Len Conapinski


Len Conapinski is a partner at DuFour Conapinski Ha LLP.  His areas of practice include infrastructure project negotiations (particular with respect to solar and energy storage applications), equipment supply contracts, joint venture and teaming agreements, commercial and legal process management, and intellectual property.  With an MBA, a JD, an engineering degree, and extensive business experience, Len brings an ideal blend of business, technical, and legal intelligence to guide firm clients. 

Prior to founding DuFour Conapinski Ha LLP, Len served as Vice President and General Counsel for Yingli Green Energy Americas Inc., the Americas region subsidiary of China-based Yingli Green Energy Holding Co. Ltd.  Len oversaw corporate expansion and operations in the US, Latin America, and South America, and helped establish the company’s internal processes and controls for a variety of business-critical systems, including sales contract negotiations, security instruments for credit protection, trade compliance, and other legal compliance matters.

During Len’s tenure, Yingli grew to be the world’s largest manufacturer of solar panels.  Len oversaw all aspects of legal in North and South America, including legal issues for the company’s half-billion dollar US sales organization.  At Yingli, Len managed the negotiation and contract process for hundreds of millions of dollars of utility-scale solar projects as well as multi-year solar panel supply agreements. Len also coordinated Yingli’s response to one of the largest and highest-profile anti-dumping and countervailing duty petitions in US history.  

Previously, Len served as in-house counsel for Caterpillar, focusing on intellectual property and commercial matters across a range of Caterpillar business and research units.  Len managed Caterpillar software patent portfolios, as well as inventions relating to sustainable energy (batteries, inverters, wind/solar system integration), machine control systems, predictive analytics, and data aggregation.  During this time, Len helped to design and program a prototype custom patent portfolio analysis tool that integrated with Caterpillar’s internal patent database and docketing system.

Before going in-house, Len was a patent litigation attorney in a private practice in Chicago, where he worked on high profile litigation and federal appeals.  Len began his legal career serving as a law clerk to the Honorable Alvin A. Schall of the United States Court of Appeals for the Federal Circuit.

In his personal time, Len is immersed with his young children:  Legos, shape tile buildings, soccer, pillow forts with couch cushions, and searching for insects and the ever-elusive dinosaur eggs.  He is an avid reader and self-taught programmer who has designed and built several data-intensive websites in his spare time.


University of California, Berkeley (M.B.A.)

Northwestern University       (J.D., magna cum laude)

University of Notre Dame     (B.S. & B.A., cum laude)


McDermott, Will & Emery LLP

McAndrews, Held & Malloy


Yingli Solar

Caterpillar Inc.



US Court of Appeals for the Federal Circuit (law clerk)

US District Court for Northern District of Illinois (extern)