Technology Talk—Getting to Zero Energy in Existing Buildings

Without upgrading our existing buildings to higher efficiency technologies we have zero hope of getting to zero energy (ZE)–or at least ultra-low energy performance–and our carbon reduction targets. We know that there are many roads to retrofits but rapid scaling relies in part on the commercialization of new technologies, integrated applications of existing products, and pure research and development.

So where are the technology priorities and gaps to help get to zero energy buildings, and where is further investment needed? That was the subject of an extensive study analyzing technology gaps* led by Itron with NBI, EPRI, Integral Group, Davis Energy Group, and UC Davis for the California Energy Commission (CEC) in 2017-2018. The research offers direction for technology changes and new emphasis for utility programs, design teams and manufacturers including:

  • Technology does not pose the biggest challenge to achieving ZE, however it is a significant solution.
  • A new frontier is emerging with smart control technologies with embedded intelligence and predictive analytics.
  • There is an increased interest and focus on grid harmonization, storage technologies and greenhouse gas (GHG) emission reductions.
  • A predominant research gap exists in the number of demonstrations and pilots, including market awareness and education.
  • The relative research priority of technologies depends on the ZE scenario and the key factors: energy impact, technology readiness and cost, load shaping and GHG reduction potential.
  • In the areas of standard building technologies, HVAC load reduction ranked the highest which in turn drives a need for both envelope solutions and efficient HVAC systems.

The outcomes of this study confirm that the market changes we are seeing related to growing applications for controls and grid-friendly buildings are on the right track, but that significantly faster deployment is needed. New climate policy models from Energy Innovation show that seven key policies would slash greenhouse gas emissions in the United States to roughly 50% by 2050, falling short of the 80% goals set in the Paris climate agreement (New York Times February 13, 2019).

Made in the Shade – Demonstration of technology integration for better HVAC and lighting outcomes
One project I am leading here at NBI is an integrated solution that can meet the trifecta challenge of providing 1) significant energy savings, 2) a retrofit that is non-disruptive to the daily building operations and tenants, and 3) a technology and installation that is cost-effective for the owner. This research project, just one of many existing building projects underway through the CEC’s EPIC program, is lab and field testing and demonstration of a combination of automated shades, advanced lighting control systems (ALCS) and some HVAC control modifications and commissioning.

Cutting down on the HVAC load was the top priority category in the CEC technology gap research described earlier. Lamp technologies had low scores in terms of their priority for research to further their advancements but scored high in their importance to getting low-energy outcomes. It seems LEDs have already taken the industry by storm, but controls across technologies remain both important and evolving. Thus this demonstration project aligns well with the gap study results. Meanwhile challenges with heat loss/gain through windows continue to have a large impact on thermal discomfort for occupants as well as glare issues. Help could come in the way of new glazing advancements which include thin-triple glass that offer increased thermal improvement of triple panes but with a weight and size configuration equal to double panes.

Our project’s approach to the windows issue is shading. While shading is very common for both exterior and interior application, the use of automation and the unique aspects of the system we are testing is not widely applied. The Rollease Acmeda Illuminate product in our research is the evolution of shading design, materials, automation, occupant needs and daylighting demands.

The shade lays interior to the window and is split approximately 70/30 respectively between the lower portion that serves the view portion of the window and the upper portion that affects daylight into the space. The blind adjusts in response to the daylight sensors in coordination with the Enlighted and Daintree ALCS systems that are also part of the research. So while the space is optimizing the use of daylight and the reduction of electrical lighting, the occupant or facility manager can create the visual and thermal space they prefer with the lower shade system.

Both systems can be set on centralized control sequences but have local control with default settings so occupants are able to make personalized adjustments. We are excited to test the wireless control system, meaning the system can be installed by standard contractors, and the functionality of the integrated mini-PV that energizes the system, meaning it has no energy impact to the building and no battery replacement maintenance issues. Because of these two features the installation should be much lower in cost.

With energy estimates for savings expected to be greater than 25% of whole building energy use and expected retrofit costs, this solution should meet most owners criteria for a less than seven year payback. More about the actual numbers will be available at the end of the research project, which will finish next year, and assess these factors as well as the ease of installation and occupant impact in both disruption and satisfaction pre and post retrofit.

While there is certainly more to do, I am encouraged by the number of projects underway to find existing building energy retrofit solutions and the incredible trends in emerging technologies that will result in deep energy savings. The complicated and critical nature of existing buildings requires an enormous toolkit of solutions in technology, training, finance, marketing, design, policy and behavior. If we are to move to zero energy and zero carbon buildings, existing buildings is a top order of business.

*The study from which these outcome are drawn was funded by California’s EPIC research program and included input from national experts including over 550 stakeholders (62% of which were design professionals with medium to high knowledge about ZE and technologies), 520 technology literature reviews, and 140 subject matter experts on specific topics the results are truly a collaboration. The results naturally will vary depending on the criteria applied and the weighting of that criteria. For example the project applied areas such as energy savings, load shape impact, greenhouse gas impact, technology readiness, community versus site scale applications, and fuel use.

by Cathy Higgins, Research Director