As solar module prices drop, the cost and performance of the rest of the solar installation becomes even more crucial. Soft costs need to be addressed, as in the recent legislation in Vermont. Balance of system needs to play a larger and more innovative role -- and the biggest piece of balance-of-system costs is the power conversion from DC to AC via microinverter, optimizer or otherwise.

Microinverter firm SolarBridge won $25 million in a round D funding led by Shea Ventures along with Battery Ventures, Rho Ventures, and Osage University Partners. Shea Ventures is part of Shea Homes, the largest private homebuilder in the U.S. Shea Ventures has also invested in SolarCity.

That brings SolarBridge's VC funding total to more than $71 million to date. SolarBridge differentiates itself from the microinverter and optimizer pack in aiming for integration into true AC modules (ACM). Ron Van Dell, the CEO of SolarBridge, claims
that an ACM is a more bankable product because it "enables an integrated 25-year warranty on the module." The firm has already announced SunPower and AUO as partners and will be naming a few more partners later this summer. The firm started shipping in 2011 with "tens of thousands" last year and will ship "hundreds of thousands" this year, according to the CEO.

Van Dell notes that the SolarBridge ACM business model doesn't require the build-out of a large sales and distribution channel. 


Optimizer firm SolarEdge joins microinverter market leader Enphase (Nasdaq:ENPH) in having attached distributed electronics to more than one million solar panels. Last week, SolarEdge, an Israel-based solar panel power optimizer company, announced the one-million-unit milestone and claimed it would reach two million units shipped by year-end. Enphase is at about 1.7 million units sold.

Last week Solantro Semiconductor completed its $10 million round A with funding led by family fund Black Coral Capital, as well as Presidio Ventures (a Sumitomo Corporation company), Business Development Bank of Canada (BDC) and Export Development Canada (EDC). Solantro designs and manufactures chipsets for use with distributed solar PV power conversion equipment, which would include microinverters from firms such as Enphase or SolarBridge and DC optimizers from firms such as SolarEdge or Tigo.