?? I'm pretty sure water will get heated above winter temperatures.
Anyway, Electricity cost of 450Kw/h vs profit will be irrelevant for a long while.
One point about this that I believe could be a future game changer:
The European Parliament debates on and brings in laws across the European Union (US-based readers may or may not know much about this). All EU countries must and do, almost without exception, abide by EU law. Now the EU are largely VERY progressive especially on 'ECO' matters - they had for example started to phase out the use of high energy-use incandescent light bulbs by 2009, whereas in the US a similar ban has still to come into effect and in California for example it wont do until 2018!
http://en.wikipedia.org/wiki/Phase-out_of_incandescent_light_bulbs
What this means is that the industrial use of electricity by BTC mining companies may be heavily taxed in the future in Europe while in the US it remains unregulated for far longer. The EU parliament has a history of introducing eco laws that are unpopular with business but are popular with the public. I think it would be very easy for btc mining operations to be priced out of the EU given enough bad publicity about 'wasting' massive amounts of electricity. Germany has decided to abandon all of it's nuclear power stations http://en.wikipedia.org/wiki/Energy_transition_in_Germany by 2022, they are planning to go completely renewable. Power is an incredibly hot topic as a result in Germany and Germans are generally very eco minded. So it's easy to see them putting pressure on the legislative body/European Commission to introduce a carbon tax on BTC mining across the EU.