Correction: See below.

One of the most closely watched smart grid companies appears to be laying the groundwork for its hotly anticipated initial public offering.

Silver Spring Networks has hired Morgan Stanley and Jefferies & Co. to underwrite an IPO, according to Dow Jones Clean Technology Insight (subscription required). Silver Spring makes routers and hubs that connect through a wireless mesh protocol. The wireless protocol can't carry as much data as protocols like WiMax, but so what, says Silver Spring. The data traffic from individual nodes on the grid is somewhat moderate compared to what a server in a data center might dish out. The radios will also improve with time.

More importantly, the company's equipment is relatively cheap and it can be deployed in a manner to provide complete coverage in a region -- the low cost means utilities can pop up boxes pretty much wherever they are needed. Pacific Gas & Electric chose Silver Spring equipment for its territory for a smart grid project, in part because of the cost and ability to provide comprehensive coverage, according to PG&E execs (see video).

While Silver Spring designs its own radios, the boxes are assembled by contract manufacturer Jabil Circuit, we've learned. Outsourcing reduces the company's capital budget. It may sound strange, but some traditional meter makers have yet to switch to contract manufacturers.  

The company has raised $275 million so far, which sort of counters the theory that smart grid is capital lite. It has also landed deals with utilities in Texas and elsewhere

Meanwhile, during the dinners and coffee breaks at the Cleantech Forum, VCs and others have been chatting about a rumored IPO for biofuel and medicine maker Amyris. We heard they were preparing for an IPO a few weeks ago. You can get the rundown at this link.

If both companies file for IPOs, investors will pore through the documents. One of the big questions will be whether either company is profitable. Many of the companies that have filed or held IPOs in recent years -- EnerNoc, A123 Systems, Tesla Motors -- have been in the red. EnerNoc and A123 went public, while Tesla has just filed.

In other notes, the Energy Collective writes about the ongoing saga of Range Fuels, which has raised millions but has yet to start cranking out the cellulosic ethanol. Range Fuels and Mascoma were two of the early cellulosic ethanol companies. (Range focuses on thermochemical processes; Mascoma has microbes.) Both have investments from Khosla Ventures and both raised funds from investors and state governments. But the fuel business isn't easy.

Correction: We said earlier that Silver Spring was founded by two guys out of Tuck and had trouble getting capital. That is actually the EnerNoc story. Silver Spring was nutured by a father and son team. Both received money from Foundation Capital. Sorry about that.