Grades 5 and 6: Renewable and Non-Renewable Sources of Energy

Everyday, millions of tons of fossil fuels are burned to provide energy for people’s need. Consequently, the thermal energy of the earth increases. When we use the heat from the sun no extra heat is produced and no gases or pollutants are released.

Solar, geothermal, hydroelectric, wind, and biomass are renewable sources of energy.

To be able to use solar energy we need to use PV panels or solar thermal devices like a solar concentrating dish. In this setup, the sun’s radiation energy is reflected and concentrated through the use of a concave mirror. The concentrated heat is then absorbed by an engine and changed into rotational energy (kinetic energy) in the yellow flywheel. The flywheel then rotates a generator to produce electrical energy.

Conservation of energy for the dual-axis sun tracker with Stirling engine:

Sun energy received by the dish = Heat released at the engine + Energy of the flywheel

EXERCISE:

Identify the forms of energy involved when the dual-axis tracker works with dish and Stirling engine.

Identify the forms of energy involved when the dual axis tracker works with PV panels.