What is a kWh?
This article answers the question "What is a kilowatt hour (kWh)?"
Energy Star CFL and LED Light Bulbs
Energy Star is a joint program of the U.S. EPA and Department of Energy. A product with the Energy Star label means that the product has met the minimum set of requirements set forth by the program. Just because a product has the Energy Star label doesn't mean it is a good product, it just means that the product is probably more energy efficient that similar products without the label and that the manufacturers have gone through the process of meeting Energy Star requirements.
Mapawatt will only recommend light bulbs with the Energy Star label.
Light bulb codes - shapes, sizes and bases
What most people visualize when the "light bulb" goes off in their head and probably the most common type of residential light bulb is the "A" shape. Common sizes of the A bulb are A15, A19, and A21. The number designation in the code is usually the width of the bulb at its widest point designated in eighths of an inch. So an A19 is an A shape bulb and is 2.375 inches in diameter (19 divided by 8). This code designation applies to almost all types of residential lighting, where the letters stand for the bulb shape and the number is the diameter at the widest point.