General

Sustainable Small House project
offers big energy efficiency payoffs

A group of OPPD employees and executives recently got a first-hand look at a prototype Sustainable Small House. The energy-efficient house is nearing completion on the University of Nebraska Omaha campus.

Bing Chen, the driving force behind the project, led the tour. He is a professor of electrical and computer engineering at the University of Nebraska-Lincoln.

“We are making a house that will stay warm in the middle of January with the equivalent of 16 birthday candles,” Chen said.

That’s quite ambitious for the 600-square-foot unit, 400 square feet of which will be livable space. However, it’s something Chen thinks is feasible. His belief is based on scholarly analysis, research and testing.

The building materials used are meant to make the house as tight as possible. The house contains the following energy-efficiency features:

• Passive solar heating, solar electrical generation, and a roof-collected rain water system
• Energy-efficient windows rated R-8 and R-10 (R-value measures the effectiveness of insulation in parts of a building’s exterior shell – walls, roof, floors and any other barrier between outside and inside.)
• Walls are R-50, and the roof with R-100
• A German-built door constructed of multiple layers, with an R-8 rating
• A ductless heat pump (SEER-rated 42) will cool space in the summer and a heat pump will heat water in the winter

Chen is partnering with OPPD and other groups on the SSH. Such houses are also called small houses or accessory dwelling units.

Bright idea

A number of things aligned to bring this project to life.

As Chen experienced the challenges of aging parents, both in his and his friends’ lives, he leaned on his expertise in electrical and computer engineering and renewable energy to find solutions.

“How do you maximize their sense of well-being as they age, let them maintain independence and minimize infringing on family members?” he said.

And, how do you do this keeping fixed incomes in mind?

Chen envisioned building “a small house on steroids.” He drew information from his involvement in passive solar research, his lifelong mission to reduce carbon footprints, and his interest in tiny home and small house projects in cities like Boulder, Austin and Alexandria, Virginia.

OPPD provided the first grant in 2018, which got the project off the ground. Chen worked with a number OPPD employees to explore how to best collaborate on the project. The utility will gain valuable information from the data collected by the home once it is up and running. The data will help determine how to use the home’s new technologies on a wider scale. Battery-stored energy is one area of interest.

“It was exciting for us to get our first look at the sustainable house,“ said Laurie Zagurski, OPPD manager, Outreach & Education/Community Connections. “OPPD takes pride in community partnerships, and Chen is pushing technology and trying to change behaviors.”

With so many baby boomers entering their golden years, Chen said, the need for good, affordable housing is growing. By 2030, the number of U.S. residents ages 66-84 will total 61 million, according to the National Institutes of Health, with an additional 9 million people born before 1946.

The UNL-UNO demonstration will be a smart home, capable of adjusting temperature, lighting and other appliances automatically and by voice control. It will also monitor residents. Owners can program the home to call their children and 911 if necessary if they fall, for example.

Tapping colleagues

Chen also has reached out to many former colleagues seeking expertise and insights.

Among them is Lee Schriever, a retired architect/builder located in Panama, Nebraska, who specialized in passive solar residential design build.

Schriever and Chen were students at UNL at the same time, but they got to know each other through various solar energy groups, starting in the 1970s.

“We have similar interests,” said Schriever, who served as architectural advisor for the house.

“Dr. Chen has many different ideas that others can emulate to build these dwellings,” Schriever said. “Cost always rears its ugly head, but there are many different things that make it easier now.”

For example, windows, Schriever said, have improved a great deal and provide an optimal way to make a home energy efficient.

“This demo house is a showpiece of what is possible,” Chen said. He plans to send drawings of the house to a manufacturer who could bring an affordable version of the SSH to market. He’d like to see a price tag of $150,000 or less, with the ability to add higher-end technology.

Teaching tool

Schriever has been impressed with the student involvement.

“The hands-on stuff Dr. Chen is doing is really important,” Schriever said. “He’s passing on his knowledge and teaching the students a different way of thinking.”

Students are largely responsible for completing the home, Chen said. Electrical engineering, computer engineering and gerontology disciplines have been involved. Upcoming work will bring chemistry and biology students on board.

“I think Dr. Chen’s views for the future are impactful, and his teachings on sustainability are necessary for the students,” said Jorge Rivera Romero, a senior majoring in electrical engineering, who also works as a part-time data analyst at OPPD.

“When you take one of his classes, you learn about our environmental impact and the significant carbon footprint we have left on earth,” Rivera Romero said. “Many students are not familiar with environmental science and sustainability. Dr. Chen effectively brings electrical engineering students to these concepts by teaching us about solar designs, as well as other sustainable methods.”

Rivera Romero has been calibrating the solar panels on the house and helping build the rear entrance deck.

“The small sustainable house enhances this learning by providing a hands-on experience with these designs,” he said. “I believe his mission is fascinating. It helps students recognize their important role as engineers in reducing carbon emissions.”

A collaboration

Chen plans to instrument the home this fall and finish up in the spring. A final touch will include Maverick Gardens, an outdoor area with eco grasses – low-growing grasses that need little mowing and are resistant to drought – and a gardening area easily accessed by those with limited mobility.

“In half of a century, the world is going to be hurting if we don’t change our ways,” Chen said.

The house has come this far thanks to his passion and a lot of goodwill from others.

In addition to the students, Chen’s colleagues and OPPD, other partners have included the University of Nebraska Foundation, the State of Nebraska, the Nebraska Environmental Trust, Metropolitan Utilities District and Home Depot, as well as sponsors from the construction industry.