Green Patent Blog®

Clipper Windpower (Clipper) currently has the distinction of building the world’s largest wind energy project.  The wind turbine maker, headquartered in both London and Carpinteria, California, has entered into a joint venture with BP Alternative Energy to build a 5,050 megawatt facility in South Dakota.

The facility will use Clipper’s Liberty wind turbine, which has patent protection from all angles.  According to Clipper’s “at a glance” page, the Liberty includes patented generators, a patented distributed powertrain and patented variable speed technology. 

Some of the patents that cover the Liberty include U.S. Patent Nos. 7,233,129 and 7,339,355 (generators), U.S. Patent Nos. 6,653,744, 6,731,017 and 7,069,802 (distributed powertrain), and U.S. Patent No. 7,042,110 (variable speed technology).  The patented innovations make the Liberty more efficient and more reliable than traditional large scale wind turbine designs.

The fundamental components of a wind turbine are the rotor, gearbox and generator.  The gearbox converts low speed rotation from the turbine blades into high speed rotation suitable for generating energy.  The gearbox output shaft turns the shaft of the generator, which, through conversion circuits, connects to the utility grid to provide current to the grid.

Typical turbine gearboxes are “planetary” gearboxes (i.e., having outer gears revolving around a central “sun” gear) with the speed change occurring in three or four stages of rpm step-up.  But planetary gearboxes for multi-megawatt turbines require huge, expensive gears and bearings as well as large generators.  The parts are very heavy and need a lot of maintenance, and repairs can take a wind turbine off-line for a long period of time.

Clipper’s distributed powertrain patents generally relate to a compact gearbox with a multiple-path design to divide and distribute torque load.  The load drives four smaller generators instead of a single big one. 

Instead of a planetary gear arrangement, the patented design has helical gears to promote smooth meshing.  The gear sets are in “cartridge” form and can be easily replaced without removing the gearbox.

Clipper’s variable speed technology uses magnet generators that improve efficiency.  Traditional variable speed systems use generators which pull current from the turbine unit or the utility grid to excite the rotor and create a magnetic field.  

The patented magnet generators don’t have to pull power from the unit or the grid because they are already magnetized.  As a result, the Liberty can operate at higher efficiency over a wide range of loads.

The Clipper Liberty wind turbine is a great example of establishing robust patent protection by breaking down new technology into its patentable constituent parts and patenting as many of those parts as possible.

The WIPO Magazine recently published an interesting online article about patent strategies in solar technology.  The article profiles Spanish photovoltaic and solar thermal company Isofoton and discusses the company’s IP strategies. 

Based on an interview with the company’s R&D director, Jesus Alonso, the article discusses Isofoton’s patent portfolio, including worldwide prosecution strategies, technology transfer strategies on licensing in and licensing out, and the company’s attitudes on patent enforcement.

In the still limited clean tech IP corpus, this article is one of the best I’ve read.  It demonstrates the importance of IP in clean tech and provides a good illustration of how patent strategy is shaped by a clean tech company’s business goals.

Litepanels LLC (Litepanels) is a North Hollywood, California company that makes and sells LED lighting systems for use in film and broadcast production.  Last month Litepanels sued Sony Corp. (Sony) and two of its U.S. subsidiaries in federal court in Marshall, Texas, alleging infringement of two of its patents relating to camera-mounted and wide lighting LED packages.

U.S. Patent Nos. 6,948,823 (’823 patent) and 7,163,302 (’302 patent) describe multiple LEDs arranged on a panel that can be attached to a camera frame (see patent figure below). 

The two patents are related (the ‘302 patent is a “continuation” of the ‘823) but differ in that the ‘823 patent claims embodiments with portable frames that can be attached to a camera while the ‘302 patent claims embodiments having a particular color range, a mechanism for dissipating heat and an element for focusing the emitted light. 

According to the patents, prior LED systems are unsuitable for film and photographic uses because they narrowly focused light, providing a very short working distance and a small illumination diameter.  Also, LED systems for live entertainment typically include colorized LEDs, which create uneven lighting unsuitable for most film, television and photographic applications.

The complaint (litepanelscomplaint.pdf) accuses Sony of infringing the patents by manufacturing, importing and selling camera-mounted lighting products and specifically names the Sony HVL-LBP Camera-Mounted Video Light (top).  Litepanels also makes the standard allegations of willful infringement and inducing infringement by encouraging distributors and retailers to sell allegedly infringing products.

Litepanels is seeking enhanced damages and attorney fees and has asked the court to issue an injunction to stop Sony from making or selling the allegedly infringing products.

This is not the first time this year Sony has been the target of an LED patent suit.  Previously, LED innovator Gertrude Neumark Rothschild sued Sony, among many others, in the U.S. International Trade Commission.  Sony quickly took a license from Rothschild.  It will be interesting to see if Sony chooses to fight this one.

There are a couple of key clean tech purchases from the end of July to report.  First, the French power solutions conglomerate Schneider Electric agreed to buy Vancouver-based solar inverter company Xantrex for $489 million.  (see the press release and the greentech media story)

Xantrex owns about 30 utility and design patents and several patent applications covering power conversion devices for solar- and wind-power systems.  As I discussed here a couple of months ago, Xantrex also is involved in trade secret litigation with competitor Advanced Energy Industries.

There also was some movement in the large and growing LED market, with Dallas-based Lighting Science Group (LSG) acquiring Lamina Lighting (Lamina) for $4.5 million.  (see the greentech media piece)  LSG makes LED lighting systems, controllers, dimmers and other components. 

Lamina owns a several patents and applications relating to LED light sources, including U.S. Patent No. 7,300,182, entitled “LED light sources for image projection systems,” U.S. Patent No. 7,095,053, directed to an LED packaged for high temperature operation, and design patent D572,385, which appears to cover the design for Lamina’s Titan Series LED lighting system.

I received an e-mail today from Pratt & Whitney (P&W) about its PurePower PW1000G demonstration engine.  P&W will announce tomorrow (pwpressrelease.doc) that the jet engine completed its first phase of flight testing, having logged about 43 hours in 12 flights on a company owned test plane. 

The PurePower engine uses P&W’s patented Geared Turbofan technology, which I discussed in a previous post.  The technology is covered at least in part by U.S. Patent Nos. 7,021,042 and 6,964,155.

The Geared Turbofan design integrates a gear box between the engine’s fan and turbine to keep the turbine and fan on the same driveshaft while allowing both to operate closer to their optimal speeds.  This boosts efficiency (by increasing turbine speed) and reduces noise (by lowering fan speed).

According to P&W, “[t]he PW1000G engine targets double-digit reductions in fuel burn, environmental emissions, engine noise and operating costs for the next generation of commercial aircraft.”

The next stop for the PW1000G is France.  The demonstration engine is on its way to Toulouse for the next phase of testing, where Airbus will become the first aircraft manufacturer to fly the PW1000G on its own A340 flight test aircraft.