Levi Yissar was an Israel

Israel

The State of Israel is a parliamentary republic located in the Middle East, along the eastern shore of the Mediterranean Sea...

i engineer

Engineer

An engineer is a professional practitioner of engineering, concerned with applying scientific knowledge, mathematics and ingenuity to develop solutions for technical problems. Engineers design materials, structures, machines and systems while considering the limitations imposed by practicality,...

 and entrepreneur

Entrepreneur

An entrepreneur is an owner or manager of a business enterprise who makes money through risk and initiative.The term was originally a loanword from French and was first defined by the Irish-French economist Richard Cantillon. Entrepreneur in English is a term applied to a person who is willing to...

. He built the first prototype Israeli solar water heater. In the 1950s there was a fuel and electricity shortage in the new Israeli state, and the government forbade heating water between 10 p.m. and 6 p.m. As the situation worsened, Yissar proposed that instead of building more electrical generators, homes should switch to solar water heaters. He built a prototype in his home, and in 1953 he started NerYah Company, Israel's first commercial manufacturer of solar water heaters. By 1967 around one in twenty household

Household

The household is "the basic residential unit in which economic production, consumption, inheritance, child rearing, and shelter are organized and carried out"; [the household] "may or may not be synonymous with family"....

s heated their water with the sun and 50,000 solar heaters had been sold. However, cheap oil from Iran and from oil fields captured in the Six-Day War

Six-Day War

The Six-Day War , also known as the June War, 1967 Arab-Israeli War, or Third Arab-Israeli War, was fought between June 5 and 10, 1967, by Israel and the neighboring states of Egypt , Jordan, and Syria...

 made Israeli electricity cheaper and the demand for solar heaters to drop. Following the energy crisis in the 1970s

1973 oil crisis

The 1973 oil crisis started in October 1973, when the members of Organization of Arab Petroleum Exporting Countries or the OAPEC proclaimed an oil embargo. This was "in response to the U.S. decision to re-supply the Israeli military" during the Yom Kippur war. It lasted until March 1974. With the...

, the Israeli Knesset

Knesset

The Knesset is the unicameral legislature of Israel, located in Givat Ram, Jerusalem.-Role in Israeli Government :The legislative branch of the Israeli government, the Knesset passes all laws, elects the President and Prime Minister , approves the cabinet, and supervises the work of the government...

 passed a law requiring the installation of solar water heaters in all new homes (except high towers with insufficient roof area). As a result, Israel is now the world leader in the use of solar energy per capita

Per capita

Per capita is a Latin prepositional phrase: per and capita . The phrase thus means "by heads" or "for each head", i.e. per individual or per person...

(3% of the primary national energy consumption).