Probably have collector concern: technical ability is, this stuff is not easy to use, and how the performance of the collector, and how the quality. Manufacturers do collectors too. Cost, look at the price of the warranty and other logistical safeguards to protect the human resources. Is to look at their talent pool, can troubleshoot and repair problems in a timely manner. The last one is the advanced nature of the technology, not every two years, this technology countries eliminated halt. You are embarrassing. Kind of new energy things to look at your needs, the need for large-scale installation, it is recommended to consult local contract energy management company, they will raise their own funds, responsible for the design and construction, to ensure the emission reduction efficiency of your unit. Interests and to share with you.