What is the maximum power my element can handle?

While your element reads the specific wattage range that it can accommodate when paired with a meter or sensor, the rule of thumb for design is to ensure that it can withstand no less than 20% above range. 

If you have a radio (or other power transmitting setup) that is rated at 100 W output but can output as much as 111 W, your 100 W element will be fine (for example, 100C). It will only reach the 100 W range max on the meter display so the extra is not visible or usable. If you need to evaluate that extra power, select an element that can handle the higher power (for example, 250C).