Here's a press release from LBNL:

New Report Sheds Light on Intricacies of Wind Project Finance

September 26, 2007 -- Berkeley, California -- A number of different financing structures have been developed in recent years to help fund the rapid expansion of the wind power sector in the United States, according to a report released today by Lawrence Berkeley National Lab.
These structures feature varying combinations of equity capital from project developers and third-party tax-oriented investors, and in some cases commercial debt. While their origins stem from variations in the financial capacity and business objectives of wind project developers, as well as the risk tolerances and objectives of equity and debt providers, each structure is, at its core, designed to manage project risk and allocate Federal tax incentives to those entities that can use them most efficiently.

The new Berkeley Lab report aims to provide a better understanding of these complex structures, in a number of ways. First, it begins with a contextual discussion of recent trends in the financing of utility-scale wind projects in the United States. "Over time, different financing structures have evolved to meet specific developer and investor needs,"
notes report co-author John Harper of Birch Tree Capital, LLC. "This evolution will continue as long as the sector continues to attract new investment capital."

Next, the report describes in both visual and textual detail the seven principal financing structures through which most utility-scale wind projects (excluding utility-owned projects) have been financed from 1999 to the present. These structures include simple balance-sheet finance, several varieties of all-equity partnership "flip" structures, and a pair of leveraged structures.

Finally, using a simplified pro forma financial model and market-based assumptions about the cost of equity and debt capital under each structure, the report analyzes the impact of these seven structures on the levelized cost of energy from a generic wind project. "The modeling finds that, under our assumptions, choice of financing structure can have a fairly significant impact on the cost of energy from a wind project," notes co-author Matt Karcher of Deacon Harbor Financial, L.P.
"This disparity suggests that the wind finance market is not entirely efficient, and that both perceptions and the pricing of risk differ among wind project investors."

The results of the modeling exercise are also somewhat out of tune with the market in terms of the relative popularity of the different structures. For example, although the model finds that the two leveraged structures yield the lowest cost of wind energy, in reality these structures have not been widely utilized in recent years, for a number of reasons both in favor of other structures (simplicity, standardization, speed) and against using debt (cost, complexity, loss of control, little-improved return). "This divergence from market reality highlights the fact that developers consider a variety of factors - other than which structure yields the most-competitive cost of energy - when choosing financing structures for their projects,"
explains co-author Mark Bolinger of Lawrence Berkeley National Lab.
"These more-qualitative considerations are difficult to capture in a financial model."

For this reason, the report also includes a discussion of the array of factors that developers take into consideration when selecting a financing structure.

The report, titled "Wind Project Financing Structures: A Review & Comparative Analysis", can be downloaded at:
http://eetd.lbl.gov/ea/emp/reports/63434.pdf For more information on
the report, contact Mark Bolinger (MABolinger@lbl.gov, 603-795-4937) or Matt Karcher (karcher@deaconharbor.com, 972-739-0242).