Innovalight, a thin-filmsolarcompany, said Thursday it raised $28 million in a Series-C round led by Convexa Capital (see posts in Earth2Tech and VentureBeat). Other investors included Scatec, Apax Partners, Arch Venture Partners, Harris & Harris Group, Sevin Rosen Funds and Triton Ventures.

The funding brings the company's total to $42 million (see Nano Solar Firm Gets Funding), according to VentureBeat and Earth2Tech. Innovalight said it will use its new capital to relocate to a 30,000-square-foot manufacturing plant in Sunnyvale, Calif.

The deal comes after another thin-film startup, Konarka Technologies, last week raised $45 million (see press release) and then got a $4.7-million U.S. government grant for solar windows (see In Brief: U.S., UK Governments Back Greentech).

Thin-film solar technologies use little or no silicon, generally depositing a thin film of active material that converts sunlight into electricity on a substrate like plastic or glass.

Like its competitors, Innovalight claims its technology uses far less silicon than regular crystalline solar panels and, because it can be coated on thinner, more flexible materials, could potentially open up new applications for solar power.

The company is developing a solvent-based process for making what it calls "silicon ink," which is made of silicon nanocrystals suspended in a liquid ink solution. The company said the lightweight soluble ink can then be printed on different substrates at potentially lower cost than traditional solar panels.

Innovalight last year said it expected to launch a product at the end of 2008.

But thin-film technologies have had limited success so far and production remains low, in spite of a silicon shortage that should give them an edge over traditional crystalline solar panels. (One notable exception is First Solar, which has the capacity to produce 210 megawatts of its cadmium telluride technology annually.)

Thin-film manufacturers could be at risk if they haven't reached high volumes and low cost before the silicon shortage eases. Will new capital help Innovalight - and its competitors - grow quickly enough?

Making Solar Smarter

Power-electronics company SmartSpark Energy Systems said Thursday it snagged its first round of financing from venture firm Battery Ventures to improve solar-panel systems' ability to convert the sun's light into power

The undisclosed funding amount will go to develop the Champaign, Ill.-based company's technology called SolarBridge, which looks to integrate a critical component of a solar power system, an inverter, into the panel itself.

Inverters convert direct current that's derived from solar to usable alternating current.

When it comes to driving down solar costs, conversations tend to turn to solar cells. But other solar companies have looked to make improvements in other technologies, like inverters, to help address costs (see Thinking Outside of the Cell).

Inverters can cost about 10 percent of a typical solar-power system. They also require cabling that is threaded through each panel of a solar system so electric conversion can occur. And this method takes a specialized electrician to do the job.

SmartSpark claims its approach allows buyers to purchase panels that already come equipped for direct connection to the power grid. So, instead of wiring up a whole system to an inverter, the electrician wires the panels directly into the AC conduit of a person's home or light commercial space.

The company also claims this approach not only brings down the cost of installing a solar system, it also allows folks to purchase panels individually, giving them the flexibility to buy only what works in their budget.

SmartSpark would not comment on when it expects SolarBridge to be ready for market.

Texas Instruments Buys PowerPrecise

PowerPrecise, a Herndon, Va.-based company that makes integrated circuits for battery management, was acquired by Texas Instruments (NYSE: TXN) on Tuesday.

Among other things, the company's chips monitor and manage battery systems in hybrid-electric cars, power tools and backup power. The company claims its technology can "radically enhance" the safety of lithium-ion battery packs, maximize run times and improve battery life.

Automakers and analysts have said batteries have been one of the main issues keeping plug-in hybrids -- hybrid-electric cars with extra batteries that can plug into a wall outlet to supplement gasoline with electricity -- and electric cars from the mainstream.

The lead-acid and nickel-metal-hydride batteries available for cars today aren't powerful enough, for their size, to provide the range carmakers want without giving up too much cabin and trunk space.

Lithium-ion batteries can deliver more power for their size than lead-acid and nickel-metal- hydride batteries, but have suffered from "thermal runaways" (read: they've caught fire) in other applications, such as laptops.

Companies such as PowerPrecise think they can help remove that problem. Of course, it's not the only one. Lithium-ion batteries also are expensive.

Incidentally, the price Texas Instruments paid for PowerPrecise was undisclosed.