Siemens is the company that just can't resist.

The German industrial giant is considering purchasing solar cell maker Q-Cells, according to Reuters (via Forbes here.).

Earlier this month, Siemens bought solar thermal vendor Solel for $418 million. Earlier, it has bought an number of water companies and ramped up its investments in smart grid.

In a list of the top ten acquirers in greentech, we picked Siemens as number two, right behind General Electric.

This is a pattern you should get used to. Small, innovative startups often have tremendous technology, but they lack the capital, distribution networks and relationships to bring their ideas to fruition. Large conglomerates often fail to capitalize on the interesting stuff in their labs, but they do know how to buy stuff that seems to work and take it commercial. Thus, greentech will be a barbell market – a lot of small companies and a few large companies with not a lot of things in between.

As acquisitions spread, you can start to think of Silicon Valley as a farm system for conglomerates. That doesn't sit well with some: Didn't Silicon Valley win out over old-style conglomerates like Digital and IBM? Yes, but it doesn't mean it happens in every situation. Green startups are born to be bought.

And if Siemens isn't interested, start talking to Philips (two lighting acquisitions this year), Toshiba, TSMC, and Cisco Systems.

Pacific Gas & Electric says its smart meters aren't the reason Bakersfield customers are seeing higher power bills this summer. Instead, it's hot summer weather, combined with electricity rate increases, that are the cause, the utility says.

California State Sen. Dean Florez has found a host of Bakersfield residents who are complaining about big power bills they've gotten after their smart meters were installed. Those complaints have focused attention on PG&E's $2.2 billion, 10 million smart meter deployment, with the California Public Utilities Commission demanding that PG&E find a third party to investigate (see San Francisco Chronicle).

But PG&E has already tested many customers' smart meters – made by General Electric and Landis+Gyr and networked by Silver Spring Networks – and have not found any problems with how they're working, PG&E spokesman Denny Boyles said Wednesday.

Rather than malfunctioning meters, PG&E thinks the higher bills have come from its two rate hikes in the past 12 months, plus a hot summer that led to many Central Valley residents cranking their air conditioners to beat the heat, Boyles said.

Still, the complaints do point out a central issue for utilities deploying smart meters. While two-way communicating meters do offer the promise of linking home appliances, AC units and other systems to networks that could reduce power bills, those home area networks haven't gotten past the pilot stage yet (see Utilities Mull Price Points, Policies for Home Energy Management).

And that means most homeowners haven't seen direct proof that the meters are worth the rate increases they're paying to cover the cost of installing them — though in PG&E's case, those increases came years ago, Boyles noted.

Right now, PG&E smart meter customers can check their power usage at the meter, or log into a PG&E Web site to get updates, Boyles noted. In one customer's case, that website inaccurately reported power usage going up during a blackout – a glitch PG&E is correcting, he said.

But PG&E is looking at more complex and useful linkages between smart meters and homes, though the initial advances on that front may come to its small commercial customers first.

Those are the target customers for PG&E's proposed $85 million project to link 75,000 smart meter-enabled businesses with energy management systems. PG&E is seeking Department of Energy smart grid stimulus grant funding for the project, which includes Cisco and IBM (see PG&E Asks Cisco to Help Make 75K Businesses Energy Wise).

One of the project's goals is to give businesses advance notice of electricity prices that will change during the course of the day. Such time-of-use and peak pricing programs are a critical component of many utility smart meter networking plans, since they won't work to encourage customers to save power during peak demand times unless those customers can get pricing signals in a reliable and timely way.

In fact, peak pricing without some kind of forewarning to the customers could yield some even louder complaints about unfair power bills - not a pleasant prospect for utilities.

General Electric's undisclosed, first-time investment in Israel-based SolarEdge Technologies was matched by two other investments in companies with which GE has quite a bit of experience.

Those would be Tendril, the maker of home energy management technology, and Grid Net, the GE-backed maker of software and systems for WiMax-enabled smart meters. GE's investment arm, GE Energy Financial Services, announced the investments Wednesday.

While GE hadn't invested in Tendril before, it and the Boulder, Colo.-based startup have a partnership to use Tendril's software platform to enable GE's planned line of "smart" home appliances that can turn on and off via homeowner or utility commands to cut down on peak power demand.

As for San Francisco-based Grid Net, GE participated in a 2006 funding round that got the company going, and has reportedly been testing Grid Net's WiMax technology in GE smart meters in pilot projects in Australia.  

GE Energy Financial Services investment arm didn't disclose the amount of its investments in the three companies.

Echelon has a new partner to bridge the gap between its smart meters and home energy controls – Eaton Corp.

The two companies said this week that they'll be marketing a combination of Echelon's networked energy services smart meter system and Eaton's home automation system to utilities in Europe, Africa and the Middle East.

While Echelon does have U.S. utility Duke Energy as a customer, Europe is where the San Jose, Calif.-based company does most of its smart meter business. Its technology underlies a 30-million smart meter deployment in Italy, and it has about 2.5 million more meters deployed or under contract elsewhere in Europe (see Echelon Expands Euro Smart Meter Biz).

Eaton is one of the big players in building automation systems, an industry where Echelon's LonWorks platform also plays a role. Other building automation heavies include Johnson Controls, Honeywell, Siemens, Schneider Electric and new entrant Cisco Systems (see Cisco Rolls Out Building Management 'Mediator').

But those automation systems are aimed at big office buildings and factories, not homes. Getting the cost of residential energy control systems down to the amount a typical homeowner is willing to pay – or a utility can afford to subsidize – is a trickier matter (see Utilities Mull Price Points, Policies for Home Energy Management).

Echelon said its newest meters will include a portal that can hook up to the radios that run Eaton's home automation systems, which includes its high-end Xanura system.

There's a lot of activity underway in linking smart meters to home energy management systems.

Examples include General Electric's partnership with home energy networking startup Tendril and Itron's partnerships with EnergyHub and OpenPeak, as well as smart meter networking provider Silver Spring Networks' purchase of home energy portal developer Greenbox and smart grid software startup GridPoint's acquisition of Lixar (see stories here, here, here and here).

Of course, utilities will have their own choices of technologies they'd like to integrate. But with smart meter-enabled home energy management systems still in pilot stage, there's still time for such partnerships to sell electricity providers on the advantages of going with an already integrated system (see The Elusive Smart Meter-Demand Response Combo).

From the living rooms of Louisville, Ky. to the halls of Masdar City, General Electric's smart appliances are being put through their paces.

Louisville was the first test bed for GE's smart washers, dryers, refrigerators and electric ranges that can power up and down to help utilities manage peak loads and customers save on power bills (see GE's Smart Appliances: Smarter With GE Home Energy Manager).

Now GE is sending its prototype smart appliances and home energy manager to the United Arab Emirates to test them out in Abu Dhabi's $22 billion showcase green urban development.

Masdar City is meant to be a zero-emissions city in the desert, powered by renewable energy and housing about 40,000 people to work in a nascent Middle Eastern green technology and manufacturing hub (see Reporter's Notebook: From Fishing Village to Energy Mecca). Masdar City is a project by Masdar, a company owned by one of the emirates, Abu Dhabi. 

Of course, there aren't 40,000 people living there yet, so GE plans to put its first appliances in the Masdar Institute of Science and Technology building some time early next year. About 10 people living there will test the appliances over two years, GE said.

Masdar is best known for bankrolling massive renewable power projects, both at home and abroad. Examples include its investment in several solar plants and solar panel manufacturing facilities and its billion-dollar stake in the London Array wind farm (see Green Light post and Masdar Bets on Massive Offshore Wind Park).

Abu Dhabi is also building a smart grid infrastructure to include 1.2 million smart meters and substation monitoring and control systems, according to Danish smart grid networking company Amplex (see Green Light post).

By the way, GE's interest in Masdar is far from limited to testing smart refrigerators.

"The Masdar City pilot project comes as part of the broader relationship between GE and the Mubudala Development Company, of which Masdar is a wholly owned subsidiary, which extends to a broad range of initiatives in the fields of aviation, commercial finance, industry and corporate learning," the companies said in a press release.

Lemnis Lighting has a new dimmable 6-watt LED bulb that can replace a 60-watt incandescent bulb, and it goes on sale in the United States today. Will consumers be willing to think long-term when it comes to the price?

Sure, the Pharox60 costs $40, which is about 40 times the price of the century-old piece of technology it seeks to replace – or about 50 times the price, once the Pharox60 goes up to $50 per bulb in 2010.

But the Dutch startup says the bulb, which is 90 percent more efficient than incandescent light bulbs, can pay back its extra costs in power bill savings over three years or so.

And it will last for 25 years, giving it a six-fold lifespan advantage over compact fluorescent light bulbs, the other competition for replacing incandescent light bulbs, the company said.

Lemnis has promised to bring 10 million Pharox60 bulbs to market by the end of next year. It has sold about 2.5 million in Europe, where incandescent light bulbs are being phased out under a European Union ban. The United States is set to start phasing out incandescent light bulbs in the coming years (see New York Times).

LED makers have been struggling to bring prices down to levels that could crack the broader market for replacing traditional light bulbs. Startups like Bridgelux, Luminus Devices and Renaissance Lighting have been tackling different sectors of the market, and lighting giants Philips, General Electric and Osram have been buying up startups with promising technology (see Green Light post).

Lemnis's new light bulb was just one of the LEDs on display this week at the West Coast Green environmental decorating and home show in San Francisco.

Green Ray Technology has its own LED light to replace incandescent bulbs, as well as a $70 LED tube light to replace fluorescent tubes with an 80-percent reduction in electricity use (see Green Light post).

And Philips has a prototype 10-watt LED light bulb - one it hopes to mass-produce for $20 to $25 – that it has submitted to the Department of Energy's $10 million "L Prize" program (see New York Times).

Silver Spring Networks has successfully tested its ability to communicate with Siemens' substation automation gear. That could open up an "up-the-grid" space for the startup's wireless mesh communications, which are now being used mainly for smart meters.

The two announced Wednesday that they've successfully tested Silver Spring's IP-based mesh networks for controlling Siemens' SICAM substation automation unit.

Siemens is one of the giants in electricity grid substation gear, along with ABB – which, by the way, said in March that Silver Springs networking technology worked for some of its substation switching gear.

ABB also announced Wednesday that it has certified smart meter communications from Elster, Sensus, Itron and Trilliant and Wi-Fi provider Tropos as working with its substation automation gear (see Tropos: Wi-Fi For the Smart Grid).

Substations have been operating on older communications technologies like radios for decades, Wes Sylvester, director of distribution solutions and smart grid for Siemens Energy, said Tuesday at the GridWeek conference in Washington, D.C.

Giving them a more modern communications system that's integrated with other utility smart grid networks could make it a lot easier to control substations as part of an integrated system, he said.

Sylvester wouldn't say if the two companies were working with any specific utilities on their interoperating technologies. Rather, the announcement was meant to let utilities know they can "feel comfortable that as they move forward on new communication technologies, our products are compatible."

There are lots of other communications options to link substation automation gear, and not all of them have to be owned by the utility.

ABB uses a communications platform hosted by Qualcomm for some substation automation, for example, and Cooper Power Systems is working with AT&T (see Qualcomm's Machine-to-Machine Smart Grid Moves and AT&T Links Cooper Power Systems' Smart Grid Devices).

And then, Cisco Systems has said it wants to network distribution grids, though what communications technologies it would use for that remain open (see IBM, Cisco Look to Tie Up Smart Grid Partners).

Cisco's gear does serve as the underpinnings of a wireless network built by Arcadian Networks for Minnesota utility Great River Energy and a host of related electricity co-ops, which might provide one example.

Silver Spring's mesh network does sacrifice some bandwidth in exchange for lower cost, compared to, say, the WiMax-based system that General Electric is installing for Texas utility Centerpoint Energy (see GE Offers WiMax Smart Grid Solution).

But as Sylvester noted, for distribution automation that "doesn't require millisecond response, the solution that Silver Spring is providing would be just fine. It all really depends on what the utility is wanting."