Free Energy from the Environment
This is a simple setup that uses the thermoelectric / seebeck effect for converting heat directly into electricity with no moving parts. There are devices available called Peltier Heat Pumps which are used to keep electronic components cool.
They are commonly used on processors as they can move heat away from a source under electrical power. When connected to a DC power supply a peltier element will heat up on one side whilst becoming cold on the opposite side. A large heatsink is necessary to dissipate the excess heat so that the other side can remain cold.
These peltier elements can also work in reverse. If it is heated on one side whilst being cooled on the other side a voltage will appear across the terminals. As long as there is a temperature difference between the two sides of the peltier device, then there will be a voltage between the electrical terminals.
Peltier heat pumps are not a very efficient method of generating electricity, but at least the supply of energy is free.
In a practical application a large heatsink could be buried in the ground to remove heat. If the peltier element is placed onto this is can be arranged to be heated on one side by the sun. A small black heatsink on the top of the peltier device could be used to collect heat from the sun that has been focused by a large mirror. Another method might be to use a larger heatsink and to place it inside a greenhouse. With this method it would be important to insulate between the hot and cold heatsinks so that the ground would not be heated directly.
I had a little Peltier generator that worked quite well.
See here http://sites.google.com/site/reukpower/teg-generator-1
What are some examples of the amount of power a peltier cooling chip in reverse can generate?
It varies with the module used. They come in all sorts of shapes and sizes.
how much maximum power can be produced from a single chip ?
The voltage produced is proportional to the temperature difference between the opposing faces of the peltier device. The current available would be dependant upon the size of the peltier module.
See the formulae under Seebeck Effect.
http://en.wikipedia.org/wiki/Peltier-Seebeck_effect
How can I determine the amount of electricity that would be generated from a peltier heat pump
when one side is heated?
A thermoelectric generator could be made that would be capable of charging SLA bateries. The device shown is purely conceptual, but a device based on these principles would be suitable for charging 12V batteries. The links below may be helpful.
http://www.pgiint.com/ThermoElectric.asp
http://www.picotech.com/experiments/thermoelectric_generator/
Another method for collecting energy from the intense radiation form the sun in India may be to use a sterling engine system. There are systems based on this device currently being developed for commercial applications.
CAN WE MAKE THOSE ELECTRICITY GENERATOR TO CHARGE 12 Volt battery of electric Moter bikes