It probably wouldnt put me off (lived in countryside as a child, seemed to have frequent power cuts!).
However....I would try not to get too caught up in thinking about the re-sell or whether it'd put future buyers off.... an earlier comment on this thread about the supposedly good advice they were given when buying a car "don't think about whether its good for you, think about whether it'll be good for the next person" is, in my opinion, just complete nonsense!
We are SO hett up in this country about resale value (eg Beeny / Kirsty & phil banging on about adding value / not adding value to a house) - if you totally love the house and are willing to buy it off grid, then chances are somebody in the future will be willing to do the same. Yes, it might take longer to sell on, but if you're prepared to live off-grid, then its highly likely somebody else will too.
I'm sick of hearing of people who won't build an extension / won't convert loft because it "won't add value" - if you love your house and want to make it work for you / your family, then surely these things 'add value' to your life, albeit not a monetary one on resale?!!
Sorry, rant over
. I would say, go for it if you really love it!