NREL Innovates Today for the Homes of Tomorrow
Shaping our energy future into one that is efficient, reliable, affordable, and sustainable is a significant undertaking. Much of this effort is focused around the energy industry, utilities, and power grids—which can seem intangible to the average consumer. But the performance and integration of the homes we all live in is a critical part of solving national energy challenges.
Deep in the heart of the Energy Systems Integration Facility (ESIF) at the Energy Department's National Renewable Energy Laboratory (NREL), a dedicated team of engineers in the Systems Performance Laboratory is tackling these challenges, developing the technologies that will help the "smart homes" of the future perform efficiently and communicate effectively with the electricity grid while also enhancing occupants' comfort and convenience.
NREL is spearheading innovation in energy systems integration (ESI) research, and the ESIF will help speed to market the tools needed for the next energy revolution. In the ESIF, NREL researchers and industry partners are demonstrating the components and strategies needed to optimize our entire energy system.
"NREL enables our industry partners to integrate renewable energy into a smarter, more resilient energy system," NREL's Associate Director for Energy Systems Integration Bryan Hannegan said. "The work being done in the Systems Performance Laboratory will ensure that the homes of the future are able to maximize their use of clean energy technologies and perform at the highest possible efficiencies while at the same time minimizing any potential disruptions to the grid."
Smart Technologies of the Future
NREL's Systems Performance Lab focuses on the development and integration of smart, communicating technologies and distributed energy resources through power electronics and home energy management. Distributed energy resources are smaller power sources that can be aggregated to provide power necessary to meet regular demand.
Within its 5,300 square feet, the Systems Performance Lab features three smart home test bays capable of evaluating a variety of household appliances and systems. The lab is designed to be highly flexible and configurable, an essential attribute when anticipating a variety of smart power applications, from integrating advanced inverters to testing residential- and commercial-scale meters and other household systems.
"One of the great features of this lab is that it really touches a lot of different research opportunities," NREL Senior Engineer Bethany Sparn said. "Some projects are as simple as testing a new design on a power meter or evaluating a new type of sensor, while others can be much more complicated, such as the testing of home energy systems using advanced simulations that are connected to the high performance computing capabilities here in the ESIF. This lab gives us tremendous flexibility to do wide variety of research in the residential buildings space going forward."
Upon entering the Systems Performance Lab, the most noticeable feature is three "test homes," which contain a full suite of kitchen appliances, water heating, washer/dryer setups, and all the other loads found in a typical home. What is different about these test homes is that each includes varying degrees of "smartness" that allow the devices to potentially communicate with the user, the utility, and even with one another.
"The home appliance industry has done a really great job in recent years making our appliances and other household loads more energy efficient. But unfortunately we, as consumers, don't generally use these devices in the most efficient manner possible," Sparn said. "Home energy management is a way to help the consumer use these loads more efficiently. This is the new frontier in residential building research."
A unique feature of the Systems Performance Lab is the ability to perform hardware-in-the-loop (HIL) simulations. HIL testing connects both the input and output of hardware testing to a computer simulation environment. This capability allows researchers to, for example, perform testing on an air-conditioning system in the laboratory, while simulating the actual conditions it would see in the home under a variety of climate or load profiles.
"This merger of simulation with actual hardware gives us the ability to test out different control strategies and demand response strategies that may be used in future applications," Sparn said. "But first you want to test these new ideas in a controlled environment without people living in the home. The hardware-in-the-loop capability allows us to create a realistic environment for this type of testing."
Partnerships with Industry Are Paramount to Success
As an Energy Department designated national user facility, the ESIF depends on partnerships with industry to fulfill its mission. These collaborations are critical to our future energy system—and the partnering opportunities in the Systems Performance Lab are an important piece of this strategy.
Future partnerships in the residential buildings space could involve appliance manufacturers testing their smart products, utilities working to understand the impacts of smart homes to the grid, or home energy management system manufacturers looking to bring everything together for the smart home of the future.
"These devices, from all manufacturers, need to be able to talk to one another effectively, and we need the industry to make that happen," NREL Manager for Residential Systems Innovation and Performance Dane Christensen said. "By partnering with industry, we are able to bring them together to demonstrate various communication methods and determine the best path forward."
Part of the Solution to the Larger Energy Puzzle
The Systems Performance Lab is connected to a solar photovoltaic (PV) system on the roof of the ESIF, and there is space outside the lab for a planned electric vehicle (EV) charging station. These capabilities allow researchers to study how solar energy generation and battery storage from EVs will play a role in future smart home scenarios.
"Utilities are struggling with the significant increase in distributed power generation from rooftop PV systems, partly because those systems are producing most of their energy at times when the home isn't using it—and the utility isn't yet set up to accommodate all of this energy flowing back into the grid," Christensen said. "Optimizing home performance to use as much of that energy as it can by offsetting energy it would use later would benefit the utility. This would also save consumers money by being able to use the energy that is being produced by the home."
Of course, the results from a single home are small in the big picture of an electrical grid. But when multiplied by many hundreds or thousands of homes on a neighborhood or community scale, the impacts become significant. Researchers in the Systems Performance Lab are using advanced simulation tools to quantify and maximize that benefit.
"This is not a one-home solution—trying to affect the impacts of how we use energy is something that we are all going to need to do together," Christensen said. "In the Systems Performance Lab, we can look at neighborhood-scale interactions to see how homes might work together in a community to maximize their efficiency. This is something that hasn't really been studied yet, and we are pioneering the way that we might be able to manage energy on a sustainable community basis."
The Home of Tomorrow
When Christensen thinks about the home of the future, he envisions a scenario where in less than 10 years all major appliances will be able to communicate with the user, the utility, and one another. Within 20 years, as current appliances require replacement, these new smart appliances will become widely adopted by consumers.
How will this impact us, as occupants of our homes? Here's an example: you finish your morning coffee and put the mug in the dishwasher, noticing that it is full and pushing the start button before heading to work. With a smart appliance that is integrated to the home and communicating with other systems, your home energy management system will know that this is not the best time to run the dishwasher because changes in the weather will bring cheaper electricity in a few short hours. The device would then adjust to run the load of dishes later in the afternoon, with plenty of time to complete a wash and dry cycle before you return home for dinner. The same quality service is delivered—clean dishes—but at a reduced cost and environmental impact.
"We're not talking about the 'Jetsons' version of the future here," said Christensen. "We're talking about a home that supports our lifestyles, just like today, but with added comforts and conveniences. Additionally, it will be more automated to make good energy decisions for us, helping to direct and guide the user to energy efficiency and cost savings while maintaining those comforts and conveniences."
— David Glickson