Archive for the 'Video Resources' Category

Evaporation as a renewable energy source

Researchers at Columbia University, led by biophysicist Ozgur Sahin, have developed an “evaporation engine” that uses bacterial spores that expand in the presence of humidity and contract when the humidity is low.

While this technology was first described in a 2015 paper in Nature, the group recently made headlines again when they wrote a paper describing the potential for natural evaporation from U.S. lakes and reservoirs to generate 325 gigawatts of power!  That represents nearly 70 percent of the electricity currently generated by the United States. Their analysis, published in Nature in Sept 2017, revealed that the energy potential available from evaporation is comparable to that of wind and solar power but unlike wind and solar is characterized as low-intermittency. According to the authors, these findings “motivate the improvement of materials and devices that convert energy from evaporation.

This is the just kind of innovation that I believe needs to make its way into classrooms to inspire the next generation of scientists and engineers.  This new technology also provides an opportunity to invite your students to evaluate the challenges that will need to be studied in order to use this technology on large bodies of water. For example, the authors cite that “using evaporation driven materials and devices on lakes or reservoirs could affect freshwater resources” but that this technology could reduce evaporative losses in regions characterized by water stress and scarcity.  The authors conclude that “these materials and devices could potentially contribute toward solving energy and water related challenges.”

Below I have listed some classroom-ready resources should you want to introduce this technology to your students:

Renewable Energy from Evaporating Water (5 minute video with Ozgur Sahin)

Evaporation-powered devices in action (4 minute video)

A miniature car driven by evaporation (Under 1 minute video)

ScienceTake | The Spore Machine (1:36 minute video from the New York Times)

Engineering Evaporation (6 minute conversation between Ozgur Sahin and Ira Flatow on NPR’s Science Friday)

Evaporation could power most of the U.S. — study
Greenwire, September 26, 2017

Water evaporation could be a promising source of renewable energy
The Verge, September 26, 2017


Guest Post: How much energy is in your water bottle? by Ryan Kingsbury

We don’t often think about the energy it takes to satisfy our thirst, but where we get our drinking water has huge consequences for how much energy is needed. In many parts of the world, fresh water sources like lakes or aquifers are becoming scarce, forcing residents to settle for supplies that aren’t as clean. And the dirtier the water, the more energy it takes to purify.

Salt is especially hard to remove. In desert or coastal regions with limited sources of freshwater, residents must use a process called desalination to turn salty groundwater or seawater into drinking water. We’ve already covered how mixing saltwater with freshwater releases a lot of energy,  so, to do the reverse– to remove salt from water– consumes a lot of energy.

Exactly how much energy is required depends on the method of desalination. Distillation (which involves boiling)  is a simple way to desalinate water, but it’s also one of the most energy-intensive. By using a technology called reverse osmosis, we can desalinate water using about 1/10th as much energy as distillation. So compared to boiling the water, using reverse osmosis is much more efficient. But reverse osmosis still requires about 100x more energy than treating fresh surface water or groundwater. In fact, you could charge your smartphone with the energy it takes to desalinate just 1 gallon of seawater!

Despite its energy demands, desalination is widely used around the world. There are more than 18,000 desalination plants in 150 countries, including about 250 in the U.S. About half of these plants use reverse osmosis, and about a third use distillation.

In the U.S., most plants are located in Florida, Texas, and California (shown on this cool map), but there are about a dozen here in North Carolina. If you’ve ever visited the Outer Banks, your drinking water probably came from a reverse osmosis desalination plant.

There are so many reverse osmosis plants in the world, that together they produce 4x as much water in one year as refineries do oil! But virtually all of these plants were built as a “last resort,” in areas where there simply isn’t enough freshwater to meet the needs of consumers, industry, and agriculture. When it’s available, treating freshwater is always preferable to desalination.

The more we have to rely on seawater and other salty water resources, the more energy it will take to slake our thirst. So next time you take a drink of water, remember that you’re not just drinking ounces, you’re drinking watts.

Want to learn more about reverse osmosis desalination? Check out this animated video from the Seven Seas Water Corporation.

Ryan Kingsbury, P.E., is a PhD student at the University of North Carolina at Chapel Hill where he is a member of the Coronell Research Group.  Orlando Coronell, PhD, and his research team study membrane-based processes for water purification and energy production and storage, with applications in municipal, industrial, and household systems. Ryan studies salinity gradient energy which you can read more about here.

New NOVA Program: The Nuclear Option

Tonight (January 11, 2017) at 9PM on PBS, a New NOVA Special titled The Nuclear Option will air. A related PBS Newshour segment, Innovating the next generation of nuclear power, is available for online viewing and may also be of interest.

Program Summary (NOVA): Five years after the earthquake and tsunami that triggered the unprecedented trio of meltdowns at the Fukushima Daiichi nuclear power plant, scientists and engineers are struggling to control an ongoing crisis. What’s next for Fukushima? What’s next for Japan? And what’s next for a world that seems determined to jettison one of our most important carbon-free sources of energy? Despite the catastrophe—and the ongoing risks associated with nuclear—a new generation of nuclear power seems poised to emerge the ashes of Fukushima. NOVA investigates how the realities of climate change, the inherent limitations of renewable energy sources, and the optimism and enthusiasm of a new generation of nuclear engineers is looking for ways to reinvent nuclear technology, all while the most recent disaster is still being managed. What are the lessons learned from Fukushima? And with all of nuclear’s inherent dangers, how might it be possible to build a safe nuclear future?

What do pickles have to do with generating electricity?

Earlier this year I heard University of North Carolina (UNC) at Chapel Hill doctoral student Ryan Kingsbury, a member of Orlando Coronell’s lab discuss his research and was introduced to the term “blue energy” for the first time.  Ryan studies energy storage and generation from salinity gradients.  Salinity gradient energy or “blue energy” refers to the energy released when water with different concentrations of salt mix (this is essentially the reverse of what happens during desalination).  For those of you who teach about diffusion, here is an opportunity to show your students how selective diffusion of positive and negative ions across membranes can drive the production of  electricity!

Salinity gradient energy is at the cutting edge of research on renewable energy.  Using ion-selective membranes and a process known as reverse electrodialysis (RED), natural and industrial waters (e.g. seawater, desalination brine, etc.) can be used to store energy, generate electricity and even treat wastewater!  Ryan recently described the physics behind blue energy and RED in a bit more detail in his own blog post.

And now for the pickle part.  It turns out one of the industrial wastewaters being investigated by researchers is the leftover salt water from making Mt. Olive pickles!  Researchers from NC State University, UNC-CH, East Carolina University and the Coastal Studies Institute are developing a process that uses salinity gradient to release energy from Mt. Olive wastewater. There is a 6 minute video describing this multi-institutional collaboration and a transcript of the video also available. The project PIs (Dr. Coronell from UNC and Dr. Call from NCSU) also participated in a February 2016 radio interview about salinity gradient energy which explains their project more broadly.

In addition to pickles, NC is also known for its estuaries; the mixing of salt and fresh water that occurs in estuaries is an untapped source of blue energy!  In fact, I learned from reading Ryan’s blog post that where rivers flow into the sea and fresh and salt water mix, the amount of energy created  is equivalent to the river falling into the ocean from the height of the Eiffel tower!

You can also learn more about blue energy in this June 2015 BBC article Blue energy: How mixing water can create electricity.





New Energy Education Newsletter from the US Department of Energy

picture_0With the 2016-2017 school year now underway, I wanted to be sure you knew about a new resource from the US Department of Energy’s – a monthly electronic newsletter titled STEM Spark  – that will highlight energy technologies, energy education resources, career information and competitions for K-12 and higher education audiences.

The August 2016 newsletter is devoted to the topic of wind energy.

Click here to subscribe to the monthly newsletter.

Energy Literacy Video Series and Social Studies Lessons

The Department of Energy (DOE), along with the American Geosciences Institute (AGI), the Center for Geoscience and Society and the National Center for Science Education have completed an Energy Literacy Video Series to accompany the DOE’s Energy Literacy: Essential Principles and Fundamental Concepts for Energy Education. This framework cites seven essential principles and fundamental concepts for teaching energy and each of the seven principles is now summarized in a 4-6 minute video! The video series is also available in Spanish through the DOE’s YouTube channel. There is a teacher guide and student analysis guide to accompany the video series  and the Energy Literacy Quick Start Guide for Educators will help you find additional resources for integrating energy literacy concepts into instruction.

In addition to the video series, AGI has developed a social studies lesson for each of the seven principles outlined in the Energy Literacy Framework.  These lessons are geared towards grades 9-12 students and are aligned to the C3 Framework for Social Studies State Standards.

Principle 1:
How should the United States deal with nuclear waste?

Principle 2:
How has water shaped human settlement?

Principle 3:
Where does our food come from?

Principle 4:
Analyzing U.S. energy infrastructure: Where does electricity come from?

Principle 5:
Should the U.S. Government subsidize specific energy initiatives?

Principle 6:
How much energy do I need?

Principle 7:
How does transportation impact the environment?


New Energy Literacy Video Series

Last week, the White House Office of Science and Technology Policy (OSTP)  launched a new Climate Education and Literacy Initiative to “help connect American students and citizens with the best-available,  science-based information about climate change.” The OSTP acknowledged a number of “commitments” made by Federal agencies and others to this initiative which included a commitment to enhance energy literacy.

In recognition of this commitment, the Department of Energy (DOE), along with the American Geosciences Institute (AGI) and the National Center for Science Education (NCSE), announced an Energy Literacy Video Series to accompany the Energy Literacy Framework. This framework cites seven essential principles and fundamental concepts for teaching energy and each of the first four principles is now summarized in a 4-6 minute video. Videos for the final three essential  principles  are expected by September 2015.

Below are the first four essential principles in the framework which is also available in Spanish:


You may also be interested in the five minute TED-Ed video, “A Guide to the Energy of the Earth,” which shows the 7 essential principles in action.

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