Intelligent Controls + Advanced Building Systems: The Potential … · 2020. 8. 29. · Intelligent Controls + Advanced Building Systems designed buildings, can easily differ by a

csdCenter for Sustainable Development

Intelligent Controls + Advanced Building Systems:

The Potential of Closing the Feedback Loop

Lisa Storer

Werner LangInstructor

UTSoA - Seminar in Sustainable Architecture

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Intelligent Controls + Advanced Building Systems

Intelligent Controls + Advanced Building Systems: The Potential of Closing the Feedback Loop

Lisa Storer

Introduction

Automated building systems technology and intelligent control methods have made tremendous advances since their introduction in the early 1980s. Intelligent control systems were initially developed as expensive, building-specific models for specialized occupancy types where life-safety, technology and security issues demand constant indoor climate regulation. This technology has since become much more prevalent, is now used in many institutional and owner-operated structures where the reduced energy-use payback for the initial investment is achievable, and is beginning to transform not only the way that buildings regulate energy use, but also the energy networks themselves.

In general, such systems work by employing microelectronic controls to monitor and adjust indoor parameters to achieve comfort while

optimizing their service systems and improving the efficiency of their maintenance and management over time. These systems function by comparing values (temperature, humidity, lighting levels), measured with a sensor, to the expected or desired values (set-points). Then an electronic controller mediates a device to equalize the actual and desired values. There are varying algorithmic types of sensor and controller operation systems, ranging from fairly simple on/off types to adaptive controllers using artificial intelligence.1

As these types of automated building systems advance, the trend in development has been one that aims to allow full systems and comfort control without the intervention of users, effectively designing the building to operate itself, and in doing so, optimizing energy efficiency. However, some automated building control research is beginning to utilize the advanced

Fig. 01 Smart grid technology has the capability of transforming energy use in American cities.


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sensoring and monitoring capabilities within these systems to specifically educate and interact with occupants in order to influence user behavior and reduce energy demand to further improve the efficiency achievable through controls. This user-feedback research and development has wide-ranging possibilities and industry implications, from altering the way consumers interact with their energy utility to vehicle, building, and infrastructure design.

Energy Consumption Statistics

The United States is the largest consumer of energy in the world, representing 21.6 percent of the 462 quadrillion BTUs of energy consumed globally, although it only contains 4.5 percent of the world’s population.2 In the U.S., commercial and residential sectors combined consume about 39 percent of total energy, and this building sector consumes most of its energy in the form of electricity. In its most recent report, The United States Energy Information Administration stated, using 2001 data, that there were 107 million households in the U.S., using a total of 1140 terawatt-hours per year. That gives an average of 10.6 megawatt-hours per year per household. Of that, the plug load due to lighting, home electronics and appliances accounts for 26 percent of the total energy use in the residential sector.3 Within the United States, Texas leads the Nation in energy and electricity consumption, and per capita residential use is significantly higher than the national average.4

Empowering the User to Reduce Energy Demands

Most domestic and commercial energy use is generally invisible to the user, except when equating that energy use with currency as he or she is paying a bill. Most people only have a vague idea of how much energy they are using for different purposes and what sort of difference they could make by

changing day-to-day behavior or investing in efficiency measures. As Sarah Darby writes, “Energy supply and consumption are sociotechnical in nature: technology and behavior interact and co-evolve with each other over time. It is well established that technical and physical improvements in housing are not enough to guarantee reduced energy consumption.”5 Consumption in identical homes, even low-energy

40%

26%

20%

8%6%

U.S. Residential Energy Use (2005)

space heating

lighting and appliances

water heating

air conditioning

refrigeration

Fig. 02 U.S. Residential Energy Use, 2005.

Fig. 03 U.S. Commercial Energy Use, 2005.

39%

23%

9%

9%

6%

8%6%

U.S. Commercial Energy Use (2003)

space heating

lighting and appliances

water heating

air conditioning

refrigeration

ventilation

computers and office equipment

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designed buildings, can easily differ by a factor of two or more depending on the behavior of the inhabitants.6 The current process of energy billing has been compared to shopping at a grocery store totally without price markers and being billed via a monthly statement, making it completely incomprehensible when it comes to economizing.

Direct feedback is an integral, yet only recently developed component of advanced building control systems. Essentially it consists of a real-time display of energy use data, accessible to the users of the building. Displays typically also have the capability of showing historic data for comparison, the cost equivalents of kilowatt-hours used, as well as estimated bills. More advanced systems with individually metered equipment can show data for each, and some systems also monitor water and gas consumption. These displays take a variety of forms, from low-tech, inexpensive countertop units for homeowners to internet-based interactive displays that can chart performance over time and calculate unit equivalents. Regardless of the type, studies have shown that any type of real-time feedback has had significant and measurable energy use reductions.

While the most immediate effects of direct feedback on energy use has been reduction of typical plug-load uses – computers, lighting, and appliances, interactive feedback displays have shown to have measurable impacts on HVAC loads as well. In combination with utility-provided information about peak load reduction, direct feedback has shown remarkable results in assisting consumers to reduce their energy

use during peak times of the day when the energy grid is stressed.

This type of energy conservation, driven by feedback and consumer action, directly benefits both consumers and utilities. Consumers benefit from using less electricity, which directly translates into lower energy bills, and environmentally-conscious customers derive additional value by decreasing their carbon footprint. At the system level, energy savings keep the consumption growth under check, which often means avoiding incremental capacity, transmission, and distribution investments. With respect to demand response measures, utilities find that interactive consumer displays, used in conjunction with time-varying rates, effectively flatten out the peak demand curve.7

As Edward Lu, Advanced Projects Program Manager for Google, Inc. stated in his testimony to the

Senate Committee on Energy and Natural Resources, “If all customers nationwide engaged in reducing peak loads, peak electricity prices would be substantially reduced and approximately $70 billion in new generation, transmission, and distribution systems could be avoided, with the savings passed along to the ratepayers.”8

Impact of Direct Feedback on Energy Consumption

Sarah Darby’s 2006 study for the Environmental Change Institute on the “Effectiveness of Feedback on Energy Consumption” reviewed over 20 years of research and literature on the subject. She states, “Overall, the literature demonstrates that clear feedback is a necessary element in learning how to control fuel use more effectively over a long period of time and that instantaneous direct feedback in combination with frequent, accurate billing (a form of indirect

Fig. 04 Demand-side energy reductions can reduce the need to invest in additional energy grid infrastructure.


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feedback) is needed as a basis for sustained demand reduction.”5 Darby’s study uncovered that the average and expected savings from direct feedback methods ranges from 5-15%, although in combination with indirect feedback methods (usually through billing) that incorporated historic data, an additional 10% could be captured. She states, “Any development of ‘smart metering’ needs to be guided by considerations of the quality and quantity of feedback that can be supplied to customers. Direct displays in combination with improved billing show promise for early energy and carbon savings, at relatively low cost. They also lay the foundations for further savings through improved energy literacy.5

Ahmad Faruqui’s study of twelve pilot programs throughout the United States and Canada that implemented in-home displays of real-time energy usage found that consumers who use an energy display can reduce their consumption of electricity by an average of seven percent, and are much more likely to augment their timing of resource use to help with peak load.7 With more advanced displays that show historic consumption, cost at the current rate, temperature data, and comparisons with other homes as well as a running meter, these energy savings can double – a 9-month trial in Japan resulted in an electricity savings of 18 percent, and a gas savings of 9 percent in comparison with controls.5

One important aspect of energy displays which chart historic data is their capability in promoting self-conducted experiments investigating what actions have the most impact on energy usage and therefore

cost. Participants of studies report that they are able to augment their behavior and observe the changes in energy based on their actions. For example, a family might decide to raise their indoor thermostat by a degree or two during a summertime day while they are not home, and be able to chart the difference from the previous day’s measurements. The average U.S. residential customer spends $1200 a year on electricity, so savings simply based on a real-time feedback monitor could amount from $60 to $180 savings per year.5

Examples in Use + Emerging Competitors in the Interactive Energy Display Field

The direct feedback display field is quickly becoming crowded with newly developed hardware and software designed to increase public information about energy use. The biggest names in information technology have all announced such products in development, including Microsoft, IBM, and General Electric. A few smaller companies got a head start in launching their products for

multi-unit institutional buildings where managers have some control over their residents’ energy billing such as schools, hotels and dormitories. These web-based interactive display products give a taste of what is to be expected as such technology begins to shape the mainstream residential and commercial sectors.

Lucid Design Group’s Building Dashboard software allows clients to monitor and manage their resource consumption in real time on the web. A building’s energy load at any given moment is continuously measured against a two-week moving average for that time of day, and each system is customized to show pertinent information for the building. At Sidwell Friends Middle School, the solar electricity produced by their PV array is charted against their real-time electricity consumption rates, and units are appropriate for a middle-school level – electricity can be converted to dollars, compact-fluorescent light bulbs, and hairdryers as well as kilo-watt hours.9

Fig. 05 Lucid Design Group’s Building Dashboard software for Sidwell Friends Middle School.

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assistant-professor of computer science and a dozen or so undergraduate students designed and implemented the program, that they call Greenlight. The real-time, animated displays in the common areas of the dormitories feature “Bula” the animated polar bear in various levels of comfort or distress, depending on the amount of energy being used in the building or on each floor depending on the style of dormitory. The student designer of the bear, Sonia Lei, said, “The polar bear animations were chosen to give a simpler representation of what still seem to be far-distant effects of humans’ energy consumption, and to visualize those effects on the bear while offering some level of interactivity.”11 Of the two dorms included in the initial pilot launch, over the course of a semester, total energy use was reduced by 14 percent in one and 22 percent in the other. The project is now in eleven dorms on campus, and the overall average energy savings for these dorms is about 10 percent. Also significant in the Dartmouth findings is the dramatic change in student opinion. In a survey given out before the program launched 60 percent of

Fig. 06 Oberlin College’s dorm energy use challenge interactive web-based tool.

Fig. 08 One of Oberlin College’s energy orbs.

in corresponding colors installed at the entrance to each residence hall, Oberlin has seen electricity reductions in the magnitude of 30 to 55 percent, and water use reductions of three percent.10

At Dartmouth, students have used real-time energy displays in dormitories for over a year. An

The Building Dashboard software is also in use at Oberlin College as a method of tracking energy use in dormitories across campus, and is set up in a competition-style layout. Each dorm is rated on a color scale, ranging from red for high-energy use to dark green for those doing well in conservation efforts. In combination with LED glowing ‘orbs’

Fig. 07 Dartmouth’s Bula the Bear energy use indicator.


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Dartmouth students said they didn’t really think about the environment. After Bula the bear joined the campus, a follow-up survey showed that 80 percent of the students cared about the environment and thought about it when they went to use electricity.12

Google Inc.’s PowerMeter, which is testing in beta mode with various utilities (Austin Energy is not currently one of them), allows users to see their electricity usage information right on their iGoogle page. It works by collecting electricity usage information directly from utilities and individuals equipped with smart meters combining that data with utility-provided information such as the pricing structure and energy rates, and graphically representing real-time and historic energy use data.13 Google intends to release this as freeware, allowing everyone access to this important data in a sophisticated interface. The potential for Google and other companies to revolutionize energy market interactivity is tremendous, provided that regulatory bodies and utilities do their part in upgrading the United States energy grid.

Maximizing Consumer Information as an Addition to the Smart Grid

As the United States upgrades its 1950s era electricity infrastructure, a consideration needs to be made to enable direct feedback to consumers. If smart meters and other improvements are implemented solely to provide more detailed information to the utility, without advanced two-way communication, a huge opportunity would be lost to engage the public to participate

in energy saving measures which would have a serious impact. As Edward Lu, Advanced Projects Program Manager for Google, Inc. stated in his testimony to the Senate Committee on Energy and Natural Resources, “First, we must develop and deploy smart grid technology in a manner that empowers consumers with greater information,

tools and choices about how they use electricity, including access to real-time energy information. Second, energy information should be made available based on open non-proprietary standards to spur the development of products and services to help consumers save energy and money.”8

Fig. 09 NPR’s Visualizing the U.S. Electricity Grid online resource.

Fig. 10 RMI’s state-specific electric productivity online resource.

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Incorporating basic information about the U.S. energy grid into communication with users would also allow the public to understand the issues involved with our over-taxed grid, and the reasons why energy-use reduction is important. Tools such as the ones NPR and the Rocky Mountain Institute have developed mapping the Nation’s energy deployment system, and breaking it down by state, are a good start. If utilities developed similar data, explaining the sourcing and implications of peak demand reduction, this type of information would be beneficial in an interactive display attached to one’s energy use as well.

The construction and building industry is also adapting to incorporate operational energy use as a measurement in comparison to energy models done during the design phase of a project. The new version of the US Green Building Council’s LEED building rating system requires energy use data to be supplied on an annual basis after a new or renovated building is occupied, simply to assure that actual energy data and user practices do not undermine the estimates made with design-phase energy modeling. As Scot Horst, Senior VP of LEED, US Green Building Council said, “Today there is all too often a disconnect, or performance gap, between the energy modeling done during the design phase and what actually happens during daily operation. We’re convinced that ongoing monitoring and reporting of data is the single best way to drive higher building performance because it will bring to light external issues such as occupant behavior or unanticipated

building usage patterns, all key factors that influence performance.”14

Interactive Energy Displays for Austin

Austin is home to 690,000 residents, making it the 16th largest city in the United States and its population is expected to double within the next 20 years. Due to the significant forecasted increases in demand for energy and resources, the Austin city government has made broad strides in implementing energy conservation and renewable grid-integration agendas. Because Austin Energy is a municipally owned utility, it has a distinct advantage in quick implementation of energy saving measures and was one of the first in the United States to establish a demand side energy program, introducing numerous and comprehensive energy efficiency and conservation efforts, the most recent of which is the roll-out of

residential smart meters that will allow consumers to physically see their energy use as well as their contributions to the grid in the form of small-scale solar or wind power. Reducing peak demand in Austin, and thereby eliminating the need constructing new municipal power plants is the goal of the Austin Energy Power Saver program. Due to record temperatures in Austin in 2008, the Austin energy grid set a new peak load record of 2,514 MW.15

With the introduction of the Austin Climate Protection Plan, which aims to eliminate CO2 emissions from all municipal activities by the year 2020 through increased energy efficiency measures and renewable energy production, as well as the introduction of new building codes which require the disclosure of energy efficiency audits, Austin is a prime market for real-time interactive energy displays and controls, not only on the personal consumer level,

Fig. 11 A depiction of the smart home of the future, highlighting its energy feedback display panel.


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but also linking one’s impact on the grid. While in the Pecan Street Project’s Operations and Systems Integration Team’s recommendation report, the implementation of Austin Energy’s Smart Grid will be powered by Software Oriented Architecture that will deliver information to all stakeholders,16 it is unclear whether the end-user is included in this group. The Team has done a fantastic job of providing a clear overview of a complicated systems roll-out, but while much effort is going into improving the electricity production, distribution, and communication methods, the demand-side management strategies that Austin Energy has already implemented appear as if they will not be upgraded similarly. While some of the team’s “Day in the Life Scenarios” refer to a smart home panel, the details of such implementation are fuzzy throughout the rest of the report.

Because Google is currently in development of its PowerMeter, and is pairing with utilities that have upgraded to smart metering, it is recommended that Austin Energy immediately look at combining with Google in an effort to develop energy feedback displays that correspond to the needs of Austin home and business-owners. While still in its beta testing stage, perhaps Austin could utilize the Energy Saver volunteer program it already has in place to identify willing consumers who would try out the system and give criticism to fuel quick development and implementation of the PowerMeter for everyone.

Conclusion

The overall energy-savings that can be expected from direct feedback strategies to consumers is five to 15 percent, and has been well documented in institutional settings. As these technologies develop, the residential and commercial sectors will begin to implement them in new buildings and consumers will begin to expect such information instead of simple monthly energy bills. If such direct feedback displays and meters are put into practice in tandem with the development of a U.S. smart grid, the energy savings will be considerable. As Dr. Steven Koonin, Under Secretary for Science for the U.S. Department of Energy, has said, “A little meter running in the corner of everyone’s computer or television screen would do wonders for reducing energy consumption.”17

Notes

1. Medved, Saso, “5. Intelligent Controls and Advanced Building Management Systems” from Santamouris (Ed.), Environmental Design of Urban Buildings, 2006.

2. Energy Information Administration, “Energy Outlook 2009”, 27 May 2009. http://www.eia.doe.gov/oiaf/ieo/highlights.html

3. Energy Information Administration, “U.S. Household Electricity Report”, 14 July 2005. http://www.eia.doe.gov/emeu/reps/enduse/er01_us.html

4. Energy Information Administration, “State Energy Profiles – Texas”, 6 August 2009. http://tonto.eia.doe.gov/state/state_energy_profiles.cfm?sid=TX

5. Darby, Sarah, “The Effectiveness of Feedback on Energy Consumption”, Environmental Change Institute, University of Oxford, April 2006. http://www.defra.gov.uk/environment/climatechange/uk/energy/research/pdf/energyconsump-feedback.pdf

6. Keesee, Mike, “Setting a New Standard

– The Premier Gardens Zero Energy Home”, September 2005. http://www.californiasolarcenter.org/pdfs/forum/2005.9.13-SolarForum_MKeesee-SMUD.pdf

7. Faruqui, Ahmad, “The Impact of Informational Feedback on Energy Consumption – A Survey of the Experimental Evidence”, 2009.http://www.smartgridcentral.com/artman/uploads/1/The_Impact_of_Informational_Feedback__05-20-09_.pdf

8. Lu, Edward, Testimony to the Senate Committee on Energy and Natural Resources, 3 March 2009. http://www.google.org/powermeter/sgtestimony.html

9. Sidwell Friends Middle School Building Dashboard, http://buildingdashboard.com/clients/sidwell/

10. Petersen, John, et al, “Dormitory Residents Reduce Electricity Consumption when Exposed to Real-Time Visual Feedback and Incentives” International Journal of Sustainability in Higher Education, 2007.

11. Dartmouth College Office of Public Affairs Press Release, “Green Screen”, 17 April 2008. http://www.dartmouth.edu/~news/releases/2008/04/17.html

12. Newhouse, Ryan, “Psychology and Social Science Inform Climate Campaigns”, Campus Ecology, 11 August 2009. http://www.nwf.org/campusEcology/climateedu/articleView.cfm?iArticleID=95

13. Google Inc’s PowerMeter http://www.google.org/powermeter

14. “Buildings Seeking LEED to Provide Performance Data”, US Green Building Council Press Release, 25 June 2009. http://www.usgbc.org/Docs/News/MPRs%200609.pdf

15. City of Austin “Resource Guide: Planning for Austin’s Future Energy Resources”, October 2008. http://www.austinsmartenergy.com/downloads/AustinEnergyResourceGuide.pdf

16. Pecan Street Project Operations and Systems Integration Team 7 Final Report, 22 July 2009.

17. Koonin, Steven, during his talk, “Global Energy Challenges”, during the Bureau of Economic Geology Centennial Symposium, UT Austin, 7 August 2009.

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Figures

Figure 01: GE Ecoimagination Print ad, http://www.ge.com/company/advertising/ads_eco.html

Figure 02: Pie-chart constructed from data from Energy Information Administration, “U.S. Residential Energy Consumption Survey”, 2005. http://www.eia.doe.gov/emeu/recs/contents.html

Figure 03: Pie-chart constructed from data from Energy Information Administration, “U.S. Commercial Buildings Energy Consumption Survey”, 2005. http://www.eia.doe.gov/emeu/cbecs/contents.html

Figure 04: Image from http://www.sandia.gov/LabNews/LN02-11-00/images/grid_pix.jpg

Figure 05: Sidwell Friends Middle School Building Dashboard, http://buildingdashboard.com/clients/sidwell/

Figure 06: Oberlin College Dorm Challenge Building Dashboard, http://www.oberlin.edu/dormenergy/

Figure 07: Dartmouth College Energy Feedback Interface, http://greenlite.dartmouth.edu/portal

Figure 08: Oberlin Energy Orb, http://farm3.static.flickr.com/2572/3747667137_c2d9b4e09c.jpg?v=0

Figure 09: NPR’s Visualizing the Electricity Grid, http://www.npr.org/templates/story/story.php?storyId=110997398

Figure 10: Rocky Mountain Institute’s Energy & Resources Team Closing the Efficiency Gap, http://ert.rmi.org/research/cgu.html

Figure 11: GE Ecoimagination Smart Home, http://files.gereports.com/wp-content/uploads/2009/07/netzero_homes_graphic.jpg

References

Austin Energy Resource Plan Updates, April 2009, http://www.austinsmartenergy.com/downloads/ResourcePlanUpdates.pdf

Austin Smart Energy, http://www.austinsmartenergy.com

U.S. Green Building Council, http://www.usgbc.org

Pecan Street Project, http://www.pecanstreetproject.org

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Intelligent Controls + Advanced Building Systems: The Potential … · 2020. 8. 29. · Intelligent Controls + Advanced Building Systems designed buildings, can easily differ by a