Use energy resources and evaluate conservation choices

Learning goal: Distinguish renewable and nonrenewable energy resources and use evidence to evaluate ways of conserving resources. Resources supply materials and energy for living things and human activities. A resource can become less available when it is used faster than it is replaced or when contamination makes it unsuitable for a needed use.

Moving air can turn a wind turbine. Flowing water can turn a water wheel or turbine. Sunlight can warm materials and can be used by a solar panel to supply electrical energy. Wind, moving water and sunlight are renewable energy resources because natural processes replenish their availability on short time scales compared with fossil-fuel formation. Renewable does not mean available at every place at every moment.

Coal, oil and natural gas are nonrenewable energy resources. Their natural formation takes far longer than a human lifetime, while people can use existing supplies much more quickly. Burning a fuel releases energy that can be used for heating or for systems that produce electricity. A battery or an electrical outlet is not an explanation of the original energy resource; trace farther back when investigating a system.

Coal, oil and natural gas have all been mined or drilled in Ohio, and Ohio also has wind turbines and solar installations that use renewable resources. A study of energy in Ohio therefore looks at three things: the fossil fuels found in the state, newer energy technologies and renewable energy development in the state, and how Ohio compares with other states. For a local study, obtain a dated, source-identified description from the school's electricity provider or a public energy agency with teacher support. Record what the document actually says, and use the same kind of source for another state if you compare the two. The source mix can change, so this lesson does not invent a current percentage or assume that every Ohio building uses one resource.

A small paper water wheel can model one energy relationship. Flowing water pushes its paddles, and the wheel turns. Use the same water flow and wheel position when comparing two paddle designs. Count turns over the same interval in repeated trials. A faster model under those conditions does not establish the electrical output of a full-size power plant; the model lacks many parts of that system.

Conservation includes reducing use and waste, reusing suitable items and recycling accepted materials. Reducing unnecessary use avoids consuming some resources in the first place. Reusing an item can delay making and discarding a replacement. Recycling processes a material for another use, but collection and processing still require resources. No single action makes resource use disappear.

Contamination can limit availability too. Water may still be physically present but unsuitable for drinking or a habitat because of what has entered it. Preventing contamination can protect usable supplies. A classroom resource plan should identify what it is conserving, how the proposed action changes use or waste, and what evidence would show a difference. A slogan without measurements is not an evaluation.

Worked comparison with fictional records: A class uses forty fresh sheets of paper in one week. During a similar week, using both sides and a scrap-paper tray reduces fresh-sheet use to twenty-eight. The reduction is twelve sheets. This comparison suggests less new paper was used, but the class should also check whether the amount and type of work were similar. These values are practice data, not a claim about the reader's class. Compare methods with the same measure too: suppose in another fictional week the class printed on one side as before but recycled every used sheet, and still took forty fresh sheets. Recycling kept used paper out of the trash but did not lower fresh-sheet use, while reducing lowered it by twelve. That is why reducing use comes first, not recycling alone.

Worked energy choice: A water-wheel model turns when water flows across it but stops when the flow stops. This supports the claim that moving water causes the wheel's motion in the model. It also shows that the resource must be available for that design to operate.

Guided performance: Build and test a teacher-supervised water-wheel model with a basin and small controlled water supply. Reuse the collected water where suitable. Separately, measure a classroom resource use for several days, propose one conservation action and compare a similar period afterward.

Independent evidence: Explain renewable and nonrenewable examples, trace one resource-to-change relationship and defend a conservation proposal with recorded data and limitations. Distinguish reducing use from recycling. If a comparison changes the number of learners or the task load, account for that difference before attributing every change to the conservation action.