The humble light bulb, little changed for over a hundred years, is due for a major overhaul, and it appears this change is fast approaching in the form of LED bulbs. LED lighting offers much greater efficiency, along with other qualities too, and will in the future be the number one choice for homes and in various devices, such as flashlights.<br><br>Lighting has been dominated by the incandescent bulb for as long as most us can remember. While they have undergone some improvements, they remain very inefficient, and less than 10% of the energy consumed by them is converted into useful light.<br><br>The energy that they waste is evident in the level of heat that they produce, and the heat is one of the reasons that they burn out fairly quickly. Remember that all of that lost energy results in more money coming from pocket in the form of high electricity bills.<br><br>With environmental and energy concerns almost certain to grow, a more efficient bulb is needed. CFL bulbs are a lot more efficient, and are already replacing incandescent bulbs in many uses, however, they have some drawbacks, such has taking approximately a minute to reach their full brightness.<br><br>LED bulbs are a much better alternative in the long-term. Their only major disadvantage is how much they cost, but their price will come down as they become more widely used. Their high level of efficiency is due to their unique, solid-state design and way of producing light.<br><br>LED lighting is based upon the movement of electrons through a semiconductor material, which consists of both negatively and positively charged components. The positive layer has small openings that free electrons from the negative component can pass through.<br><br>When an electric charge is applied to the semiconductor, a flow of excited electrons passes through the holes. Since they are passing from a higher to lower energy state, they give off energy in the form of photons, that can be directed to produce light.<br><br>This kind of lighting provides many advantages. Being solid-state and without filaments to burn out, LED bulbs last much longer (some can last up to 50,000 hours). Additionally, they are significantly more durable, and can withstand shocks that other bulbs cannot.<br><br>As they are so much more efficient, they run much cooler. This reduces the risk of being burned by touching a hot bulb, and also cuts down on cooling costs in the summer, since the bulbs are not producing so much heat.<br><br>Unlike CFL bulbs, which take time to reach their full brightness, LED bulbs come on within a second or two. They are also able to be dimmed, can produce colored lighting without filters, and create a highly directional light, which is ideal for task lighting.<br><br>Their durability and efficiency make them great for other purposes too, such as for use in flashlights. Since flashlights are required to contain their own power source, and are often dropped and exposed to other shocks, the efficiency and durability of LED bulbs make a significant practical improvement.