wind turbines and power lines over a field
Image: GettyImages / kflGALORE

Re-Imagining Energy: Pulling It All Together

Combining green and traditional energy systems brings new challenges.

As the land-grant university for the energy-rich state of Pennsylvania, it isn’t surprising that Penn State counts among its core strengths a broad and deep expertise in energy-related research. Today, in areas from materials science to policy, from environmental chemistry to architectural and electrical engineering, the range and quality of our research make Penn State a world leader in energy research.

We've produced a package of five stories that capture just a sliver of that expertise, briefly sampling some of the more innovative ideas of Penn State researchers working together to solve key questions of making and using energy.

Please visit our other posts on:

Generating energy—tapping natural processes to power our future

Storing energy—revolutions in materials to make batteries that charge faster, last longer, and are safer than conventional batteries

Catching carbon—new technology to capture CO2 before it gets into the atmosphere and either sequester it or use it to create new products

The built environment—how new inventions and design principles are making our buildings and appliances more energy-efficient

And for an inside look at how Penn State students are making a mark in the field of wind energy, see A Shift in the Wind.https://www.psu.edu/feature/2018/11/14/shift-wind


Shifting from fossil fuels to renewable energy sources requires more than the invention of better solar cells or batteries. Because photovoltaics and wind turbines depend on the time of day and the weather, we also need ways to combine different power sources and storage systems so we have steady, reliable service; and we need to integrate the new technologies with traditional power plants and electric grids.

Penn State scientists, policy experts, and physical plant managers are exploring how to navigate this transition so we can get the greatest value out of the green technologies that are becoming available.

DISTRIBUTED POWER AND NEW CHALLENGES

The increasing popularity and affordability of alternative energy challenge our existing power systems in many ways. Where the traditional power grid has a central source of electricity—a large power plant—and a massive network of transmission lines carrying the electricity to customers, today, electrical supply is much more distributed, with many customers generating some or all of their own electricity with wind turbines or solar cells. At times, they still draw power from the grid, but at other times they send power back onto the grid or unplug from the grid completely.

That complexity doesn’t fit well in the existing utility system, says Seth Blumsack, who studies the regulatory and market environments for new technologies.

“The business models and policies that support the traditional power grid are rapidly becoming outdated,” he says. As more customers opt out, electric utilities lose income. They may struggle to keep their lines in good repair so they can continue to serve those who do not unplug.

Blumsack and his colleagues use models to simulate how grid systems might operate under different market conditions or policies. He emphasizes that regulations need to take into account that access to electricity is not just a market good; it has social value as well.

“As much as we want to encourage different technologies, when it comes down to it, there are certain things that we as a society are not going to tolerate,” he says. “Electricity being broadly unaffordable is one of them. Massive blackouts are another. This is part of the challenge—how do you encourage that kind of sustainable transformation while at the same time maintaining accessible and affordable and highly reliable power? That’s the big challenge.”

—Cherie Winner


WELCOME TO THE MICROGRID

The ultimate in distributed energy is a microgrid, in which a small area like a community or a campus generates enough electricity on-site that it can survive without a connection to the external grid. It may still be connected to the grid, but it doesn’t have to be—if the big grid suffers a massive blackout, in the microgrid area the lights will still be burning.

At the Philadelphia Navy Yard, Penn State is testing a building-scale microgrid that combines solar, gas, battery, and control technologies. Part of 7R, a new 20,000-square-foot classroom building that opened in 2016, the microgrid has a solar photovoltaic array backed up by a natural gas-fueled microturbine. “You can’t count on solar being consistent all the time,” says program manager Lisa Shulock. “It rains, it’s cloudy, it’s night—but if you have another resource locally, like this microturbine that can power up when the sun is going down, then you still see steady energy production.”

The 7R microgrid was partially funded by the Pennsylvania Department of Environmental Protection as a demonstration project to show that a gas microturbine can actually increase the use of solar photovoltaic arrays. It does that because it’s a CHP, or combined heat and power, system: The “waste” heat it generates is used to warm up water, which in turn can be used to heat or cool the building. Combining a gas-fueled microturbine with solar, says Shulock, “you can actually increase the amount of solar in the grid, because you have something to back it up when the solar goes away.”

building 7R at Navy Yard

Building 7R at the Navy Yard is home to a single-building microgrid that combines solar power, a gas microturbine, fast- and slow-responding batteries, and a sophisticated control system.

Image: Michelle Bixby

When the solar cells generate more power than the building uses, the excess is stored in two banks of batteries, which provide power while the microturbine revs up. A lead-acid battery bank eases the transition from solar to gas during predictable, slower shifts, such as when the sun goes down. For times when solar array production drops more suddenly, such as when clouds roll in, the system draws on a bank of fast-responding lithium ion batteries.

The whole system is operated by a sophisticated microcontroller than can be programmed to optimize savings or power, minimize carbon-emitting fuels, supply power to the external grid when that would be profitable, or accommodate a range of other conditions and goals.

“When you combine all these technologies, you get the best of all worlds,” says assistant research professor Mark Stutman.

—Cherie Winner

inside building 7R at the Navy Yard

Building 7R at the Navy Yard features passive solar design as well as its own electrical microgrid. Energy efficiency and occupant comfort were major goals of the building's designers.

Image: Michelle Bixby

Seth Blumsack is associate professor of energy policy and economics. Lisa Shulock is sustainable energy program manager at Penn State at the Navy Yard. Mark Stutman is assistant research professor at Penn State at the Navy Yard. 

This story first appeared in the Fall 2018 issue of Research/Penn State magazine.

Contacts: 

Cherie Winner

Work Phone: 
814-863-4750