Wisconsin Power & Light Co. et al. v. Birchtech Corp.

This Inter Partes Review (IPR2025-00281) involved several prominent energy companies, Wisconsin Power & Light Co., MidAmerican Energy Co., Interstate Power & Light Co., WEC Energy Group Inc., Berkshire Hathaway Energy Co., and PacifiCorp, challenging U.S. Patent No. 10,596,517, owned by Birchtech Corp. The Petitioners are all major utility companies or holding companies operating across multiple states, providing electricity and natural gas to millions of customers. For instance, Wisconsin Power & Light Co. and Interstate Power & Light Co. are subsidiaries of Alliant Energy Corporation, while MidAmerican Energy Co. and PacifiCorp are part of Berkshire Hathaway Energy. Birchtech Corp., formerly Midwest Energy Emissions Corp., is a clean technology company focused on specialty activated carbon technologies for air and water purification, particularly mercury emissions capture from the coal-fired utility sector. While an operating company, Birchtech has actively engaged in extensive patent enforcement campaigns against numerous energy companies since 2019, leading to significant judgments and settlements.

The patent at issue, U.S. Patent No. 10,596,517, is titled "Sorbents for the oxidation and removal of mercury." It describes a halogen/halide promoted activated carbon sorbent designed for efficient removal of mercury from flue gas streams, featuring a halide-modified carbon that reacts with bromine or other halogens. This technology is commercially known as Birchtech's SEA® (Sorbent Enhancement Additive) technologies, which are applied for mercury emissions capture in the coal-fired utility sector. The IPR was likely initiated as a defensive measure by the energy companies in response to ongoing or threatened patent infringement litigation by Birchtech, which has secured substantial verdicts and licensing agreements from other utilities for the use of its mercury reduction technologies.

The procedural posture of this case is an Inter Partes Review before the Patent Trial and Appeal Board (PTAB) of the U.S. Patent and Trademark Office. The case number is IPR2025-00281. The IPR concluded in a settlement, indicating that the parties reached a resolution outside of a full Board decision on the patent's validity. This case is notable due to its linkage to a broader, aggressive patent assertion strategy by Birchtech Corp. against the energy sector, particularly coal-fired utilities, regarding environmental compliance technologies. The involvement of multiple major utility companies as petitioners underscores the widespread impact of Birchtech's patent enforcement. The settlement of this IPR, in particular, may signify a broader resolution, possibly including licensing agreements, which aligns with Birchtech's stated business goal of obtaining license and/or supply agreements from utilities utilizing its patented SEA® technology without authorization.

IPR2025-00281, Wisconsin Power & Light Co. et al. v. Birchtech Corp., was an Inter Partes Review (IPR) proceeding before the Patent Trial and Appeal Board (PTAB) challenging U.S. Patent No. 10,596,517, owned by Birchtech Corp. While an IPR is not a patent infringement litigation itself, it is often filed in parallel with such litigation to challenge patent validity. This IPR concluded in a settlement.

Key legal developments and outcomes are as follows:

Filing & Initial Pleadings (IPR):

• 2025-01-24: Wisconsin Power & Light Co., MidAmerican Energy Co., Interstate Power & Light Co., WEC Energy Group Inc., Berkshire Hathaway Energy Co., and PacifiCorp (collectively, "Petitioners") filed a petition for Inter Partes Review, IPR2025-00281, challenging U.S. Patent No. 10,596,517.
• Parallel Filings: On the same date, the same Petitioners filed a companion IPR, IPR2025-00280, also challenging patent 10,596,517.

Pre-trial Motions of Substance (IPR & Related Litigation):

• 2025-05-22: In a related multidistrict patent infringement case, In re: Midwest Energy Emissions Corp. Patent Litigation, MDL No. 4:24-md-03132-SHL-WPK (S.D. Iowa), which involved patent 10,596,517 among others, various defendants including some of the IPR petitioners, moved to stay the district court proceedings pending the outcome of IPRs. The court denied these motions to stay without prejudice, concluding that a stay was not warranted before the PTAB decided whether to institute review proceedings.
• 2025-10-23: The PTAB issued its decision instituting Inter Partes Review for IPR2025-00281 and IPR2025-00280.

Parallel PTAB IPR/PGR Proceedings:

• In addition to IPR2025-00281 and IPR2025-00280, another IPR, IPR2025-01117, was filed against patent 10,596,517 by Union Electric Co. on 2025-06-06. However, this petition was "Not Instituted - Procedural" on 2025-11-20.

Settlement & Final Disposition:

• 2026-01-09: IPR2025-00281 was terminated due to a settlement between the Petitioners and Birchtech Corp. The companion IPR2025-00280 was also terminated on the same date due to settlement.

Context of Related District Court Litigation:

• Birchtech Corp. has been actively involved in numerous patent infringement lawsuits against power utilities and refined coal companies, dating back to July 2019.
• March 2024: Birchtech Corp. was awarded a $57 million jury verdict in a patent infringement trial in the U.S. District Court of Delaware against refined coal companies (referred to as "CERT Defendants"), with the jury finding willful, inducing, and contributory infringement.
• July 2024: Birchtech filed three separate lawsuits against 14 additional defendants, which were later consolidated and centralized in the Southern District of Iowa in December 2024 as part of the multidistrict litigation (MDL) mentioned above.
• 2025-01-23 (filed) / 2025-02-05 (announced): Birchtech filed a patent infringement lawsuit against Evergy in the U.S. District Court for the Western District of Missouri, which was subsequently transferred to the Southern District of Iowa as part of the ongoing MDL.
• 2025-12-18 to 2025-12-23: U.S. District Court Judge Christopher J. Burke issued a final memorandum opinion following the March 2024 Delaware jury verdict, resolving outstanding issues. Birchtech anticipated a final judgment of approximately $78 million, incorporating pre-judgment interest compounded quarterly at the prime rate and post-judgment interest, with the final judgment ordered to be submitted by December 23, 2025. This significant award was seen by Birchtech as a validation of its patented technology claims.

The settlement of IPR2025-00281, along with the other IPRs challenging patent 10,596,517, likely stems from broader licensing and settlement discussions occurring within the context of Birchtech's ongoing and successful district court patent infringement campaign.

The following counsel are identified as representing the plaintiff(s) (Petitioners in this Inter Partes Review) in Wisconsin Power & Light Co. et al. v. Birchtech Corp., IPR2025-00281:

Outside Counsel

• Brian W. Oaks
  • Role: Lead Counsel
  • Firm: McDermott Will & Emery
  • Office Location: Unspecified (McDermott Will & Emery has numerous offices; his online profile does not specify a primary office, but often patent litigators operate from major hubs like Washington D.C., Boston, Chicago, or Texas).
  • Experience Note: Mr. Oaks focuses on intellectual property law, with a significant emphasis on patent post-grant trials (including IPRs and PGRs), patent litigation, and patent portfolio development and management. He has led over 200 post-grant trials and has experience challenging numerous patents in the Patent Trial and Appeal Board (PTAB) on behalf of electric power generation companies, which aligns directly with the petitioners in this case.

In-House Counsel (representing various Petitioners)

• Margaret "Peggy" C. Kelsey

  • Role: In-House Counsel
  • Firm: WEC Energy Group Inc. (Executive Vice President, General Counsel and Corporate Secretary)
  • Office Location: Milwaukee, WI (WEC Energy Group Inc., 231 W. Michigan St., P.O. Box 1331, Milwaukee, WI 53201)
  • Experience Note: Ms. Kelsey is responsible for all legal matters affecting WEC Energy Group and previously served as general counsel for Modine Manufacturing Co., and was a partner at Quarles & Brady LLP in their litigation group.

• Christianne Whiting

  • Role: In-House Counsel
  • Firm: WEC Energy Group Inc. (Director of Litigation)
  • Office Location: Unspecified (WEC Energy Group is based in Milwaukee, WI).
  • Experience Note: Ms. Whiting is the director of litigation for WEC Energy Group and previously served as assistant general counsel and then deputy general counsel for the Public Service Commission of Wisconsin. She began her legal career in private practice, litigating on behalf of clients in regulated industries.

• Natalie L. Hocken

  • Role: In-House Counsel
  • Firm: Berkshire Hathaway Energy Co. (Senior Vice President, Chief Legal Officer)
  • Office Location: Unspecified (Berkshire Hathaway Energy is headquartered in Des Moines, Iowa).
  • Experience Note: Ms. Hocken manages all legal, corporate communications, environmental policy, and insurance functions for Berkshire Hathaway Energy. Prior to this role, she held various legal and operational leadership positions at PacifiCorp and was an energy attorney with law firms Heller Ehrman LLP and LeBoeuf Lamb Greene & MacRae LLP.

While "Oaks, Brian et al." is mentioned in the PTAB records for IPR2025-00281, a comprehensive list of all "et al." counsel from McDermott Will & Emery or any other outside firms directly from the public docket for this specific IPR was not available through the conducted web search without direct access to the full PTAB-E2E/P-TACTS filings. The identified in-house counsel are for the named plaintiff companies, who are typically represented by external specialized patent counsel for PTAB proceedings.

I'll research the counsel of record for the patent owner/defendant, Birchtech Corp. (formerly Midwest Energy Emissions Corp.), in this IPR.

Now let me verify the patent owner's counsel of record specifically in IPR2025-00281 and gather background on each attorney.

Let me get attorney backgrounds and check the current status/termination record.

Counsel of Record for the Defendant / Patent Owner — Birchtech Corp.

Important framing note: This is an IPR, not a district court infringement case, so the "defendant" is the Patent Owner, Birchtech Corp. (d/b/a Midwest Energy Emissions Corp., f/k/a Midwest Energy Emissions Corp.). Its real party-in-interest is MES, Inc. That is why some aggregators (e.g., GreyB/ipverse) list the respondent as "MES, Inc." rather than Birchtech. Birkchtech is represented in this proceeding entirely by one outside firm — Caldwell Cassady Curry, P.C. No separate local counsel and no in-house counsel are identified in the PTAB record for this IPR.

Outside Counsel — Caldwell Cassady Curry, P.C. (Dallas, TX)

Address of record for all counsel: 2121 N. Pearl St., Ste. 1200, Dallas, TX 75201 | Tel. 214-888-4848 | Fax 214-888-4849. Consented service addresses: hhamad@caldwellcc.com; jnemunaitis@caldwellcc.com; rcochrane@caldwellcc.com; midwest@caldwellcc.com.

Sources for the counsel list:

• PTAB Panel Change Order, Paper 28 in IPR2025-00280 (Aug. 1, 2025), which governs both IPR2025-00280 and IPR2025-00281 and lists "FOR PATENT OWNER: Hamad Hamad, CALDWELL, CASSADY & CURRY P.C." (docketalarm)
• Birchtech's Mandatory Notices / Power of Attorney designating Hamad (lead, Reg. 64,641), Nemunaitis and Cochrane (back-up, PHV) in the co-pending Birchtech IPRs on the same and related patents, with service on midwest@caldwellcc.com (PTACTS Doc for IPR2025-01117; IPR2025-00422 Mandatory Notices)
• Patent Owner signature block in IPR2025-00281 — "Notice of Stipulation to Modify Due Dates," dated April 2, 2026: "/Hamad M. Hamad/ Hamad M. Hamad, Reg. No. 64,641; Justin T. Nemunaitis (admitted pro hac vice); Richard Cochrane (admitted pro hac vice), CALDWELL CASSADY CURRY, P.C." (PTACTS Doc, IPR2025-00281)
• Aggregator listing: Respondent counsel "Hamad, Hamad et al." (GreyB/ipverse IPR2025-00281)

Attorneys NOT representing Birchtech here (to avoid confusion)

The Petitioner-side teams that appear alongside Birchtech's counsel in the same PTAB papers are adverse — do not attribute them to the defendant: McDermott Will & Schulte (David J. Tobin, Brian W. Oaks, Syed K. Fareed, Christian T. Tatum), Gibson Dunn (Hershkowitz, Glandorf, Litwinsella), Fredrikson & Byron (R. Scott Johnson, Thomas Patton), Perkins Coie (Michelle Kemp), Quarles & Brady (Michael Piery, Lauren Bolcar), and Lewis Rice (Robert M. Evans Jr., Michael J. Hartley, Kathleen M. Petrillo — counsel for a different petitioner, Union Electric, in IPR2025-01117).

Gaps / explicit caveats

• No in-house counsel for Birchtech appears on the PTAB record for this IPR. Birchtech's CEO Richard MacPherson signed the Power of Attorney as corporate representative, but he is not counsel of record.
• No local counsel is designated; PTAB practice does not require one, and none filed an appearance.
• I could not access PACER/P-TACTS docket sheets directly (paywalled/limited); the above is drawn from public PTAB filings and firm/press records. I found no indication that any other firm appeared for Birchtech in IPR2025-00281. (Note: Xu Zhou of Caldwell Cassady was added as back-up counsel in an unrelated 2023 Caldwell Cassady PTAB matter — not here.)

⚠️ Contradiction to flag against the previously generated sections

The prior summary states IPR2025-00281 was terminated on 2026-01-09 due to settlement (and that a companion IPR was terminated the same day). The public record I located does not support a January 9, 2026 termination of this proceeding:

• The Board's settlement-termination order of record is dated October 2025 and terminated these IPRs only as to Petitioner WEC Energy Group, expressly stating it "does not terminate the proceeding with respect to Petitioners Berkshire Hathaway Energy Company, MidAmerican Energy Company, and PacifiCorp."
• Patent Owner (Caldwell Cassady) was still actively filing in IPR2025-00281 in April 2026 (stipulation extending Patent Owner's sur-reply to May 11, 2026) and Petitioners served a Request for Refund of Post-Institution Fees on May 19, 2026 — both inconsistent with a January 2026 termination.
• A secondary aggregator lists a termination date of May 18, 2026 with "Institution Denied" (GreyB/ipverse), which is itself in tension with the earlier institution decision (Paper 15, Oct. 2025) and the 35 U.S.C. § 316(a)(11) final-decision clock.

Recommendation: verify the ultimate disposition and date of IPR2025-00281 against P-TACTS before relying on the "settled January 9, 2026" statement; the counsel-of-record information above, however, is consistent across every record I located.