Flood lights are used to illuminate exterior areas and are usually mounted on buildings or poles. They provide directional lighting for a wide variety of spaces such as stadiums, arenas, billboards, street corners, and buildings.
High Intensity Discharge (HID) lamps are commonly used for these types of fixtures. These include Metal Halide (MH) and High Pressure Sodium (HPS). By way of comparison, MH lights have much better color rendering than HPS but are not as long-lasting or efficient. Also, MH lights tend to experience a reduction in light level as they age, unlike HPS lights.
In recent years, LED lighting has been found to be superior to HID lighting in every way. The same applies to parking lot and area lighting. Here is how it breaks down.
LED provides much better energy cost savings than HID
Common wattages used for HID flood lighting are in the 400 to 1000 watt range. For LED, this range is 40-600 watt. Light output increases with an increase with wattage. Switching to LED results in a savings of up to $300 per fixture, per year.
LED provides much better maintenance cost savings than HID
LED lights have a significantly longer lifespan than HID. This means that there is less time spent maintaining the fixtures due to replacing the lamps. Also, since the mounting height of the flood lights are 15 feet or higher, special equipment such as a bucket truck or a lift would be required to reach the light in order to replace it (and possibly the ballast), and in turn may require an outside contractor to maintain the fixtures. Less time required to maintain the fixtures means less maintenance costs.
LED provides much better lighting performance than HID
Metal halide lamps tend to have a decreased light output over time after they are installed. This is not a problem with high pressure sodium lamps but the quality of the light output is much lower. In other words, the MH lamp output has more of a white light and the HPS lamp output appears more orange or yellow.
By contrast, LED lights have much better color rendering and experience little to no drop in light output. They are also better at distributing the light evenly across a given surface.
In summary, LED is a superior choice for flood lighting compared to HID for all the reasons stated above.