ArcLight Capital Partners has acquired wind farm assets through new portfolio company Leeward Renewable Energy LLC. Leeward is buying equity interests in 18 U.S. wind farms from Infigen Energy. Boston private equity firm ArcLight created Leeward to buy the Infigen assets, and to serve as a platform for further renewable energy acquisitions. "This creates a growth opportunity for our wind business in the U.S.," says Leeward president David Smith. The firm focuses on North American energy infrastructure, and has invested more than $13.1 billion since it was founded in 2001. In September, the firm partnered with energy industry executives to form an oil company, Element Petroleum III LP, which will focus on finding, developing and acquiring oil and gas reserves in the Permian Basin. Latham & Watkins LLP was legal counsel, and Ernst & Young LLP provided tax advice to ArcLight on the deal. UBS Investment Bank provided financial advice, and Skadden Arps Slate Meagher & Flom LLP provided legal advice to Infigen.