Sliver Spring Networks -- which makes equipment for creating NANs, or neighborhood area networks -- said it raised $75 million, underscoring the growing interest in smart grids. The company effectively makes Cisco-like equipment that can monitor electricity, gas and water consumption. It doesn't insert equipment into individual buildings like Tendril or GainSpan. Instead, the company's equipment harvests information from a variety of buildings and then shuttles it off to a utility. Ultimately, utilities hope to use this sort of equipment to curb power consumption during peak periods. That will cut consumer costs, reduce the odds of brown-outs and cut their own demand for peaker plants. Investors began to warm up to smart grid technologies in 2005 and 2006. Smart grid doesn't get as much attention or money as solar or biofuels, but the sector has a few things going for it. One, it's familiar. A lot of these companies are porting computer technologies to the grid. Two, these companies don't have the same capital requirements of solar or biofuel companies. Three, some companies -- Comverge and EnerNoc -- have already had IPOs. And four, who knows, Cisco may buy your company. It's a pretty good bet that the networking giant will try to turn that WiFi box in your home into an energy management device that they are known to like to acquire. There's probably someone right now designing a "Cisco + Your Name Here" coffee mug for the next buyout. In the third quarter, companies touting smart grid technologies, demand response and energy efficiency pulled in $272 million, according to research conducted by Greentech Media. Some of the notable deals include the $40 million raised by Trilliant. Investors in this latest round for Silver Spring include Kleiner, Perkins, Caufield and Byers and Foundation Capital. Foundation was also an investor in EnerNoc.

The new competitive battleground in solar cells is 3-D. Rather than produce flat solar cells, a slew of relatively new – and until now relatively silent – companies will try to improve the efficiency and economics of solar by making solar panels and/or cells that are curved or that sport curved components. The advantage of adding more shape to the cell comes in operating time. Planar solar cells can only capture sunlight for a few limited hours. The sun is too low in the sky during the morning and afternoon hours for a planar solar panel to work at optimal efficiencies. You can put these panels on a tracker that moves with the sun, but that adds cost. Because of their shape, curved solar cells can better harvest early morning or late afternoon light. (Think of it for a second – at least part of the active surface will directly face the sun as long as it is in the sky.) Solyndra, which came out of stealth mode today, has a cylindrical solar cell activated with copper indium gallium selenide. But Solyndra isn't alone. Bloo Solar has come up with a planar solar cell that contains cylindrical solar brushes that harvest light. Under an electron microscope, the brushes look like bristles from a toothbrush. Although the cells are flat, the brushes allow it to exploit the 3-D effect. The Sacramento, Calif.-area company hopes to be in mass production in 2011. (Bloo will also present at End-to-End Electricity sponsored by Greentech Media in November.) Meanwhile, over in Denmark, Sunflake is working on a III-V solar cell that it says achieves 30-plus percent efficiencies. Inside the solar cell tree-like structures harvest light. The material was discovered by accident during an experiment at the Niels Bohr Institute. It is currently seeking a Series A round of funding. Solexel is also doing something in 3D, my colleague Eric Wesoff tells me. Clearly, something is going on.

Remember back in the '90s when everyone insisted on capitalizing a consonant in the middle of their names. That's out. The Polynesian double-vowel sound is in, at least for the greentech market. In recent years, we've seen the formation of Soraa (LEDs), Kaai (LEDs), Deeya (flow batteries), Oorja (fuel cells), Bloo Solar (solar panels), Jadoo Power (fuel cells) and Eestor (ultracapacitors). You can add Bloom Energy to the list too if you want to be cheeky. As far as I can tell, only Oorja and Deeya are real words. Oorja means energy in Sanskrit and Deeya means small light. Thus, the rest of these are made up to some degree. You can argue Bloo is a word, but usually it's spelled differently on most walls. Kaai and Soraa – which were founded in part by LED pioneer Shuji Nakamura – are corruptions of the words for ocean and sky in Japanese, but often aren't spelled with double vowels in translation. It looks like a whole new trend in artificial names. Expect "I" and "U" to join soon.