How many watts does a LED billboard for a stall have?

The power does not need to be high. Twenty to thirty watts per square meter is enough (very bright). If you are worried that it is not bright enough, pre ss 40W. But if you use LED If you want to make dot matrix (straw hat lamp), please calculate it as 50mW per lamp. You can calculate how many lamps are arranged per square meter.
The former is a high-power and efficient LED light source, and the latter is an ordinary white LED lamp. Please Decide for yourself.