How can we use the most impactful packages of energy savings measures, big data from buildings and strategic investment planning to capture 20-30 percent more whole building energy savings than just the "low-hanging fruit?"
Building from current research and development by DOE’s Commercial Buildings Integration team and Lawrence Berkeley National Laboratory1, the #3 Summit Panel in our 2017 Top 4, Beyond Widgets: Racking Up Savings from Systems Approaches to Building Performance, tackled building energy systems efficiency and integration topics including phased retrofits across portfolios as well as lessons learned and best practices from actual projects. The Better Buildings Beat Team caught up with panel moderator Laura Van Wie McGrory of the Alliance to Save Energy for her thoughts, as well as her fellow panelists Scott Williams, Rick Tonielli, and Matt Jungclaus.
Beat Blog: In layman’s terms, what is a systems approach to improving building performance?
Laura Van Wie McGrory, Alliance to Save Energy: A systems approach to building performance refers to looking beyond energy-saving measures that focus on the efficiency of individual building components (appliances and equipment), and considering additional energy efficiency opportunities at the building systems level.
Scott Williams, Williams Building Systems Engineering: [It’s about] understanding how components (widgets) work and interact within a building. HVAC systems have components such as fans, heating coils, dampers, controls. Individually, those components may be very efficient, but if they are not properly designed and operated as a system, they may not be optimized. Money can be wasted on expensive components that don't improve overall building performance.
Rick Tonielli, ComEd: The order in which energy efficiency projects are performed is also important in a systems approach. For example, installation of variable speed drives can improve the ability to control mechanical systems under various operating conditions, thus increasing the amount of potential savings. So it makes sense to install VSDs prior to, rather than after, optimization of system operations if feasible.
BB: What are some quick-fix systems that buildings can use for short-term fixes as they hash out a more strategic, long-term energy management strategy?
LVWM: Examples of short-term systems approaches for mechanical systems include: the use (and optimized control) of variable frequency drives and efficient fans and pumps to improve the overall efficiency of HVAC&R systems; the use of “demand-controlled” ventilation; heat transfer from cooling to heating zones and energy recovery from exhaust air; system enhancements, such as economizers and evaporative cooling; and optimized control of cooling towers, pumping systems, and strategic chiller sequencing to improve annual chiller system efficiency.
For lighting systems, lighting controls are a primary strategy for achieving energy savings. Primarily, controls are used for occupancy-based lighting, dimming (in response to daylight availability, occupant preference, and/or demand-response signals from the utility grid), or for lumen maintenance (to adjust light output for declining lamp efficacy over time while avoiding initial excess illumination). Other lighting system-oriented strategies include the use of glazing and light shelves (horizontal surfaces that reflect daylight deep into a building), specialized window films, or other means of projecting daylight further into a building, and appropriate use of task lighting.
Matt Jungclaus, Rocky Mountain Institute: It's critical that quick and short-term fixes become part of a much larger plan for deep energy savings over time, or an energy master plan for the building. RMI recommends that building owners develop a deep over time (DOT) plan for their buildings to perform upgrades as funding becomes available. As part of a DOT plan, ‘quick-fixes’ are implemented in accordance with a larger plan so that they do not prevent future deep energy retrofits from being performed economically and in concert with these earlier upgrades.
BB: How can an organization improve its energy-performance benchmarking?
LVWM: In general, benchmarking is conducted at the whole-building level. Whole building benchmarking, by nature, assesses the overall energy performance of buildings by capturing the efficiency from the building equipment and systems, building controls, maintenance and occupant behavior to provide a general assessment of how the building performs. To the extent practical, sub-metering and benchmarking at the systems level would be extremely valuable to measure and compare the efficiencies of various building systems, and to help organizations pinpoint areas for improvement.
RT: Buildings can take advantage of widely available benchmarking tools such as the ENERGY STAR Portfolio Manager to track energy and water consumption
SW: For any building, Energy Star for buildings provides good benchmarking and makes adjustments for differences between buildings with input data.
RT: Some utilities have software tools available to help buildings view and aggregate whole-building energy usage data for the benchmarking process. For example, ComEd offers the Energy Usage Data Tool to its customers, which allows a multi-tenant building owner to collect usage data for the whole building and to upload the data to ENERGY STAR Portfolio Manager.
BB: What forms of software exist that can immediately help organizations improve their building performance?
SW: I think a knowledgeable building operator is more important than any software. Software is valuable if properly applied but can miss opportunities if the person running the program doesn't thoroughly understand building operations.
MJ: RMI has supported innovative software solutions that look beyond simple building performance optimization, to consider the implications of the emissions that result from energy usage in the building. We are particularly excited by a potentially disruptive solution from WattTime—which recently joined RMI as a non-profit subsidiary—who has pioneered a new software solution that supports automated emissions reductions based on the real-time emissions data for the power stations in a given building or campus's locale. By tracking this real-time data, WattTime helps building owners automate their systems to use electricity at the cleanest times of the day, leading to carbon emissions reductions without negatively impacting building operations. WattTime is being piloted in several campus environments currently and early collaborations show great promise. In time their software will be scaled more broadly for additional residential and commercial applications.
RT: A knowledgeable building engineer can evaluate software-generated recommendations and determine which make the most sense for his or her building. These tools also provide an educational function to users, helping them better understand energy usage so that they can better manage it.
BB: Are there any case studies you can think of in which a company implemented a systems-approach to improving building performance?
LVWM: The recent Pacific Northwest National Lab study contains a number of case studies showing the results of systems efficiency improvements through the use of commercial building controls:
SW: Check Better Buildings for case studies from prototypical building owners such as Target, Walmart, and Whole Foods. These companies and others spend significant time and resources fine-tuning building operations that get rolled out system wide. Many of the items they roll out are applicable to other buildings and building types beyond retail.
MJ: One classic example is the 2009 retrofit of the Empire State Building. The original plan for the building's retrofit included a $17.4 million effort to replace the existing chillers with newer, larger chillers, which would require closing down Fifth Avenue in New York City. RMI and the team working on this project determined that these chillers would not need to be up-sized or replaced if the team could reduce the required cooling loads within the building. If they could reduce internal heat gains, they could avoid triggering the chiller replacement (and the expensive shutdown of Fifth Avenue). RMI and the team's approach was to implement substantial lighting retrofits, plug load reductions, and building envelope retrofits to reduce loads and avoid the chiller replacement. This included a novel approach to re-manufacturing the Empire State Building's historic windows on-site to be more energy-efficient and prevent heat transfer out of the building. Ultimately, the team avoided the expensive chiller replacement in favor of a much less expensive chiller retrofit that enabled the existing chillers to cool the building more efficiently.
BB: Is there any additional information from the session we should include for the Beat Blog audience?
LVWM: I’d like to refer readers to the Systems Efficiency Initiative (SEI), which has informed my responses. The SEI is a multi-year collaboration among industry leaders, utilities, NGOs, and national and state-level government agencies, focused on advancing energy efficiency in building systems. The Alliance to Save Energy launched the initiative in 2015 to investigate the significant untapped energy savings potential of a systems-level approach to building efficiency, which considers the interactions of equipment and controls within and among HVAC, lighting, and other building systems; interactions among multiple buildings; and interactions between buildings and the grid.
The SEI has produced two reports, which are available at www.ase.org/sei:
- Greater than the Sum of its Parts: The Case for a Systems Approach to Energy Efficiency (2016) discusses opportunities for improving efficiency in mechanical systems, lighting systems, and miscellaneous electric loads, and through the use of DC power and building-to-grid integration.
- Going Beyond Zero: A Systems Efficiency Blueprint for Building Energy Optimization and Resilience (May 2017) contains 84 recommendations for various audiences (e.g., U.S. Congress, federal and state agencies, utilities, manufacturers, architects) designed to move the market toward systems efficiency.
MJ: Dwight D. Eisenhower is quoted as saying "Whenever I run into a problem I can’t solve, I always make it bigger. I can never solve it by trying to make it smaller, but if I make it big enough, I can begin to see the outlines of a solution.” RMI feels that this quotation has direct relevance to taking a systems approach to improving building performance. Rather than utilizing one or two widgets to improve building performance at a time, we need to consider all of the energy-consuming systems in a building as well as the other building factors like occupancy, usage, operations, maintenance, and the goals of the building owner. We could make the problem even bigger by capturing value in districts, communities, and the electric grid beyond the building.
1Regnier C, Mathew P, Robinson A, Schwartz P, Walter T, 2016, ACEEE Conference Paper, Beyond Widgets - Systems Incentive Programs for Utilities, LBNL-1006195