| Water Treatment | Purification of water to make it suitable for drinking or for any other use. |
| Charcoal | A drawing pencil or crayon made from this material. |
| Alternator | An electromechanical device that converts mechanical energy to alternating current electrical energy. |
| Activated Carbon | Powdered or granular carbon used for purifying by adsorption; given orally (as a slurry) it is an antidote for some kinds of poisons. |
| Solar Power System | The conversion of the energy of the sun's radiation to useful work. |