There are certain products that do more harm than good for the planet. This much is true. There are products out there with questionable manufacturing requirements and precious metals. These will often make a higher carbon footprint than what will eventually be saved by the product. Windmills still require metals and petroleum products to operate, but the amount of energy created and the footprint left from the creation and maintenance is lower than the footprint produced. Evaluations of the carbon footprints is how to identify whether these new products are good for the environment or not.
Yes, buying energy-efficient products really does help the planet, because in the aggregate it can have a big impact. With energy-efficient products, we have to use less coal. We do not have to pump as much oil out of the earth. This preserves the earth in its natural state and for future generations.
Buying energy-efficient products helps the environment. They reduce greenhouse gases which can cause global warming. The plants that supply the energy to consumers create harmful emissions, so the less energy that is being used by consumers, the less the plant has to supply. This reduces the amount of emissions from the factory.
Buy energy efficient product helps the planet a lot and will encourage people to seek alternatives that deal less damage to the product. For instance, buying fuel efficient cars will produce less emissions, and people should be given incentives that do so. There are many products that could encourage people to buy that helps the planet a lot.
Buying an energy efficient light bulb or even a refrigerator probably does more to save one's utility bill from rising than it does to save the planet. It is a symbolic gesture, though, and one that it is worth taking, just as one's donation to a charity will not alleviate world poverty.