Geothermal Heats Up!

Mark Metzner joined CDM Smith last year. He has spent two decades working on major geothermal utility programs across the United States and Canada. His expertise includes district energy systems, ground instal­la­tion elements for major commercial geothermal systems and structuring geo exchange utility rates. In a recent interview, he discussed why geothermal energy is on the rise across North America.

Why is geothermal a good option for decar­boniza­tion?

While not a silver bullet, it’s a good, shiny, brass addition to our arsenal as humanity takes on the challenge of climate change.

The allure of this technology lies in its simplicity and elegance, coupled with its significant envi­ron­men­tal benefits: greenhouse gas reduction, carbon footprint reduction, and enhanced energy efficiency. It’s a very simple and resilient technology that ticks a lot of essential boxes; foremost among them is that you’re not burning fossil fuels, which is a large issue in every building. Instead, geothermal relies on electricity to shift energy back and forth between the ground and the building, or even between various buildings.

That said, the source of electricity powering these ground-source heat pumps remains significant. Electricity generated from coal-fired plants or natural gas contributes more to the carbon footprint. In contrast, hydro dams, wind, solar, or a combination thereof result in nearly zero carbon footprint.

How do you assess the viability of geothermal for a particular project or site?

Geothermal technology is applicable in 95 to 98% of all project locations from a technical point of view. Only a few geological and atmospheric areas exist where it doesn’t align, but these cases are rare exceptions.

Ideally, the project would take place on a greenfield site—a completely vacant area without any prior development. This scenario allows for seamless collab­o­ra­tion between building architects and mechanical engineers, enabling iterative adjustments in the design process for optimal outcomes. Addi­tion­ally, there are no constraints related to cont­a­m­i­nated soil or space limitations.

However, when dealing with a brownfield site—an existing property with prior development—you are generally dealing with the hand dealt and inheriting certain conditions that cannot be altered. Whether it’s existing structures within the building or limitations on the site itself, these factors shape the project’s scope and approach.

When clients seek energy solutions for their projects, we should be evaluating the inclusion of a geothermal component. Our internal expertise should guide us: if it’s a viable option, we present it confidently. If not, we need to address it with our client and explain the reasons behind our recom­men­da­tion.

How important is stakeholder engagement on these projects?

Stakeholder engagement is huge. Once people understand the concept of geothermal, they seem to be genuinely excited about its potential. Therefore, getting stake­hold­ers engaged across the board is vital to educate people on what the technology can and cannot do.

Geothermal systems are basically hidden, which is part of their beauty because they don’t impinge on the visuals of a building. If you were to drive by a building that’s powered by geothermal, there’s not going to be any indication on the outside, whereas something like solar panels is going to be glaringly obvious.

Given this invis­i­bil­ity, we need stakeholder engagement to raise awareness and showcase how these systems function and their overall benefits.

What upcoming project are you most excited about?

Currently, I hold the position of Vice Chair for the ANSI/CSA C448 standard—an essential binational guideline governing the design and instal­la­tion of ground source heat pump systems. This standard is poised for public review in the coming months, with publication scheduled for early Fall 2024.

My involvement in this initiative dates back to 2014. By aligning the United States and Canada, we’ve achieved consistency and uniformity in instal­la­tion practices. I firmly believe that this standard will bring much-needed clarity and consistency to the geothermal industry, ultimately benefiting both profes­sion­als and customers.

For more information about geothermal energy and utility thermal energy networks, visit cdmsmith.com/energy.