5 ms·
Good catch. Some optimistic back-of-the-envelope says it could be around 5 min for the liter of water. (The egg should go faster, if I remember my WWII-in-North
by ableal 18y ago
Good catch. Some optimistic back-of-the-envelope says it could be around 5 min for the liter of water. (The egg should go faster, if I remember my WWII-in-North-Africa frying-eggs-on-tanks movie scenes right ;-)
Assumptions: 1 square meter blackbody collector for 1 kW/m2 solar radiation, plus dt of 80C (which, for 1l water, needs 80 kcal = 80 x 1.162 Wh) -> 335 seconds.
I'd say a one square meter (~10 sq.feet) box is about equivalent to a standard 700W microwave - between 10 am and 3 pm on sunny days ...
- ableal 18y agoJust for the record: a couple of days later, a local newspaper had this story; their short piece said the box would boil 10 liters in 2 hours. That's about double my optimistic estimate, which did not take into account any losses by conduction or convection. From the pics, the box doesn't seem to be as big as 1 meter square either.