Our Leadership Team

Guided by veteran executives who pioneered the RNG space,

Viridi’s team is a leader in waste-to-energy project development. Collectively, the team has more than 100 years of experience developing and operating energy assets and has successfully developed more than 30 RNG projects.
With significant equity backing led by Warburg Pincus and additional funding from Green Rock Energy Partners, we are well-positioned to identify strong opportunities and invest quickly, leveraging our expertise and capital to unlock greater value.
Andy Kelleher is a seasoned energy executive with significant experience in the trading sector. In addition to his strategic leadership role as Executive Chairman at Viridi, Kelleher is co-founder and Managing Partner of Green Rock Energy Partners. Previously, he held senior positions at Glencore, JP Morgan and ConocoPhillips.
With more than 15 years of experience in the landfill gas-to-RNG industry, Chief Executive Officer Dan Crouse joined Viridi in 2022 from Air Liquide, where he was responsible for development, construction, and operations activity across the United States. He also served as CEO of Air Liquide Advanced Technologies, U.S., overseeing all U.S.-based RNG businesses. Previously, Crouse led Keystone Renewable Energy, a closely held business focused on biogas development, where he was CEO.
Chet Benham has held leadership positions in the gas separation and biogas processing business for the past 15 years. Before Viridi, he spent more than 10 years working for Air Liquide, spearheading gas processing, biogas, and midstream development projects. Benham also held the title of CEO of Air Liquide Advanced Technologies, U.S.
Matthew Innamorati joined Viridi in 2022 from Mettle Midstream Partners, where he was co-founding partner and Chief Executive Officer of the Pearl Energy and NGP-backed company that offers midstream infrastructure services to energy companies throughout North America. He also was a co-founder & CFO of Align Midstream, which was sold to Enable Midstream in 2017.
Mark Cresanti joined Viridi with more than two decades of operations leadership experience and several recent years of work in the biogas-to-RNG space. From 2020 to 2023, he was Director of Operations for RNG Operating Assets at Air Liquide Advanced Technologies, responsible for managing the operations team supporting new and existing biogas-to-RNG projects nationwide. Prior to that, he was the Northeast Director of Operations for the same firm and also worked for The Dow Chemical Company.
Jake Crouse has worked in the landfill gas-to-RNG industry for the past 19 years and was responsible for nine landfill gas-to-RNG projects, overseeing each project from development through to operations. Crouse was previously the Vice President of Investment Development for Archaea Energy, Director of Biogas for Air Liquide, and President of Keystone Renewable Energy.
Dana Husnay joined Viridi from Air Liquide Advanced Technologies, where he was responsible for all U.S. biogas operations in his role as Director of Operations and Risk Management. Husnay also worked as Director of Operations with Archaea Energy, where he managed engineering activities related to gas separation membrane technology.
Bill Keller brings to Viridi more than 15 years of diverse RNG experience, including specialization in advanced gas processing technologies and equipment. His previous employment includes Air Liquide, Archaea Energy, and Unconventional Gas Solutions. Keller has honed expertise in management, development, manufacturing, and sales, in addition to RNG offtake projects and project development.
Prior to joining Viridi, Evan Kirchen was CEO of Orbital Renewables for 3 years, delivering investment-grade RNG projects from a wide variety of feedstocks throughout North America. Kirchen also has over 20 years in the natural gas processing sector. He served as VP of Engineering & Construction at Williams, leading a $6 billion capital asset expansion project.
Dan Shirley joined the Viridi team after a lengthy career in tax-related roles across the energy and infrastructure sectors. Most recently, he worked as the outsourced tax director for a publicly traded regional bank and as Senior Advisor to a newly launched energy and infrastructure firm. Previously, he was Head of Tax at Rice Energy. Before that, he was a tax partner at one of the “big four” accounting firms, focused on state and local tax and tax credits across the energy and financial services spaces.
Stephen Modory came to Viridi after working as Senior Associate at Lang Partners, a Dallas-based single-family office. His past experience also includes working as an Associate at First Reserve, an energy-focused middle market private equity firm, and also as an Investment Banking Analyst at Barclays.
Prior to joining Viridi, Tamara Siskind led U.S. sales for Wärtsilä's Puregas CA biogas upgrading technology. Her experience also includes more than 10 years as an engineer in the oil & gas sector, with roles spanning operations, commissioning, and capital project development. Prior project experiences include facility scoping for a grassroots petrochemical plant in Southeast Asia and commissioning of gas treating equipment for an offshore oil platform at the DSME Shipyard in Okpo, South Korea.
Joshua Bush brings more than two-and-a-half decades of management, engineering, design, and construction expertise to Viridi. With a five-year track record working specifically in the renewable energy space, he also has experience in the petrochemical, refining, natural gas, wastewater, manufacturing, and paper mill industries. In his previous role as Regional Construction Manager at Montauk Renewables, Bush helped lead the successful development, construction, and commissioning of new RNG facilities, while also supporting existing assets nationwide.
Andy DiFonso has been active in the landfill gas-to-RNG industry for the past 11 years. Before joining Viridi, he was Lead Project Manager of all development activities for more than 10 landfill gas and AD projects. DiFonso previously worked with Air Liquide as a Biogas Project Developer and Venture Engineering as a mechanical engineer.