There are essentially 3 types of Solar Cell Companies .The tier 1 comprising top 2% do core R&d and are integrated end-to-end.The experience is more than 10 years. The second line about 8% do not indulge in R&d but use partial robotics etc for manufacturing. They have experience of 2-5 years .The rest 90% are assemblers and use human production lines for manual soldering.The projects however have a good capital output ratio .

There are essentially 3 types of Solar Cell Companies .The tier 1 comprising top 2% do core R&d and are integrated end-to-end.The experience is more than 10 years. The second line about 8% do not indulge in R&d but use partial robotics etc for manufacturing. They have experience of 2-5 years .The rest 90% are assemblers and use human production lines for manual soldering.The projects however have a good capital output ratio . 

Here's a good link to review the top Solar Companies 

http://www.forbes.com/sites/uciliawang/2014/12/03/guess-who-are-the-top-10-solar-panel-makers-in-the-world/#2e34708f2812

Solar equipment makers are gearing up to expand production again after many of them had to idle production lines or close factories. So who are the top 10 solar panel makers these days?

IHS released its ranking today that put Trina Solar as the top shipper of solar panels in 2014, followed by Yingli Green Energy. Both companies are based in China, which has dominated the solar equipment manufacturing business for many years now.

In fact, six of the 10 manufacturers ranked by IHS are Chinese (if you count Canadian Solar CSIQ -4.07% which, though based in Canada, has its manufacturing base in China). The two biggest American solar panel makers, First Solar FSLR -1.92% and SunPower SPWR -4.19%, also made the list.

The ranking reflected shipment figures, including estimates for the fourth quarter of this year. IHS noted that it didn’t count panels produced by these companies that are used internally for building solar power projects, from rooftop installations to big solar farms.

Here is the IHS ranking:

1. Trina Solar

2. Yingli Green Energy

3. Canadian Solar