4. The chemical energy in the person's body is transformed into when they peddle the bike, causing the generator to rotate. Some energy in the bike wheel is lost to . The generator produces electricity, which heats the water, causing it to produce thermal energy in the form of steam. When the person's chemical energy runs out, how do you replenish it? 5. Change the initial energy source to sun, the intermediate energy source to the solar panel, and the final energy source to the windmill. In this system, is produced from the sun and transformed into electricity in the solar panel. Both of these types of energy are considered forms of . The result of this system is that the windmill produces mechanical energy. 6. Try a few more scenarios, choosing different initial, intermediate, and final energy sources. Observe places where energy is transformed and lost. Creating systems with the least amount of energy is important in engineering design.