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.





2017 BioenergizeME Infographic Challenge from the U.S. Department of Energy

The 2017 BioenergizeME Infographic Challenge kicks off today!  This year’s theme is  Exploring the Future American Energy Landscape.  The US Department of Energy’s Bioenergies Technologies Office is  asking 9th- through 12th-grade student teams to use technology to research, interpret, apply, and then design an infographic that responds to one of five research topic areas selected for 2017:

History of Modern Bioenergy

Bioenergy and Society
Workforce and Education

Science and Technology

Even better, all of the tools necessary to integrate this challenge into your curriculum or offer it as an after-school activity are provided!

BioenergizeME Toolkit

Five steps to building an infographic

Social media guide

BioenergizeME Research Strategy Guide

BioenergizeME Resource Library

To date no past submissions have come from NC – let’s change this!

To be considered for the competition, teams must register by Feb. 3, 2017 and infographics must be submitted by March 3, 2017.

Check out the 2016 award winning infographics on cellulosic ethanol, algae as a biofuel and energy from biomass You can view all previous winning infographics here. One NC teacher remarked that she would incorporate these  infographics into her AP Environmental Science class by having her students review and critique the infographics to decide which they would fund for further development.

Pipeline shutdown & gasoline supply in the Southeast

I live in the Triangle and have seen firsthand the effects of the partial shutdown of the Columbia pipeline as I have driven by many gas stations this week where no fuel was available.  An event such as this can be used to remind students where our gasoline comes from and to prompt them to consider the consequences of having to transport fuels over long distances.

The U.S. Energy Information Administration (EIA) featured the pipeline disruption and provided the map below in its September 21st, Today in Energy feature article (which you can sign up to receive each weekday via email).  According to this article “the U.S. Southeast is supplied primarily by pipeline flows from refineries along the U.S. Gulf Coast and supplemented by marine shipments from the U.S. Gulf Coast and imports.” Seeing this map helped me to understand why this pipeline disruption impacted central North Carolina to a great extent.

Source: U.S. Energy Information Administration

There is an online mapping tool available that enable users to create their own maps as they evaluate different energy sources.  I used the EIAs U.S. Energy Mapping System to quickly create a similar map that shows petroleum refineries (boxes); petroleum pipelines (dashed lines); and petroleum ports (ships):ppile

Then I added additional map layers to also show oil wells (light brown dots) and oil/gas platforms (dark brown dots) in federal waters so students can also see the distribution of wells and platforms in relation to petroleum refineries.


I would love to hear from teachers who have incorporated this current event into their instruction.

Wind Roses

Wind rose for the month of June, Raleigh, NC

Wind rose for the month of June, Raleigh, NC

Here is another idea for exposing your students to real data – have them create and/or analyze wind roses!  Wind roses are visual representations of the distribution of wind speed and direction for a particular location based on meteorological observations. Wind roses are useful in evaluating the wind potential for a site, comparing wind potential at two or more sites and assessing how wind potential changes seasonally. To learn how to interpret a wind rose click here.

Wind rose plots from the National Weather and Climate Center are available for 237 cities across the United States based on wind measurements for each month of the year from 1961-1990.  Wind rose plots for the following North Carolina cities are available: Asheville, Cape Hatteras, Charlotte, Greensboro, Raleigh and Wilmington. Your students could compare wind roses for coastal, Piedmont and western regions of the state.

Students can even plot their own wind rose using the Danish Wind Industry Association’s Wind Rose Plotter Programme. Wind data from local weather stations can be obtained from the State Climate Office of NC (NC CRONOS/ECONet Database).

Who has seen the wind? Harnessing Alternative Energy (2010) is a lesson written by a NC science teacher and available at Learn NC.  In Activity 2 of this lesson, students assess wind potential of an area by evaluating local wind data and constructing a wind rose.  Sample wind data and instructions for using the Wind Rose Plotter Programme are provided in the student worksheet (NOTE: the url for the wind rose plotter program is not accurate, use the link provided in this post instead).

Accessing local, regional and national data on electricity supply and demand

I am an advocate for having students engage with real data and when that data is locally relevant, even better!  Access to real data about the electrical grid is what I like about the newly released U.S. Electric System Operating Data tool from the U.S. Energy Information Administration. This tool provides “analysis and visualizations of hourly, daily, and weekly electricity supply and demand on a national and regional level for all of the 66 electric system balancing authorities that make up the U.S. electric grid.”

There are three Duke Energy balancing authorities (BAs) in NC – Duke Energy Carolinas (DUK), Duke Energy Progress West (CPLW) and Duke Energy Progress East (CPLW).  From the tool’s interactive Status Map, you can view demand (actual & forecasted) and supply data for the BA that is servicing your school.  Hourly, daily, weekly and monthly demand data is available and can even be downloaded in excel should you want your students to conduct a graphing activity.

Map showing balancing authorities in North Carolina

Status map showing NC’s three Duke Energy BAs in blue, with data for Duke Energy Carolinas (DUK) shown (Sept 7, 2016). The size of the circle roughly corresponds to the system size.  By clicking on the corresponding blue dot you will find hourly, daily, weekly and monthly demand curves with these data available for download into excel for a graphing activity.

There is also a live feed that runs across the top of the tool that shows how many total megawatthours the US (the lower 48 states) consumed yesterday (approximately 9.77 million MWh on September 6th, 2016) as well as the latest US hourly demand and yesterday’s peak demand values.

From the Grid Overview home page students can also examine national or regional demand curves, like the weekly demand curve shown here for the Carolinas (CAR) region.

Weekly demand curve for the Carolinas (CAR) region.

What can students learn by examining a  daily or weekly demand curve?  In addition to seeing how many megawatt hours of electricity the Carolinas (CAR) region or a specific BA requires in any given day or week, students may also be able to examine and explain trends in electrical consumption over time and even seasonally.  For example, students could be tasked with examining the extent to which electrical consumption is tied to the weather and recent weather events. For example, the recent hurricane that passed through this region on Sept 3rd brought cooler weather and perhaps some power outages that reduced demand for electricity compared to the days before the hurricane.

This tool also enable users to assess the demand-supply balance for a given region (see below) or balancing authority such as Duke Energy Carolinas.  What can students learn by examining a visualization of demand and supply?  They will observe that  demand and supply closely match (they need to!) and that energy transfers (interchanges) occur to address any differences between demand and supply. The EIA’s About the Grid page in addition to the glossary may also be useful as you familiarize yourself with this tool and the terminology encountered.


Comparing demand and supply for the Carolinas region.





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.

Don’t forget the infrastructure!

Earlier this month I conducted a teacher workshop devoted to the topic of electricity for science teachers from North Carolina’s coastal region. During the workshop I asked the teachers to tell me about the kinds of local energy issues they are confronting with their students and what questions arise in the classroom as a result.  One teacher remarked that in light of the Desert Wind Power Project being constructed in the northeastern part of the state, he asks his students to consider the infrastructure needed to build a wind farm.  His comment was timely, given that roads are currently being built to enable construction of the wind farm. When we evaluate the different energy sources that can be used to generate electricity we want our students to consider the accompanying infrastructure and land use change that results from the acquisition, management and use of those energy sources.eagleford_vir_2016046

NASA’s recent Image of the Day titled Shale Revolution featured the infrastructure and land use change brought about by oil and gas acquisition in the Eagle Ford Shale Play in Texas. The speckles of light in the nighttime satellite image below are “the electric glow of drilling equipment, worker camps, and other gas and oil infrastructure combine with flickering gas flares.” Comparing daylight satellite imagery from the years 2000 and 2015 revealed a “bustling network of roads and rectangular drill pads had completely transformed the landscape.”  Furthermore, this visual transformation invites the viewer to also consider the societal impacts of such development as well; Cotulla, Texas saw its population more than double in a very short time period!  Thus, these images could be used to prompt a class discussion about the implications of oil and gas development, including the accompanying infrastructure and land use changes, on the local community.

It will be interesting to compare satellite images of the land that will house the Desert Wind Power Project before and after the project is complete and to use these images to prompt student thinking about the environmental, economic and societal impacts of a land-based wind farm in rural North Carolina.

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