Happy New Year to our readers, and congratulations! You are helping to change the world. Hang on to your hat, and keep your families safe. We unquestionably have serious problems, but from a clean energy standpoint, we are beginning to turn the corner.

Sales of heat pumps, clean water technology and electric vehicles continue to soar worldwide. Reuters reported in November 2023 that, following a lead from Europe, meetings in California between climate envoys for the United States and China — John Kerry and Xie Zhenhua — have resulted in the two countries saying they support a declaration by G20 leaders to triple global renewable energy capacity by 2030. 

They also agreed to “accelerate the substitution for coal, oil and gas generation,” resulting in “meaningful absolute power sector emission reductions” this decade. 

Recent data from the International Energy Agency shows that carbon dioxide emissions peaked in 2023, with current global government policies resulting in a decline that is too slow, and new 2023 pledges resulting in a more encouraging decline. In addition, the United States and China agreed to attack methane and work toward a circular economy to cut plastic waste and water pollution. Let’s hope these are more than only promises.

For the first time, China stated it would include noncarbon dioxide greenhouse gases such as nitrogen oxide in its 2035 national climate plan and specific actions to curb methane emissions, major sources of global emissions. The United States has already established policies to attack methane emissions; tougher rules are expected soon.

The Next Big Thing for Buildings: Wastewater Energy Recovery

Although I’ve reported on wastewater energy recovery in the past, my recent visits to projects around North America have confirmed for me that the technology has moved well beyond wishful thinking and established itself as a proven renewable technology, offering superb technical and economic performance. Existing projects and the buzz among municipal government planners both underscore that its potential will be huge and its business case impossible to ignore. 

I’m expecting awareness of wastewater energy recovery to accelerate significantly during 2024.

It’s a very simple technology with relatively fast paybacks that creates a compelling story: cost savings for building owners, a new and meaningful revenue stream for cities, and significant greenhouse gas reductions for everyone.

One of the biggest projects in North America is the National Western Rodeo in Denver, where management is upgrading and adding buildings, including about 1 million square feet of new indoor spaces, on its 250-acre property. Approximately 90% will now be cooled and heated using mostly wastewater energy.

The rodeo has secured the rights for energy from a nearby 72-inch sewer trunk line. “This project is significant for waste energy transfer systems,” says Lynn Mueller, CEO of Sharc Energy and one of the pioneers of the North American generation of the technology. “They are doing tours every week.”

About 80% of the load in Denver is for cooling, and the first five buildings connected are already saving about 30,000 gallons of water every day that would otherwise have been used by cooling towers. “When the world is starved for water, especially the U.S. West Coast, it’s a big deal to save 10 million gallons of water a year,” he notes.

It is also an emblematic project for Denver, which is promoting its wastewater energy resources with additional customers around town. Cities all over the continent are celebrating the maturing of the technology and the benefits it offers. Mueller says there are some 350-billion-kilowatt hours of hot water going down the drain in the United States, worth $40 billion. 

For those seeking high-impact ways to meet greenhouse gas reduction targets, wastewater energy recovery is an essential consideration for any building, but especially for large complexes and district energy systems. 

DC Water

My usual modus operandi is to travel to North American green buildings in my hybrid car or, more recently, a fully electric vehicle, meet with engineers or developers, review the technical details, snap some photos, and talk about economics and emissions.

During 2022, with COVID-19 still peaking, this meant several vaccinations, masks and so forth, making the whole thing more difficult for my hosts. Nevertheless, some were very gracious and went out of their way during a difficult time, and I was able to continue visiting about 20 cities in the eastern United States (and 13 in the west in 2023).

One of the kind souls who gave me a tour in 2022 was Saul Kinter of DC Water in Washington, D.C. The company had built a new head office atop its water treatment plant; Kinter explained how easy it was to heat and cool 170,000 square feet of office space using recovered wastewater energy. As he said at the time, the system is economically viable and efficient, and the energy resource is already built; you simply tap into it.

DC Water saves about 35% on air conditioning and 85% on heating, plus 4 million to 6 million gallons of water each year that would have been used by a cooling tower. The system has been sized for the building on the hottest and coldest days, reaching about 40 MW monthly in July and August, but the resource available at the site is far bigger than that. 

“It might be able to do 10 buildings of this size,” Kinter says. DC Water has been in talks with nearby potential customers about leasing rights to use its excess capacity. Also in Washington, the American Geophysical Union has installed wastewater energy recovery at its headquarters.

lelm’ Village Multifamily Project

In 2023, Mueller showed me a district energy loop in Vancouver for 17 buildings at lelm’ Village, an affordable multifamily project for indigenous people. All the development’s cooling, space heating and domestic hot water needs for kitchens and bathrooms (140 F) are met by using a wastewater energy recovery system that is part of a district energy loop. 

Mueller says the wastewater energy transfer system reduces the amount of electricity needed for the heat pumps by 80%. The technology can also help with up-front geothermal costs, reducing 1,000 boreholes to 300 or 400 wells. “For every 25 cents you invest in this system, you get a dollar’s worth of energy and offset the need for natural gas,” he adds.

Sharc has partnered with engineering firms to create standard equations for reducing geothermal loop needs and mapping potential in key cities, using existing temperature and flow data collected by water system operators.

Their systems include wastewater collection tanks and a filter system to remove solid particles exceeding 20 millimeters (mm), then 3mm. Drain water flows through a copper heat exchanger equipped with auto-reverse flushing. Heat exchangers never need to be dismantled for cleaning. Cleaning is done once per year, the only time there’s really any smell. Systemized processes quickly eliminate most of these escaping odors.

Operating efficiencies of the heat pumps used in conjunction with Mueller’s system are, on average, 20% to 30% better than conventional ground-source heat pumps.

“When comparing the efficiency of heat pumps on our system to that of air-source heat pumps, the average efficiency gains can be 30% to 50% with longer life cycles,” Mueller says. “Air conditioning operation of heat pumps are 25% to 50% more efficient.”

Heat pumps with wastewater energy recovery are 3.5 to 4.5 times more efficient than electric resistance heating. A conventional boiler using natural gas as a fuel is less than 100% efficient, compared to 350% to 450% for heat pumps with wastewater energy recovery.

“There are 200 trillion gallons of wastewater available in the world that’s already been heated up,” he notes. “It’s perhaps the most ubiquitous, widespread renewable energy source in the world.”

The Next Big Thing For Electric Vehicles: Cybertruck 

The many-years-anticipated Tesla Cybertruck pickup will finally go into full-scale production in 2024. As I write this, the official Nov. 30 production launch has not yet happened. Specifications have thus been scant, with no real verification on anything that has been leaked. 

Car & Driver wrote in 2023 that three versions would be offered, with a single-motor, rear-wheel drive model serving as the entry point and a more powerful tri-motor version with all-wheel drive as the most powerful initial model. Tesla claims the latter will tow up to 14,000 pounds with an estimated range of 500-plus miles.

Apparently, Tesla has received more than 2 million reservations for Cybertruck and was trying to trim these and minimize resale profiteering by creating reservation rules that ban third-party resales in the first year (although Tesla may buy it back from you). This, too, is unverified.

Cybertruck will have to compete with the Ford F-150 Lightning, GMC Hummer EV, Rivian R1T, electric Chevy Silverado and Ram 1500 REV. If the past is any indication, Tesla will offer a competitive proposition on specifications and selling prices, and will likely have a significant impact on the U.S. pickup marketplace in the future.

To you and your family, best wishes for a successful 2024 as we turn the corner toward a brighter future for clean energy.