The following excellent article is by Charles F. Kutcher of the Renewable Energy Institute, University of Colorado Boulder. It was originally in The Conversation and is republished with permission of Creative Commons.


Artist rendition of the National Western Center, a net-zero campus under construction in Denver to house multiple activities. City and County of Denver | Mayor’s Office of the National Western Center, CC BY-ND Charles F. Kutscher, University of Colorado Boulder


Buildings consume lots of energy – here’s how to design whole communities that give back as much as they take.


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

Buildings account for 40% of total energy consumption in the U.S., compared to 32% for industry and 28% for transportation. States and cities 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. 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.

(What is a Zero Energy Building 2 minute overview)  https://youtu.be/FysJKq5yCfg  


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, 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 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.



Schematic of the ambient loop system for the Whistler Olympic Village in British Columbia. Integral Group, CC BY-ND


Putting wastewater to use

One example of a potentially zero-energy district currently being developed, the National Western Center, 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, under construction in Austin, Texas. This 2,000-acre multi-use development 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.


Whisper Valley subdivision

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.


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 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, convert building heating and cooling systems to electricity and provide the electricity with solar photovoltaics.

Utilities are increasingly offering time-of-use rate schedules, 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.


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

This article is republished from The Conversation under a Creative Commons license. Read the original article.



Cheers ~ Bruce



My offering


“I offer you peace. I offer you love. I offer you friendship. I see your beauty. I hear your need. I feel your feelings. My wisdom flows from the Highest Source. I salute that Source in you. Let us work together for unity and love.”

Mohandas Gandhi


Charcoal drawing in Ottawa Art Gallery - artist unknown

Charcoal drawing from the Ottawa Art Gallery – artist unknown


Peace, love and unity


Happy Mothers Day


“It is not half so important to know as to feel.”
Rachel Carson


Our grandaughters group selfie July 1, 2019 - Emma Keely photo, edited by Bruce (2)


For all mothers – thank you for carrying us forward into the world


Happy mothers day


Love ~ Bruce


“If what I say resonates with you, it is merely because we are both branches on the same tree.”


W.B. Yeats


Kohan reflection garden Slocan Lake, BC 2014-10-13  Fran Guenette photo 

Kohan Reflection Garden in New Denver BC Oct. 13-2014 – next to The Nikkei Internment Memorial Centre

Peace ~ Bruce

The way in the heart

In the sky, there is no distinction of east and west; people create distinctions out of their own minds and then believe them to be true . . . The way is not in the sky. The way is in the heart.

the Buddha

Reflection on the lake 2020-02-17 bruce witzel photo(1)(1)

Sky and clouds on the lake, Feb 17 – 2008 (with a polarizing filter)


Prayer flags 2017-02-26 bruce witzel photo

Prayer flags in our yard, Feb 26 –2017


Cheers ~ Bruce



Reflections 2020-02-17 bruce witzel photo


“The human race is challenged more than ever before to demonstrate our mastery, not over nature but of ourselves.”

Rachel Carson



Earth flag 2020-03-25 bruce witzel photo



View over Phoenix 2007-03-01  bruce witzel photo


~ Peace ~



Pieta Easter – and a John Prine Tribute

My good friend Charles Brandt  sent me this yesterday – Jesus’ mother Mary, holding him after the crucifixion. Not a rousing Easter image, but somehow to the point.

Look below for a couple more Easter COVID 19 reflections including a tribute to John Prine.


by Michelangelo  ~ Pieta

“The Pity”

Michaelangelo  sculpture - from c.branct.

photographer and source unknown



My granddaughters Britney’s Easter 2020 dough art


Britney's Easter doe art ornament




Easter morning  – “The rising sun”


Easter morning lignt  is over the lake 2020-04-12 bruce witzel photo


My Easter Tribute to John Prine


Many people have universal feelings of loss for the music legend John Prine. He died this past week, April 7 – 2020, from complications due to COVID 19.  He was 73 years old.

John wrote with humor and poignancy  – anti war songs like “Your Flag Decal Won’t Get You Into Heaven Anymore” and  “Sam Stone”…  “There’s a hole in daddy’s arm where all the money goes; Jesus Christ died for nothing, I suppose.” Prine explained later how the line came to him as an expression of the complete hopelessness of addiction.

Prine wrote the true precautionary tale “Paradise” (click link for a listen). The song became an environmental anthem – “Mr Peabody’s coal train hauled it away.”

And of course, “Angel from Montgomery.”


Angel form Montgomery cartoon


Here is a message from Johns wife, Fiona Whelan Prine:

Our beloved John died yesterday evening at Vanderbilt Medical Center in Nashville TN. We have no words to describe the grief our family is experiencing at this time. John was the love of my life and adored by our sons Jody, Jack and Tommy, daughter in law Fanny, and by our grandchildren.

John contracted Covid-19 and in spite of the incredible skill and care of his medical team at Vanderbilt he could not overcome the damage this virus inflicted on his body.

I sat with John – who was deeply sedated- in the hours before he passed and will be forever grateful for that opportunity.

My dearest wish is that people of all ages take this virus seriously and follow guidelines set by the CDC (Center for Disease Control). We send our condolences and love to the thousands of other American families who are grieving the loss of loved ones at this time – and to so many other families across the world.

Thank you from the bottom of our hearts for the outpouring of love we have received from family, friends, and fans all over the world. John will be so missed but he will continue to comfort us with his words and music and the gifts of kindness, humor and love he left for all of us to share.

In lieu of flowers or gifts at this time we would ask that a donation be made to one of the following non profits:





“When I Get to Heaven” (click to listen)

John Prine

When I get to heaven, I’m gonna shake God’s hand
Thank him for more blessings than one man can stand
Then I’m gonna get a guitar and start a rock-n-roll band
Check into a swell hotel; ain’t the afterlife grand?


Happy Easter, Dear John


john_prine photo by_Danny_Clinch                                                                                                                                              photo by Danny Clinch


Love and Cheers,





Many people who carry the COVID 19 virus have no symptoms – but they are still spreading it.


This 10 sec. graphic first shows the exponential growth rate of the virus. Then it shows a slowed pattern of growth created by our social distancing and our working or staying at home.




This discipline is crucial for our success in defeating these microbes, along with simple 20 second hand washing.



A beautiful rainbow powered garden - Powell River, BC - photo by Bruce Witzel


Cheers to all, Bruce


Wisdom of the Past – Fitting for the Present


quoted from E.F. Schumacher 


We must do what we conceive to be right and not bother our heads or burden our souls with whether we’ll be successful. Because if we don’t do the right thing, we’ll do the wrong thing and we’ll be part of the disease and not part of the cure . . .


Holiday In the Sun by Dan Hudson 1984 - photo from exhibit at Banff museum and art gallery                                                                                                                             Holiday in the Sun – painting by Dan Hudson


We cannot say: “Hold it! I am not quite ready. Wait until I have sorted things out.” Decisions have to be taken that we are not ready for; aims have to be chosen that we cannot see clearly. This is very strange and, on the face of it, quite irrational. Human beings … hesitate, doubt, change their minds, run hither and thither, uncertain not simply of how to get what they want, but above all of what they want. . .

  At Watson's -bruce witzel photo


There is no economic problem and, in a sense, there never has been. But there is a moral problem, and moral problems are not convergent; that is, capable of being solved so future generations can live without effort. No, they are divergent problems, which have to be understood and transcended.


Downtown Montreal, Augut 2005 - bruce witzel photo


Can we rely on it that a “turning around” will be accomplished by enough people quickly enough to save the modern world? This question is often asked, but no matter what the answer, it will mislead. The answer “Yes” would lead to complacency, the answer “No” to despair. It is desirable to leave these perplexities behind us and get down to work. . .


  Photo of Painting (artist unknown)

                                                                                                              photo of painting – artist unknown


It is amazing how much theory we can do without when work actually begins.



E.F. Schumacher 

author of Guide for the Perplexed, Good Work, and Small is Beautiful



    please stay safe, wash your hands and practice social distancing.


                        cheers – Bruce


A GOOD Free read for troubled times


Blue-green Book Cover photo for The Light Never lies - by bruce witzel


My wife and partner Francis has her first 2 novels below, free till Monday at midnight. If you don’t have an e-reader you can download an app. With more time at home to consider things, starting a new series of books may be just that bit of relief we need.


Ultimately uplifting, these are stories of heartbreaking need and desperate measures. Apropos to these troubling times. Some of the links are listed below.


https://www.amazon.ca/dp/B00TTNEEB0    in Canada                                 https://www.amazon.ca/dp/B00I8XKIDK  in Canada

https://www.amazon.com/dp/B00TTNEEB0  in US                                        https://www.amazon.com/dp/B00I8XKIDK  in US

(also available in other countries, though you will have to do a web search locally)





Please enjoy the 1st two books of the Crater Lake Series for free!


Crater Lake series




~ Bruce ~

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