Day 15: pure energy

The road from Point A to Point B often includes some points you hadn’t really known were there.  Visiting them can be every bit as interesting as the places you planned to visit.  This is one of those places.

When heading east on the ring road you eventually come to a spot where enormous plumes of steam rise into the sky, just a few miles before you get to Hveragerði.  It’s pretty much impossible to miss them: there’s nothing else around except the roiling steam and a low-slung, angular grey building just visible from the road.

GP - Hellisheiði

This is the Hellisheiði Power Station, the largest geothermal power plant in Iceland and one of the largest in the world.

The mountain in the background is part of Hengill, a largely dormant volcano.  The ground is fractured over a wide area, and steam vents and hot springs can be found throughout the region.  There are several fissures in the roughly 110 square kilometers of the Hengill system that have erupted in the past, although the most recent eruption is believed to have occurred about 2,000 years ago.  It’s part of the plume of molten rock underneath Iceland whose shape has earned the nickname “The Headless Cat.”

I'm really glad Hobbes isn't reading this.
I’m really glad Hobbes isn’t reading this.

Hellisheiði currently produces electrical power using superheated steam and high-temperature groundwater obtained from dozens of wells dug between 1 ¼ to 2 miles into the earth.  Most of these wells are located miles away from the power plant: the mixed steam and groundwater arrives in large, insulated pipes, where they’re separated and put to use.

Separation units.
Separation units.

The steam spins turbines to produce electricity: there are six 45-megawatt high-pressure turbines and one 33-megawatt low-pressure turbine at the site.  Most of the electricity they generate is used to power aluminum smelters: ships arrive in Iceland loaded with bauxite ore and leave with the refined metal.  in this fashion, Iceland “exports” power to other countries.

45 MW steam turbines.
45 MW steam turbines.

The plant also pumps cool, fresh water from the ground (at considerably shallower depths than the high-temperature wells) and uses the steam to heat the cool groundwater to 180 degrees Farenheit.  This newly-heated fresh water is piped from the power station to Reykjavik to be used by the city and its people.  The total power output from Hellisheiði is about 700 megawatts of electrical and thermal energy.

The plant is surprisingly quiet.  There are several large cooling tower units used to bleed off excess heat before the water not shipped to the city can be reinjected into the water table below, and various steam separators, aerators, and pressure relief towers.

Cooling towers.
Cooling towers are … well … cool.

Parts of it look like bits of flotsam from a 1950s science-fiction movie, while other parts have a definite Cylon base-star vibe.

I think the Krell started off with one of these.
I think the Krell started off with one of these.
All this has happened before, and will happen again.
All this has happened before, and will happen again.

Still, for a nearly billion-dollar facility, it’s remarkably low-key – but very much worth the stop on the way from Point A to Point B.

4 thoughts on “Day 15: pure energy

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