Why does 30 kg mass at the top of a hill have more potential energy?

So when it comes to Gravitational Potential Energy the higher an object of mass is the more energy it has as the equation for EPG is = MGH so the M is Mass of the object , the G is the gravitational constant which on earth is roughly 9.8 m/s and the H is the height of the object. So the greater the H value is the more energy you'll have. An example would be using your 30kg mass say at a height of 10 meters would have the EPG of 2940 Joules of energy since EPG= MGH so EPG= (30)(9.8)(10) . Now if the object was at a height of 20 meters the EPG would be greater as EPG=(30)(9.8)(20) which would be 5880 joules of energy