Are Your Energy Savings Real? Energy Modeling and Management at Rice University

Posted on November 17, 2009. Filed under: Uncategorized | Tags: , , , , , , |

When are reductions in energy consumption verifiable savings?

With the emergence of the American College and University Presidents’ Climate Commitment (ACUPCC) and increasing focus on energy costs and supplies, universities across America are pursuing measures to reduce their energy consumption and their greenhouse gas emissions.  As these schools attempt to measure their results and document savings, I ask how do they really know when they are saving energy?

Let’s assume that a campus building is metered for all utilities, and that these utilities can be tracked on a weekly basis.  And further, let’s assume a two-week experiment, and that at the beginning of the second week space temperatures in the building are changed as part of a new campus building temperature policy to reflect what is considered to be a more efficient range.  If the meter readings were lower in week two than week one, can a utility manager conclude that the energy conservation measure was a success?  Given our experience at Rice University, we would argue that the answer is no.

The energy consumption of a building from one time period to the next is influenced by a number of variables, including outdoor temperature, humidity, time of day, day of the week, and day of the year.  In the example above, week two could have been significantly cooler than week one, potentially leading to a false conclusion about the effectiveness of the new policy, and even masking unintended consequences of changing space temperatures.  However, by creating a weather-normalized baseline model for energy consumption as our energy managers have done at Rice and then comparing this baseline against actual meter data, we submit that utility managers can be much more confident in interpreting their results.

How might one visualize this?  Figure 1 presents one week of data for chilled water consumption at our student center, the Rice Memorial Center.  The y-axis expresses chilled water consumption, and the x-axis represents time (click the graphic to enlarge).  The red line shows the modeled baseline for chilled water consumption for that building.  The variation in the red baseline between daytime and nighttime is obvious, reflecting that we use more chilled water to condition the building during the day than we do at night.  And yet, while the model for each day looks generally similar in shape, it is not exactly the same, because in reality these days were of course not the same.  The blue line represents actual consumption, drawn straight from the chilled water meter at the building in near real-time.  What we see is that due to a variety of conservation measures enacted in that building during the summer of 2009, actual chilled water consumption is now consistently well below the baseline model.  Prior to these initiatives, the baseline and the actual meter readings would have been quite similar.  These results are weather-normalized: we’re not having to guess whether the savings might be related to a cold front or a series of cloudy days.

Figure 1

Figure 1 RMC Chilled Water Consumption

We can use this system to express cumulative building-level savings (or losses) from electricity, chilled water, and steam in dollars.  Figure 2 shows daily utility expenditures for the Rice Memorial Center over a 30-day period (click the graphic to enlarge).  The green bars represent actual daily costs, while the black lines are the predicted costs according to the baseline model.  Notice how each day has a different predicted consumption?  The blue space between the green bars and black lines indicates savings.  On the right side of Figure 2, we see that over a 30-day period, we saved $4,931.49 in steam, $1,618.11 in chilled water, and $780.13 in electricity, for a total utility savings of $7,329.74.

Figure 2

Figure 2 RMC Utility Expenditures

The ability to plot meter data against a predictive baseline is a game-changer for campus energy conservation.  Every two weeks, we hold an interdepartmental meeting to review the performance of a number of our campus buildings using this tool.  Sometimes we see unexpected results that trigger maintenance work orders.  Sometimes we find buildings whose nighttime setback temperatures have been placed in an override mode and need to be restored (and we can see the amount of money that we lost as a result of that decision).  In the case of our own facilities building, when an unexpected electrical load caused us to consume more electricity than predicted by the model, we were able to estimate the size of the additional load, and our maintenance manager tracked it down to a baking booth in the paint shop that had been switched on and left on for several days.  As one of my colleagues frequently observes, this tool allows us to shine the bright light of truth on how we’re consuming energy on our campus.

Rice’s approach to energy modeling is now the basis of a campus energy management product in development by Incuity Software, a subsidiary of Rockwell Automation.  We are working to embed within this system the ability to track greenhouse gas emissions, which would enable us to display and report campus-level and building-level predicted and actual carbon footprints, divisible by type of utility.  The position of our energy management team is that unless energy consumption is tracked against a weather-normalized baseline, we are suspicious of claims of actual savings.  The implications for greenhouse gas reporting are clear: as we develop our inventories and compare them with previous years, did we enact measures that genuinely reduced our emissions, or did cooperative weather make us lucky?  Without a proper baseline, we just don’t know.

(note: a modified version of this posting appeared in the November 2009 edition of the ACUPCC Implementer newsletter)

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The Day of Energy Policy

Posted on January 7, 2009. Filed under: sustainability | Tags: , , , , , , , , , |

Today was perhaps the biggest day ever for energy policy at Rice University. Famed Texas oilman T. Boone Pickens presented his vision for weaning the United States off of foreign oil to a packed auditorium on the Rice campus in the energy capital of the world, Houston. The thrust of the Pickens Plan features a significant investment in wind power (though curiously he hardly mentioned this at all in his talk), accompanied by a shift of natural gas away from electricity generation to use as a fuel for 18-wheelers and other large trucks (present battery technology won’t power these vehicles). True to Texan mythology, this is no small effort. Mr. Pickens has already spent $50 million to promote his plan; he intends to spend tens of millions more.

From my perspective, the visit by Mr. Pickens was not Rice’s lead energy policy headline for the day. That distinction is reserved for our university president, who sent an email to the entire Rice community announcing a Building Temperature Policy, outlining a series of tangible steps that members of our community can take to save energy, and calling for a broader culture of energy conservation on our campus. The Pickens event will garner media attention, enliven classroom discussions for the classes that attended, and perhaps even lead some students to focus their careers on energy. However, the Building Temperature Policy – as unglamorous as it sounds – is the real game changer.

Houston’s climate is quite similar to that of New Orleans or Tampa. That is, hot and humid. Air conditioning – providing relief from both the heat and humidity – was one of the technologies that enabled Houston (and the South for that matter) to grow into the major population and economic center that it is today. For years, locals used to boast that Houston was the “world’s most air conditioned city,” and anyone who has visited can attest that thermostats across this city are set to levels that are almost uncomfortably cold during our long, hot summers. It is not uncommon for women on our campus to wear sweaters indoors during the summer, and we even have instances where some employees use space heaters to counteract the aggressively cold air conditioning. We have taken a technology that has rendered our heat and humidity a mere inconvenience (rather than a threat to human life) and abused it. On our campus, air conditioning is our primary energy expenditure, and this is where we believe a lot of “low hanging fruit” can be found to cut our utility bills and reduce our carbon footprint.

In the 4+ years that I have worked as a campus sustainability professional, I have become involved in a variety of energy conservation efforts, from awareness campaigns to dorm energy competitions to design reviews to operational changes in facilities. There have been a number of successes along the way, mixed in with a healthy dose of frustrating moments (despite working with good, well-intentioned people). What I have come to conclude is that in absence of a comprehensive policy that outlines temperature settings, building hours, off-hour setbacks, and general expectations related to thermal comfort, we’d forever be acting in a piecemeal fashion, making adjustments here and there as time permitted, but never fully realizing the financial and environmental savings that would come with a comprehensive approach.

So why should it be so hard to create indoor conditions without a formal policy such that a worker doesn’t have to wear a sweater indoors when it’s 95 degrees and humid outside? In the absence of guidelines, the facilities personnel who actually set space temperatures are inclined to please their customers rather than conserve energy, and in doing so a space is often cooled to a level that satisfies the most heat-sensitive building occupant, as fewer people will complain about too much air conditioning than too little. Further, in the absence of guidelines, air conditioning schedules for buildings are gradually eroded as requests come in for off-hour (over-)cooling that are then never re-set, eventually leading to 24/7 over-cooling for an entire building. Facilities workers are busy and they want customers to be happy. If a customer demands that his office be cooled to 70 degrees instead of 76, why would the responding facility worker not make the change if no such policy existed to prevent it? And what if he took a conscientious stand and refused to make the change, but had no policy to fall back upon? That worker would likely be overruled.  And let us also not overlook that the customer, freed from the burden of paying their own energy bill in the workplace, will consume energy in ways that they wouldn’t dream of doing at home.

In his talk, Mr. Pickens made numerous references to the first 100 days of the Obama administration, and the need to enact a comprehensive national energy plan within that timespan. We’ll have our own first 100 days on campus as we begin rolling-out our building temperature policy, communicating with our campus community, and setting implementation processes and milestones. I see this as happening not a moment too soon. In this economic climate, universities need financial savings, and energy efficiency can be one of the ways to help keep universities strong. Imagine what even a 5% reduction in energy costs could do for your university? For us, that’s close to a million dollars. And rest assured that as soon as the economy recovers, the soaring energy prices that we witnessed in the first 8-9 months of 2008 will return.

This will be nothing compared to what’s further ahead. Quite chillingly, in his final remark during the question and answer session, Mr. Pickens noted in a rather off-hand way that we have perhaps 20-30 years worth of recoverable domestic natural gas reserves left, but that that’s enough of a bridge (and, in his view, the only available bridge) for us to cross as we race to develop new technologies to feed the energy demands of America. I suspect that crossing that bridge might take on the appearance of an Indiana Jones movie, as we race desperately to safety while the structure crumbles beneath our feet. Where does your campus’s power come from? We generate ours through natural gas fired cogeneration turbines, and we also purchase electricity from the grid that is generated in large part from natural gas. Clearly, we have long-term vulnerabilities and unavoidable challenges ahead. A building temperature policy is an important step, but ultimately each university will need to consider developing its own energy plan for the future. As Mr. Pickens joked, it’s better to be a fool with a plan than a genius with no plan at all.  Let’s hope that in academia, we’re geniuses with plans, because otherwise we’ll be nothing but planless fools.

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In 100 Years (Your Campus May Resemble Venice)

Posted on December 4, 2008. Filed under: Uncategorized | Tags: , , , , , |

Earlier this week, the tides of the Adriatic Sea submerged the Italian city of Venice. The New York Times published an astonishing set of photographs of Venetians and tourists attempting to go about their days, seemingly defiant of the flood. One picture captured tourists thigh-deep in water in Saint Mark’s Square, another showed fashionably-dressed teens strolling down a street and casting a glance at a shopkeeper bailing-out his store, and my favorite featured a group of gondoliers eating their breakfast at an outdoor café table… in several feet of water. As I clicked through these images, I couldn’t help but think that I was not only glimpsing the past (which is unavoidable with Venice) but also the future.

The past and the future of my employer, Rice University, have been on my mind a lot lately. The year 2012 will mark the 100th anniversary of the first entering class at Rice (then known as the Rice Institute). An observer in 1912 would have noted that a tuition-free institution of higher education had opened to serve the white men and women of Houston and the state of Texas. (S)he would likely have wondered – at least privately – about the wisdom of placing this institute beyond the reach of the streetcar, past the end of any paved road, outside the edge of the small but growing city of Houston (population approx. 80,000), upon a mostly treeless and entirely remote muddy campus of prairies and swamps.

That same observer today would find the place utterly unrecognizable. That muddy swamp is now a heavily-wooded thriving university campus, a park-like oasis set within the heart of our nation’s fourth largest city. That white Texan student body is now international, multi-racial, and tuition-paying. That remote location is across the (now paved) street from the world’s largest medical complex, the Texas Medical Center. Searching for any reminder of 1912, perhaps that observer would remark that at least the nearby streetcar is still there, not knowing that it had be removed around 1940 and only recently rebuilt at great expense. The world can change a lot in a single century.

One change not readily visible but no less important to this discussion is that Rice is now six feet lower in elevation than in 1912.<!–[if !supportFootnotes]–>[1]<!–[endif]–> When the university was founded, the campus was approximately 56 feet above sea level; now it’s 50 feet (and at 50 miles inland, you get a sense of the flat slopes of the Texas coast). How does that happen? Heavy withdrawals of groundwater across greater Houston caused some areas to subside by as much as 10 feet between 1906 and 2000.<!–[if !supportFootnotes]–>[2]<!–[endif]–> One suburban neighborhood – the Brownwood subdivision – literally sank into Galveston Bay, and following Hurricane Alicia in 1983 was condemned and converted into a nature preserve.<!–[if !supportFootnotes]–>[3]<!–[endif]–> Thankfully, after nearly half a century of inaction despite compelling scientific evidence (sound familiar?), a special regulatory district was formed to prevent further subsidence, and elevations in most of the Houston area have since stabilized.

With the 100th anniversary of Rice rapidly approaching, we are enacting a 10-point plan to shape the next century on our campus, known to the Rice community as the Vision for the Second Century. As I look ahead to these next 100 years of Rice University, I recognize that we will continue to lose elevation, not due to subsidence but to the effects of global climate change. The question is by how much. The 2007 report from the Intergovernmental Panel on Climate Change (IPCC) projects a global sea level rise of between 0.18 and 0.59 meters (7-23 inches) by the end of the century (mostly due to thermal expansion and the melting of glaciers and polar ice caps).<!–[if !supportFootnotes]–>[4]<!–[endif]–> However, the wild cards in the deck are the Greenland and West Antarctic ice sheets, which were not taken into account in the IPCC’s estimates due to uncertainties of how quickly these sheets would melt.<!–[if !supportFootnotes]–>[5]<!–[endif]–> In other words, the estimate they provide is too conservative. NASA climate scientist James Hansen suggests that a more appropriate estimate is several meters under a business-as-usual scenario.<!–[if !supportFootnotes]–>[6]<!–[endif]–> The lab of Dr. Jonathan Overpeck of the University of Arizona reports that “Our work… suggests that the Earth will be warm enough to melt the Greenland Ice Sheet in less than 150 years. Unless, that is, efforts are made to slow global warming.”<!–[if !supportFootnotes]–>[7]<!–[endif]–> Such an event would result in a sea-level rise of 23 feet.<!–[if !supportFootnotes]–>[8]<!–[endif]–> As for the West Antarctic ice sheet, researchers at the British Antarctic Survey estimate such a melting would produce at least a 16 foot rise in sea levels.<!–[if !supportFootnotes]–>[9]<!–[endif]–>

The Overpeck lab has created a viewer that uses a map with a 1-km resolution that shows the effect of sea level increases between 1 and 6 meters at increments of 1 meter. If you’re a map geek like me, you’ll love this tool. Using their viewer, you’ll quickly see how vulnerable certain areas of our country (and world) are to even slight increases in elevation, such as south Florida and most of southern Louisiana below Interstate 10.

Let’s suppose that sea levels rise by 3 meters by the end of the century (about 10 feet). For those of us on the Gulf and Atlantic coasts, I will note for reference that the storm surge for the recent Hurricane Ike peaked at 17.48 feet, and with waves on top of the storm surge, the maximum high water mark was 21.2 feet.<!–[if !supportFootnotes]–>[10]<!–[endif]–> A 3-meter rise brings Rice’s elevation down to 40 feet above sea level. While that news is not good for Rice, a 3-meter increase in sea level is positively alarming for a number of other universities. For example, the University of Miami would be at sea level, and its medical school 7 feet below sea level. Lamar University in southeast Texas would be 3 feet under water, as would The Citadel in Charleston, South Carolina, and the Borough of Manhattan Community College in New York City. The University of Texas Medical Branch in Galveston, Texas – the state’s oldest medical school – would be at sea level. Ditto for Old Dominion University in Norfolk, Virginia, and MIT in Cambridge, Massachusetts. The United States Naval Academy in Annapolis, Maryland, would take on water when tides reach 3 feet above normal.

If we assume a scenario of a 6-meter rise in sea level (about 20 feet), Rice drops to 30 feet in elevation, just past the reach of the storm surge. Harvard University in Cambridge, Massachusetts would sit right at sea level. LSU in Baton Rouge, Louisiana, a city that may become the post-Katrina economic engine of Louisiana, would be just 19 feet above sea level, within striking range of a significant storm surge, and much closer to the coastline. And what about if both the Greenland and West Antarctic ice sheets collapse over the next century or two? These losses, combined with thermal expansion of ocean waters due to warming, could result in a sea level rise of about 41 feet (23 feet + 16 feet + 23 inches). This would place the Rice campus at less than 10 feet above sea level, easily within the storm surge of a hurricane. In that case, our Vision for the Third Century had better include a seawall.

The idea that many of our campuses might someday resemble the images from Venice is shocking. However, it is certainly well within the realm of possibility. In a century or two, those wading tourists in Venice’s Saint Mark’s Square could instead be in Harvard Square, those fashionable teens strolling thigh-deep in water past a flooded store could be midshipmen at the US Naval Academy in Annapolis dressed in their white uniforms filing through the tide of the Chesapeake Bay past the Nimitz Library, and those dining gondoliers with seawater just below their tablecloth could instead be University of Miami students sipping a Starbuck’s in the surf outside the University Center (near the ironically named Storm Surge Café).

We know that the world can change rapidly in a single century, especially this coming century. We know that a host of external environmental factors will shape the future of our campuses at a level never seen before. As campus sustainability professionals, we have a lot of hard work ahead of us. If we fail, our future might be Venice, a beautiful curiosity losing a long battle with the sea, and we can’t let that be so.


<!–[if !supportFootnotes]–>[4]<!–[endif]–> Intergovernmental Panel on Climate Change 2007, Climate Change 2007: The Physical Basis – Summary for Policy Makers, p. 13, http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-spm.pdf, accessed November 29, 2008.

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An Hour Well Spent

Posted on July 16, 2008. Filed under: Uncategorized | Tags: , , , |

Our new fiscal year at Rice began on July 1, and with it, a new reality of energy prices that have blown a multi-million dollar hole in our budget. Like many of you I’m sure, we’re now drafting a campus energy policy, we’re identifying and implementing various energy conservation measures, and we’re preparing a set of proposed conservation projects for the next capital budget cycle. Running parallel is the effort to reduce greenhouse gas emissions and to draft a climate action plan. Sound familiar?

Not long ago, being the standard-bearer for sustainability meant flying into a strong headwind. My observation is that the winds shifted direction for many of us over the past couple of years, and we’re instead being propelled by a robust tailwind. We’re now awash in opportunities, and yet ours is such a young profession that we’re still learning how to run campus sustainability offices and how to function effectively in our roles. With so many of us in similar places on the learning curve, we are quite fortunate when we can tap the knowledge of one of our few counterparts that has actually been working in this business for a decade or more.

One of the true leaders in energy conservation in higher education is Walter Simpson, the University Energy Officer for University at Buffalo, in the SUNY system. Walter was the featured speaker in a recent free APPA Webinar entitled “Reducing Greenhouse Gases & Achieving Climate Neutrality” that originally streamed on June 18, 2008. In his talk, he presented twenty “programmatic ingredients” as part of a “recipe for success” for saving energy and cutting greenhouse gas emissions, many of which were discussed in-depth, with valuable lessons offered. The presentation is still accessible online (click here). If you too are engaged in the twin efforts of energy conservation and greenhouse gas reductions, do consider devoting a quiet hour of time to learn from Walter’s experiences.

Afterwards, explore the web site of the playfully-named UB Green office, including their You Have the Power energy conservation campaign. Finally, give some serious thought to what it means to have saved a university over $100 million in cumulative energy costs – and the associated emissions and environmental impact prevented – as Walter has done. If AASHE ever develops an award for lifetime achievement for campus sustainability professionals, my nomination for first recipient would be Walter Simpson.

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Putting Recycling in Perspective (A Perspective on Recycling)

Posted on July 10, 2008. Filed under: Uncategorized | Tags: , , |

I spend a lot of time in the classroom. Often when I’m making my first appearance in front of a particular class, I will begin by asking the students to “grade” Rice’s sustainability efforts. After I’ve tallied the votes for the various letter grades, I will then ask for comments for why people voted as they did. The replies are almost always about the same thing: recycling.

I love recycling. I’ll readily confess that I derive perhaps a bit too much satisfaction out of recycling oddball items like worn-out athletic shoes and 80’s-vintage personal computers. My garage is full of miscellaneous items waiting to be recycled. For those of us who were kids in the 70s, how could you not feel good about recycling after watching all of those Keep America Beautiful commercials with “the crying Indian” (see here and here)? Certainly a campus solid waste recycling program needs to be a component of a university’s overall bundle of sustainability initiatives, but if students are viewing recycling as the most critical initiative, is it time that we put recycling into perspective?

Suppose for the sake of discussion that we believe global warming to be our greatest environmental challenge. Let’s then assume that Rice neither recycled nor composted a single pound of waste, and instead all of that material was trucked to a landfill without methane capture. The result would be that our solid waste would account for about 2,000 metric tons (“tonnes”) of CO2-equivalent emissions each year, which sounds like a lot but is actually just below 2% of the university’s total annual greenhouse gas emissions for 2006, far behind energy consumption (first) and transportation (a distant second). Under this scenario, if we recycled or composted everything, then we’d avoid emitting those 2,000 tonnes, which is the combined annual carbon footprint of about 150 of our students.

However, our solid waste goes to a landfill with methane capture used for electricity generation. Even if we didn’t recycle or compost anything, this switch to a better landfill reduces the greenhouse gas impact of our solid waste by 85%, down to about 300 tonnes. At best, if we recycled or composted everything, we’d avoid emitting those 300 tonnes, which is the combined annual carbon footprint of about 22 of our students.

We do of course recycle and we compost much of our landscaping waste too. In total, our institutional solid waste stream including recycling and composting accounts for just 0.25% of our total campus greenhouse gas emissions. If contribution to global warming is your yardstick for measuring the success of a university’s sustainability initiatives, then you’ve lost your sense of scale if you grade that program based on recycling.

Looking beyond just global warming impact to total ecological footprint, we see a similar conclusion: it’s all about energy. The report Ecological Footprint of Nations: 2005 Update shows that more than 90% of the ecological footprint of the United States is related to the production and consumption of energy.

Some of you might be gritting your teeth at this point because I’ve not discussed the upstream impacts and benefits of recycling, which are much more significant than the downstream effects, and I’ve also treated recycling as if there’s no connection to energy consumption. Fair enough. For years recycling has been represented as a necessary action due to vanishing landfill capacity, which is an argument that misses the big picture. The reason to recycle is because of the upstream benefits. In our economy, only 4% of the materials that we extract end up in actual products, and the other 96% are already waste by the time we’ve even purchased the products.[1] Then most products we buy are thrown away almost immediately, meaning perhaps just 1-2% of the materials in our economy end up in goods of long-term value. The rest is waste. By recycling, we can eliminate a considerable share of this “upstream” environmental impact. Forget the landfill; recycling is all about preventing the future extraction and manufacturing of materials, the consumption of energy to drive these processes, and the associated environmental consequences of each. This is especially true for the recycling of metals.

What does recycling mean from an energy perspective? According to the US Green Building Council, the heating, cooling, and powering of buildings accounts for 39% of our national energy consumption, followed by the fueling of the transportation sector at 32%, and finally industry at 29%. The energy benefits of recycling are most likely to be realized within the industry category. While I have no sense of the exact amount of such benefits, it certainly would not exceed the total share of energy consumed by industry. Again, this simply helps us to see recycling in a proper scale.

This brings us back to the classroom. Despite the overwhelming number of responses concerning recycling, there is always at least one student who comments that our buildings are over-cooled, and that student is the one on the right track. Another might then ask where our energy comes from, and that is critically important, but it’s not a question that I frequently hear.

Yes, there are numerous environmental benefits to recycling, and beyond just that, it’s conceptually representative of the kind of closed-loop materials economy that we need to be moving towards. There is genuine value in people participating in such a system in a reflexive and visible way. However, more importantly, that closed-loop economy needs to be powered by clean, renewable, affordable energy. So is recycling an important part of a campus sustainability program? Yes. Should it be the primary measure by which a campus sustainability program is judged? Absolutely not.


[1] Data obtained in personal communication with Professor Robert Ayres in 2005. See his work in Frontiers of Environmental Economics, edited by Folmer, Gabel, Gerking and Rose (Elgar, 2001).

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