Energy Choices at Two City Cinemas

Two Cinemas on a Busy Block

Buses pass shops and tall buildings on a busy city block. East Cinema and West Cinema show movies there. A fourth-grade class studies how the two small cinemas get energy. Both buildings use electricity for projectors, lights, and fans. Both also burn natural gas in furnaces for heat. The class collects information from the cinemas and their energy suppliers. The graph in the next section shows the class's example records for one week.

East Cinema gets its electricity from a power station that burns coal. Coal is a solid fuel dug from the ground. At the station, burning coal releases energy used to produce electricity. West Cinema gets some electricity from coal and some from wind turbines. Moving air turns the turbines, which produce electricity without burning fuel. Natural gas, used by both cinemas, comes from underground deposits. Wells bring the gas to the surface, and pipes carry it to buildings.

Coal and natural gas formed from ancient living things over millions of years. People use these fuels much faster than nature replaces them. Renewable resources are replaced naturally on a much shorter timescale. Winds keep forming as Earth is warmed unevenly by the sun. Sunlight is another renewable energy resource. Solar panels can use sunlight to produce electricity. The cinemas do not have solar panels, but West Cinema is considering adding some to its roof.

The class also gathers environmental notes. At the coal mine, workers remove soil and plants to reach the fuel. Loose soil can wash into nearby streams. The coal station releases air pollutants when it burns fuel. Burning gas in the cinemas' furnaces also releases air pollutants. At a proposed wind project, a new access road would remove a strip of grassland. Turbine bases would replace patches of shrubs. Making solar panels requires materials that may be mined from the ground. The students keep these notes beside the energy records as they compare possible plans.