A Sterling Engine can convert temperature difference (heat) into mechanical energy (or electrical energy), directly.
Do you even get the implications of such a system for a hot country like India? WE CAN GENERATE A LOT OF ENERGY BY USING SUN'S HEAT THAT IS AVAILABLE ABUNDANTLY, HERE!!!
Make no mistake: Solar PV that converts sunlight into energy is different from Solar Thermal that converts sun's heat into energy.
You may already be familiar with solar water heaters that use vacuum tubes to collect sun's heat to make hot water. There are large-scale CSP (Concentrated Solar Power plants) that use mirrors to reflect sun's heat, concentrate it onto a small point, and use it to create steam or something else that drives turbines and generates electricity.
But sterling engines are different. They are like our vehicle engines, but don't use explosions like petrol/diesel to move the piston. Instead, they use heat and cold, alternatively, to move the pistons. Read this article to understand how sterling engines work - http://auto.howstuffworks.com/stirling-engine.htm.
Although using sterling engines in automobiles is a far-fetched idea, using them to pump water in places that are not connected to the grid is a very practical idea. Sunvention's SunPulse Water, based out of Germany, is one such system that has been built using sterling engine and can pump as much as 80,000 liters of water everyday from a depth of 10 meters just using the sun's heat energy! Technical details about this system is available here and here. I am not sure if they have a commercial product based on this technology, yet.
Something that I don't understand is, when Europeans are able to work passionately and design such systems, in spite of getting very little sunlight and heat, why are WE not able to work on such concepts and adapt the technology to suit our needs, especially given that we are so close to the equator and receive both sunlight and heat ABUNDANTLY? We don't have even have to invent the wheel from scratch, we just need to licence the technology and manufacture it locally and adapt it to local conditions.
Note: The video embedded above doesn't show the water pump, but it shows the other components - Sterling Engine & Heat collectors. They have even used a greenhouse to capture heat, while growing plants inside. Vacuum tube collectors and solar dish concentrators are two other methods to capture heat efficiently.
Note: The video embedded above doesn't show the water pump, but it shows the other components - Sterling Engine & Heat collectors. They have even used a greenhouse to capture heat, while growing plants inside. Vacuum tube collectors and solar dish concentrators are two other methods to capture heat efficiently.
