For years, the knock on fuel cell maker Bloom Energy Corp. has been that its boxes cost more to make than they cost to buy. Not exactly the sort of dynamic that would help Bloom make it up on volume.

But perhaps things are finally about to change, after 10 years and nearly $1 billion in venture capital funding.

Fortune recently obtained confidential documents sent by Bloom to its "significant investors," detailing third quarter earnings and the company's broader financial position. We also have managed to learn some broader context around the numbers, and have received what is believed to be the company's first on-the-record statement about its top-line projections for 2013 (all prior requests for information had gone unanswered).

For the uninitiated, Bloom was founded by K.R. Sridhar in 2001 to translate a NASA science experiment into self-generating energy boxes for commercial customers like warehouses and data centers. The idea is basically to place solid oxide fuel cells on a company's premise, which convert air and natural gas into electricity via an electrochemical process. After several field trials, it shipped its first boxes to Google (GOOG) in July 2008 and since has secured paying customers like Wal-Mart (WMT), Federal Express (FDX) and AT&T (T). It also has expanded the business model to include box rentals (where customers pay on a consumption basis, kind of energy-as-a-service), and also is rolling out advanced boxes that can operate independent of the gas grid if needed (the new module also can be added onto existing boxes).

Despite the customer wins and technological advancements, however, Bloom has a reputation for burning money.