GT Energy has applied for permission for a deep geothermal power plant in South Dublin. This has attracted some media attention (here, here, here) and Paul Cunningham cast me in my standard naysayer/party-pooper role.
The media attention is overblown. The project is small. It is only an application for planning permission. The legal framework for exploiting these resources has yet to be designed. Subsidies for geothermal power are zero at present.
The cost of geothermal energy depends, to a large extent, on the depth of the hole that needs to be drilled to get to the heat below our feet. In Iceland, Mother Nature nicely brings the hot water to the surface. GT Energy plans to drill 4 kilometers deep in South Dublin.
Unfortunately, Ireland is at a geological disadvantage in this regard (although mercifully free of volcanoes by the same token). As shown on this map (peer-reviewed version here, but in B&W and behind a pay wall), you’d need to drill deeper in Ireland than elsewhere in Europe to get to the hot stuff.
Therefore, if GT Energy can get this to work at a profit in Ireland, they’d be best advised to apply the technology elsewhere and make buckets of money. I will not invest in their company, but others are free to try their luck.