As we suggested in this article from earlier this week, Enphase would soon be announcing the shipment of its one-millionth microinverter. That's one million pieces over the last three years.

Sure enough, Enphase just published news of the milestone on its blog and appears to be commemorating the event with a gold-plated (painted?) microinverter. The millionth unit shipped in September. Congratulations are in order -- anytime a startup can get to a million units shipped in a product category that it essentially created and singlehandedly validated, kudos are definitely deserved.

This is also the month that the United States installed a total of one gigawatt ofsolarpanels. The 1-gigawatt mark will be achieved on October 18. At 3:15 PM. When Mr. and Mrs. Shane McHenry install a 3-kilowatt system on their guest house. Strangely enough, that's also the installation site for the one millionth microinverter from Enphase.

Enphase can allow itself about 15 minutes of celebration -- and then it's back to reality.

Competitors like SolarBridge are trying to leapfrog Enphase by integrating the microinverter directly into the solar panel. Involar, Enecsys, and Direct Grid are looking to undercut on price, second-source, or supplant the Enphase sockets. DC panel optimizers from SolarEdge, Tigo, Azuray and others like eIQ offer different approaches to panel-level electronics. ArrayPower has its own unique approach and has partnered with Canadian Solar to get to market. SMA and Power-One have their own microinverter models coming to market.

And Enphase has to deal with the hellhounds on its trail, with the distraction of an SEC IPO filing in the works in the midst of a less-than-cooperative IPO market. All while having to maintain the SEC-required quiet period. While still scrubbing cost out of the product.

In any case, innovation lives in solar, greentech, and the Northern reaches of Silicon Valley.