User blog comment:Thunderblunder66/Gem armour flight?/@comment-24231180-20140128173554

As far as I know, in order for most EE2 power items to work you need some sort of fuel source (coal, glowstone dust, redstone, etc.). The most common way to achieve this is with a Klien Star which basically holds EMC. If you only have the armour in your inventory, then you would need a fuel source in order for it to function.