Yes, your screen saver is mesmerizing, but it's not conserving any energy. And instead of letting your computer doze, turn it off if you don't plan to use it for several hours. Left on, a sleeping computer, depending on the model, can use from 15 watts for a laptop to 250 watts for a desktop, not including the monitor. While that amount might seem puny compared to energy-gobbling air-conditioners, heaters and lighting, factor in the cell phone and iPod chargers, clock radios, DVD players and other electronic gadgets that are perennially plugged in, and you're still draining power, watt by watt, from the grid. Coal and nukes are North Carolina's primary energy sources, so by powering down, you're decreasing your use of dirty fuels.