Field Notes Research Updates Spring 2019
This post complements our Field Notes newsletter, which features quarterly updates on CEE's research projects. Sign up for Field Notes to get this information in your inbox.
Field Study of Tier 2 Advanced Power Strips
Background: Plug load energy use in commercial buildings has been growing by about 3 percent annually, a marked departure from other energy use trends — cooling and lighting have both seen decreases.
CEE researchers recently partnered with Slipsteam to complete a CARD-funded study on plug load management strategies with potential for 20 to 30 percent savings in offices. Since that initial study, a new product entered the market with purportedly larger savings — tier 2 power strips.
Supplementing the earlier plug loads research, CEE’s team conducted a field study to measure the new technology’s potential. Using similar methods, the study measured workstation and device-level electrical use to yield results that are applicable to a wide variety of office types.
This six-month study monitored office workstation loads — including PCs, monitors, task lighting, and personal printers — to determine energy savings due to tier 2 power strips, and surveyed both users and IT management about their experiences with the new technology.
Research update: The field study found a 28.1 percent reduction in energy use, or about 98 kWh annually per work station, with one type of tier 2 power strip. This was essentially equivalent to findings in CEE’s previous study, which found 29.1 percent savings in the effect of computer power management on plug load energy.
Using their findings, researchers estimate a six- to seven-year return on investments made in tier 2 power strips. They noted that evolving technologies provide successive marginal improvements, as opposed to a sudden groundbreaking solution.
Additionally, by administering the survey, the research team observed an increased willingness among less technologically enthused office workers to endure minor hindrances in the name of using less power, suggesting an overall increased awareness of energy efficiency and what it looks like in an office setting.
In addition to the recently presented webinar and factsheet composed by Slipstream, researchers will release a full final report in conjunction with the Minnesota Department of Commerce.
Learn more on the project page
Geotargeted Distributed Clean Energy Initiative
Background: In terms of utilities and efficiency, geotargeting is the practice of reducing the energy needed in a particular area to defer growth in power consumption. CEE’s research team is working with Xcel Energy to explore utilities’ potential to use geotargeting in Minnesota to serve customers with clean energy resources to postpone infrastructure updates in response to increased demand for electricity.
Traditional utility planning involves forecasting electricity use by service area and building additional infrastructure in areas where demand exceeds the utility’s defined capacity threshold. However, a larger grid capacity may not be the most cost-effective method to reliably meet demand. In addition, sometimes load forecasts change over time and a fixed, permanent utility-sided asset is no longer needed.
This project explores geotargeting as a way to reduce net costs and environmental impact of the electric utility sector by determining the potential for clean, distributed energy resources to replace planned infrastructure upgrades. Beyond deferring capital investments, geotargeting can help mitigate emissions such as greenhouse gases, mercury, and fine particulates.
Researchers will plan for the distribution of clean energy sources in two communities within Xcel Energy’s Minnesota service territory, and select one area to implement a pilot program. A final report will document lessons learned and policy recommendations, including the total potential for emissions reduction and local energy investment if a policy is adopted statewide. This project is made possible by funding from the Legislative-Citizen Commission on Minnesota Resources, which is funded by Minnesota State Lottery proceeds and investment income.
Research update: To determine the time of day and season of the typical peak usage, CEE’s researchers analyzed data from relevant substation distribution feeders. The team determined that peaks on the feeders typically occurred between 6 p.m. and 7 p.m. during the summer.
Researchers also identified a series of measures they could offer to Xcel Energy electricity customers to directly address the peak. Among these potential measures are upgrades to residential lighting and smart thermostats, as well as commercial refrigeration, lighting, and cooling.
In summer 2019, the researchers hope to implement the identified energy efficiency measures through existing programs delivered by CEE for home energy audits and small commercial lighting and HVAC measures. Also, CEE recommended that Xcel Energy implement additional energy efficiency measures for commercial refrigeration, lighting, and cooling.
Learn more on the project page
Field Study of Electric Heat Pump System
Background: CEE’s researchers recently extended a CARD-funded project on air source heat pumps in an additional field study of two homes. With the extension, researchers monitored an all-electric heat pump system that was not available on the market at the launch of the CARD study.
As with the previously completed project, the team installed detailed monitoring equipment to analyze the performance of the new heat pump systems. They measured system temperatures, component runtime, energy consumption, energy delivery, and real-time coefficient of performance. Researchers used the earlier data to characterize the results of the extended study.
Research update: Generally, the newer system met expectations both in terms of performance and homeowner satisfaction. Homeowners did not complain about comfort, and the system met the home’s demand for heating in extreme climate conditions.
Researchers determined that the heat pump system showed significant reduction in total energy use over other heating systems (57 percent reduction from furnaces and 45 percent compared to electric resistance), as well as cost and emissions reductions.
CEE’s researchers have multiple proposals in for new projects to continue research into heat pumps and their energy-saving potential. Additionally, researchers are working with CEE’s program development team to help utilities facilitate installs. Moreover, in the future researchers plan to look more into the heat pump’s ability to consistently function in a cold climate, as some of the negative 40 degrees days in January may have given the heat pumps a run for their money.
The many projects under the umbrella of CEE’s heat pump research have indicated that the pumps look promising for energy efficiency. Most of the future work will be focused on application — getting them to operate when and how homeowners want them to. Data suggests there is an opportunity to improve the application of the heat pumps and increase their operating hours, while relying less on backup or auxiliary heating. CEE continues to work with installers, manufacturers, and other stakeholders to optimize the performance of these systems.
Learn more on the project page
Field Study of Residential Furnace Fan Controller
Background: HVAC systems in residential homes often represent a significant amount of a home’s total energy use. CEE’s research team is conducting a preliminary study around the market and savings potential of a fan controller that has the potential to boost the efficiency of HVAC systems.
Previous studies in other climates have demonstrated the fan controller’s potential, but this project will explore the potential for Minnesota specifically. The study will examine the current equipment in Minnesota homes, including power usage, equipment sizes, and cycling behavior of HVAC systems, and measure actual savings in heating and cooling that the fan controller achieves.
If selected for a full project, for preliminary sites will be expanded to include at least 30 homes for monitoring. The project involves five major phases: (1) fan controller installation, (2) monitoring its operation, (3) analysis of the results, (4) decommissioning of the fan controller (optional per the decision of the homeowner), and, (5) compilation of a full final report detailing the project and including specific recommendations and guidance for CIP programs.
Research update: One of the key features of the device is that fan controllers are typically a simple install on existing furnaces. This means that a fan controller would be an easy install for programs like the Home Energy Squad.® Combining that ease of installation with a potential heating energy savings of 5 to 10 percent, would provide a huge opportunity for residential energy efficiency.
Researchers are currently collecting data on four fan controllers installed in homes, and say that they don’t have enough data to speak to annual energy savings in a cold climate as of yet, but that the fan controllers are showing promise.
CEE’s researchers have submitted another proposal to continue exploring fan controllers’ energy saving potential in Minnesota. They have been working with Xcel Energy to develop the proposal and get started on early stages of the project.
Projects are funded by grants from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program, or the Legislative-Citizen Commission on Minnesota Resources. Co-funding is provided by project partners and by CEE in support of its nonprofit mission to advance research, program design, and knowledge dissemination in the field of energy efficiency.