Energy From the Earth

The Phenomenon: A Town That Went Dark

Some families had backup generators that ran on gasoline. Others burned firewood in their fireplaces to stay warm. A few homes had solar panels on their roofs and still had some electricity even while their neighbors did not. Restaurants that cooked with natural gas could still prepare food, while restaurants with electric-only kitchens had to close.

Why did some families have energy when others did not? Why do different homes and businesses rely on different types of fuel and energy?

💭 Thinking Questions

• Why did some homes still have energy while others did not?
• Where does the energy that powers homes, cars, and businesses actually come from?
• What would you want to find out about how people get the energy they need every day?

What Scientists Know About Energy and Natural Resources

Every time you turn on a light, ride in a car, or warm up food in a microwave, you are using energy. But that energy has to come from somewhere. Humans get almost all of their energy from natural resources — materials found in or on the Earth that people use to meet their needs.

Some of those natural resources are fuels, which are materials that can be burned or processed to release energy. Others, like sunlight and wind, provide energy without being burned at all. Understanding where energy comes from — and what happens when we use it — is a big part of understanding how humans interact with Earth.

Let's Investigate: Gathering Information About Energy Use

Scientists and engineers don't just guess where energy comes from. They gather information by researching, collecting data, and analyzing how communities use energy. This is an important Science and Engineering Practice — obtaining, evaluating, and communicating information. Let's practice this skill ourselves.

Your investigation: Imagine you are a scientist studying how your community uses energy. You walk through your neighborhood and record every way people use energy and what natural resource provides it.

Materials you might use:

• A notebook and pencil for recording observations
• A chart to organize information by energy source
• Books, articles, or reliable websites about energy resources

What you would observe: Cars burn gasoline (from oil). Homes use electricity (often from coal, natural gas, or solar panels). Some homes burn natural gas for heating and cooking. Wind turbines and solar panels appear in some places. Every activity that involves heat, light, or motion requires an energy source — and each source traces back to a natural resource.

What We Discovered: How Humans Use Energy Every Day

When we gather information about energy use, a clear picture emerges. Humans depend on energy for almost everything — from the moment an alarm clock buzzes in the morning to the moment the lights go out at bedtime. That energy can be traced back to natural resources that come from the Earth.

Fossil fuels currently provide the largest share of the world's energy. Coal is burned in power plants to create electricity. Oil is refined into gasoline and diesel to power cars, trucks, and airplanes. Natural gas heats homes and fuels stoves. These resources are extremely useful because they store a large amount of energy in a small amount of material. However, burning fossil fuels releases carbon dioxide and other gases into the atmosphere, which can affect air quality and Earth's climate over time.

Renewable energy sources are growing rapidly. Solar panels convert sunlight directly into electricity. Wind turbines capture the energy of moving air. Hydroelectric dams use the force of flowing water to generate power. These sources produce much less pollution, but they depend on conditions like weather and geography — the sun doesn't always shine, and the wind doesn't always blow.

Now we can return to our anchoring phenomenon. The town that lost power during the ice storm was connected to the electrical grid, which depended on a power plant burning fossil fuels. When the power lines broke, the connection was lost. But homes with solar panels generated their own electricity from sunlight. Homes with gas generators burned gasoline (from oil) locally. Families who burned firewood used a different natural resource — wood from trees — directly. Each family used a different natural resource, and the type of resource determined whether they could still get energy when the grid failed.

Patterns and Connections: Cause and Effect

One of the most important ideas in all of science is cause and effect. Scientists look for what causes something to happen and what effects result from it. When it comes to energy and natural resources, cause and effect shows up everywhere.

When humans burn fossil fuels (cause), carbon dioxide is released into the air (effect). When a community installs solar panels (cause), less fossil fuel is needed and less pollution is produced (effect). When a nonrenewable resource runs low (cause), its price goes up and people look for alternatives (effect). This pattern of cause and effect helps scientists predict what will happen and helps engineers design better solutions.

Notice that this same pattern — an action leads to a result — appears across life science, physical science, and earth science. Scientists use cause and effect thinking to understand problems and design solutions in every field.

Real-World Connections and Engineering

Understanding how humans use natural resources for energy is not just a science topic — it is one of the most important challenges of our time. Engineers, scientists, and communities around the world are working to find better ways to meet our energy needs while protecting the Earth.

🌍 Real-World Example: Solar-Powered Schools

Across the United States, thousands of schools have installed solar panels on their roofs. These panels convert sunlight into electricity, reducing the amount of fossil fuel the school needs to buy. Some schools generate so much solar energy that they can sell extra electricity back to the power company! This saves the school money and reduces the carbon dioxide released into the air.

🔧 Engineering Design Challenge

Imagine you are an engineer asked to design an energy plan for a new neighborhood. The neighborhood needs energy for lighting, heating, cooking, and transportation. Here is how you might use the engineering design process:

1. Define the problem: The neighborhood needs reliable energy that is affordable and produces as little pollution as possible.

2. Brainstorm solutions: You could use all fossil fuels, all renewable energy, or a mix of both. Each choice has different benefits and trade-offs.

3. Compare solutions: Solar panels work great on sunny days but not at night. Natural gas is reliable but produces pollution. A mix of solar panels, wind turbines, and a small natural gas backup might give the best balance.

4. Test and improve: Build a small version of the plan, measure energy production over several months, and adjust the mix based on what the data shows.

Engineers think carefully about trade-offs — the advantages and disadvantages of each choice. There is no single "perfect" solution, but gathering information helps engineers make the best decision for their community.

Key Vocabulary Review

📖 KEY VOCABULARY

• Natural Resource — Any material from nature that humans use to meet their needs, such as water, soil, sunlight, wind, minerals, and fossil fuels.
• Energy — The ability to do work or cause change. Humans use energy for heating, lighting, transportation, cooking, and powering machines.
• Fuel — A material that is burned or processed to release energy, such as coal, oil, natural gas, or wood.
• Fossil Fuel — A nonrenewable fuel formed over millions of years from the remains of ancient plants and animals. Coal, oil, and natural gas are fossil fuels.
• Renewable Resource — A natural resource that can be replaced naturally in a relatively short time, such as sunlight, wind, and flowing water.
• Nonrenewable Resource — A natural resource that takes millions of years to form and cannot be replaced once it is used up, such as coal, oil, and natural gas.
• Solar Energy — Energy from sunlight, which can be captured by solar panels and converted into electricity.
• Trade-off — A balance between the advantages and disadvantages of a choice. Engineers consider trade-offs when choosing energy solutions.

Practice: Test Your Understanding

What's Next?