1. Human power

2. Draught animal power

3. Mechanical power

        a. Stationary engines

        b. Power tiller or two-wheeler tractor

        c. Tractors

        d. Truck/haulage tractor

4. Electric Power source

          a. Fuel cells (batteries)

                         i. Alkaline battery

                        ii. Lead-acid battery

                        iii. Lithium battery

                        iv. Lithium-ion battery

                        v. Nickel-cadmium

                         vi. Zinc-carbon battery

         b. Induction motor

         c. Generators

5. Renewable power