Turn on your light switch. Instant daylight. Your heating. Instant summer. Or hot water tap. Luxurious heated water.
Where do you think all that comes from? Electricity? Fairy blood.
We have been using them for generations now, to power our modern world. Hydro electricity? from mashing up Undines through Turbines. Wind turbines? Sylphs. Fossil fuels? Gnomes. And fire? Salamanders. All the elementals are now being harvested like wheat. Trapped and channelled along copper wires to fuel our homes, manufacture our technologies. Getting used up to power our love of the internal combustion engine. The decreasing numbers of wild Fairys are not too well disposed towards us. Tsunamis, Earthquakes, Floods, are all attempts to redress the balance a little. So next time you want to 'feel their energies' people, stick your fingers in a light socket. Or short the poles between a car battery with a rod of iron. Iron has always been known to disrupt them, but copper traps and enslaves them, because of it's lower resistance. Gold, with it's resistance of zero, traps them inertly, and the power is then transmuted into another kind of magic. Economics. A glamour. A spell that makes people value a worthless metal.
After all, what good is gold? You can't eat it, or drink it, you can't carry much of it around. It's too soft to use for tools, and gives no useful chemicals, as it cannot oxidise. Yet it can bankrupt whole economies, drive men mad, and makes people fall in love with it.
So next time you think about fairies, try not to think of them as little winged, pointy eared Tinkerbells, (A Tinker was one who worked metal) but as Slaves, purely valued as industry driving captives. Now do you still wonder why they hate and avoid us?