Residential water heating with Fresnel lens

France

 * http://wims.unice.fr/xiao/solar/diy.html and http://wims.unice.fr/xiao/solar/index.html
 * http://wims.unice.fr/xiao/solar/storage.html

Use http://www.patentstorm.us/patents/6971756.html for troughs from http://www.svvti.com/projects/ringarrayconcentrator/rac_index.htm instead of the usual parabolic troughs. It is patented but in South-Africa this isn't a problem as described under HackPatents.

SolarLinks is used to provide a mirror surface.


 * This link http://wims.unice.fr/xiao/solar/diy.html

Generate hot water for the home
To increase the effective power of a FresnelLens focus the suns rays on it via parabolic reflectors. http://www.sohara.org is the best design. The same idea where square flexible mirror reflectors are bent in an arch shape using screws, strut and glue, somewhere in the energy section links. The curved silver reflector mirror idea is somewhere in the links, multiple of these are stacked in a grid pattern lets say 5x3 meters with spacing in between to reduce wind loading. Each square pan/tilts with RcServos and cpu with some look-up table based on time of day and date. A square focuses automatically on a central point as the main platform is turned from side to side with the servos. To calibrate each square, block out the others and position the square as the main table turns. Then do the same to each other square in turn.

For generating hot water this shouldn't be necessary because only a single FresnelLens will be used.

Focus a FresnelLens on coiled copper pipe. The hot water is pumped into a self-made galvanized container. The container is first rapped in fiber glass, then in layers of thing polystyrene which provides so much insulation that water will remain at 70degrees for two weeks as per the Pop mechanics letter the idea is taken from, somewhere between 2007 and 2009 SA edition.

Multiple of these FresnelLens coiled pipe combinations are installed down a line on top of the roof, which reduces wind loading and increases the effective energy available. The heated water from one tube assembly is heated further with the next Fresnel lens.

Suspend the container above the shower, should there be to little pressure install a small battery driven pump at the shower head, the same campers use. 220volt electricity shouldn't be used to pump water inside the home for domestic usage.

The FresnelLens tracks the sun via a cheap ingenious sun tracking device that uses two green diodes, the link of which is somewhere in the energy section of Sasecurity. To minimize wind loading multiple smaller FresnelLens could be used.

Boiling hot water for kitchen usage
Focus the FresnelLens lens on coiled copper at an elevated hight for gravity to channel the water through the wall at the kitchen sink. Or use a heat resistant stainless steal pump. Wrap the hot water piping in fiber glass and then finally in layers of thin polystyrene if the distance from the FresnelLens to the sink is to large.

The water can also be stored in a small galvanized container in the kitchen rapped in fiber glass/polystyrene. AT a much reduced Eskom load such warm water can be brought to boiling point after sun set.

Use some contraption with linear positionar RcServos to position the cooking pot at exactly the temperature spot needed above or directly in contact with the solar stove coil. Some sort of thermocouple can be used to measure the stove temperature. Safety from the incoming parabolic focused rays needs to be dealt with.

Sohara.org parabolic design
With the http://www.sohara.org/ design a huge 5x5m single parabolic lens can be simulated using smaller lenses inside round balls all tracking the sun at the same time. Focus this energy and a power StirlingEngine designs is feasible.