Even renewable energy sources can produce greenhouse gas emissions, it seems. A new report from a European investment bank found that many of the geothermal projects it’s funding in Turkey emit nearly as much carbon dioxide as coal-fired power plants, thanks to the country’s unique geology. Bloomberg reports:
Geothermal plants tap hot water and steam from deep underground to drive electric turbines. The liquid is injected back into the ground, but gases that come up with steam escape. In Turkey, the problem comes from a band of limestone prevailing in western Anatolia where most of the wells are drilled. Limestone is mostly calcium carbonate and breaks down into carbon dioxide and other calcium compounds when heated. […]
The report puts development banks in an uncomfortable position, since they assess projects based on environmental criteria including carbon emissions. The [ European Bank for Reconstruction and Development (EBRD)] in January set aside $100 million to lend for geothermal projects in Turkey. It also partnered with the World Bank’s Clean Technology Fund to spend another $25 million on exploring for further geothermal capacity in Turkey.
There are two stories here, and both deserve closer inspection. First, just because something has earned the label “renewable,” or because it might provide clean power in one location under certain circumstances, does not mean it ought to get carte blanche (or carte verte, as it were) from environmentalists. Geothermal has some impressive potential if it’s installed in the right locations—places where the geology is favorable and the subterranean hot water and steam is abundant. Many of Turkey’s geothermal plants don’t seem to meet both of those criteria, being built over limestone that produces CO2 when it comes into contact with steam. Geothermal energy still has an important role to play in future sustainable energy mixes, but like any other energy source, it needs to be sited intelligently.
But there’s a deeper worry hear for the clean energy investment community. With the Paris deal spurring countries around the world into creating national plans for reducing emissions, there’s more money than ever sloshing around climate funds and investment banks seeking clean energy projects in far-flung places that can be used to offset other emissions. Without the proper oversight and due diligence, though, there’s a significant risk of funding projects that won’t do what they purport to do. Turkey’s sandstone-sited geothermal plants are a great example of this, because while they might look good on paper and sound nice to clueless greens, some of them are apparently no cleaner than coal plants. The more money environmentalists manage to mobilize for the climate change cause, the more chances there are for wasteful spending and fraud.