Mechanical Energy
Needs for Mechanical Energy
Needs for mechanical energy are often overlooked when rural energy demands are addressed by international donor organisations; one reason might be the fact that the most common applications of mechanical energy such as water-supply, agriculture, agro-processing, natural resource extraction, small scale manufacturing and mobility are often falling into the scope of programmes of other sectors such as water, agriculture, business development or transport. The energy needs, however, are real and providing mechanical energy can have highly-significant effects on income generation and poverty reduction. Mechanical power is today obtained from motorised equipment such as steam, diesel and gas engines/turbines, electrical and hydraulic motors. In spite of these technological improvements, the 2.5 billion people without access to modern energy services still depend on unimproved versions of mechanical power equipment that inefficiently use human or animal power to meet their energy needs. However, in spite of these technical challenges, motive power has remained an important driver of livelihood activities in impoverished regions of the world.
The most common needs for mechanical energy and technological options are presented in the following. Only static applications of mechanical power are covered, so applications to assist mobility are limited to lifting and crossing.
Water supply
| Service | Typical "traditional" Technology | Improved alternative technology |
|
Drinking water supply Irrigation Livestock Watering |
Container (bucket) for lifting / carrying water | Diesel pump, treadle pump, rope pump, ram pump, Persian wheel, hand pump, river turbine, wind pump |
Having a clean and reliable source of drinking water is essential in improving the health of a community. In rural areas, water collection often makes up a large part of a woman’s day, so a nearby water source allows her to focus more on other activities, such as spending time with her children and taking care of her own health. Some technologies have even been altered to change the chore of water collection to a more enjoyable activity via mechanical power, such as the Play Pump. The applicability of technologies is context-specific, with factors including demand levels and local resources.
For some technologies, such as wind pumps, options are available in different sizes – ranging from household (e.g. wind/rope pump) to village scale, where wind speeds are sufficient for economic operation. The treadle pump, a human powered technology, can be advantageous because it can accommodate a wide range of weather conditions and is only used when needed. A simple irrigation system, like a drip system, can also reduce water consumption for a crop by 50%, compared with conventional irrigation practices, and increase the yield by 30–40%. It should be used in tandem with a water pumping device in dry areas.
Agriculture
Agriculture in developing countries relies heavily on the physical capability of the farmers. The introduction of mechanical power machinery can greatly improve their productivity and hence their livelihoods. In Bangladesh, power tillers (12–15hp) are used for about 70% of farm work because of their versatility; they can be used for tilling, irrigation pumping, threshing, husking and transporting. Locally made attachments to the tiller, such as a bed planter with a seeder, allow bed formation and seeding to be done in one pass. A study has shown that the yield of wheat, maize and mungbean on beds was around 19–23% higher than on beds using conventional systems. In one year, the total cost of planting in a bed system can be reduced by 59% compared to that of conventional methods. Research has found that by using this system, the irrigation method can be changed, and this can lead to a reduction of the demand for water by 30%
