Navigant Research Blog

What Robots Can Teach Us about Energy Management

— October 14, 2014

The Tennessee Valley Authority (TVA) has learned some valuable lessons from a study involving the use of robotics to simulate human behavior.  The results show that dramatic improvements in efficiency can be obtained with a combination of new technology and a focus on energy efficient construction techniques.

The 5-year Campbell Creek project involved three similar Knoxville, Tennessee-area homes.  Each has the same floor plan, with two stories, and measures between 2,400 and 2,500 square feet.  Here is how they differ:

  • Builder House: This was the control home, or benchmark, built to represent a typical residence constructed for the Tennessee Valley and built to local building codes.
  • Retrofit House: This house was essentially the Builder House, but retrofitted with energy efficiency technologies, such as more energy efficient windows, ENERGY STAR appliances, compact fluorescent lights, sealed attic with foam insulation, and high efficiency heat pumps.
  • High Performance House: This house was built using the latest available construction technologies aimed at energy efficiency, as well as PV panels and solar water heating to help make it a near zero energy house.

The TVA then outfitted each home with robotic devices to mimic human behavior.  For example, a robotic arm on the refrigerator in each home would open the door simultaneously at 3:00 in the afternoon, when kids typically arrive home from school.  Each home had the same automated systems to turn on lights, televisions, appliances, and showers.  The homes also had a device that replicates how a person’s body heat affects the temperature and humidity of a room.  In addition, each home had hundreds of sensors installed to monitor energy consumption of all the subsystems.

Results and Lessons

The Builder House had a utility bill of about $1,600 a year, the Retrofit about $1,000, and the High Performance was slightly more than $400, according to project managers.  Based on the Home Energy Rating System (HERS) Index, the homes scored as follows: Builder House, 101; Retrofit House, 68; and High Performance House, 34 (a lower score is better).

The TVA project was conducted with partners Oak Ridge National Laboratory (ORNL) and Electric Power Research Institute (EPRI).  Near real-time data from the project as well as archived results are available at the EPRI web site.

These are not exactly startling results, but this intriguing study has valuable lessons for all stakeholders – utilities, homebuilders, and homeowners.  One main lesson is that doing basic things like tightening a home’s envelope with enhanced insulation and energy efficient windows will have lasting benefits.  Also, investing in the most efficient HVAC and water heating systems one can afford will pay off in energy savings.  The manager of the project, David Dinse, who has just retired, told me the project has generated quite useful data – so why aren’t more builders and utilities taking these lessons and running with them?

 

Building Automation Shifts to Integrated Controls

— October 12, 2014

Building automation system (BAS) controls have long acted as a cash cow for vendors.  Historically, they were built on closed, proprietary communications protocols, virtually guaranteeing steady revenue from future maintenance and upgrades.  Now, though, customers are migrating to control systems with open protocols, such as BACnet and LonWorks, to gain greater flexibility and interoperability.  The emergence of these standards is changing the landscape of building controls.

The shift to open protocols largely benefits building owners (and has unsurprisingly been driven by the demand of building owners).  Competition is increased, as all vendors are on equal footing, which drives down prices.  Naturally, controls vendors are now exploring alternatives to gain a competitive advantage and regain steady revenue.  One emerging strategy is integrating more intelligence and more controls into HVAC equipment.  Even though more vendors can compete with open systems, the more intelligence that is shipped with HVAC equipment, the less there is available for controls companies to install, thereby protecting revenue from the increased competition.

Rapid Adaptation

Johnson Controls seems to be adapting to the changing environment rapidly.  The company made two important announcements in September.  First, it is reorganizing its building efficiency business to separate the North America branch from the global products business.  This will enable the company to focus on high-margin HVAC product lines, notably air distribution and ventilation solutions and variable refrigerant flow (VRF) systems.  The second announcement signaled plans to divest Johnson Controls’ Global Workplace Solutions business.

As I noted after Johnson Controls’ acquisition of Air Distribution Technologies, the move was not about products but about controls.  Johnson Controls’ joint venture with Hitachi to provide VRF systems follows the same strategy.  VRF systems represent lower potential revenue for controls suppliers because controls are typically provided by the equipment manufacturer.  Moreover, because VRF systems use refrigerant as the heat transfer medium instead of air, the need for complex air-side control of supply air temperature and humidity is obviated.  By shifting its focus to HVAC products, Johnson Controls is ensuring that its controls stay relevant.

 

The NFL Tackles Energy Efficiency

— October 12, 2014

On September 14, the San Francisco 49ers played the first game at their new home, Levi’s Stadium in Santa Clara, California.  Though it has its detractors, the new stadium is one of the most energy efficient sports venues in the world.  The 49ers partnered with clean energy leader NRG Energy to install a 375 kW solar power system across the stadium.  The installation will generate enough electricity annually to offset the power consumed during all home games.

In addition to onsite power generation, the stadium has installed low-flow water fixtures in all bathrooms, and water is reclaimed whenever possible to be reused for irrigation and other purposes.  A 27,000 SF green roof provides extra insulation and reduces the demand for heating and cooling.  Whenever possible, the builders used recycled and reclaimed materials during construction.  All of these features have led to Levi’s Stadium being the first U.S. professional football stadium to achieve LEED Gold certification.

Efficient Competition

Unfortunately for San Francisco fans, the 49ers lost their opening home game to another team that has made a commitment to sustainability.  The Chicago Bears completed a full renovation of the iconic Soldier Field in 2003, making it a goal to improve performance and efficiency while also reducing the stadium’s carbon footprint.  These efforts also earned recognition from the U.S. Green Building Council (USGBC) in the form of a LEED – Existing Building Certification.  Although Soldier Field does not have any onsite renewable power generation, it does boast many energy saving features, such as LED lighting with a networked control system and a green roof on the parking structure.

Given their very high energy usage, many other stadiums around the world have implemented efficiency features.  The most popular are efficient lighting/control systems and low-flow water fixtures.  More capital-intensive projects to install renewable power generation on stadiums are also becoming common.  Lincoln Financial Field, home of the Philadelphia Eagles, has the ability to generate 3,000 kW of renewable electricity onsite, the most of any stadium.  Eleven thousand solar panels have been installed, along with 14 eye-catching vertical axis wind turbines, which are intended to be a visual representation of the team’s commitment to sustainability.  FedEx Field outside of Washington, D.C. and MetLife Stadium in New Jersey boast 2,000 kW and 314 kW of generating capacity, respectively.

Power Houses

Two other highly efficient stadiums belong to two of the league’s top teams.  The Seattle Seahawks and the New England Patriots are both powerhouse teams, likely to meet in this season’s Super Bowl in Arizona.  Seattle’s CenturyLink Field produces 830,000 kWh annually with an onsite solar installation.  The Patriots’ home field in Foxborough, Massachusetts also features solar power generation, a 525 kW array installed by NRG Energy.  One of the distinctive features of this stadium is an integrated building energy management system that optimizes HVAC, lighting, and other systems.

Sports teams have a unique ability to influence their home communities in positive ways; their visible commitments to sustainability tend to have ripple effects throughout the community.  Energy efficient stadiums support local green businesses that are able to put their expertise on display in large-scale projects.  Saving energy and money and helping fans understand the impacts of their actions is a win for everyone.

 

Low and Zero Energy Buildings Driven by Policy Measures

— October 7, 2014

New York City Mayor Bill de Blasio has announced an ambitious plan to tackle greenhouse gas (GHG) emissions by retrofitting public and private buildings throughout the state.  De Blasio’s plan strives for 80% reduction of GHGs by 2050, a target that, as The New York Times put it, “would be a truly impressive feat if he were actually able to make good on that promise.”

With this plan, New York is continuing its efforts to become a leader in energy efficiency and GHG emissions reductions efforts across the United States.  Other states with similar GHG reduction targets include Massachusetts and California.  One emerging strategy employed by states with emissions reduction targets is the zero energy building.  Zero energy buildings (ZEBs) produce enough energy to offset their annual consumption, typically through the use of renewable installations.  ZEBs are built using highly efficient building materials and technologies and often rely on methods such as daylighting to reduce energy consumption.

Policy-Driven Change

According to the recent Navigant Research report Zero Energy Buildings, growth in the market for energy efficiency in buildings is expected to be driven by regional and local policies.  This is true both in the United States and internationally, where the European Union leads the way with the Energy Performance of Buildings Directive (EPBD).  The EPBD requires new public construction to be zero energy after 2018 and all new construction to be zero energy by 2020.  In addition, the EPBD requires individual member states to develop national plans for increasing the number of ZEBs.

California’s Title 24 building code aims to achieve all new residential construction as zero net energy (ZNE) by 2020, with all new commercial buildings achieving ZNE by 2030.  In Massachusetts, utility- and state-funded pilots have helped to drive building energy efficiency.  The Massachusetts Department of Energy Resources launched the Pathways to Zero Net Energy Program in 2014, designed to support ZNE building construction and facilitate market development.

Federal Legislation

With technology improvements and the growing availability of energy efficient building materials, policy has become the most important driver in prompting energy efficient retrofits and new construction.  Although several states have adopted targets for building energy efficiency, the most relevant federal legislation is Executive Order 13541.  The Order mandated that by 2015, 15% of existing federal buildings conform to energy efficiency standards and by 2030, 100% of all new federal buildings achieve zero net energy.  Although sweeping national legislation requiring ZEBs for commercial or residential construction seems unlikely in the immediate future, federal incentives could prompt builders to pursue more efficient building and strive to make zero energy more common in the United States.

 

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