AMERICA's National Christmas Tree, a stone's throw from the White House, is greener than usual this yule. The festive lights are partly powered by the Sun - at least, according to officials from the electricity industry, who are keen to persuade people of the virtues of solar power.
Several manufacturers of solar panels have provided 63 solar power units around the tree, which together generate about 6 kilowatts of electricity, or about 15 per cent of the power needed to light up the tree at night.
But the Christmas lights are not kept glowing directly by solar electricity. Instead, the power generated in daylight hours is fed into the local grid and consumed during the day by offices and homes. Hours later, the tree's lights draw their power from the same grid.
Susan Shaw, a spokeswoman from Siemens Solar Industries, the Californian company that donated 26 of the solar units, ...
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