Unit Overview
P.1 Energy Flow from Earth’s Systems

How can we design more reliable systems to meet our communities’ energy needs?

Unit Summary

How can we design more reliable systems to meet our communities’ energy needs? This unit is designed to introduce students to the concept of energy transfer in a relevant and grounded context: the Texas power crisis of February 2021. Students read articles and wonder about the complex social, environmental, and physical realities that led to such a crisis. They figure out how energy transfers between systems from a generator to our communities, and what makes an energy source reliable. This allows the class to model and explain what happened in Texas at multiple scales, from the electrons in the wires to the power companies making difficult decisions to maintain stability. Students consider engineering tradeoffs, criteria, and constraints inherent in making decisions about our energy systems, and apply them in a culminating task: design a reliable energy solution that meets our communities' needs, as articulated by interviews with friends and family members. The task is designed to give students the tools to speak up in their local and global community for a better energy future, one that aligns with their own values, and those of their families.

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Unit Examples

Additional Unit Information

Building Toward the Following Standards and Practices
Performance Expectations

This unit builds toward these performance expectations:

  • HS-PS2-5* Plan and conduct an investigation to provide evidence that an electric current can produce a magnetic field and that a changing magnetic field can produce an electric current.
  • HS-PS3-5† Develop and use a model of two objects interacting through electric or magnetic fields to illustrate the changes in energy of the objects due to the interaction.
  • HS-PS3-2† Develop and use models to illustrate that energy at the macroscopic scale can be accounted for as a combination of energy associated with the motion of particles (objects) and energy associated with the relative positions of particles (objects).
  • HS-PS3-3 Design, build, and refine a device that works within given constraints to convert one form of energy into another form of energy.
  • HS-PS3-1† Create a computational model to calculate the change in the energy of one component in a system when the change in energy of the other component(s) and energy flows in and out of the system are known.
  • HS-ETS1-3† Evaluate a solution to a complex real-world problem based on prioritized criteria and trade-offs that account for a range of constraints, including cost, safety, reliability, and aesthetics as well as possible social, cultural, and environmental impacts.
  • HS-ETS1-4† Use a computer simulation to model the impact of proposed solutions to a complex real-world problem with numerous criteria and constraints on interactions within and between systems relevant to the problem.
  • HS-ESS3-2† Evaluate competing design solutions for developing, managing, and utilizing energy and mineral resources based on cost-benefit ratios.

*This performance expectation is developed across multiple units. This unit reinforces these NGSS PEs in a physics context. 

†This performance expectation is developed across multiple courses. This unit reinforces or works toward these NGSS PEs that students will have previously developed in the OpenSciEd chemistry and/or biology courses.

Disciplinary Core Ideas

ETS1.A: Defining and Delimiting Engineering Problems 

  • Humanity faces major global challenges today, such as the need for supplies of clean water and food or for energy sources that minimize pollution, which can be addressed through engineering. These global challenges also may have manifestations in local communities. (HS-ETS1-1) 

ETS1.B: Developing Possible Solutions 

  • When evaluating solutions, it is important to take into account a range of constraints, including cost, safety, reliability, and aesthetics, and to consider social, cultural, and environmental impacts. (HS-ETS1-3) 
  • Both physical models and computers can be used in various ways to aid in the engineering design process. Computers are useful for a variety of purposes, such as running simulations to test different ways of solving a problem or to see which one is most efficient or economical; and in making a persuasive presentation to a client about how a given design will meet their needs. (HS-ETS1-4)

PS2.B: Types of Interactions 

  • Forces at a distance are explained by fields (gravitational, electric, and magnetic) permeating space that can transfer energy through space. Magnets or electric currents cause magnetic fields; electric charges or changing magnetic fields cause electric fields. (HS-PS2-4),(HS-PS2-5)

PS3.A: Definitions of Energy 

  • “Electrical energy” may mean energy stored in a battery or energy transmitted by electric currents. (secondary to HS-PS2-5)
  • At the macroscopic scale, energy manifests itself in multiple ways, such as in motion, sound, light, and thermal energy. (HSPS3-2) (HS-PS3-3) 
  • Energy is a quantitative property of a system that depends on the motion and interactions of matter and radiation within that system. That there is a single quantity called energy is due to the fact that a system’s total energy is conserved, even as, within the system, energy is continually transferred from one object to another and between its various possible forms. (HSPS3-1),(HS-PS3-2) 
  • These relationships are better understood at the microscopic scale, at which all of the different manifestations of energy can be modeled as a combination of energy associated with the motion of particles and energy associated with the configuration (relative position of the particles). In some cases the relative position energy can be thought of as stored in fields (which mediate interactions between particles). This last concept includes radiation, a phenomenon in which energy stored in fields moves across space. (HS-PS3-2)

PS3.B: Conservation of Energy and Energy Transfer 

  • The availability of energy limits what can occur in any system. (HS-PS3-1) 
  •  Energy cannot be created or destroyed, but it can be transported from one place to another and transferred between systems. (HS-PS3-1),(HS-PS3-4) 
  • Conservation of energy means that the total change of energy in any system is always equal to the total energy transferred into or out of the system. (HS-PS3-1) 

PS3.C: Relationship Between Energy and Forces 

  • Although energy cannot be destroyed, it can be converted to less useful forms—for example, to thermal energy in the surrounding environment. (HS-PS3-3),(HS-PS3-4)

ESS3.A Natural Resources

  • All forms of energy production and other resource extraction have associated economic, social, environmental, and geopolitical costs and risks as well as benefits. New technologies and social regulations can change the balance of these factors. (HS-ESS3-2)
Focal Science & Engineering Practices

Asking questions and defining problems in 9–12 builds on K–8 experiences and progresses to formulating, refining, and evaluating empirically testable questions and design problems using models and simulations. The following elements of this practice are intentionally developed across this unit:

  • Ask questions to determine relationships, including quantitative relationships, between independent and dependent variables. 
  • Ask questions to clarify and refine a model, an explanation, or an engineering problem. 
  • Ask and/or evaluate questions that challenge the premise(s) of an argument, the interpretation of a data set, or the suitability of a design.  
  • Define a design problem that involves the development of a process or system with interacting components and criteria and constraints that may include social, technical, and/or environmental considerations.

Developing and using models in 9–12 builds on K–8 experiences and progresses to using, synthesizing, and developing models to predict and show relationships among variables between systems and their components in the natural and designed worlds. The following elements of this practice are intentionally developed across this unit:

  • Develop, revise, and/or use a model based on evidence to illustrate and/or predict the relationships between systems or between components of a system.  
  • Develop and/or use a model (including mathematical and computational) to generate data to support explanations, predict phenomena, analyze systems, and/or solve problems.

Analyzing and interpreting data in 9–12 builds on K–8 experiences and progresses to introducing more detailed statistical analysis, the comparison of data sets for consistency, and the use of models to generate and analyze data. The following elements of this practice are intentionally developed across this unit:  

  • Apply concepts of statistics and probability (including determining function fits to data, slope, intercept, and correlation coefficient for linear fits) to scientific and engineering questions and problems, using digital tools when feasible.  
  • Consider limitations of data analysis (e.g., measurement error, sample selection) when analyzing and interpreting data.   
  • Evaluate the impact of new data on a working explanation and/or model of a proposed process or system.  
  • Analyze data to identify design features or characteristics of the components of a proposed process or system to optimize it relative to criteria for success.

Constructing explanations and designing solutions in 9–12 builds on K–8 experiences and progresses to explanations and designs that are supported by multiple and independent student-generated sources of evidence consistent with scientific ideas, principles, and theories. The following element of this practice is intentionally developed across this unit: 

  • Design, evaluate, and/or refine a solution to a complex real-world problem, based on scientific knowledge, student-generated sources of evidence, prioritized criteria, and tradeoff considerations.

Elements from the following practices are also key to the sensemaking in this unit:

  • Using Mathematics and Computational Thinking.
  • Planning and Carrying out Investigations
  • Obtaining, Evaluating, and Communicating Information
Focal Crosscutting Concepts

Systems and System Models. A system is an organized group of related objects or components; models can be used for understanding and predicting the behavior of systems. The following elements of this crosscutting concept  are intentionally developed across this unit:

  • Systems can be designed to do specific tasks.  
  • Models (e.g., physical, mathematical, computer models) can be used to simulate systems and interactions—including energy, matter, and information flows—within and between systems at different scales. 

Energy and Matter. Tracking energy and matter flows, into, out of, and within systems helps one understand their system’s behavior. he following elements of this crosscutting concept  are intentionally developed across this unit:

  • The total amount of energy and matter in closed systems is conserved.  
  • Changes of energy and matter in a system can be described in terms of energy and matter flows into, out of, and within that system.  
  • Energy cannot be created or destroyed—only moves between one place and another place, between objects and/or fields, or between systems.  

Stability and Change. For both designed and natural systems, conditions that affect stability and factors that control rates of change are critical elements to consider and understand.

  • Much of science deals with constructing explanations of how things change and how they remain stable.  
  • Systems can be designed for greater or lesser stability.

Elements from the following crosscutting concepts are also key to the sensemaking in this unit: 

  • Patterns
  • Structure and Function
  • Cause and Effect
Connections to the Nature of Science

Which elements of the Nature of Science (NOS) are developed in the unit?

  • Science Addresses Questions About the Natural and Material World.
    • Science and technology may raise ethical issues for which science, by itself, does not provide answers and solutions.
      • These ideas are woven throughout the unit but appear at the forefront of Lessons 7 and 8, where students learn about disparities in who lost power in Texas. Students reflect on how human decision-making interacted with natural systems to cause these disparities and consider whether decisions made by the power company were fair.
    • Science knowledge indicates what can happen in natural systems–not what should happen. The latter involves ethics, values, and human decisions about the use of knowledge.
      • In Lesson 10, students figure out that the way we extract energy sources from Earth’s systems can have a profound impact on those systems. They read about how if we want to prevent further damage, we need to make decisions that reflect what we value. Students go on to interview their friends and families to learn about what criteria they value most, and reflect on how values impact engineering decision-making.
    • Many decisions are not made using science alone, but rely on social and cultural contexts to resolve issues.
      • In Lesson 8, students listen to a podcast where a researcher explains that just because harmful decisions were unintentional doesn’t mean that we shouldn’t strive to do better.
  • Science is a Human Endeavor.
    • Science and engineering are influenced by society and society is influenced by science and engineering.
      • In Lesson 2, students learn about the human-made structures we see every day in and around our homes and school, and how science ideas shape these structures, which have in turn changed the way we live.
Unit Information
Where does this unit fall within the OpenSciEd Scope and Sequence?

This unit is the first in the OpenSciEd High School Physics course sequence, and is designed to transition students into high school level physics ideas and practices in a relevant context grounded in real-world decision making. While students have been asking questions, modeling systems, designing solutions, and engaging in argument from evidence throughout K-12, this may be the first time they are using these practices the way physicists do, to figure out how and why matter moves and changes using the lens of energy transfer.  Students develop ideas around energy transfer and conservation in the context of charged particles (electrons) colliding with other electrons (electricity) to transfer energy across great distances. This unit builds a foundation for energy transfer and conservation in a physics context that students will carry forward into the rest of the course, but does not yet focus on forces as a way to model interactions.

In the second unit of the course, OpenSciEd Unit P.2: How forces in Earth’s interior determine what will happen to its surface? (Earth’s Interior Unit), a sudden rip in the Earth’s crust will motivate the need for forces to explain our observations. In the third unit, OpenSciEd Unit P.3: What can we do to make driving safer for everyone? (Vehicle Collisions Unit), students will develop a more robust understanding of forces as vectors, and uses conservation of momentum to make predictions about the outcomes of collisions. In the fourth unit, OpenSciEd Unit P.4: Meteors, Orbits, and Gravity (Meteors Unit),  students will expand their model of forces to include forces of gravity at great distances, using ideas about fields developed in the first unit to understand the relationships between gravity and energy transfer. In the fifth unit, OpenSciEd Unit P.5: How do we use radiation in our lives and is it safe for humans? (Microwave Unit), students use energy transfer, electromagnetism, wave mechanics, and forces at a distance to explain how food heats up in a microwave, and if/how this technology might be dangerous for humans. In the final unit of the course, OpenSciEd Unit P.6: Earth’s History and the Big Bang (Cosmology Unit), students will explore cosmology and the Big Bang, applying ideas about forces and energy from all five previous units on the largest scale.

This unit is intended as the first in the OpenSciEd High School Physics sequence and intentionally incorporates, in the moment, a number of activities that would typically take place in a “Unit 0.” These include co-construction of Community Agreements, use of a progress tracker, and energy transfer diagram conventions. We recommend that you begin this unit at the start of the school year, following any requirements in your school or district.

What is the anchoring phenomenon, and why was it chosen?

This unit is anchored by the story of the 2021 power crisis in Texas and the accompanying design problem of improving the reliability of our own electric infrastructure. This event provides a rich context in which to investigate the nature of electrical energy transfer, the stability and change of energy inputs and outputs, the impact of energy transfer on our everyday lives, and the social/environmental trade-offs inherent in sourcing energy from Earth’s systems. Over the course of the unit, students read about what happened in Texas and analyze multiple types of real data from the event. They investigate each part of the electrical system at various scales, from designing investigations using a simulation of the inside of a wire, to building their own working generators. They also model an electric grid in the classroom using power strips, alligator clips, LED bulbs, and cardboard buildings.


The Texas blackouts anchoring phenomenon was chosen from a group of phenomena aligned with the target performance expectations, based on the results of a survey administered to almost 1,000 students across the country and in consultation with external advisory panels that included teachers, subject matter experts, and state science administrators. This phenomenon includes a strong engineering component linked to a complex global problem, and includes humans and human activity in the systems under study. The full physics course is designed to purposefully highlight various types of phenomena. Although we design to privilege the interests of students to whom we owe an educational debt, we must not essentialize minoritized groups by assuming that a trend in the data equates to homogenous interests and experiences. Providing a diverse suite of entry points into content and practices creates more opportunities for every student to connect with the content.

The blackouts phenomenon was chosen for the following reasons:

  • Students showed high interest in explaining electricity-related phenomena.
  • To provide a diverse suite of entry points across the course, we sought an event that allowed students to consider a relevant societal problem.
  • Teachers and administrators saw the phenomenon as interesting and on grade band.
  • Explaining the mechanisms that bring electricity to communities grounds abstract ideas about energy transfer in a real-world context.
  • Explaining the phenomenon addresses all the DCIs in the bundle at a high school level.
  • Explaining the phenomenon requires the use of mathematical thinking at a middle school level, helping students transition into high school physics.
How is the unit structured?

The unit is organized into two main lesson sets. In the first lesson set (Lessons 1-8), students read articles about an energy crisis in Texas that left much of the state in the dark and develop models for how energy transfers through systems when the electricity grid is stable, and when conditions change. They document the energy infrastructure in their school, homes, and community, and look for patterns that can provide clues as to how energy transfers. They follow these clues to an outlet, and dissect a power strip to investigate circuits, then wire several power strips together inside cardboard boxes to simulate the wiring of a small model community, complete with substations and a battery “power plant.” They investigate various sources of power and determine that supply (energy input) and demand (energy output) must be equal to keep the system stable. They begin to keep track of engineering solutions and constraints with a tracker and trace the energy back to a generator in the power plant. They build generators, and model energy flow through electric and magnetic fields to explain how they work. They zoom in on the wires to understand the particle nature of electrical energy transfer, and then zoom back out to put the pieces together and explain how an imbalance of inputs and outputs caused the crisis they read about in Texas. In Lessons 7-8 they problematize the explanation for what happened in Texas, motivating them to investigate the cause of disparities in the pattern of outages on a state, county, and municipal scale using data and computational models, and talk about how power outages have an inequitable impact on those people in low income neighborhoods due to existing disparities.

In the second lesson set (Lessons 9-11), students turn their attention to their own community and consider what decisions they will need to make to design more reliable power systems that meet their specific needs. They investigate considerations and tradeoffs associated with battery storage to improve reliability of renewable and low-carbon energy sources, including chemical, mechanical, and thermal solutions. Finally, they put the pieces together to design energy solutions they want to speak up for in their communities. Students apply these ideas in a culminating project that they begin in Lesson 10, and a transfer task in Lesson 11.

What modifications will I need to make if this unit is taught out of sequence?

This is the first unit of the High School Physics Course in the OpenSciEd Scope and Sequence. Given this placement, several modifications would need to be made if teaching physics first, or teaching this unit later in the Physics course. These include the following adjustments:

  • If taught before OpenSciEd High School Chemistry, supplemental teaching of the particle model of matter will be required, including conceptual understanding of the nature of electrons, nuclei and atoms.
  • If taught later in the school year, additional supplementary materials related to forces should be incorporated into class discussions to help students integrate a forces and energy perspective.
  • If taught as part of an AP Physics course, be prepared to provide students with additional support around equations that are not treated in depth. Extension opportunities to support students who want to go on to AP Physics are provided.
How do I shorten or condense the unit if needed? How can I extend the unit if needed?

The following are example options to shorten or condense parts of the unit without eliminating important sensemaking for students:

  • Lessons 2, 5, 6, and 7: You can film demonstrations in Electric City ahead of time, and cut these investigations from the unit. This will reduce the number of hands-on activities available to students, but will cut time significantly.
  • Lessons 9-11: The second lesson set addresses engineering performance expectations. If these are not a priority for your school or your district, you can end the unit after putting the pieces together in Lesson 8. Students will not get the opportunity to design their community solutions.

To extend or enhance the unit, consider the following:

  • Lesson 2: Give students the opportunity to design and build Electric City, rather than having the buildings and structures pre-assembled. Students can model the city after their own community, and spend time experimenting with various configurations to see how it affects the reliability of the system.
  • Lesson 6: This lesson includes guidance on how to provide a coherent enrichment experience for students who are interested in learning more about circuits, or who have met and exceeded the performance expectations. These might also be helpful if your state has standards in addition to those laid out in the NGSS related to electricity and circuits. Look for guidance with heading “Extension opportunity” to find optional enrichment support.
  • Lesson 11: Give students additional time and resources to complete the culminating task. Consider planning an assembly, or inviting friends, family, and community members into the classroom to see the presentations.
  • All lessons: Remove scaffolds provided with Science and Engineering Practices as a way to give students more independent work with the elements of these practices.
Unit Acknowledgements
Unit Development Team
  • Zoë Buck Bracey, Unit Lead, BSCS Science Learning
  • Jairo Botero Espinosa, Consultant Expert
  • Juan Pablo Carvallo, Consultant Expert
  • Joseph Hardcastle, Writer, BSCS Science Learning
  • Joseph Kremer, Writer, Denver Public Schools
  • Michael Novak, Writer, Northwestern University
  • Diego Rojas-Perilla, Writer, BSCS Science Learning
  • Nicole Vick, Writer, Northwestern University
Production Team
  • Madison Hammer, Production Manager, University of Colorado Boulder
  • Kate Herman, Copy Editor, Independent Consultant 
  • Erin Howe, Project Manager, University of Colorado Boulder
  • Whitney Mills, BSCS Science Learning
  • Tyler Morris-Rains, BSCS Science Learning
  • Jamie Deutch Noll, BSCS Science Learning
  • Laura Zeller, BSCS Science Learning
Unit External Evaluation
NextGenScience’s Science Peer Review Panel

An integral component of OpenSciEd’s development process is external validation of alignment to the Next Generation Science Standards by NextGenScience’s Science Peer Review Panel using the EQuIP Rubric for Science. We are proud that this unit has earned the highest score available and has been awarded the NGSS Design Badge. You can find additional information about the EQuIP rubric and the peer review process at the nextgenscience.org website.