Clean Tech in Court: Green Patent Complaint Update


Two green patent lawsuits have been filed in the last few weeks in the areas of smart grid and solar.

Smart Grid

Sensus USA Inc. v. Nxegen LLC

Sensus USA filed a complaint (Sensus-Nxegen_Complaint) against Nxegen on October 19, 2011 in the U.S. District Court for the District of Delaware. 

Sensus asserts two patents against Nxegen, U.S. Patent No. 5,438,329 (‘329 Patent), entitled “Duplex Bi-Directional Multi-Mode Remote Instrument Reading and Telemetry System,” and U.S. Patent No. 7,012,546, entitled “Modular Wireless Fixed Network for Wide-Area Metering Data Collection and Meter Module Apparatus” (‘546 Patent).

The ‘546 Patent covers a transmitting device connected to a gas or water meter which transmits signals relaying data related to the meter.  The ‘329 Patent covers a receiver designed to receive signals transmitted by a remote transmitter (such as described in the ‘546 Patent). 

The receiver described in the ‘329 Patent can be located in either a fixed or remote station, enabling a vehicle to remotely receive utility data by merely driving by a meter.  Figure 1 of the ‘329 Patent depicts the different possible configurations.


This is the second lawsuit in a growing legal battle in which the two companies are each asserting patents against each other.  A previous post discussed a patent infringement complaint Nxegen filed a against Sensus in July.


HeliOptix LLC v. Enfocus Engineering Corp.

HeliOptix, a New York manufacturer of building integrated solar energy systems, filed a complaint (Helioptix_Complaint) in the U.S. District Court for the Southern District of New York on October 14, 2011 accusing its California competitor, Enfocus Engineering (Enfocus), of infringing U.S. Patent No. 7,190,531 (‘531 Patent).

The ‘531 Patent is entitled “Concentrating Type Solar Collection and Daylighting System within Glazed Building Envelopes.”  The system utilizes a plurality of miniaturized solar modules, a focusing lens and an activating mechanism attached to the solar modules for actively tracking the sun. 

Figure 4A depicts the concentrating lens (220) and the solar cell (202).  

The system is designed to utilize concentrated solar energy to provide both electric and thermal energy, and to reduce the solar gain within a building.  The system utilizes a Fresnel lens to focus sunlight onto a photovoltaic cell mounted at a distance from the lens.  In addition, the collected solar energy can also be used for thermal energy production. 

The solar collectors are miniaturized in order to enable them to be mounted in a building façade, preferably between window panes as depicted in Figure 10A. 

Due to the size of the solar modules and their spacing, daylight is able to pass through the system to light a room.

The accused product is EnFocus’s Diamond-Power Solar Panel.

David Gibbs is a contributor to Green Patent Blog.  David is currently in his third and final year at Thomas Jefferson School of Law in San Diego.  He received his undergraduate degree in Geology from the University of California, Berkeley.

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Eric Lane

Eric Lane, the founder and principal of Green Patent Law, is an intellectual property lawyer and registered U.S. patent attorney in New York and is a member of the bar in New York and California. Eric has more than two decades of experience working with wind, solar PV, CSP, biofuels, and geothermal, energy storage technologies, carbon capture and sequestration, medical devices, data communications, mechanical, chemical, internet and software.