Teacher: "Your spelling is really improving, Henry, I only counted three mistakes."
Henry: "That's great!"
Teacher: "And now, let's check the second sentence."
Solar cellsIn 1994, the U.S. Department of Energy announced production of solar panels giving nearly twice the efficiency of existing panels. Made by United Solar Systems of Troy, Mich., these amorphous silicon submodule (1 ft2) panels converted 10.2% of solar energy into electricity, as compared to 6% previously possible. This was possible by using new thin-film photovoltaic technology. The company has subsequently produced flexible solar shingles based on thin film photovoltaics that can permit the roofs of ordinary commercial and residential buildings to evolve from simply providing protection from the weather to becoming a source of much-needed electric power. |
