In his five-year stint at communications chipmaker Broadcom (NSDQ: BRCM), Ford Tamer grew the company's networking semiconductor revenue from $300 million to $1.2 billion per year.

Now the former senior vice president and general manager of Broadcom's enterprise networking group is planning to use his money-making skills in a new way.

Tamer is the newest operating partner for Khosla Ventures, the Silicon Valley venture-capital firm started by Sun Microsystems co-founder Vinod Khosla, who has become one of the world's foremost greentech financiers.

Shortly after Labor Day, Tamer took a stealth position as operating partner for the firm, which officially announced his arrival last week.

Khosla Ventures already has thrown in quite a bit of money in areas like biofuels,solar-thermal and battery technologies. Tamer will invest mostly in mechanical and electrical efficiency, solar and IT.

Prior to his time at Broadcom, Tamer was CEO and co-founder of Agere, a network processor company that was bought by Lucent, then spun out as Agere Systems. Before that, he led marketing and international operations for Dazel Corp., which was acquired by Hewlett-Packard, and co-founded software firm Megaknowledge, which was acquired by Intellicorp.

But how does all this qualify him for a career in cleantech?

"I've got a background in semiconductors and materials science from education," he said, referring to a master's degree and Ph.D. in engineering, with a focus on material science and system numerical modeling, from the Massachusetts Institute of Technology.

He's certainly not the first to cross over from IT to greentech.

Among the best-known examples is Khosla himself. Then there's Bob Metcalfe, one of the inventors of the Ethernet and founder of computer-networking company 3Com. In October, he took the helm of GreenFuel Technologies, which is using algae to eat carbon dioxide and make biofuel, on an interim basis.

Dozens of other IT-to-greentech examples abound, including SunPower CEO Tom Werner and Nanosolar CEO Martin Roscheisen,

Still, Tamer seems eager to prove himself. He already has led four investments at Khosla Ventures: backing EcoMotors, which is developing a fuel-efficient diesel engine; Kaai and Soraa, which are focused on lasers; and Topanga, a lighting company.

He wouldn't tell us how much he invested in those companies. But we got him on the phone to find out more.

Q: Tell me more about the companies you invested in?

A: Kaai and Soraa, they are two companies in lasers. Lasers are the most efficient form of lighting. An example would be a laser TV, which would only consume a few watts. (Kaai and Sorra) are basically taking efficiency up by an order of magnitude.

Topanga, which is an outside lighting company, (is working) on High Intensity Discharge lighting. Topanga provides much higher efficiency than traditional HID lamps, measured in lumens per watt.

And EcoMotors, which is an engine company. EcoMotors would be a similar aim as far as efficiency, but focused on mechanical efficiency for improving miles per gallon, as well as emissions, significantly as compared to traditional engines that are in production today.

Q: Vinod Khosla has been a vocal proponent and investor in biofuels. Does your focus on energy efficiency mean Khosla Ventures is switching its focus from biofuels?

A: No. It doesn't signify any lessening of investments in existing areas. It's just an addition to the team to expand our bandwidth to go out to new areas.

Q: Has the firm's portfolio capped out on any one investing area?

A: Not at this point.

Q: Vinod Khosla is an outspoken guy who is not afraid to take a contrarian stance. He's called plug-in hybrids "toys." What stances does he take that you disagree with?

A: Actually, so far, we are in agreement. And he was referring to parallel hybrids, as opposed to series hybrids. [Editor's note: In parallel hybrids, like the Toyota Prius, both the internal combustion engine and the electric motor propel the vehicle. In series hybrids, like the Chevrolet Volt, only the motor propels the vehicle, and the engine feeds electricity into the motor.]

He was also referring to the cost of a hybrid platform being too expensive for developing markets. We are in agreement there, in the sense that you've got to improve the efficiency of the combustion engine first and combine it with a smaller battery and regenerative braking, which is what we are trying to do with EcoMotors.

You've got to both reduce the emissions, reduce the cost and increase [the] efficiency of the combustion engine and then come up with a better hybrid plan, which is a series hybrid, in order to make that platform cost-effective for large-scale markets such as China and India.

[A series hybrid] results in a lower transmission cost and, with regenerative braking, a smaller battery. Combined with a more efficient engine, it is a better platform.

Q: Your background is heavy in traditional IT. How can you leverage this into the cleantech space?

A: From an IT perspective, there is an interesting play in looking at green in the data center or green in some of the IT equipment. … Demand response is one example. But, you know, the power used in data centers today is a pretty big amount of power, and I think trying to focus on more energy-efficient servers and energy-efficient networking equipment is an example.

Q: 2007 proved to be a record-breaking year when it came to cleantech investments. And with more cleantech funds still raising money, some industry watchers have questioned whether there are enough good investments to go around. Are you worried about a dearth of investment opportunity as a result?

A: We have been very selective in what we invest in. For example, on the solar front, I've been looking at dozens of solar deals and still haven't found one that I like. The company, Khosla Ventures, has obviously invested in Stion, which is a solar PV company, and Ausra, which is a solar-thermal company. So we do have investments in solar. But we aren't going to lower the bar to invest in 'me-too' deals

Q: Where do you think the next wave of innovation is going to come from and what are you looking at investing in next?

A: I still believe there is room in efficiency, mechanical-electrical efficiency and battery technologies. We have a range of potential investments, but we are certainly looking at appliances, turbines and batteries.

-- Editor Jennifer Kho contributed to this story.