From the standpoint of looking at the initial costs of setting up a grow operation, HID grow lights, or High Intensity Discharge grow lights, are a very affordable option for people who grow plants indoors. Over time, though, that initial saving can be overcome by additional costs as you spend more on other costs.

HID grow lighting works by sending electrical currents through metal vapors that charge the electrons and cause them to bump into each other, creating light. It takes a few seconds, but within half a minute they are at full output and then will have to cool completely if they are turned off before they can be turned back on. This can cause them to use a good deal of power, but many people still swear by their use in large part.

Contrast to the way of HID grow lighting works, the way LED grow lights work is that the individual diodes that are in the light are focused to specific wavelengths of the light spectrum necessary for plant photosynthesis while other light bulb gives off white light, which encompasses all the colors of the visible light spectrum. Plant photosynthesis requires only specific wavelengths of light and all the extra wavelengths that are in white light are wasted. LED grow light diodes have a blend of only the wavelengths that are needed in the correct ratios necessary for photosynthesis. These wavelengths are mainly the reds, oranges and blues in the 580-630nm and 420-470nm ranges.

While growing with LED grow lights, LED grow lights consume less than 30% when compared to other various bulbs. Which does really saves a lot of growing energy bill.
LED grow lights give off less than 10% of the heat that a high intensity discharge bulb such as high-pressure sodium (HPS) or metal halide (MH) bulbs do. Less heat equals less energy consumption. As the majority of the wasted electricity in HID systems is given off as heat, you will find that after just a few minutes of use, the HID bulb will become extremely hot and will burn the skin if touched and has been known to cause fires. So you can imagine what it will cause to the growing plants. It may make plants dry to death or burn it. But with LED grow lights, this problem completely eliminated as even after being on for 24 hours, the LED grow light is only slightly warm.

On the other hand, HID grow lights, fall short in those categories. The HID grow lights are very bright and very powerful, but they unfortunately produce a large amount of heat that has to be diffused by airflow systems and maintained at all times. That also means you will be forced to deal with the extra costs of running the lights themselves, which can grow incredibly expensive when they are being run on a daily basis. They will effectively grow plants at any stage of life, but it will come at a cost and they require a great deal of attention.