What if the next major clean energy opportunity is all around us in the systems cities already use every day?

In this episode of Green Giants: Titans of Renewable Energy, host Wes Ashworth, President of Lee Group Search sits down with Drew Maggio, Technical Director at Highmark Building Efficiency, to explore how heat pumps, waste heat recovery, wastewater energy transfer, subway systems, data centers, thermal energy networks, and building electrification are reshaping the future of urban decarbonization.

Drew brings a rare blend of hands-on mechanical experience, engineering depth, and real-world building systems expertise. At Highmark, he works across emerging HVAC and plumbing technologies, regulatory compliance, industry partnerships, and the practical challenge of helping advanced building efficiency solutions make it from concept to installed, operating assets.

This conversation starts with the fundamentals: why heat pumps are not simply electric boilers, why coefficient of performance matters, and why building electrification requires more than swapping fossil fuel equipment for electric equipment. Drew explains how the best projects depend on insulation, sizing, design assumptions, controls, contractor familiarity, and a clear understanding of how buildings actually operate.

From there, the episode expands into a bigger idea: cities are full of hidden thermal energy. Wastewater flowing through sewer systems, heat trapped in subway tunnels, data centers rejecting excess heat, and buildings cooling year-round can all become part of a smarter thermal energy ecosystem.

Wes and Drew also discuss wastewater energy transfer, why adoption has been slower in New York than in some other cities, how thermal energy networks could allow buildings to share heat like the electric grid shares power, and why Local Law 97 is pushing building owners to rethink long-term compliance and operating costs.

This episode is especially relevant for professionals in renewable energy, HVAC, building efficiency, real estate, engineering, sustainability, infrastructure, and energy policy. It is a practical, systems-level look at how cities can decarbonize not only by generating more clean power, but by recovering, moving, storing, and sharing the energy already inside them.

Topics include:

• Heat pumps and building electrification
• Waste heat recovery from sewers, subways, and data centers
• Wastewater energy transfer and thermal energy networks
• NYC Local Law 97 and compliance-driven retrofits
• Thermal storage and flexible building loads
• Building envelope performance and project sizing
• The future of urban decarbonization

Links
Drew Maggio on LinkedIn
HIGHMARK's Website

Wes Ashworth: https://www.linkedin.com/in/weslgs/

• Email: wes@leegroupsearch.com
• https://leegroupsearch.com/green-giants-podcast/
• https://leegroupsearch.com/