For D Day at ABC Wednesday, let's take the Hebrew word dood.
Some 90% of Israeli families have one on their roof.
The first two photos are not representative because these tanks are sitting on the ground, next to their house. (Well, actually it is a converted chicken house, with a roof apparently not strong enough for a dood on top.) But it is a good chance to show you a dood up close.
Typical domestic units consist of a 150 liter insulated storage tank and a 2 square meter flat panel. The black collector panel collects solar radiation, heats the water, and passes it to storage in a pumpless, gravity-driven loop.
Convection carries colder water from the bottom of the tank into the collector and hot water rises to the upper intake on the tank.
After a few hours of good Israeli sunshine, you just open your taps and out comes near-boiling water!
If the sun hides for a few days (which happens only in winter), set the timer or flip the switch to run the immersion heater built into the tank for half an hour before you want a shower.
The ubiquitous dood shemesh is found on apartment building roofs,
on buildings in Jerusalem's Old City,
and on Bedouin village houses in the desert.
In short, EVERYWHERE.
Good system to let the sun do the work, eh? Saving fuel, saving money.
Would it, or does it, work in your country?
In 2005 Spain became the second country (after Israel) to require solar water heaters by law.
And in 2010 Hawaii will require all new houses to have one!
How do you say dood shemesh in Hawaiian?