There are a few apparent issues with this and whenever there is some optimism there seems to be a balancing by the naysayers (but to be fair, there are a lot of good points made in the comments section).
‘Why do we have such a negative attitude in the UK to renewable energy? Every time some other Green group or NIMBYs comes up with objections or scares. Wind turbines they object to noise and visual impact, Hydro they object about damage to river or fish, Tidal they object to impact on mud flats. Okay, so what are their alternatives? Basically do nothing, no wonder we are becoming an Industrial museum and gradually losing wealth. Get a grip, we need more innovation, change and positive attitude to get things done.’ (lxy001 – January 2011 5:26PM)
Negative attitude partly because…
‘The problem is that the amount of heat available under the UK is just not all that much compared to our energy demand.
David Mackay calculated that the amount of heat that can be sustainably tapped from beneath the Uk is only about 2kWh per person per day. That’s about 2% of what we need. And this would involve drilling to 15km and fanning out to cover the entire landmass of the uk at that depth. The equivalent, about 4 nuclear powerstations, would be quite a lot easier and cheaper.
Alternatively it is possible to extract heat at an unsustainable rate (which is gradually depleted therefore not strictly renewable). Picking the best sites for “heat mining” would yield about 1% of our energy needs by Mackay’s estimates; or the equivalent of perhaps 2 EPR nuclear powerstations.
To quote Mackay: “Other places in the world have more promising hot dry rocks, so if you want to know the geothermal answers for other countries, be sure to ask a local. But sadly for Britain, geothermal will only ever play a tiny part.” (ColinG – 18 January 2011 5:03PM)
Either way, we are way behind many other industrialised nations in developing our sustainable energy sources. Wind in catching up but this is a global green industry for the present and future which we’re sleep-walking out of.