Levi Yissar was an Israeli engineer and entrepreneur. 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 , Israel's first commercial manufacturer of solar water heaters. By 1967 around one in twenty households 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 made Israeli electricity cheaper and the demand for solar heaters to drop. Following the