 
The sun is an immense source of free power. We already make use of its energy by harnessing the power of water falling through turbines at hydro-electric plants; it is the sun's energy, causing evaporation and winds, that returns the water to the mountains. We also can convert small amounts of sunlight directly to electricity, through the use of solar cells.But there is a great amount of the sun's energy that we haven't even begun to use. It's the energy that makes hot air rise. When sunlight heats the ground (1), the ground warms up, and begins to radiate infra-red energy (2). This causes the air near the ground to get warm too, and because it's now less dense than the air around it, it rises (3). 
Soaring birds make use of this free source of power, to lift themselves to great heights. The air moving upwards does all the work. We have learned to use this free energy source too, when flying gliders. Air that is rising, because it has been warmed indirectly by the sun, will carry the glider upwards, also to great heights, for free; no motor required!But this is hardly using the free energy source of rising air to its maximum potential. Is there some way to harness the power of rising hot air to generate large amounts of power, perhaps electrical power? Let's find out about EnviroMission ... go on to page 2. |