About The Pragmatic Steward

Professor of Physics at Oberlin College. I was originally trained as a condensed matter experimentalist. In the last 15 years my research has focused on photovoltaic devices, PV arrays, wind energy, energy efficiency, and energy use in buildings.

EPA Energy Star Review Report Fails to Account for Uncertainties

The other day a friend emailed me a link to the EPA’s April 2019 report of its Review of the Energy Star Hotel benchmarking score.  In a nutshell, after suspending Energy Star Certification for the last six months or so pending a review of its revised methodology, the EPA has issued a report saying their revised methodology is correct and they are resuming operations.  But the statistics reported in this “Analysis and Key Findings” simply confirms what I have documented earlier in my book, that the Energy Star staff do not understand the difference between real trends and random noise.

On page 1 of their report the EPA Energy Star folks publish this table demonstrating how U.S. Lodging buildings have evolved between 2003 and 2012.

The EPA’s text accompanying this table says, “Between 2003 and 2012, the estimated number of hotel buildings in the United States increased by 14%. During that period, the average site EUI decreased by 3% while the source EUI increased by 7%.”

Presumably these statements are made in order to justify changes in Energy Star scores for Hotels/Motels — the building stock has changed so the relative ranking of a particular building with respect to this building stock will change.  Unfortunately the two EPA claims are false.

The table they used to justify this statement is not for Hotels — it is for all buildings classified by CBECS as Lodging.  This includes hotels, motels, inns, dormitories, fraternities, sororities, nursing home or assisted living, and “other lodging.”  Moreover, when you include the EIA’s relative standard errors (RSE) for both the 2003 and 2012 statistics you find these differences are absolutely meaningless.  In particular, the Site EUI figures for 2003 and 2012 in the above tables are uncertain by 17% (2003) and 8% (2012), respectively.  The differences between the 2003 and 2012 SiteEUI are just as likely to be due to random sampling errors as they are real trends!

The EPA’s Hotel Energy Star model applies only to Hotels and Motels/Inns.  When you look at these CBECS data for 2003 and 2012 you find even larger RSE that swamp any differences.  The relevant statistics are shown in the Table below.  The EIA did not calculate statistics for these two categories in 2003; these numbers are calculated by me using CBECS 2003 microdata.  The EIA did perform the calculations for these categories in 2012.  SourceEUI figures are calculated by me using the EPA’s 2012 site-to-source energy conversion figures (3.14 for electric).  The percentages listed are the RSE’s for each statistic.

The number of Hotels increased by 50% from 2003 to 2012.  During this same time the number or motels/inns decreased by 23%; their combined number showed no significant change and their combined floor area increased by 8%, hardly resolvable given the uncertainties in these quantities.  The Site and Source EUI for these two types of facilities did not change in any significant way.  The uncertainties in the survey far exceed the small changes in these EUI.  It is impossible to know whether the changes reflect real trends or just sampling errors.

Joelle Michaels, who oversees the CBECS operation, is well aware of the limitations of the CBECS methodology.  It must drive her nuts to see the Energy Star staff present such silly numbers and reports based on CBECS data.

This gets at the heart of my criticism in my book, Building Energy Star scores: good idea, bad science.  The numbers employed by the EPA in their statistical analysis are so uncertain that in most cases they are studying noise and reading into it things that cannot be found.  The science is sophomoric.  It is the result of teaching a little statistics to people who lack the mathematical and scientific knowledge to use it properly.

 

 

 

 

LEED Platinum Hotel embodies the failings of LEED

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On March 14, 2019 the US Green Building Council (USGBC) finally awarded the Hotel at Oberlin its LEED-platinum rating after earning 81 points under the LEED NC v2009 system, just over the 80-point minimum required for the platinum rating.  This milestone comes as a relief to Oberlin College which has for three years falsely claimed the Hotel at Oberlin to be a LEED-platinum building.  But a good day for Oberlin College is a bad day for the US Green Building Council because there is nothing exemplary about the Hotel’s energy performance — it is the very definition of mediocrity.  This latest member of the elite club of LEED-platinum hotels – I think it is the fifth such hotel in the U.S. – uses more energy per square foot than do 75% of other U.S. hotels and uses more natural gas than any other Oberlin College building except its Science Center.

The design team for the Hotel at Oberlin projected that it would annually use 1.43 million kWh of electric energy and 8,350 therms of natural gas.  These energy projections, if realized, would correspond to a site EUI of 56 kBtu/sf and a source EUI of 151 kBtu/sf.  The LEED Scorecard for the building shows that the USGBC awarded the building the maximum possible points for energy efficiency –19 out of 19 possible.

Had the Hotel achieved this projected target energy, however, it would not be an impressive accomplishment.  This target site EUI is still higher than that of 25% of the estimated 30,000 U.S. Hotels  We know about energy use by U.S. Hotels from the 2012 Commercial Building Energy Consumption Survey (CBECS).  The graph below shows the SiteEUI distribution for U.S. Hotels as determined from this survey.  It is clear that the projected site EUI use for the Hotel at Oberlin is lower than 75% of these hotels.  A similar statement can be made about the projected source EUI for the hotel.

More importantly, the Hotel at Oberlin has never achieved this projected energy use figure.  Since opening nearly three years ago the natural gas use has been 4-6 times higher than projected by its design team!  For the last 12 months the electric and natural gas use have been 1,680,000 kWh and 48,000 therms, respectively.  These correspond to annual site and source EUI of 104 and 215 kBtu/sf, respectively.  The graph below shows that this SiteEUI for the Hotel at Oberlin is higher than that of 75% or 22,500 of U.S. Hotels. The energy performance of this LEED Platinum Hotel is worse than mediocre.

The bottom line is that the Hotel at Oberlin, one of only five LEED-platinum hotels in the US, has energy use that is typical of U.S. Hotels — near the middle of the distribution.  There is nothing noteworthy or remarkable about its energy use, either site or source.  Its certification as one of the nation’s most energy-efficient hotels is simply an embarrassment to the USGBC.  It illustrates how meaningless energy efficiency points are for LEED certification.

Harvard Group publishes flawed estimate of the environmental benefits of green buildings

Late last year a group from Harvard’s T. H. Chan School of Public Health published a paper entitled, “Energy savings, emission reductions, and health co-benefits of the green building movement” in Nature’s Journal of Exposure Science & Environmental Epidemiology.  In their paper MacNaughton, Cao, Buonocore, Cedeno-Laurent, Spengler, Bernstein, and Allen consider the cumulative energy savings of some 20,000 commercial buildings, world-wide, that have been certified under the U. S. Green Building Counci’s Leadership in Energy and Environmental Design (LEED) since the program’s inception.  Their focus is to calculate environmental co-benefits associated with this (assumed) energy savings.  Unfortunately their entire thesis is predicated on assumptions that are not supported by facts.  Their paper, masquerading as a peer-reviewed journal article, is little more than a marketing brochure for the USGBC and is devoid of credibility.

MacNaughton et al. make the naive assumption that LEED-certified buildings demonstrate, year after year, the energy savings their design teams predicted during the certification process.  This was essentially the same assumption that underpinned the now-discredited Kats report from 2003.  Numerous studies have shown that buildings in general, and green buildings in particular, use significantly more energy than predicted by their design teams.  This so-called “building performance energy gap” is pervasive and well-documented.  The Harvard paper is entirely based on the results of the 2008 NBI study which has long been discredited.

Frankly these energy-performance assumptions are sophomoric.  The authors cite only three references to support their assumptions — all published a decade ago — and they misrepresent the results of one of these papers — I know, because I wrote it!  They apparently are unaware of upwards of 12 studies published in the last decade that look  at energy performance of LEED buildings.

The Harvard paper should have been rejected in the review process.  If I were at liberty to do so I would publish the reviews of my critique as they affirm essentially all the claims I have made.  One of the Harvard authors served on the Board of the USGBC which should have raised a red flag.  The paper was received by the Journal on October 12, 2017 and accepted for publication five days later.  This accelerated time frame raises questions about the substance of the peer-review process.  And finally, the authors make several factual claims about LEED buildings in their paper that are simply incorrect.

To their credit the editors of this Nature journal allowed me to submit and publish a critique of this Harvard paper.  My paper is entitled, “A critical look at ‘Energy savings, emissions reductions, and health co-benefits of the green building movement.'”  Interested readers should read my critique of the Harvard paper which contains numerous references and relevant facts.

 

2015 Benchmarking data show LEED-certified buildings in Chicago save no primary energy

As more and more building energy data become available a consistent picture is emerging that shows that LEED-certified buildings use no less primary energy than other buildings.  The latest contribution in this area is a paper soon to be published in Energy and Buildings entitled, “Energy Performance of LEED-Certified Buildings from 2015 Chicago Benchmarking Data.”  This paper compares the annual energy use and green house gas emission for some 130 LEED-certified commercial buildings in Chicago with that of other Chicago buildings in 2015.  Chicago, it turns out, has one of the highest rates of LEED-certification among major U.S. cities.

The data clearly show that the source energy used by LEED-certified offices, K-12 Schools, and multifamily housing is no less than that used by other similar Chicago buildings.  In the case of K-12 Schools, LEED-certified schools actually use 17% more source energy than other schools!

Many studies that address building energy use only discuss energy used on site, called site energy.  We found that LEED-certified buildings in Chicago use about 10% less energy on site than do other similar buildings.  No doubt green building advocates will emphasize this apparent energy savings.

But energy used on site – called site energy – is only part of the story.  Site energy fails to account for the off-site losses incurred in producing the energy and delivering it to the building – particularly important for electric energy that, on average, is generated and distributed with 33% efficiency.  The EPA defines source energy to account for both on- and off-site energy consumption associated with a building; building Energy Star scores are based on source energy consumption.  The issue is similar to one encountered when comparing the environmental impact of electric vehicles with internal combustion vehicles — you must trace the energy back to the electric power sector.

How is it that LEED buildings use less energy on-site than other buildings while consuming more source energy?  Simple — more of their (indirect) energy use occurs off-site in the electric power sector.  They use less natural gas but more electric energy than other buildings.  Essentially a larger fraction of their energy use occurs off-site in the electric power sector.

This is the trend in newer buildings, to use more electric energy and less natural gas or district heat energy.  Part of this is convenience and part of it is driven by the belief, or rather hope, that the electric power sector will soon be dominated by renewable energy.  It is true that the contribution of renewable energy (solar, wind, etc.) in the electric power sector is growing, but this is a very slow process and, for many years to come, natural gas and even coal will remain the dominant source for electricity.

This trend is not unique to LEED buildings — it is present in all new buildings.  When you compare Chicago’s LEED buildings with other Chicago buildings of similar vintage you find that they use similar site and source energy.

Bottom line, 2015 Chicago data show that LEED-certified buildings are not providing any significant reduction in energy use or GHG emission.

These results are similar to those observed earlier for LEED-certified buildings in NYC.

Hotel at Oberlin — poster child for “Green Wash”

In May 2016 Oberlin College opened its newly constructed Hotel at Oberlin.  The New York Times ranked the Hotel third in its list of 5 Hotels and 5 Tours for the Eco-conciousTraveler.  It is all part of the ongoing marketing effort to paint Oberlin College as a sustainable and green institution.  Hard to believe that any amount of eco-spin can convince people that a view of Oberlin’s Tappan Square is  environmentally rewarding.

Of course what makes the Hotel at Oberlin a green destination is not it surroundings — it is the building itself.  Like the Taj Mahal, committed environmentalists will simply swoon in the presence of this green wonder.  The second (and larger) of Oberlin College’s highly-publicized green buildings, the College has claimed that the Hotel is the first 100% solar powered hotel in the world and one of only five Hotels in the world to win the coveted LEED Platinum rating.  In addition to claims of solar power the building is said to be heated by a geothermal well field and to include other green technologies — including radiant-cooled rooms.  Its web site boldly claims that it has achieved the LEED platinum rating.

Truth is the hotel is not powered by the sun nor is it LEED-certified at any level.

I  wrote about this Hotel nearly two years ago when it opened.  The main focus of that post was to address the solar claim.  I will not rehash the evidence here — please read the blog.  The claim is a brazen and clever lie — Donald Trump would admire its creativity!  Simply stated, the Hotel is no more solar powered than is my century-old home.  There is not one solar panel on the building site.  The 2.2 MW OSSO array that is claimed to power the Hotel was built years before the hotel, is located a mile away, and, by contract, sends all of its electricity to the City of Oberlin until 2037 at a price of $85/MWh.

Today I write to share the Hotel’s energy-performance data and to discuss its LEED rating.  The Hotel is well into its second year of operation and we now have 21 months of utility data.

In my 2016 post I suggested that the Hotel would use two million kWh annually, more than double the 800,000 kWh used by the Oberlin Inn it replaced.  For 2017 the Hotel actually used 1,400,000 kWh of electric energy.  This is 75% more electric energy than was used by the former Oberlin Inn, but less than my estimate.  It is consistent with the annual electric use projected for the Hotel by its design team.

But the Hotel also uses natural gas.  The marketing literature for the Hotel says that the building is heated with ground-source heat pumps.  Natural gas, we are told, is primarily for heating domestic water (laundry, showers, etc.) — available, but not anticipated for backup heat.  The design team projected the annual gas use to be 8,350 therms (Ccf).

In fact, for 2017 the Hotel at Oberlin used 39,000 therms (Ccf), nearly 5X that predicted by the design team.  This is more natural gas than is used by any other Oberlin College building save one — the 130,000 sf Science Center!  The Science Center, constructed 17 years ago, contains numerous research and teaching laboratories and chemical hoods and has never been described as a green building.  It used 58,000 therm of natural gas in FY2017.  The natural gas use of the Hotel at Oberlin exceeds that of any other College building including the Firelands Dormitory (26,000 therm), the new Austin E. Knowlton complex (26,000 therms) and Stevenson Dining Hall (23,000 therms).

How does the Hotel at Oberlin’s energy performance compare with that of other hotels?  Consider its Energy Star score.  This can be estimated using the EPA’s Target Finder web site that allows quick data entry to estimate scores.  Entering the Hotel’s floor area (103,000 sf), number of guest rooms (70), cooking facility (Yes), 100% of the space heated and cooled, and actual FY2017 energy use, and accepting other default parameters, the Hotel at Oberlin is awarded an Energy Star score of 56.  According to the EPA — just a bit above average.  Don’t get me wrong — I am a huge critic of the Energy Star benchmarking score.  But it is one way to compare energy use with other hotels.

The monthly gas usage for the Hotel at Oberlin is shown below.  The excessive use in months Nov. – Feb. is clear evidence that significant gas is used for heating.  But even if you eliminate this heating use, the remaining use is nearly 3X the design estimate.

Finally, let me address the claim that the Hotel at Oberlin is certified LEED Platinum.  It simply is a lie.  I downloaded the USGBC LEED project database today.  The Hotel at Oberlin was registered on March 8, 2013 as “Confidential.”  Its LEED project ID is 1000031165.  As of today, February 23, 2017 the Hotel at Oberlin is not LEED-certified at any level.  The LEED project database says it has achieved 53 points — not enough to even achieve certification at even the Gold level.

Perhaps one day the claims being made for the Hotel at Oberlin will become true.  There is a lesson to be learned by looking at Oberlin’s Green building, generation-I, the Adam Joseph Lewis Center.

Oberlin College’s Adam Joseph Lewis Center  opened in 2000 to much acclaim.  Its proponents claimed it was a zero energy building (ZEB) for more than a decade when it just wasn’t true.  The claims were repeated by two Oberlin College presidents, College literature, and the College web site. The College never issued a retraction — it spent hundreds of thousands of dollars to correct flaws in the building’s HVAC design hoping to lower building energy use to a level that could be met by its 45 kW rooftop PV array.  The College eventually switched from “sticks” to “carrots” and in 2006, with the gift of a million dollars, built a second, 100 kW PV array over the adjacent parking lot and, with tripled electric production, renewed its ZEB claim for the building.  The building continued to use more energy than all of its arrays generated through 2011.  Even when faced with incontrovertible evidence that the claim was false the College continued to print the claim for another year in admissions literature distributed to students.  The College has never issued a public retraction or correction.  In 2012, after hiring a full-time building manager, the building finally used less energy that year than its PV arrays generated.  These arrays now feed two buildings, the AJLC and its adjacent annex.  Energy-intensive functions have been located in the annex and, collectively, these two buildings use more energy than the arrays produce.

Maybe in the next decade the College will build a parking garage next to the Hotel at Oberlin and put a huge PV array on it.  This could make the Hotel at Oberlin solar-powered — but not 100%.  Not sure how it will solve its natural gas problem — but clever minds will think of something.

The era of Donald Trump is here.  It is not illegal to lie, and no lie is too big to sell.

The bottom line is this.  The Hotel at Oberlin is just a normal, expensive hotel that purchases both electricity and natural gas from the local utility companies.  It uses more energy than the hotel it replaced.  It is the perfect symbol of modern green wash — 20 % substance, 60% exaggeration, 20% lies.

USGBC gives new meaning to Energy Star Score

This weekend I have been gathering data regarding LEED certified buildings made available at the Green Building Information Gateway.  In browsing through the web site I ran across a page that described Top Performing Buildings.  On that page I read this statement:

“One percent of buildings earned an Energy Star Score of 90+”

I don’t know if this statement is true or not — but I am humored by its implications.

According to the EPA, the building Energy Star score is a ranking of a building’s energy efficiency as compared with similar buildings in the U.S. commercial building stock.  It is assumed that the mean or median building score is 50 — simply reflecting the inescapable fact that half U.S. buildings are better than average and half are worse.  This is a necessary consequence of the meaning of a cumulative population distribution!

It also follows that 10% of the buildings necessarily have scores below 11 and 10% have scores higher than 90.

Perhaps it is true that only 1% receive scores that are 90 and higher.  But if true, the score clearly cannot reflect the meaning given it by the EPA.  Perhaps the author of that gbig web page needs to reflect on the meaning his/her/their statement.

NYC’s building energy grade discredits both Energy Star and LEED

I receive occasional newsletters from HVAC consultant Larry Spielvogel concerning building energy and the HVAC industry.  Yesterday he sent out a link to an editorial that appeared in Crains New York Business concerning a recent ordinance passed in New York City that “forces large buildings to post letter grades reflecting their energy use.”  These grades will apparently be based upon a building’s Energy Star score.

The Crains’ editor is aghast that a fine building like One World Trade Center which is LEED-gold certified, receives only a B grade.  Worse yet, the highly-acclaimed, LEED-platinum One Bryant Park building receives a C grade.  In closing the essay the editor writes, “Slapping a C next to a LEED Platinum rating will discredit both metrics, confuse the public and accomplish nothing.”

He is right on the first two counts but wrong on the third.  This will accomplish something very important, it will further the cause of truth!

It is better that the public be confused by the truth than to be told lies that bring clarity.  Confusion may lead to investigation and resolution.  The City’s new grade is based on the EPA’s building Energy Star score.  As I have shown in multiple venues, this score is largely garbage.  (See, for instance, earlier blogs from 2016-11-21, 2016-12-14, 2015-09-19, or 2014-08-22.)  The scoring system is mostly ad hoc, made up by non-engineers with a political agenda.  Armed with the knowledge acquired in a semester college statistics course they have developed scores that lack basis in building science or engineering .  They mean well — they want to help the environment.  Their approach is to condense building energy efficiency into a single metric that masses can understand and they can control.  But the score is largely meaningless and the DOE building scientists who helped develop the score 15 years ago have long since distanced themselves from this runaway system that lost its connection with reality.

LEED building certification, a system also born with good intentions, has been shown to have little average impact on building energy use!  LEED-certified office buildings in NYC use just as much energy as do other NYC office buildings.  Similar results have been uncovered in Chicago building energy benchmarking data.

The excessive energy used by One Bryant Park (aka The Bank of America Building) has been discussed before.  (See my earlier post and the New Republic article by Sam Roudman.)  For 2016, One Bryant Park had an annual site energy intensity of 211 kBtu/sf, more than twice that of the average NYC office building for 2015 (94 kBtu/sf). (For 2015 its energy use was somehow omitted from NYC’s public disclosure.)  The energy use of One World Trade Center (aka The Freedom Tower) has not appeared in the 2014, 2015, or 2016 NYC disclosures, despite the fact that the building opened in November 2014.  No doubt the Port Authority keeps its energy use secret as a matter of national security.

Nature does not care what awards these buildings have won or the clever technologies their owners have employed.  Nature only cares about total GHG emission and fossil fuel consumption and, by these measures, these buildings are not exemplary.

No doubt these building owners believe they are not responsible for the excessive energy use — it is their tenants.  True or not, it does not matter.  The building and its occupants are judged together.  If the owner is embarrassed — find different tenants.