IP Law Daily Infringement suit over solar-panel roof mounts to proceed in part
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Monday, April 4, 2016

Infringement suit over solar-panel roof mounts to proceed in part

By Thomas Long, J.D.

Devices made and sold by PanelClaw, Inc., for mounting solar panels to building roofs did not infringe a SunPower Corp. patent for a photovoltaic roofing assembly, as a matter of law, the federal district court in Wilmington, Delaware, has decided (SunPower Corp. v. PanelClaw, Inc., April 1, 2016, Thynge, M.). PanelClaw’s accused products could, however, infringe another SunPower patent. The court rejected PanelClaw’s arguments that the second patent’s asserted claims were invalid.

Patents-in-suit. Plaintiff SunPower developed high-efficiency solar power solutions for private residences, businesses, utilities, and governmental customers. Defendant PanelClaw made mounting products that consisted of a support for a solar panel, a “claw” for securing the panel to the support, and, in some cases, a wind deflector. According to SunPower, PanelClaw’s “Polar Bear” and “Grizzly Bear” products competed with SunPower’s “T5” and :T10” product lines in the market for photovoltaic systems on commercial building roofs. The T5 and T10 product lines allegedly embodied the inventions of two patents held by SunPower: U.S. Patent Nos. 5,505,788 (“the ’788 patent”) and RE38,988 (“the ’988 patent”).

The ’788 patent, titled “Thermally Regulated Photovoltaic Roofing Assembly,” was filed in 1994, issued in 1996, and expired in 2012. The invention generally related to a photovoltaic roofing assembly, and in particular to a photovoltaic roofing assembly which could regulate the temperatures experienced by the solar cells and required no roof penetrations for hold-down to the roof surface. The ’988 patent, titled “Lightweight, Self-Ballasting Photovoltaic Roofing Assembly,” a reissue of U.S. Patent No. 5,746,839 issued in 1998, was filed in 2003 and issued in 2006. The invention generally related to a photovoltaic roofing assembly, and in particular to a lightweight photovoltaic roofing assembly requiring no roofing penetrations and which resisted wind up-lift due to specialized component geometry and by acting as an integral assembly.

Infringement suit; IPR proceedings. SunPower filed an infringement suit against PanelClaw; PanelClaw then filed petitions for inter partes review (IPR) of the asserted patents. The court stayed the lawsuit pending resolution of the IPRs.

The USPTO granted institution of IPR with respect to five claims of the ’988 patent but denied institution of IPR with respect to the rest of the asserted claims of the ’988 and all asserted claims of the ’788 patent. In a final written decision, the USPTO found the reviewed claims unpatentable due to anticipation.

The stay in the civil suit was lifted, and PanelClaw moved for summary judgment of noninfringement of the asserted claims of the ’788 patent and that the asserted claims of the ’988 patent were invalid due to indefiniteness, lack of enablement, and failure to meet the written description requirement. PanelClaw also contended that the claims of the ’988 patent were invalid as inoperative and lacking utility.

Noninfringement of ’788 patent. Claim 1 of the ’788 patent described a photovoltaic roofing assembly comprising, among other things, photovoltaic modules “disposed as a layer” on top of a roofing membrane. According to PanelClaw, its accused products did not meet the “disposed as a layer” limitation. Pointing to prior art references, PanelClaw contended that the term “disposed as a layer” meant that the photovoltaic modules were arranged as an overlying surface on top of the roofing membrane. Under this construction—which had been adopted by the Patent Trial and Appeal Board during the IPR proceeding—PanelClaw said, its accused products could not infringe because, when assembled with photovoltaic panels, those products supported the panels at an angle with gaps of exposed roof between rows.

The court adopted the Board’s construction and determined that PanelClaw’s accused products did not infringe the ’788 patent. The evidence showed that the Grizzly Bear and Polar Bear products both had rows of panels with significant gaps between them leaving the roof exposed in those gaps. With such an arrangement, the photovoltaic modules could not perform the functions of the invention—that is, could not “perform the multiple functions normally provided by a roofing paver, including ballast, UV protection, and weather protection for the membrane and insulation layers below”—and they did not meet the requirement that “the photovoltaic modules or integral units, as the case may be, are arranged as an overlying surface on top of the roofing membrane.” Therefore, the court granted PanelClaw’s motion for summary judgment of noninfringement of the ’788 patent.

Invalidity of ’988 patent—indefiniteness. Each of the asserted claims of the ‘988 patent recited a “photovoltaic assembly,” which PanelClaw noted comprised a photovoltaic module and a spacer secured to the bottom of the photovoltaic module that creates an “open region” underneath the module and “access openings.” Each of the claims included the language “whereby wind uplift forces are resisted when said photovoltaic assembly is mounted to a support surface” (“the Whereby Clause”).

According to PanelClaw, the Whereby Clause was indefinite because it had no discernible scope, as every object on Earth resisted some amount of wind uplift forces. The structural characteristics that would achieve the “whereby” language—for example, aerodynamics, size, shape, and weight—were not claimed.

The court determined that PanelClaw failed to meet its burden of demonstrating indefiniteness. An expert’s declaration stated that a person of ordinary skill in the art would understand the Whereby Clause to refer to aerodynamic features of the claimed assemblies. The court rejected the argument that the Whereby Clause was not capable of construction, citing another case involving the same patent, in which the court construed the claim.

Invalidity of ’988 patent—enablement, written description, inoperativeness. PanelClaw also argued that the asserted claims of the ’988 patent did not teach any assembly that was able to resist wind uplift force using only an individual photovoltaic panel and a spacer. According to PanelClaw, the claims were directed to individual “assemblies” made of a single panel and a single spacer with no mention of the perimeter securement. PanelClaw further argued that embodiments of the invention described by the patent stated that “perimeter securement” was needed for the invention to function.

The court rejected PanelClaw’s contention as conclusory attorney argument, not evidence. Moreover, specific aspects of a preferred embodiment were not required to be incorporated into claims that did not recite such aspects. Finally, SunPower’s expert opined that a person of ordinary skill in the art would understand that the invention resisted wind uplift not by weight alone by because of the aerodynamic features of the assemblies. According to the expert, a skilled person could readily understand how to build the claimed assemblies. Therefore, the court denied PanelClaw’s motion as to invalidity.

The case is No. 1:12-cv-01633-MPT.

Attorneys: Annamartina Tyreus Hufnal (Fish & Richardson, PC) for SunPower Corp. Frederick L. Cottrell, III (Richards, Layton & Finger, PA) and Lucas Silva (Foley & Lardner LLP) for PanelClaw Inc.

Companies: SunPower Corp.; PanelClaw Inc.

MainStory: TopStory DelawareNews

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