Numeric (Year/Power) product attribute WooCommerce

Hi,
I am trying to add ‘power’ as a numeric product attribute (ex.: 50W). I would like my customers to be able to sort on frontend all products that have more than ‘X’W, just like the price filter. The problem is that right now the numeric filter is treated like a size and when ’50W’ is selected will show only the products with this value and not the ones equal and above the power. A good example will be an year attribute as well… Am I missing something? Is there a plugin for something like that?