Nothing special about this at all, technology wise. It's just a generator powered by human grunt power to lift the weight.
As for the original poster, it's a complete waste. It's not free energy and it doesn't run off gravity. It runs off the power you consumed to LIFT the weight. So, if you wanted this for your home, you'd not save ANY energy because you'd still have to power the lift to get that 2 ton weight up. And you'd actually WASTE energy in the process because every time you convert from electric to mechanical or back, you lose some energy. So, his idea is lift it (consuming electricity to lift it), losing energy while converting to the mechanical lift, then convert it again from mechanical to electric as the weight falls, losing even more energy.
Now, as for the cost savings for the villagers, that's important.