The firm, based in San Francisco and New York, had originally planned a target of $60 million for the oversubscribed Clean Technology Fund II.

But it expanded the fund after attracting investments from a dozen large companies as well as family foundations, corporate strategic investors and financial institutions.

The fund is the latest in a series of large fund closes in the cleantech industry. Climate Change Capital closed a €200-million fund on Wednesday, and Technology Partners closed a $300-million fund in late July for cleantech and biotech.

The glut of funding has left some industry insiders wondering whether there are enough good investments available to justify the amount of capital raised. In other words, is there a venture-capital bubble on the horizon?

A recent study by New Energy Finance found that VCs were able to invest just 73 percent of the funds they had raised and had not been able to spend $2 billion of the money they had available.

Despite the amount of available funding, Expansion claims it is still finding many investment opportunities. "We are seeing the quality and quantity of deal flow has increased markedly," said co-founder Diana Propper de Callejon. "We're looking at 50 to 75 new ventures each month and there has been no slowdown."

However, she noted the firm only chooses to do three to four new investments each year and invests more money in those deals. "We haven't seen, with the increase of capital flowing into the sector, any slowdown in deal flow," she said.

Expansion focuses on "expansion-stage" investments in U.S. and Canadian companies with $2 million to $3 million in revenue and the prospect of a return in three to five years.

The company plans to spend the money backing innovations across the cleantech industry, including in energy, advanced materials, waste and waste water, manufacturing and transportation.