How many watt do I need to light up a badminton court?
Watts (Power) is the most imperfect unit of measuring light. Light output is measured in lumens and lighting level in lux. You need to know how much lux level on ground is required for your badminton court. Usually sports requires high lux level as compared to open area or street lighting (30lux).
Based on the lux levels you may be able to convert it to the suitable lumen package output for the flood light fixture. Now based on the efficacy (lm/W) you can reverse calculate the power of the fixture suitable for your badminton court.
You would need about 400 watts led flood light to light the badminton court. Assuming four standard 400 watt led flood light fixtures would light the court, based on the efficacy of current commercial LEDs you could use 400w badminton court lighting.