Sun Boilers Create Solar Energy Like a Genie In a Bottle

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solar-water-heaters-on-roof.jpgIsraeli solar energy companies such as Solel Solar, Aora, Ormat technologies, and a host of others are now world leaders in the development of sun power to produce electricity. But Israel, a small country of 7 million, with more than half its land area being desert, has been a solar energy pioneer virtually since its beginning in 1948.

What is now fondly known to many Israelis as a “dude shemesh”  or  sun boiler, was invented by a guy named Levi Yissar back in the early 1950’s, when electricity was very expensive due to a severe energy shortage.

His innovation consisted of a modified  electric water boiler that was erected on the roof of a building and attached by pipes to two simple glass faced collector plates that heated water running through them from the boiler, when the sun’s rays struck them during certain hours of the day. The heated water then returned by gravity feed to the insulated boiler, where it was stored for later use in kitchens and bathrooms.

Yissar, an engineer, and entrepreneur, soon opened the first company selling such devices, the Neryah Company, in 1953. The device soon became so popular that people waited for weeks to purchase their own “dude shemesh”; and it wasn’t long before other companies got into the act. By the mid 1960’s, one in every 20 households already had their own sun boiler, and more than 50,000 had been sold.

Israeli companies also began exporting the device, particularly to other Mediterranean countries such as Greece, Turkey and Italy.  More modified versions included an auxiliary electric heating device to heat water at night or on cloudy days. More modern versions have also been developed  for large apartment buildings, where large collecting plates send water to either  individual private water tanks or to large condominium ones where the heated water is shared by tenants in the building.

Nowadays, residents of most private dwellings or smaller apartment buildings in Israel have these sun boilers installed; which reduces electricity consumption considerably – by an estimated two million barrels of oil a year.

And it must be noted that all of this came into being long before the invention of photovoltaic solar energy cells and panels (PV) that are now being used to produce thousands of megawatts of electricity.

The old “dude shemesh” is still very much in use, however, even in many homes in the USA, Australia, and other countries. Middle Eastern countries like Jordan and Egypt, which has more than 500,000 solar collectors, are also availing themselves to this simple, yet efficient way of harnessing the sun’s power.

Egypt uses them in hotels and commercial buildings, as well in apartment blocks and private homes. Jordan has more than 200,000, many of them purchased from Israel. And even North African countries like Tunisia have also gotten into the act (110,000) with the assistance of the Global Environment Facility (GEF)  to which more than 170 countries now belong.

The credit for much of this can be given to Israeli pioneer innovator Levi Yissar, who had the idea that the sun’s power could be harnessed, almost like a genie in a bottle.

Appearing courtesy of Green Prophet.

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  • http://www.elrst.com Edouard

    Interesting article, thanks Karin !

    I wonder what solar water heaters would account for if they become as much widespread around the Mediterranean that they are in Israel…

  • Bob Roach

    1. The water doers not boil in a dude shemesh so using the term “subn boiler” is misleading. A term coming into more prominence for these systems is “solar thermal” device. Unfortunately this term is also used for systems which use secondary devices to convert hot working fluid into power or chilled water or air. I prefer “solar water heater” as Edouard above says.

    2. While credit can be given to Levi Yissar for a good design, the invention of the dude shemesh dates at least one hundred years earlier. They were in common use in Florida in the 1920’s before Fla Power & Light came in with cheap power. They all but died out there until recently.

    3. Use of a Dude shemesh is an excellent idea because they are inexpensive and effective. Higher efficiency would be appreciated (they are currently averaging 40-60%) and can be accomplished with slightly more complex systems like sun-following.

    4. A competing design makes use of evacuated tubes instead of the flat panels with claims of higher efficiency. So far, though, I have yet to read of any great advantage over the inexpensive flat panel.

    5. Israel has the highest density of solar water heaters in the world (Cyprus is second). If the entire Mediterranean basin were to have a similar density then the number of barrels of oil saved would be similar to the population ratios since Israel has a similar standard of living.

  • Tom Wolters, Beijing

    Just come and have a look in China, number one solar water heater country, Edouard.

  • http://www.plumbingandheating24.co.uk Plumbing & Heating

    I came across your blog while researching into solar heaters as I’m thinking of having one installed and I wasn’t aware that Israel had the most amount of solar water heaters. I’m sure a lot of country will think about this in the future. I know I want to because it’s much better for the economy.