Excess Keys & Chests

I currently have 11 keys and I do not play many champions, which I understand is my fault. However, I would be very appreciative to see a system introduced that had a transfer rate of keys to chests:

Examples: 3x Keys = 1x Chests 5x Keys = 1x Chests + 100 Orange Essence 10x Keys = 2x Chests + 250 Orange Essence

It is very unlikely anyone will save up 10 keys, currently I have 11, maxed at 15, dropped as low as 8 once. I would really like to use my keys for something. They're given as a reward for keeping it positive and so far they are just gathering dust.