The only disadvantage I can think of is that there would have to be a system of pipes throughout the person's house, which may by pricy as well, although I'm not sure about that part. You would have to hire someone to dig down for you and lay the initial pipe for it, which could also be quite expensive. I couldn't think of anything else, so I googled it: the piping can often take up a large area, so it would be better suited for places that are more spread out and therefore couldn't really be used for apartment complexes or in cities. http://funadvice.com/r/1545f89vvs1 In some cases, like those in which the geothermal energy is steam spouting straight from the earth, the source may someday simply stop, but if you mean piping down toward the core, you're pretty much set. If that stops giving off heat, then there's something bigger to worry about than energy sources. http://funadvice.com/r/3mq4n7crtl If you just google "geothermic energy disadvantages" you get a load of answers, I just took from the first two there.
Well geothermal for heating and cooling a home is simply pipes buried in the ground deep enough where the temperature stays about 55 degrees all year around. Water, or other substances are circulated through the through the pipes and into an energy pump to help heat or cool your home. Positive effects: energy efficient and environmentally clean. It does use electricity, but very little compared to the heat or cool it produces. Negative effects: Expensive to purchase and install, and the heat / cool is not imediate and obvious, rather just suttle and constant. It takes some getting used to. In other words, you won't come in from the cold, stand over a register while it's running and get instantly warm like you would with a gas furnace for example.
Takes more energy to find the rocks to make the energy than to just use regular methods. Hope I helped!
Apparently none. Except for the environment that is going to be exploited,
Not as much as it is through drilling for oil. Not nearly as much.