Earlier this week, I suggested that we were entering a spring full of glorious greentech IPOs.

I was wrong.

BrightSource, an IPO aspirant, just pulled its registration statement with the SEC, almost a year after registering, claiming that "the continued market and economic volatility are not optimal conditions for an IPO."

It's less than happy news for BrightSource, its VC funders such as VantagePoint, DBL Ventures, DFJ, Alstom, et al., and the cleantech community as a whole. Google and NRG Energy were investors in the project.

Rumors were rampant in the days before withdrawing the IPO that the company was having trouble making its book as it sought to raise up to $182.5 million in its initial public offering. 

BrightSource is in the massive-scale concentrating solar power (CSP) business, a technology which addresses a common refrain about the limitations of photovoltaic solar power -- namely, that the technology only works when the sun is shining. CSP boasts the ability to store thermal energy long after the sun goes down. This ability improves CSP's capacity factor and dispatchability, and has the potential to improve CSP's levelized cost of energy (LCOE). For the year ending December 2011, BrightSource generated $159.10 million in revenues, and lost $110 million.

BrightSource has signed 13 power purchase agreements (PPAs) to deliver approximately 2.4 gigawatts of installed capacity to two of the largest electric utilities in the U.S.: PG&E and Southern California Edison.

But that wasn't enough to excite institutional investors who seem to have delivered their verdict on CSP, or at least BrightSource's version of CSP.

CSP has massive scale at potentially low cost, but CSP faces environmental risks, as well as permitting and financing risk. BrightSource was the recipient of a massive $1.6 billion DOE loan (Fox News will love this information). And experts I spoke with saw institutional investors as flinchy about subsidized solar in an environment flooded with cheap natural gas.

The company issued a statement:

“While we received significant interest from potential investors, the continued market and economic volatility are not optimal conditions for an IPO,” said John Woolard, President and CEO of BrightSource Energy. “As a company, we’ve consistently made decisions in the best interest of our shareholders, employees and customers, and we will continue to do so. Fortunately, we’re in a strong financial position and have the support of world-class investors and partners.”

Woolard added, “With our pipeline of U.S. contracts and our flagship Ivanpah project, we have established a leading position in the domestic solar thermal energy space,” added Woolard. “We will continue to execute on our business plan to grow domestically and expand internationally to meet the growing demand for our technology.”

It remains discouraging news for cleantech startups and investors, but the market usually has its own rationale. The cleantech market is still awaiting the IPO that disrupts the current tepid trend. And in the flight to quality -- the market has deemed BrightSource inadequate.