From the Solar Cooker Wiki Archive, Nov 2010 – Retired 3M engineers create a solar water pasteurizer for use in Third World countries. Inspired by the potential capacity for heat transfer they saw in plastic political signs, Bob Nepper and Bill Stevenson, long time members of the Solar Oven Society in Minnesota, USA, set about designing their version of a water purifier. Water is first filtered, then passes through a field of channels in a black corrugated plastic collector.
When the water reaches 71°C (160°F), and is suitable for drinking, a thermostat will open and allow the potable water to flow into an adjacent bucket. Capacity for the system is approximately four gallons of pasteurized water per hour.
