nec208":2pac9315 said:

How much energy will be needed to create coffee ?

E = mc².

m is the mass of whatever you want to create from pure energy. Let's say a coffee with a cup weighs 200 grams, so m = 0.2 kg.

c is the speed of light, defined as c = 299792458 m/s.

So you end up with E = 17975103574736352 joules, or about 25 minutes of global energy production (powerplants, cars, planes, ... all put together), or about 4 megatons of TNT, or about the same energy the rock that digged

this little puppy had. To make a cup of coffee. Insane, right?

And that's all assuming 100% efficiency. If the machine was say 50% efficient, you'd need to input twice the energy, because only half of it would actually end up doing the work you wanted.

If some thing goes wrong with the replicator and it is only 99% efficient at making coffee what will happen. (...) I don't understand we have light and heat now and things do not explode? Things are not 100% efficient now and things do not explode.

A light for example might be only 25% efficient, but it also consumes just a couple watts (joules/s) of power. A 25% efficient 100 W light bulb will turn 25 W into useful light and 75 W into waste heat, but since 75 W is very little it gets cooled of easily with just air.

More powerful devices produce more heat, so they need active cooling (like fans or water cooling) to take that heat away.

As you're increasing the power at some ridiculous point the power that comes out as waste heat gets so insanely high, that it looks more like an explosion (the device heats up so fast that it evaporates explosively).

So I get the big problem why we do not have replicator is a enegy problem and also it is not 100% efficient .

Pretty much, yeah. There are also a couple quantum physics-level issues with precision and reliability (see Heisenberg's principle for example).