🌐 The Underground Climate Economy: Modernizing Cities from Below

Cities have nowhere to go but down to tap new renewable energy sources, strengthen climate resilience, cut costs, and enhance urban life for their residents above.

This week, we delve into the underground climate economy, a Supercool trend we've identified after completing our first 20 podcast episodes and newsletter issues since launching in July.

For space-constrained cities contending with growing urbanization (55% of humanity lives in cities, which will reach 70% by 2050), establishing operations below ground presents exciting opportunities to:

• Modernize infrastructure

• Localize clean energy generation

• Retain control of their climate destiny—diminishing reliance on regional, state, and federal governments whose interests and timelines for action are not always swift.

Time is of the essence; while cities comprise just 3% of the earth’s land, they account for 75% of global carbon emissions.

The underground climate economy centers on three accelerating low-carbon technologies.

1. Automated Waste Removal

2. Sewer Heat Recovery

3. Networked Geothermal Energy

Take me to the podcast:

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1. Automated Waste Removal: Piping Out Trash in Jetson-LIke Pneumatic Tubes

Since opening in 1971 in Orlando, Florida, Disney World has captivated imaginations. While most of the kingdom’s magic occurs above ground, there are still wonders below. The park operates the first automated waste collection system ever installed in the U.S., utilizing a network of pneumatic tubes to whisk away visitor trash at speeds up to 40 miles per hour.

No malodorous, diesel-fume-belching garbage trucks ever enter Disney World. They simply don’t exist there.

But it’s not magic. It’s Envac, a Swedish company that pioneered automated underground waste collection in the 1960s and has since installed 1,200 systems in over 40 countries.

Pamplona, Spain, has the greatest traditional bullfighting on earth. Like Madrid, Barcelona, and over twenty other Spanish cities, it has a modern, low-carbon underground waste collection system. And so do cities stretching from Stockholm to Singapore.

Bergen, Norway, has implemented the world's most extensive underground trash removal system, which saves $2 million annually on waste management.

Wembley Park, an 85-acre district surrounding London’s Wembley Stadium, paid $16 million for its underground system. It serves 25,000 residents plus hotel guests, office workers, and thousands of stadium event-goers. The local government saves $625,000 annually on trash hauling (from $900K  to $275K) and has a recycling compliance rate four times above the national average.

In episode 12, I spoke to Joakim Karlsson, CEO of Envac. He described how automated underground waste collection on Roosevelt Island in New York City enabled continuous trash removal after Superstorm Sandy in 2012. It was the only city neighborhood to do so.

By going underground and eliminating conventional curbside trash pickup, cities benefit from:

• Lower operational costs

• Less wear and tear on city streets from heavy garbage trucks

• Greater resilience against extreme weather storms

• Up to 90% reduction in carbon emissions

• Up to 5X greater compliance with recycling mandates

City residents get a quality of life boost from::

• Cleaner streets 

• Quieter neighborhoods

• Fresher air

• Less road congestion 

• More street space for urban amenities like bike lanes, trees, benches, and outdoor cafe seating.

Last month, the Polo Towers in NYC’s Harlem neighborhood became the first public housing complex in the U.S. to operationalize automated underground waste collection for its 4,000 residents.

Guess who no longer comes to visit the buildings. 

Answer: Rats.

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2. Sewer Heat Recovery: Sewers Are Batteries 

Lynn Mueller presumed he was in the twilight of his career in the heating and cooling industry when the idea struck. The millions of single-use hot water instances from showers, clothes washers, and dishwashers that occur daily in cities could be worth a fortune.

Lynn just had to invent a way to recapture the heat spiraling down drains into sewers and then make it simple and affordable for cities to adopt.

All that warm water continuously flowing through sewer pipes is like an always-charged battery. Reclaim the heat, and make a mint.

For Lynn, climate change wasn’t theoretical. A native Canadian, he began his career with the Hudson Bay Company, delivering freezers to fur trappers in Canada’s Northwest Territories. Summer season had grown too long to keep their furs continually frozen in ice.

Driven by profit and climate motivations, Lynn did what many sixty-somethings do: He went on a world tour. Only Lynn’s tour—from Albania to Beijing—was of global sewer systems working on heat recovery. 

Back home, Lynne devised an elegant closed-loop system that plugs directly into existing city infrastructure. His Sharc system uses:

1. Heat exchangers to remove heat from flowing sewer water and

2. Heat pumps to transfer that heat into clean water, which cities use for their networked heating systems.

Under Mayor Gregor Robertson, Vancouver bought and installed the first Sharc systems for the 2012 Olympics. These systems provided space and water heating to the Olympic Village in the city’s False Creek neighborhood.

Today, Vancouver’s Sharc systems provide low-carbon space and water heating to more than 6,000 apartment units and 6.4 million square feet of mixed-use buildings.

Its operation is so successful that the Neighborhood Energy Utility (NEU) in False Creek has become a city profit center. It provides a return on investment to taxpayers, keeps energy rates affordable for customers, and diminishes the city’s reliance on natural gas.

I spoke with Lynn Mueller in episode 2 about Vancouver. We also discussed Sharc’s project in Washington, DC, which uses sewer heat recovery to provide heating and cooling to the DC Water Administrative Building. In Denver, the National Western Center uses Sharc technology to heat and cool its one-million-square-foot complex. It’s the largest sewer heat recovery system in the U.S.

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3. Networked Geothermal Energy: Geothermal Is The New Solar

Sewers are one source of underground energy available to cities. Cities are going even deeper to tap geothermal energy.

In two critical aspects, geothermal is even more attractive than solar energy to cities:

1. Limited land mass is not a scale constraint.

2. The earth is warm day and night, making geothermal always available.

The history of urban geothermal energy in America dates back to the 19th century. Before the Wright Brothers invented flight or the first Ford Model-T rolled off an assembly line, the residents of Boise, Idaho, enjoyed the cost and comfort benefits of heating their homes with geothermal. 

Today, a 20-mile network of underground pipes stretches from Boise’s nearby foothills throughout its downtown core, pulling up heat from 3,000 feet down below. Geothermal energy provides clean, emissions-free heating to over 100 downtown buildings, totaling 6 million square feet of indoor space. It’s the largest geothermal system in America. 

Another of Boise’s geothermal benefits? It melts ice and snow off sidewalks in winter.

In episode 5, I spoke with Tina Riley, Boise’s Geothermal Coordinator. Tina spent the first half of her career working as a geologist in the oil and gas industry. Today, her skillset and expertise—and those of her former colleagues—are in demand as the geothermal industry expands.

That expansion is happening in places like Framingham, Massachusetts, where Eversource, the largest natural gas utility in New England, built and now operates a networked geothermal energy system. The system draws heat directly below the city and channels it to dozens of downtown buildings.

It’s the first such system operated by a fossil fuel company in America. It’s also a shining example of how the clean energy transition is taking root, how underground climate technologies are essential to its success, and how even entrenched fossil fuel companies can contribute to and benefit from advancing the low-carbon economy.

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Here are a couple more geothermal notes on the way out:

Inner City Net-Zero Energy Schools in Baltimore Tap Geothermal Energy

A combination of solar on the roof, geothermal below the ball fields, and a super-tight energy-efficient building envelope enables Holabird Academy, a modern K-8th grade school in Baltimore, to generate more clean, renewable than the total amount of energy it consumes.

In episode 8, I spoke with Stephanie Novak Pappas, Holabird’s award-winning Principal, about the impact on student performance, teacher recruitment, and community engagement.

Dandelion Makes Home Geothermal The Cheapest Option For New Homes

Kathy Hannun is a relentless innovator. She spent years at Google X, Alphabet’s moonshot factory for world-changing business ideas, reviewing renewable energy technology. Geothermal energy captured her imagination and set her on a path, leading her to found and grow Dandelion Energy into the leading home geothermal company in the country.

In episode 14, I spoke with Kathy Hannun, Dandelion’s founder and President. The company now works with a national network of contractors and directly with Lennar, the nation’s second-largest homebuilder. She outlined how, for new single-family and multifamily homes, geothermal energy is now the country's cheapest heating and cooling source.

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