> The batteries are "charged" not from the electrical grid, but from hydroelectric power generated at Alcoa's smelter in Baie-Comeau, Que., Tzidon said. When th

> The batteries are "charged" not from the electrical grid, but from hydroelectric power generated at Alcoa's smelter in Baie-Comeau, Que., Tzidon said. When they are full-charged, they are thick, heavy panels made mostly of aluminum. In a sense it's green if they are produced from green energy, like hydroelectric power in remote Canada. In that case it's not just green because it's hydroelectric, but also because it's inconveniently located hydroelectric it's not displacing more productive uses of the electricity. Maybe geothermal energy in Iceland would be another option.