(Image source: investorplace.com) Shares of the alternative fuel cell energy company Plug Power Inc (NASDAQ:PLUG) are sinking in the early session on news that the company will participate in a secondary stock offering to raise capital. The proceeds from the offering will be used on working capital and general corporate purposes. The stock offering will be in the form of an underwritten public offering. Plug Power is seeking to sell an additional 15 million shares. The pricing of the shares are not available at the moment.