From the Ground Up: Energy resilience begins with our buildings

houses with solar panels

Local generation of electricity, whether through renewable resources or fossil fuels, is much more efficient than producing it at power plants far from the consumers who will use it.

Credit: Getty Images/bruev

Sez Atamturktur has a problem with buildings.

Not buildings themselves; she is an architectural engineer, after all. Her problem is with buildings as we currently think of them, design them, and most of all, power them.

Atamturktur, Harry and Arlene Schell Professor and head of Penn State’s department of architectural engineering, thinks our national conversation about energy issues starts from the wrong vantage point, with residential and commercial buildings viewed as passive consumers of electricity that is produced far away and distributed by centralized systems.

“Almost everybody starts from the power grid and looks down,” she said. “In our department, we start from the building, and look upward to the grid.”

In her view, thinking about energy from the ground up doesn’t just change how we see the problems; it also changes what we’re able to come up with as possible solutions.

Sealing the envelope

The rationale for focusing on buildings first is a matter of simple arithmetic: They consume about 40% of the primary energy we use in the United States — coal, gas, oil, nuclear, hydroelectric, wind and solar — and a full 70% of all the electricity. “So we can continue to improve the efficiency of planes and trains and automobiles all we want,” said James Freihaut, professor of architectural engineering. “But if we want to conserve energy and stop global warming, we’ve got to make the buildings a lot better.”

Individual subsystems (lights, heating, cooling) have gotten more efficient, he said, but buildings as a whole have not improved much over the last 70 years. He attributes that to a fragmented design process, lack of integration of the systems, and lack of regulations setting efficiency and performance goals.

James Freihaut by solar panels

For James Freihaut, improving our energy resilience is a perfect example of what a land-grant university should do: make a difference for people, communities, the economy, and the planet. "We do the laboratory work, all the way up to prototype demonstrations, to actual, real applications," he said.

Credit: Michael Garrett

Freihaut leads several projects at the Philadelphia Navy Yard aimed at making buildings and communities more energy efficient and more resilient in the face of shortages and blackouts. One focuses on individual buildings, using insulation, low-E windows, and other “passive” measures to make the envelope — the barrier separating indoors from out — as snug as it can be. In a nifty experiment, he and his colleagues built two small houses, one to current code and one with an improved envelope. They put 600 pounds of ice in each, closed the doors and windows, and let them sit in the mid-summer heat. After three weeks, there was no ice left in the conventional house — but 400 pounds remained in the passive house.

“Not only did it isolate the inside from the outside, the temperature swings were much lower, meaning that I could predict exactly how much energy demand there was in that building as a function of weather conditions,” said Freihaut. In a real-life situation, that would allow a builder to install smaller, less energy-intensive heating and cooling systems and let them operate more efficiently.

Take a deep breath. Or not.

While improving the building envelope reduces energy use and keeps buildings more comfortable for their human occupants, by reducing outdoor air exchange it contributes to a different problem: indoor air pollution.

“We spend more than 20 hours every day in the indoor environment,” said Donghyun Rim, assistant professor of architectural engineering. “Indoor air is actually most of the air we are breathing over our life, and often we see more than 10 times higher pollution levels in the indoor environment compared to the outdoor environment.”

Donghyun Rim

At the MorningStar solar home in University Park, Donghyun Rim describes how ozone in the air interacts with our own skin and clothing to produce other substances, some of them harmful to human health.

Credit: Michael Garrett

Rim has measured pollutants in a variety of buildings including homes, classrooms, and day-care centers, where toddlers spend up to nine hours a day. Indoor air hazards include pollutants that drift in from outside, plus a host more: dust mites, fungi, and harmful substances we generate ourselves through daily activities such as cooking and cleaning.

One of the worst is nanoparticles between one and 100 nanometers (nm) in size. (For comparison, human hairs range from about 17,000 to 181,000 nm diameter.) Dangerous on their own, these tiny bits of matter can also carry pesticides, plasticizers, flame retardants, protein allergens, and other chemicals deep into our lungs, our bloodstreams, and other tissues in our bodies. They’re especially worrisome because the damage they do is not immediately apparent. Rim and Freihaut, who also works on indoor air quality, said recent studies link nanoparticles to cognitive problems and to a wide range of slow-simmering health problems, including asthma, Parkinson’s disease, autism, and dementia.

Flinging open the windows to let outdoor air blow through can help, but only in areas where the outdoor air is relatively clean and only when temperatures are mild. What we need, said Rim and Freihaut, are sensors to monitor a building’s air, and systems to filter out, dilute, or inactivate any harmful substances and microbes present.

James Freihaut and Donghyun Rim in lab

Freihaut and Rim open a chamber in which they test techniques for removing or de-activating harmful substances in indoor air.

Credit: Michael Garrett

Electricity begins at home

Many of us have made our homes and workplaces more efficient, but Freihaut and Atamturktur said that if we’re serious about cutting our energy use, we need to address the massively inefficient way we produce electric power and get it to consumers.

When a conventional generator burns fuel to create electricity, 60% to 65% of the energy in that fuel is lost as heat. It goes into the air or a nearby river, lake, or ocean. When we transmit the electricity to customers many miles distant, we lose another 5% to 15%. “With electricity coming from central power plants, at your building you only use about 30% to 35% of the primary energy that was used to make the electricity,” said Freihaut. “You threw two-thirds of it away. And buildings use 70% of all our electricity. This is a problem.”

It’s so wasteful, he said, that an all-electric building can’t be deemed energy-efficient, no matter how good its individual systems are, if its power comes from a central grid. “If I stop my calculations at the wall of the building, I have a super-efficient electric building, but from a global, environmental, cultural perspective, it doesn’t help until we go to an all-renewable-energy electric grid system,” Freihaut said.

Until we have such a system, their interim solution, and the subject of a test project at the Navy Yard, is to make electricity with a Combined Heat and Power (CHP) system located close to the consumers who will use it. CHP generates power by burning a fuel such as natural gas to run a turbine, just like traditional generators do. But instead of losing almost two-thirds of the energy in that fuel by spitting out heat, it uses the heat to do other work.

“I capture as much of that heat as I can, instead of throwing it into some river,” said Freihaut. “There are technologies where I can actually convert heat into cooling. So I can use it for making domestic hot water, I can use it for space heat, I can use it to make space coolant, I can use it to run refrigerators.”

The project at the Navy Yard goes a step further by including solar panels to generate electricity when the sun is shining and banks of batteries to store excess electricity from the panels. Freihaut calls it a “hybrid” CHP system. With the ability to store electricity until it’s needed, and a gas generator to produce more when the sun is not shining, a hybrid CHP is cushioned against the ups and downs of a solar-only system. A CHP generator could also be paired with other renewable sources such as wind turbines. Such hybrid systems could provide a bridge to an all-renewable energy infrastructure.

James Freihaut at East Campus steam plant

Freihaut at the East Campus Steam Plant at University Park, where a Combined Heat and Power (CHP) system burns natural gas to generate electricity, then captures the hot exhaust to make steam that further helps heat buildings on campus. The plant operates at 80 percent efficiency, much higher than a conventional power plant, where exhaust heat is lost to the environment.

Credit: Michael Garrett

Scaling up

Another program at the Navy Yard deals with the next step — how an entire community can become more energy-efficient and -independent. “Suppose I have a whole bunch of buildings that are individually efficient; is that it?” asked Freihaut. “Can I save any more energy or use less fossil fuel to operate these buildings? How do I do that?”

What we need, said Freihaut and Atamturktur, is a way to fill the gap between individual buildings and the central power grid. Their answer: microgrids.

A microgrid distributes electricity to customers within a few miles, at most, of where the power was generated. That saves the energy that would be lost during long-distance transmission. Freihaut oversees Penn State’s microgrid at the Navy Yard, a test project providing electricity from the hybrid CHP system to stores, office buildings, and small businesses. In the works for five years, it is now nearly ready to go into full operation. “If we can show that it works in a real system, this could be a path to greater use of renewables,” said Freihaut.

This kind of “distributed energy” arrangement has been used by rural co-ops and municipal grids for decades to bring electricity to homes, businesses, and small communities that were deemed too spread out or too far from the main grid to be worth the cost of running lines to them. These small grids are already substantial players on the national energy scene. According to Freihaut, in the U.S. there are about 2,000 municipal grids serving nearly 50 million people, about one-seventh of our total population. About 600 rural co-ops supply 56% of the land area in the country. In Pennsylvania alone, we have 13 rural co-ops and 35 towns with their own municipal grid. Currently, these systems plug into the central grid, but with options like CHP and hybrid systems becoming more affordable, many are considering switching to produce their own electricity, locally. They won’t lose their connection to the big grid, but they’ll be able to “island” — operate independently of it — in the event of damage to the central grid.

Getting smart

To get the most out of these new kinds of systems, our buildings need to be smarter, said Atamturktur; not smart in the sense of having a refrigerator you can talk to or a webcam by the front door, but smart as a quality deep in the bones of the building, an intelligence that senses its own actions and interacts with its human occupants.

After earning her doctorate from Penn State, Atamturktur spent several years developing models to determine how well predictive models of engineering systems would perform in various scenarios, such as the shielding materials used in nuclear power plants — a field where precise and accurate predictions are absolutely essential. Now she is bringing that level of rigor to models for building systems. “Modeling and simulation are so important for everything this department works on,” she said. “However, models are inaccurate and imprecise representations of reality. What designers predict with current models of energy usage and what really happens in the end don’t often match.” Then builders and consumers become disillusioned with the whole effort of designing energy-efficient buildings.

Sez Atamturktur stands outside the Hintz Alumni Hall

Sez Atamturktur, head of Penn State's department of architectural engineering, foresees a time when our buildings will integrate physical, cyber, and human elements to be very energy-efficient and healthier and more comfortable for the people who live and work in them.

Credit: Penn State

Even the best current models leave out one major factor: human behavior. To address that omission, Atamturktur is enlisting researchers from social and behavioral sciences in the effort to better understand the relationship between architectural design, building systems, and human comfort and performance. She’s aiming for the development of cyber-physical-human systems that include us as essential parts of a building’s design and function. What it comes down to, she said, is, “How can the building influence the people in it, and how can the people influence the building?”

Our current buildings are rudimentary cyber-physical systems — mechanical structures with a few basic cyber elements such as timed thermostats and daylight-sensitive outdoor lights. But they’re actually quite dumb, said Atamturktur. A truly smart building will be able to sense who is in it and what their needs are at different times throughout the day. Instead of a simple timer set to turn up the heat when people are expected to be in the building and turn it down again when the building is expected to be empty, sensors would detect when people actually are in the building, how many of them are present, where they are, and what equipment they are using, and adjust the heat, humidity, lighting, and air flow accordingly. In effect, our buildings will be keeping tabs on us and responding to us in real time, without direct, intentional input from us.

Has anyone ever told her that this sounds a little creepy?

“Oh, it is creepy!” she agreed. “But it’s no more creepy than self-driving cars.”

Or ordinary, person-driven cars, said Freihaut. Today’s average car carries about a hundred sensors that constantly monitor everything from internal cabin conditions to whether you’re driving up or down a hill, the load on the engine, and whether the headlights need to turn on, he said. “In five or 10 years, there will be 200. Your car has what, maybe 15, 25 square feet of seating space? How many sensors per square foot do we use in buildings? Very, very few. The building industry is way behind on this. We’re the last to really employ information technology in any sophisticated way.”

How we get there

Freihaut thinks we already have engineering solutions — practical solutions — to many of the energy challenges we face, and that the rest are within reach in five to 10 years, if we invest the time and effort needed to develop them. At the top of his list is a safe, affordable way to store energy at the building itself, so that heat generated by a CHP turbine can be banked for later use.

“Just a simple hot water tank doesn’t cut it,” he said. “We need to invent a material that can safely store energy at a high temperature and that doesn’t take up a lot of space.’ ”  

He likens this challenge to one tackled by scientists in the space program’s early years — inventing a lightweight, extremely heat-resistant material to keep manned vehicles from burning up during re-entry. “They invented these little tiles that are a quarter of an inch or so thick, and it’s 3,000 degrees out there and it’s only 100 degrees in the capsule,” he said. “That’s a hell of a material! How much money did we spend inventing that? Don’t tell me we can’t afford to do research to invent a new material that we need to conserve 40% of all the energy used in this country.”

Even more than scientific and engineering solutions, he said, what we need most, and might be hardest to achieve, is support for these efforts: public awareness and a desire to improve on our current systems; a regulatory climate that doesn’t prop up the old systems and penalize new ventures into renewables; and, most of all, leadership. That could come from many sources: small communities with their own power grids showing how well a decentralized system works; government officials more focused on solving problems than on scoring political points; scientists and engineers who push us to see old problems in new ways.

Atamturktur, speaking from her office in a 110-year-old building at University Park, said researchers in her department are doing that with every major building system. She believes architectural engineers hold a unique responsibility. “The products we make have such a long-term effect on humanity,” she said. “Every tiny bit of improvement that you make stays with you for decades.”

This story first appeared in the Fall 2019 issue of Research/Penn State magazine.