Since then, we've been treated to one of the most innovative periods in the history of the planet, one that has generated trillions of dollars of follow-on investment and increased the productivity of just about anyone with access to a computer.
(Read more: Apple plans Nevada solar farm and clean energy push)
The hard truth of investing in start-up companies is they often don't pan out. The growth trajectory for most industries isn't a straight line—it's a series of fits and starts.
When a new industry's growth takes the world by storm—as it did with the Internet and clean energy technology—those fits can be epic, fueling periods where a lot of half-baked ideas get funded along with the really good ones. Eventually, those ideas are seen for what they are and investors pull the plug, if the lights don't shut off before they can.
That's why this latest VC rationalization in the clean energy technology space is both inevitable and positive. The shakeout is forcing the industry's survivors to revisit their business models, seek out strategic partnerships and basically run their businesses better.
That's all for the good, as those leaner and meaner companies will likely define the industry in the years and decades to come.
And here's the other thing: The pendulum is starting to swing back the other way. Declines in year-over-year clean energy technology venture investments might be garnering the headlines right now, but beneath the surface a number of very smart and capable VC firms are opening new funds dedicated to helping develop clean energy technology start-ups.
(Read more: Tesla outsells Porsche and Jaguar in California)
Earlier this year, Lux Capital and The Westly Group closed new clean energy technology funds to go along with other recent fundraising successes by Braemar Energy Ventures and True North Venture Partners.
In these new funds, multinational corporations and other "strategic investors" are beginning to replace the pension funds and university endowments that helped push the clean energy technology sector to new heights over the past decade.
Investments from family offices and overseas players are also becoming increasingly prevalent and Chinese businesses are continuing a string of acquisitions in the LED, solar, electric vehicle and battery fields.