At Open Biotecture, we’ve been thinking of what could be achieved with a Fresnel lens. Greenpower Science has shown how water can be purified through solar distillation with a Fresnel lens. Such a lens allows a liter of water to boil in about 30 seconds!
Now since we have seen this, we thought we ought to get our hands on a Fresnel lens and try something. FoST in Kathmandu has such a Fresnel lens and agreed to lend it to us so we could experiment.
Hence we have started sketching two ideas based on a Fresnel lens, which we are keen on trying.
1. Fersnel Water Heater
The Fresnel water heater would replace the conventional solar water heater, based on the assumption it is more powerful. The rotating arm and frame of the lens would allow for manual adjustment. This manual adjustment could eventually be automated with a solar tracker.
2. Fresnel Greywater Distillation
This water purifier could be used to recycle greywater into domestic water (possibly into drinking water). Long showers should not be a problem anymore. Almost-closed loops could be created. The reed-bed is used to pre-filter the greywater, the lens boils the water which evaporates and condenses into a water tank above.
Hopefully we’ll be able to start building prototypes soon. We’ll keep you updated.