Greenwich, Connecticut-based private equity firm First Reserve has closed a second energy infrastructure fund with $2.5 billion in commitments. The news comes during the best fundraising climate PE groups have seen in years.

The fund, First Reserve Energy Infrastructure Fund II LP, launched eight months ago and oversubscribed its original $2 billion target. Now the firm has more than $4 billion dedicated to investing in energy infrastructure companies.

The new fund will look to invest in pipelines, oil storage and liquid natural gas facilities, contracted power, regulated transmission and contracted energy assets.

In October, the firm bought TNT Crane & Rigging Inc., which provides equipment to the oil and gas industry. Before that, in September, First Reserve acquired Utility Services Associates Inc. First Reserve was named Mergers & Acquisitions M&A Mid-Market Private Equity Firm of the Year for 2012.

There have been several energy-focused private equity fund closes during the past year. In April, Energy Capital Partners closed a $5 billion fund in April, and Intervale Capital, in February, closed a $495 million energy-focused fund.

For more, see “3Qs with … Craig Jarchow, Managing Director, Pine Brook Partners.”