Is it theoretically possible to harness a planets gravitational energy

 

 

 

 

 

ps i am a really stupid guy compared to all of you so pls bear with me if i ask dumb qs

We use tidal energy (energy from waves at sea and waterfalls etc). If you think that gravity can make something move down we can use that movement (kinetic) energy, it's just a case of getting the thing up in the first place so that it can be pulled down. Water is easy because of the rain cycle, other physical objects normally you lose most of the gained energy by moving it back up (against gravity) so that it can fall again.

 

The answer to your question, or what I assume you are looking for, is basically no.

Hydroelectric power stations harness gravitational energy to produce power.

Hydroelectric power stations harness gravitational energy to produce power.

 

Interesting point to what 5614 said: sometimes they pump water upstream (above the hydroelectric dam) during non peak hours in some systems so that it (the energy) is available for peak time use.

 

Obviously there is an energy cost involved in doing this but it allows for a smaller system.

Well, yes. Electricity cost the most during peak times (7>9 am and 4>6pm) when the demand almost outstrips the capacity to produce. The electricity grid has no capacity to store electricity (apart from two places in America) and can only fluctuate production from power stations a finite amount. The deficit of electricity caused by the load increases needs to be supplemented, and the hydroelectric power stations do this. A hydroelectric plant can go from zero production to full in a matter of seconds, but the cost is that the reservoir of water that powers the turbines can take over a week to replenish. The water is pumped back into place to allow the plant to 'reset', and the electricity company buys approximately the same amount of power it produced but at a lower rate. It's an economic policy, rather than part of the design of a hydroelectric plant.

You can get energy from stuff falling.

umm.... eh, perhaps, the only problem is that when you take an object up to a certain elevation and drop it, you yourself have put the same amount of energy into it as you are gaining by dropping. So in theory, your net energy is zero. I suppose if you went to a cliff, tied a rock to a long rod connected to a turbine shaft and threw the rock off the cliff attached to the rod, you could create energy. But uh... there are only so many rocks..

 

Hydro electric works too, like was just said.

what about slingshoting rockets around planet's and stuff.

 

we do that.

 

so we can harness gravity but can we saddle and train it

Play with gravity?? Eh, I don't really think that's an option right now. We really don't know what gravity truly is or where it comes from.

 

It's one of my favorite forces though!