Always calculate if the investment is it worth.
I agree. however I don't think stretching todays numbers over 12 months is solid enough to come to something I'd call a 'credible' calculation. Like the numbers in above post: it's fingers crossed and I'm telling myself it's profitable because of the 'free' electricity and speculating on a rise in value.
I posted it above to see if this calculation is realistic, what's do you think of those numbers?