why should such energy credits not be able to be saved or given away ?
it should be obvious that its unlikely that someone will always manage to "spend" all of his credits now if we take those wasted credits from all of the population then that would be an enormous waste of production capacity.
to me such a system is not flexible enough because afterall there might be months where i dont need to spend much credits at all and then all of a sudden my pc is fried my fridge gets broken and my car needs to be replaced would i have to go without credits for the rest of the month then ?