Winniecat they grow upwards towards the light
The earthing up isn't just to keep the light out and the potatoes from turning green - it actually increases the yield as the more of the stem that is underground the more potatoes it grows.
Farmers used to use polythene over potatoes to keep frost off and warm the soil, but I'm assured by my brother (large potato farmer in every sense of the word ) that fleece produces better crops that also store better due to more even uptake of water. They only use fleece now for potatoes.
You could try using straw to 'earth' them up. I've not used that method, but I've seen it recommended as an alternative in various magazines. It would certainly be less work.
Here is a link to an experiment in France between mulching with straw versus traditional 'earthing up'. In general they seemed to produce less, but there was plenty of success stories too. Those that had similar outcomes between the two methods much preferred using straw mulch.
I generally dig a trench about 6in deep place the seed potato and give them a covering with compost and a few slug pellets for good measure then refill the trench with the removed soil taking a bit extra from the ground at either side of the edge of the trench, this builds the trench covering up to about 6 to 8 inches high, that is generally about all the earthing up that is necessary but as the buds show through I just scrape a bit of soil up and cover them over and that's as far as my earthing up goes and I've never had any problems.