A laptop with optimus technology is useful for power conservation. Keeping the laptop at less than 95 watts is another step. I would say 65 watts, but keeping in mind you'll want a dedicated card that probably raises it some. Quality is... well.... um, tough. Does any manufacturer use quality parts in their laptops anymore? *shrug*http://www.newegg.com/Product/Product.aspx?Item=N82E16834230141
<---- pretty powerful, no clue on efficiency. But honestly, asking for power effeciency in a gaming laptop isn't going to happen. For on the grid, if you are concerned about your power bill, laptops aren't going to use more than what a 100 watt light bulb will use. If you want it to use without plugged in, then you don't want to game on it.