New Study Shows How a District Energy System Design Further Cuts Emissions at DiSC

By David M. Greenwald
Executive Editor

Davis, CA – While much of the focus has been on the sustainability aspect of DiSC, a huge component of energy comes from homes and businesses, which use over 25 percent of California’s energy.  A new study found that with a number of different space heating and cooling technologies available to developers, there are further ways to reduce GHG impacts.

study, published by the UC Davis Western Cooling Efficiency Center (WCEC), analyzed the GHG emissions for two different heating and cooling options for a proposed development in Davis – the Davis Innovation Sustainability Campus (DiSC). Researchers analyzed GHG emissions for: 1) the proposed all-electric, high-efficiency design, which would use packaged heat pump equipment for heating and cooling the buildings and 2) a potential upgrade to an all-electric, very high efficiency design, which would use a district energy system.

According to a release from UC Davis, “A district energy system uses a central plant heat pump and chiller to heat and cool water that is piped to buildings for heating and cooling.”

“Based on predicted energy consumption data provided be Trane, we found that a district energy system could further improve energy efficiency by 26%, reduce total energy consumption by 14%, and reduce GHG emissions by 16% over the already highly efficient proposed design,” said lead researcher David Vernon, Co-Director of Engineering for the UC Davis Western Cooling Efficiency Center.

“We’re serious about making the DiSC a truly sustainable project and are very interested in the heating and cooling concept proposed by Trane and evaluated by the WCEC. If DiSC is approved by the voters, we’ll be seriously considering use of the district energy system because it makes sense and would help us achieve our energy-use and GHG emission-reduction goals. This innovative approach would help to further establish Davis as a state and national leader in energy-efficient development, and we’re excited about its potential implementation at the DiSC,” Dan Ramos, project manager for DiSC 2022 said in a statement on Wednesday.

UC Davis noted that DiSC is a proposed development that would build new residential, office, laboratory, and manufacturing buildings on the eastern edge of Davis.

The developer team is required by the Davis City Council to build an all-electric design with an energy efficiency level 30% more efficient than required by Title 24 building codes.

“The developer funded us to look at a district energy system design with large thermal energy storage because it has the potential to greatly reduce GHG emissions,” Vernon said. “It can help stabilize the grid by using energy when renewable generation is high and reducing energy consumption when renewable generation is low.”

“To meet California’s climate goals requires large increases in renewable energy generation, energy storage, and load shifting technologies. District energy systems with large thermal energy storage have the potential to be an effective energy storage and load shifting strategy,” the release pointed out. “The WCEC mission is to advance design, monitoring, and objective reporting of the performance of these types of technologies to inform policy and economic decisionmakers.”

In their Energy modeling and analysis, the researchers found, “The heating, ventilation, and air conditioning (HVAC) manufacturer Trane completed energy models of the proposed baseline and district energy system designs and provided the hourly energy consumption results.”

The WCEC researchers then “used these hourly energy consumption results to calculate Time Dependent Valuation—a metric that incorporates the social and environmental impacts of energy used to evaluate energy efficiency, total energy consumption, and GHG emissions of the designs.”

“Our analysis shows that district energy systems offer significant opportunities to reduce energy consumption and GHG emissions compared to more common HVAC designs,” said Vernon. “It is important to note that our results are on the conservative side, and implementation of this design could result in even larger GHG savings.”

In a disclosure from the university, they note, “This study was funded by Ramco Enterprises, Inc. and the Buzz Oates Group of Companies.”

The full study from the Western Cooling Efficiency Center is available here.

Author

  • David Greenwald

    Greenwald is the founder, editor, and executive director of the Davis Vanguard. He founded the Vanguard in 2006. David Greenwald moved to Davis in 1996 to attend Graduate School at UC Davis in Political Science. He lives in South Davis with his wife Cecilia Escamilla Greenwald and three children.

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21 comments

  1. The study addresses only the energy efficiency (hence the carbon footprint) of the proposed commercial and residential buildings of the DiSC project. However, operational energy use of buildings at DiSC only accounts for 11% of the project’s projected total carbon footprint at DiSC – or about 2,153 metric tons of the total  20,118 metric tons of CO2e emissions the project will produce per year (see p. 108 of the DiSC 2022 Addendum to the EIR).

    Efforts like this to reduce the building energy use at DiSC, while laudable, will not substantially impact the project’s overall carbon footprint because the vast majority (over 75%) of emissions produced by this auto-centric project are due to vehicular travel associated with DiSC (which are projected to equal 15,330 metric tons per year). Unitl DiSC gets serious about reducing vehicular traffic (primarily single-passenger commuters), there will not be significant reductions in the project’s total carbon footprint.

    But the developer(s) of DiSC refused to commit to a number of mitigation measures recommended by the City’s Natural Resources Commission that would have significantly reduced this vehicular travel to and from the site including 1) reserving 50% of the housing units at the project for project employees, 2) requiring paid commercial parking, and 3) limiting development of phase 2 of the project until substantial reductions in business-as-usual traffic reductions were demonstrated during phase 1.

     

     

    1. DiSC is taking care of the sustainability elements that are under its control by adopting technologies and designs that will make this the most sustainable innovation center in the country.

      As for GHG emissions from transportation, these emissions will be solved through a combination of action by the state and federal government along with the automotive industry which is rapidly shifting their production lines to be all electric. The governor’s office just announced that California has now sold more than 1 million electric vehicles which is more than the next 10 states combined. Link here. In ten years they went from 7,000 per year sold to more than 250,000 per year sold this year. Given these dynamics, along with widespread popularity and interest in owning EVs (surveys throughout the past few years show strong and growing interest in EV ownership among all age groups but particularly strong among Millenials and Gen Z), the emissions from transportation will be significantly reduced by the time DiSC is built out ten years from now. This trend will continue and emissions from transportation will trend towards zero.

      Alan already knows all of this, yet continues to present these numbers as if they are coming from Mount Sinai because it creates a rather uncomfortable narrative for the No on H team. DiSC is already taking the steps in its built environment to become a national leader in sustainability and the regulatory environment and market dynamics in car production and ownership are going to solve one of the principal problems they like to trumpet. Anyone and everyone should be able to see that GHG emissions from car travel will soon be insignficant.

      The irony is that the people who say they oppose DiSC for environmental reasons are missing the forest for the trees (sometimes quite literally being fixated on the individual number of trees planted). The local emissions will be negligible since DiSC’s built environment must achieve carbon neutrality by 2040, and the potential GHG emissions from transportation will continue to trend down to zero as we have greater adoption of EVs–simply continuing the trend that has been present for more than a decade now. In the meantime, the research that can be pursued at DiSC in collaboration with institutions such as UCD, UCANR, and private R&D efforts can continue to make advances in sustainability in ag, energy, transportation, etc. Bolstering R&D is the most effective way we can advance sustainability while improving human flourishing and the human condition.

  2. It’s an incremental improvement and that’s important.  You’re never going to get an ideal environmental solution.  That’s why I laugh when I hear the YES statements: “Yes on H restores and improves native habitat for endangered species, while permanently preserving farmland in Yolo County”  Really?  Developing DISC will improve native habitat over….I dunno…NOT DEVELOPING IT AND LEAVING IT AS FARMLAND?  The real story is an incremental improvement over simply paving over the whole thing and doing nothing for the environment.  But it’s kind of hard to sell that.  So the message is that environmentally speaking…it won’t be great but then no development would be.  Voters need to recognize that they’re sacrificing some of their environment and all the natural benefits that come with it for some much needed tax revenue for the city.   That’s the additional cost to the community over simply providing the new development with services.  Is it worth it?  That’s what this vote is about.

    But the developer(s) of DiSC refused to commit to a number of mitigation measures recommended by the City’s Natural Resources Commission that would have significantly reduced this vehicular travel to and from the site including 1) reserving 50% of the housing units at the project for project employees, 2) requiring paid commercial parking, and 3) limiting development of phase 2 of the project until substantial reductions in business-as-usual traffic reductions were demonstrated during phase 1.

    Yeah…I’m a realist.  Those demands would essentially cripple the project.  For the camp that is essentially a hard NO on any peripheral development; making these demands seems reasonable.  Because if the big bad greedy developer doesn’t agree….oh well…I guess we’re stuck with a nice piece of farmland (and no new source of tax revenue for the city)

      1. Can you imagine a campaign slogan: “we marginally improve the environment”

        That wouldn’t even be accurate.  It’s more like: “We’re not going to scr-w up the environment as badly as we could have”.

      2. imagine

        How ’bout “we don’t improve the environment, and we might produce some revenue”

        or

        “When you drive your kids to the nearest elementary that’s not safely accessible by bicycle, you can have peace of mind that you use a bit less energy than other parents also driving their children to school…. and save a few minutes doing it.”

        or

        “Because the nearest complete supermarket is not safely accessible by bicycle and is far and unpleasant by foot, we purchased a larger fridge that uses more energy that average, as we don’t go shopping that often and buy lots of stuff, perhaps more than we need. So we also find it hard to not waste food.”

        or

        “I sleep well in my old, energy-intensive home, knowing that when I drive to DISC the next morning, my workplace will be more efficient.”

        1. How ’bout “we don’t improve the environment, and we might produce some revenue”

          Accurate

          “When you drive your kids to the nearest elementary that’s not safely accessible by bicycle,

          “Because the nearest complete supermarket is not safely accessible by bicycle 

          I’m starting to wonder if you’re in a bicycle cult.  Or are in Big Bicycle’s pocket (The evil Trek, Cannondale, Specialized…etc.  A cabal of the Bicycle Industry’s Special Interests) as a grassroots activist/lobbyist.

          “I sleep well in my old, energy-intensive home, knowing that when I drive to DISC the next morning, my workplace will be more efficient.”

          I’m not sure what you mean.  My home is energy inefficient but I’m working on it.  I don’t think I have any reason to go to DISC.  What does DISC’s efficiency have to do with anything?  I think you mean profitable for the developer (in other words all the things Alan listed would eat into the developer’s profits…..thereby making the project dead from the start).

        2. bicycle cult.

          For DISC I the proponents showed how Pioneer ES was close, for DISC II they claim “safe routes to schools” on their website but there ain’t squat to Pioneer. Nothing culty ’bout makin’ note of this, just stating the obvious – and the high school, alternative junior high schools, and Spanish immersion school are 20 to 30 min away by bike, meaning that a car journey will be the likely solution or possibly also the school not attended if the inconvenience born of peripheral development outweighs the advantages.

          energy inefficient

          DISC II will create more housing demand than housing, so people who work at DISC II will still – and increasingly – live outside of Davis in less green housing, and will mostly likely drive to DISC II or other facilities… two points against sustainability vs true infill with a lot more housing.

          There’s probably some useful formula that compares GHG reduction per dollar of spending on increasing housing efficiency vs increasing transportation efficiency, but in the case of DISC II where 75% of carbon emissions will come from the latter – it seems that a dollar will go further in the case of transportation.

          And while it’s true that the proportion of EV’s powered only from renewable energy will increase, industry and President Biden’s projections in this Reuters piece claim, respectively, that 50 to 70% of all vehicles on the road will be EV’s by 2050, but without note of the type of energy they will be using.  Guessing a bit here, but let’s say that in the more EV- and friendly California that ends up being 60% with no GHG impacts by that year, and still that gas cars will still be sold then and that these will be used for at least 15 years or so, it seems like it will be the year 2075 to 2085 before GHGs from car travel are insignificant, yet Wesley Sagewalker says that this will be

          soon.

          1. DISC II will create more housing demand than housing, so people who work at DISC II will still – and increasingly – live outside of Davis in less green housing,

            Unless, of course, more housing gets built in Davis somewhere. And more housing is already being proposed.

        3. Unless, of course, more housing gets built in Davis somewhere. And more housing is already being proposed.

          And when that occurs, it will likely be another battle.  Certainly nothing to “count on” at this point.

          This is what I don’t understand about the DiSC advocates, in that they’re consistently the same people who claim to be concerned about “housing shortages”.

          And if more housing is subsequently approved, the city simply becomes “larger” (more commercial, more housing).  For what benefit, no one has been able to articulate. But for sure, there seems to be a cadre of people for whom “more of everything” is their mantra.

          Except for open space and farmland. They support less of that. Apparently, the Sacramento region hasn’t sprawled enough yet, for those folks.

          I do know the drawbacks of this type of continued advocacy (loss of farmland, open space, more traffic and greenhouse gasses, etc.). In fact, we call that “business as usual”, and is exactly what’s led to current development patterns throughout the state and beyond.

           

        4. Todd never lets facts get in the way of a sensational claim. If passed, DiSC will construct a separated bike lane along the interior of the Mace curve connecting to Harper Junior High School in addition to a separated bike path going from the grade-separated bike and pedestrian crossing of Mace to Korematsu Elementary along the southern edge of the Mariani property and DJUSD property. Children who live at DiSC will be able to bike to their elementary and middle school without ever having to worry about conflicts with cars. This will undoubtedly be one of the safest and most accessible bike routes to school in Davis.

          Moreover, if passed, Ikeda’s fruit stand is planning to expand its facilities, which it is currently legally prohibited from doing, to offer more produce and grocery items similar to their operation in Auburn. Nevermind, of course, that Target has a grocery section across the street and Nugget is located a mile south on Mace. DiSC will be surrounded by grocery options which are accessible by bike.

        5. Moreover, if passed, Ikeda’s fruit stand is planning to expand its facilities, which it is currently legally prohibited from doing, to offer more produce and grocery items similar to their operation in Auburn.

          Perhaps just “one” of their options.  Perhaps another gas station (I’ve heard), as well. Who knows what they might pursue, or what the city might then approve. One thing for sure – it would no longer be up to the voters in Davis.

          In any case, I try not to support businesses which support sprawl.  Especially fruit/vegetable stands, which (supposedly) have a connection to “local farms”.

          I’ll remember this going forward, regardless of the result.  I’m already sorry that Ikeda’s bought the pre-existing stand.  Maybe they’ll sell it to someone actually interested in running a local fruit/vegetable stand, if DiSC fails. (Fingers crossed.)

          As far as your bicycle (“undercrossing” to the development?), your client isn’t even committing to funding it in the first place. And certainly not before housing is already built, on the site.

          The “good news” regarding that is that they’re probably wouldn’t be more than a handful of kids living at the site. Do a lot of families want to live in a business park in the first place?

        6. wesley is correct if the neighborhood school for the elementary school kids is Korematsu, but I have been told that Pioneer is the likely neighborhood school for DiSC residents.

          Perhaps DJUSD can clarify what the reality is on that.

          1. That doesn’t make a lot of sense. Not saying that means it’s wrong. But Korematsu is literally across the street from DiSC whereas Pioneer the students would have to cross I-80 and Chiles.

        7. Ron, the commitment to constructing the grade separated crossing is in the DA and the MOU that was just approved unanimously by the Yolo County Board of Supervisors which clarifies that it will be constructed in Phase 1.

          The expansion of the fruit market is what will happen. This gas station you “heard about” is just some figment of you or someone else’s imagination.

          As for kids living at DiSC, it would be a wonderful place for children. 23 acres of greenbelts and open space populated with native species and pollinator friendly landscaping, a five acre lighted sports field, access to miles and miles of bike trails to the east of DiSC all the way out to the causeway, and easy and safe bicycle access to school. Sounds pretty great to me.

        8. Wesley:

          You already know that development agreements can be changed.

          In any case, there is no requirement to construct a grade-separated crossing prior to Phase II.  Which means that if Phase II gets delayed, so would the crossing.  (And by that time, new residents would already be living in the Phase I housing units.)

          The DiSC developers have made no commitment to fund the crossing.  They are seeking outside sources to fund it (e.g., grants, the city, the “other half” of DiSC, etc.).

          By the way, where are visitors to the 5-acre “sports field” going to park?

          As far as Ikeda’s is concerned, I haven’t seen anything which limits the type of development that they may pursue if incorporated into the city.

          But again, I’m happy with Ikeda’s as is.  I hope that they subsequently sell it (after DiSC fails) to someone who appreciates it, as well.  I do know that I’m reluctant to support it, given the current owners’ apparent support of sprawl.

          How nice it would be, if the DiSC site remained a farm and actually provided vegetables or fruit to the adjacent fruit/vegetable stand.

        9. To clarify, Phase I can be completed (or nearly-completed) with no grade-separated crossing in place. Which means that people would be living there, with no crossing.

          I suspect that as Phase I is nearing completion, the “other half” of DiSC will arise as a campaign. (Partly due to reliance upon the other half to help fund the crossing.) I understand that the crossing itself is tentatively planned on land owned by the “other half” of DiSC, already.

          I still don’t know many families who would willingly-choose to live in a business park, in some tiny overpriced housing. I suspect it will be UCD students living in the apartments, and commuters (couples, or singles) living in the for-sale units. (Assuming those aren’t subsequently rented out to students, as well.)

  3. For DISC I the proponents showed how Pioneer ES was close, for DISC II they claim “safe routes to schools” on their website but there ain’t squat to Pioneer. Nothing culty ’bout makin’ note of this, 

    Well, Todd denies the bicycle cult.  But I don’t hear a denial about being in the pocket of Big Bicycle….the two wheeled Illuminati of Davis politics.

    DISC II will create more housing demand than housing, so people who work at DISC II will still – and increasingly – live outside of Davis in less green housing, and will mostly likely drive to DISC II or other facilities… two points against sustainability vs true infill with a lot more housing.

    No matter what you do; if you add people it’s going to be a negative impact on the environment.  That’s the trade off.  Commenting on it is like criticizing new development for needing a sewage system.

  4. DISC II will create more housing demand than housing, so people who work at DISC II will still – and increasingly – live outside of Davis in less green housing, and will mostly likely drive to DISC II or other facilities… two points against sustainability vs true infill with a lot more housing.

    This is false reasoning based on assuming an entirely static environment. Busineess, jobs and housing tend to grow in tandem, unless constrained in some manner other than market forces. Sometimes its physical, but the fact that San Francisco managed to grow by 22% since 1990 shows that even that may not slow growth. We are in control of the jobs/housing balance in Davis, not some external force or other people.

    1. This is false reasoning based on assuming an entirely static environment.

      Sounds like you’d have a disagreement with the DiSC EIR, as well as common sense.  [edited]

      Should we go over it, again?  Really?  2,500 jobs “promised”, but only 460 housing units onsite.  Some of which would be occupied by those employed elsewhere.  Again, the EIR itself notes that 1,269 housing units are needed for DiSC workers that won’t be accommodated onsite.

      Are you actually claiming something different?

      Busineess, jobs and housing tend to grow in tandem, unless constrained in some manner other than market forces.

      No, they don’t.  See the San Francisco peninsula (including Silicon Valley).  That’s what happens when you ignore the “demand” side of the equation, when pursuing “economic development”.

      Sometimes its physical, but the fact that San Francisco managed to grow by 22% since 1990 shows that even that may not slow growth. We are in control of the jobs/housing balance in Davis, not some external force or other people.

      Source, please?

      San Francisco has been losing population for the past couple of years.  So have other large cities.

      So has California as a whole.

       

      1. We are in control of the jobs/housing balance in Davis, not some external force or other people.

        This claim is incorrect.

        The state (SACOG) has something to say about this, as well.  Especially if more jobs are added.

        Davis (and just about every other city in California) is already having challenges meeting those new requirements.

        No one has put forth a coherent reason why the city should simply “grow” (e.g., more commercial development, jobs, and housing).  Why is “bigger better”, in the eyes of the development activists?

         

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