Metro

  • Written by Charles F. Kutscher, Fellow and Senior Research Associate, Renewable & Sustainable Energy Institute, University of Colorado Boulder

Although the coronavirus pandemic has dominated recent headlines, climate change hasn’t gone away[1]. Many experts are calling for a “green” economic recovery[2] that directs investments into low-carbon energy sources and technologies[3].

Buildings account for 40% of total energy consumption in the U.S.[4], compared to 32% for industry and 28% for transportation. States[5] and cities[6] with ambitious climate action plans are working to reduce emissions from the building sector to zero. This means maximizing energy efficiency to reduce building energy use, and then supplying the remaining energy needs with electricity generated by carbon-free sources.

My colleagues and I study the best ways to rapidly reduce carbon emissions from the building sector[7]. In recent years, construction designs have advanced dramatically. Net zero energy buildings, which produce the energy they need on site from renewable sources, increasingly are the default choice. But to speed the transition to zero carbon emissions, I believe the United States must think bigger and focus on designing or redeveloping entire communities that are zero energy.

Tackling energy use in buildings at the district level provides economies of scale. Architects can deploy large heat pumps and other equipment to serve multiple buildings on a staggered schedule across the day. Districts that bring homes, places of work, restaurants, recreation centers and other services together in walkable communities also significantly reduce the energy needed for transportation. In my view, this growing movement will play an increasingly important role in helping the U.S. and the world address the climate crisis.

Zero energy buildings produce enough renewable energy to offset or even exceed the energy they consume.

Ambient loops heat and cool

Heating and cooling are the biggest energy uses in buildings. District design strategies can address these loads more efficiently.

District heating has long been used in Europe[8], as well as on some U.S. college and other campuses. These systems typically have a central plant that burns natural gas to heat water, which then is circulated to the various buildings.

To achieve zero carbon emissions, the latest strategy uses a design known as an ambient temperature loop[9] that simultaneously and efficiently both heats and cools different buildings. This concept was first developed for the Whistler Olympic Village in British Columbia.

In a typical ambient loop system, a pump circulates water through an uninsulated pipe network buried below the frost line. At this depth, the soil temperature is near that of the yearly average air temperature for that location. As water moves through the pipe, it warms or cools toward this temperature.

Heat pumps at individual buildings or other points along the ambient loop add or extract heat from the loop. They can also move heat between deep geothermal wells and the circulating water.

The loop also circulates through a central plant that keeps it in an optimum temperature range for maximum heat pump performance. The plant can use cooling towers or wastewater to remove heat. It can add heat via renewable sources, such as solar thermal collectors, renewable fuel or heat pumps powered by renewable electricity.

Buildings consume lots of energy – here's how to design whole communities that give back as much as they take Schematic of the ambient loop system for the Whistler Olympic Village in British Columbia. Integral Group, CC BY-ND[10]

Putting wastewater to use

One example of a potentially zero-energy district currently being developed, the National Western Center[11], is a multi-use campus currently under construction in Denver to house the annual National Western Stock Show and other public events focused on food and agriculture.

A 6-foot-diameter pipe carrying the city’s wastewater runs underground through the property before delivering the water to a treatment plant. The water temperature stays within a narrow range of 61 to 77 degrees F throughout the year.

The wastewater pipe and a heat exchanger transfer heat to and from an ambient loop circulating water throughout the district. The system provides heat in winter and absorbs heat in the summer via heat recovery chillers, which are heat pumps that can simultaneously provide heating and cooling. This strategy serves individual buildings at very high efficiency.

Electricity used to operate the heat pumps, lighting and other equipment will come from on-site photovoltaics and wind- and solar-generated electricity imported from off-site.

Integrated low-energy housing in Austin

Another district that will minimize carbon emissions is the Whisper Valley Community[12], under construction in Austin, Texas. This 2,000-acre multi-use development[13] includes 7,500 all-electric houses, 2 million square feet of commercial space, two schools, and a 600-acre park. Its design has already received a green building award[14].

Whisper Valley will run on an integrated energy system that includes an extensive ambient loop network heated and cooled by heat pumps and geothermal wells located at each house. Each homeowner has the option to include a 5-kilowatt rooftop solar photovoltaic array to operate the heat pump and energy-efficient appliances, including heat pump water heaters and inductive stovetops. According to the developer, Whisper Valley’s economy of scale allows for a median sale price US$50,000 below that of typical Austin houses.

Ross Trethewey of “This Old House” visits the low-energy Whisper Valley development outside Austin, Texas, in 2018.

The future of zero-energy communities

The National Renewable Energy Laboratory, Lawrence Berkeley National Laboratory, and other project partners are developing an open source software development kit called URBANopt[15] that models elements of zero energy districts, such as building efficiency/demand flexibility strategies, rooftop photovoltaic arrays, ambient loop district thermal systems. The software can be integrated into other computer models to aid in the design of zero energy communities. NREL engineers have been engaging with high-performance district projects across the country, such as the National Western Center, to help inform and guide the development of the URBANopt platform.

The projects I’ve described are new construction. It’s harder to achieve net zero energy in existing buildings or communities economically, but there are ways to do it. It makes sense to apply those efficiency measures that are the most cost-effective to retrofit[16], convert building heating and cooling systems to electricity and provide the electricity with solar photovoltaics.

Utilities are increasingly offering time-of-use rate schedules[17], which charge more for power use during high demand periods. Emerging home energy management systems will allow home owners to heat water, charge home batteries and electric vehicles and run other appliances at times when electricity prices are lowest. Whether we’re talking about new or existing buildings, I see sustainable zero energy communities powered by renewable energy as the wave of the future as we tackle the climate change crisis.

[You’re smart and curious about the world. So are The Conversation’s authors and editors. You can get our highlights each weekend[18].]

References

  1. ^ hasn’t gone away (www.scientificamerican.com)
  2. ^ green” economic recovery (www.carbonbrief.org)
  3. ^ low-carbon energy sources and technologies (time.com)
  4. ^ 40% of total energy consumption in the U.S. (www.eia.gov)
  5. ^ States (www.cpuc.ca.gov)
  6. ^ cities (www.boston.gov)
  7. ^ rapidly reduce carbon emissions from the building sector (www.nrel.gov)
  8. ^ long been used in Europe (www.euroheat.org)
  9. ^ ambient temperature loop (www.integralgroup.com)
  10. ^ CC BY-ND (creativecommons.org)
  11. ^ National Western Center (www.thesolutionsjournal.com)
  12. ^ Whisper Valley Community (www.whispervalleyaustin.com)
  13. ^ multi-use development (www.businesswire.com)
  14. ^ green building award (www.greenbuildermedia.com)
  15. ^ URBANopt (www.nrel.gov)
  16. ^ most cost-effective to retrofit (resstock.nrel.gov)
  17. ^ time-of-use rate schedules (news.energysage.com)
  18. ^ You can get our highlights each weekend (theconversation.com)

Authors: Charles F. Kutscher, Fellow and Senior Research Associate, Renewable & Sustainable Energy Institute, University of Colorado Boulder

Read more https://theconversation.com/buildings-consume-lots-of-energy-heres-how-to-design-whole-communities-that-give-back-as-much-as-they-take-133871

Metropolitan republishes selected articles from The Conversation USA with permission

Visit The Conversation to see more

Entertainment News

Gonna Tell You A Bit About Me & My Journey

There was a time that I didn’t like seeing myself in a mirror. I lacked confidence. I was shy. Then, I found modeling. When I first started modeling, being in front of the camera didn’t feel natural and I was nervous. Like most things – practice ...

Thorn Castillo - avatar Thorn Castillo

#1 Chart-Topping Band GREYE Comes Full Circle With “I Don’t Mind”

Six years after releasing their debut album Providence, Greye’s evolution from progressive Americana upstart to trailblazing indie rock powerhouse is complete. Pandemic and lockdown be damned, the well-traveled multi-generational Daytona Beach, F...

News Co - avatar News Co

AN INAUGURATION AND AMERICAN GREED’S SINGLE “TOGETHER” START AMERICA ON A PATH TOWARD'S HEALING

From COVID-19 To the Shocking Events of January 6, This Is Michael Mesey’s Song of Hope to A Weary Nation and World This Inauguration Day is a chance to turn the page from a difficult, divisive era and embrace a more hopeful spirit of unity m...

Michael Mesey - avatar Michael Mesey

EMODULARI Releases The Hard-Driving, Intensely Visceral “Craniotomy”

Caught up in the maelstrom of bad to worse news in the New York Times one morning, Eli Soiefer spotted an uplifting article offering respite from the crazy. It was a piece about an open-brain surgical procedure where they keep the patient awake t...

News Co - avatar News Co

AV SUPER SUNSHINE “Super Cool”

“Super Cool” is more than the name of rising international hitmaker AV Super Sunshine’s latest infectious 80’s techno inflected single. It’s the dizzying, freewheeling world he’s been living in these past months since the release of his previous ...

News Co - avatar News Co

Angela Predhomme - “Warmest Wish for You”

What could possibly help us heal from the exceptionally trying year of 2020? Singer-songwriter Angela Predhomme hopes that an inspiring new holiday song might give us a little solace. “Warmest Wish for You” is soul-tinged, feel-good song with a ...

News Co - avatar News Co

Metropolitan Business News

Do Directories Still Help SEO?

Directories were once one of the main staples of SEO and they were definitely in existence before search engines took over. Directories were once the main way that people navigated the world wide we...

News Co - avatar News Co

Shipping Container FAQs

If you are looking to rent or purchase a shipping container, you probably have a few questions. We have selected some of the most common questions and answered them here. We hope that you find this ...

News Co - avatar News Co

Is Duplicate Content an SEO Myth?

Any marketer you speak to about duplicate content is concerned about a “duplicate content penalty” but they are probably not very experienced with SEO. Google has specific guidelines on duplicate co...

News Co - avatar News Co

5 Key Factors To Starting A Website

Every business needs a website to be successful. However, this is a challenge for many due to the lack of coding and designing skills. The good news is, you do have a way around this—hire a deve...

News Co - avatar News Co

So You Want To Be A Project Manager? Here's What You Must Do

Project management is often a popular choice for people looking to make a mark in the organizations they work for. It's a great choice as well. If you hate monotony, love getting people and res...

News Co - avatar News Co

How to Deliver the Perfect Elevator Pitch

Do you struggle with explaining your career with professional or personal contacts, and you want to make a lasting impression? Whether you're looking for a job or building up your network, a wel...

Adam Jacobs - avatar Adam Jacobs

Writers Wanted


News Co Media Group

Content & Technology Connecting Global Audiences

More Information - Less Opinion