A Vertical Field Array (VFA) operates in the same way as the field generator in IC with the exception of the field is produced vertically. When the field comes into contact with a block it will not extend any further, no matter how many EU's you put into it. The VFA acts as a battery storing a certain amount of EU, and when the field is damaged, energy is taken from the battery to repair the field. The field also requires energy to maintain.
What do you think?