Iceland Geothermal Plant Steams To The Top

In Iceland, one of the world’s largest geothermal plants just got a lot bigger. Mannvit Engineering said a fifth phase of development of the Hellisheidi plant near Reykjavik had added 90 megawatts (MW) of capacity, bringing the plant to 303 MW on the electrical side along with 133 MW of thermal energy for hot water and space heating.

So, where exactly does this put Hellisheidi among the world’s big geothermal power producers? That all depends on whether separate facilities drawing from the same geothermal field are considered a single plant or not. If this is the measure, than the four-powerhouse Cerro Prieto plant in Baja California, Mexico, wins at 720 MW. But if we’re talking about a single power station, the newly added capacity at Hellisheidi appears to push the Icelandic outpost to the top of the list.

Hellisheidi geothermal power plant

image via Mannvit Engineering

In any case, it’s a lot of clean, green power. According to Mannvit – the mechanical and overall plant designer for Reykjavik’s utility company, Orkuveita Reykjavikur – this fifth phase added two 45 MW Mitsubishi turbines at a total cost of 23.5 billion Icelandic krona ($197 million).

And there is more to come, Mannvit said. “In response to increased demand for space heating and hot water in the region, additional development plans for the Hellisheidi CHP geothermal plant includes two more heating plant phases of 133 MWth (megawatts of thermal power) each,” the company said. “When complete, these additional units will bring the heating capacity of the plant to 400 MWth.”

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.