TODAY’S STUDY: ENERGY EFFICIENCY DEMOS IN PACIFIC PARADISES
Residential Energy Efficiency Demonstration; Hawaii and Guam Energy Improvement Technology Demonstration Project
L. Earle and B. Sparn and A. Rutter and D. Briggs, March 2014 (National Renewable Energy Laboratory and Guam Sustainability Solutions LLC and Naval Base Guam)
In order to meet its energy goals, the U.S. Department of Defense has partnered with the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) to rapidly demonstrate and deploy cost-effective renewable energy and energy efficiency technologies. The scope of this project was to demonstrate tools and technologies to reduce energy use in military housing, with particular emphasis on measuring and reducing loads related to consumer electronics (commonly referred to as “plug loads”), hot water, and whole-house cooling.
A plug load-reducing technology called the advanced power strip (APS) was installed in homes and monitored for energy savings, and the residents were trained in the use of these new devices. For hot water and cooling, building energy simulation tools were used to select the enhanced energy efficiency (EEE) package of cost-effective retrofit technologies. The technologies installed in these homes included high-efficiency air conditioners and air handlers, in-line dehumidifiers (in a subset of homes), internet-connected programmable thermostats, low-flow shower heads, and heat pump water heaters. The impact on energy use of the space-conditioning and hot water system upgrades was measured to determine annual energy savings. The design of the EEE demonstration was facilitated by Building Energy Optimization (BEopt), an optimization software developed at NREL.
Overall, the APS and EEE demonstrations both saved energy, although house-to-house variations in achieved savings were large. The results from the APS demonstration indicate expected annual energy savings of 58 kilowatt-hours (kWh) in a home entertainment center and 40 kWh in a home office. The APS demonstration is projected to save $600 total for 30 homes over the next four years. Economic results of the APS demonstration were not positive, indicating deployment of this technology in a military housing environment may not yield appreciable savings without further study to evaluate effective options to implementation. The EEE demonstration resulted in much higher annual energy savings, with an average of 4,000 kWh in heating, ventilation, and air conditioning energy savings and 1,400 kWh in domestic hot water savings. These savings translate to substantial cost savings in Guam, where electricity costs 50¢/kWh. The EEE demonstration is projected to result in a net savings (after paying for the initial investment in the first three years) of $120,000 over the next 10 years for all eight homes, or an average of $15,000 per home over 10 years.
All of the products evaluated in this demonstration are commercially available and can be purchased from a variety of companies and retailers. A number of different strategies could be used to increase the use of APSs in base housing, including stocking APSs in the base Naval Exchange, distributing APSs to all new families during move-ins, or employing a direct installation program. The EEE technologies have already been integrated into the standards for new equipment for new and existing homes on Naval Base Guam.
The residential energy-efficiency equipment evaluated in this demonstration is projected to save energy and money while maintaining or improving indoor comfort, and thus, are a good investment for the U.S. Navy. APSs are a simple, low-cost way to reduce plug load consumption, but it may be a challenge to ensure they are installed properly.
In order to meet its energy goals, the U.S. Department of Defense (DOD) has partnered with the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) to rapidly demonstrate and deploy cost-effective renewable energy and energy efficiency technologies. The common goal is to demonstrate and measure the performance and economic benefit of the system while monitoring any ancillary impacts to related standards of service and operation and maintenance practices. The standards of service may include acceptable temperature and humidity ranges, power quality, allowable setbacks, noise criteria, air quality parameters, lighting levels, and other related factors. In short, demonstrations at DOD facilities simultaneously evaluate the benefits and compatibility of the technology with the DOD mission, and with its design, construction, and operation and maintenance practices, in particular.
This report discusses one of several demonstrations of new or underutilized commercial energy technologies.
The scope of this project was to demonstrate tools and technologies to reduce energy use in military housing, with particular emphasis on measuring and reducing loads related to consumer electronics (commonly referred to as “plug loads”), hot water, and whole-house cooling. Plug load-reducing technologies were installed and monitored for energy savings, and the tenants were trained in the use of these new devices. For hot water and cooling, building energy simulation tools were used to select cost-effective retrofit technologies. The results were compared to the simulation tool’s predicted outcomes to validate the use of the tool in the retrofit selection process. The impact on energy use of the space-conditioning and hot water system upgrades was measured to determine annual energy savings.
The demonstration was organized in two tiers. As little is known about the magnitude of plug load energy use and the potential to reduce it in military housing, residential plug load measurement and reduction were the focus of the first part of this demonstration. Through the demonstration, NREL measured and provided user-friendly control over the energy consumption of consumer electronics used in the home entertainment center (TV and peripherals) and the home office (computer and peripherals) areas. In addition to the common problem of users neglecting to turn off unused appliances, plug loads waste energy in the form of “vampire” or “phantom” loads—many devices continue to draw current as long as they remain plugged into receptacles, even after the appliances are switched off. The emerging technology class of products called the advanced power strip (APS) seeks to address the growing plug load energy waste via auto-switching capabilities, where supply power is automatically shut off when the end-use appliance is detected to be in an unused state. In this project, APS devices were installed on all home office and entertainment center areas in 30 Naval Base Guam (NBG) houses, and the electrical outlets were monitored for changes in energy use. Throughout this report, the authors refer to this component of the project as the “APS demonstration.”
The second part, which is called the “enhanced energy efficiency (EEE) demonstration,” is a more comprehensive upgrade package designed to cost-effectively reduce energy consumption of the largest loads in these homes. Using basic information on floor plan and building construction, energy models were developed using Building Energy Optimization (BEopt) with EnergyPlus1 for several typical houses on NBG (Christensen, Anderson, Horowitz, Courtney, & Spencer, 2006). Using these models, NREL determined the most effective strategy to reducing energy consumption in these concrete, all-electric homes is to reduce the heating, ventilation, and air conditioning (HVAC) and domestic hot water (DHW) loads. The best way to decrease HVAC-related energy use is to improve the efficiency of the equipment, and if occupancy schedules allow, employ thermostat setups. Improving supplemental dehumidification could improve comfort, substantially decrease the sensible cooling requirements, and increase the durability of the homes by reducing moisture, which can contribute to mold growth and related health concerns. Heat pump water heaters (HPWH) are an excellent alternative to electric resistance water heaters, especially in a consistently hot and humid climate such as Guam's. NREL demonstrated the energy-saving potential of these technologies in eight NBG houses so that they may be considered in future equipment replacement, as well as new construction…
Recommended Next Steps
Recommended Next Steps for Advanced Power Strips
Despite the challenges of the APS demonstration, advanced power strips are a promising low-cost technology. The energy savings per APS is small, but so is the cost of each device. There are few options available to curb the ever-growing segment of plug loads in residential buildings, and APSs are a simple solution that can be employed in all types of residences. This technology is ready for deployment, though the best deployment method may depend on the situation and goals for the specific base.
Recommendations for future APS deployment:
• The best time to install APSs is when residents are moving into their homes, so APSs could be included in a move-in package.
• If a large-scale deployment was planned in the future, the APS installation should be performed by a third party to ensure the devices are installed and installed properly. This would add to the cost of the deployment, but the savings number may be better because the installation of the APS would be guaranteed.
• The net cost savings in Table 17 show that a larger deployment would result in positive savings, so the bigger the deployment, the better.
• Lack of education is a large barrier with APSs, so awareness or training activities could be used to help educate people about how to install and use an APS, and its energy savings benefits.
• Children are often more tech-savvy than their parents. At least one home in the demonstration was signed up by the family’s middle school-aged daughter. Tapping into the interest of children and teenagers may be a good way to bridge education and energy efficiency.
• Especially on bases where residents pay their electricity bill, stocking APSs in the on-base Navy Exchange store may encourage the more energy-conscious residents to invest in an APS, especially if copies of the consumer education flyer (Appendix F) developed by NREL were available as well. Another option would be to provide residents with a small coupon for the APS models available at the Naval Exchange. Having the residents purchase the APS may also improve installation rates as people would be personally invested.
Lessons learned with the APS demonstration:
• No matter how enthusiastic a resident may be, the effort required to install APS on their own is usually too much.
• Once installed, residents are generally willing to adapt their habits.
• People seemed more concerned with the monitoring part of the demonstration than actually using the APS. Several of our participants uninstalled their monitoring equipment before the APSs were installed, for no obvious reason.
Recommended Next Steps for Enhanced Energy Efficiency Technologies
When NBG housing air conditioners and water heaters reach the end of their lives, they should be replaced with SEER 21 air conditioners and heat pump water heaters. NBG is already following NREL recommendations for next steps by updating the current standards to specify energy efficient technology.
This will ensure new homes and existing homes in need of new appliances or large equipment will receive energy efficient products.
The technologies included in the EEE demonstration had a significant impact on the houses’ energy consumption, while maintaining comfort and user satisfaction. The only exception was the in-line dehumidifier that did not have a measurable impact on the indoor air conditions. High-efficiency air conditioners and HPWHs have already been integrated into plans for future upgrades on Naval Base Guam. The standard for all new water heaters was previously changed to solar thermal water heaters (found in all new homes in the North Tipalao neighborhood), but they have since changed that standard to mandate HPWHs instead. HPWHs are much cheaper than solar water heaters, especially when solar water heaters have to be protected in hurricane/typhoon prone areas, and they still provide significant energy savings.
A follow-on project currently underway will outfit 20 additional homes with the energy efficiency technologies from the EEE demonstration (excluding the in-line dehumidifier) in the Lockwood Terrace and Apra View neighborhoods on NBG. One difference in these installations is the water heater is located inside the conditioned space, in the laundry room, in the Apra View homes, so this will be a good opportunity to see if the same magnitude of energy savings is achieved and if user satisfaction is maintained for conditioned space installations.
There may be opportunities for further education on technology like programmable thermostats. Few people had used the scheduling feature of their programmable thermostat, which provides an opportunity for further energy savings. If there are people at home during the day, there is less opportunity to set a daily schedule. Education about the features and benefits of programmable thermostats may help those on base that can set up their thermostat during the day to save energy.
These recommendations are generally restricted to Guam, as the warm climate and high electricity prices lead to short payback periods for high-efficiency equipment. Even a climate like Hawaii may be mild enough to require a change in the recommendations from this demonstration. Even if the recommendations are specific to Guam, there are opportunities to work with the rest of Guam to inform the public of their options and the cost/benefit trade-offs for these energy efficient technologies. HPWHs are a technology that Guamanians are interested in but had no experience with. This demonstration may encourage more people on the island to invest in better technology in their own homes.
Lessons learned with the EEE demonstration:
• People are generally impressed by the look of new technology, even if they do not understand it.
• Noise may trump other comfort concerns, like humidity. Every single resident said they were happy with the new air conditioner because it was quieter. On the other hand, a few people noted they turned off their standalone dehumidifiers because they were too loud.
• BEopt can be used to define similar packages of energy-efficient and cost-effective retrofit measures for any home in any climate. Major retrofit efforts in other climates can use this tool to select a package of measures, including an estimate of predicted energy savings.