has agreed to acquire the solar-project pipeline of US peer OptiSolar for US$400 million in stock, a deal that will give the solar-panel maker a bigger foothold in the US utility segment.

First Solar's thin-film panels might be piling up in European warehouses, a bad omen for a company envied by many in the solar industry. A ThinkEquity research note on Friday estimated that six key First Solar customers aren't able to install the solar panels quick enough.