I visited the Hellisheiði geothermal power plant, to learn more about the climate-friendly system that supplies Reykjavik and surrounding area with hot water as well as power. They are also pioneering a method for capturing CO2 and storing it permanently in the form of rock.
Energy from the Earth
Hellisheiði (pronounced “het-li-shay-thee”) power plant is located about a half hour drive from Reykjavik, among rock and heath covered hills that were dusted with snow on the day of my visit. The facility, owned and operated by ON Power, a subsidiary of Reykjavik Energy, is the largest geothermal district energy utility in the world, producing 303 MW of power (about 30% of the future output of BC’s site C dam), and 133 MW of thermal energy.
Iceland has abundant volcanic activity which heats groundwater, creating geothermal fields. Water temperature in these fields can vary. The higher temperature areas, around 300C, are usually tapped at greater depths, up to 3000m below the surface, to produce steam that’s used to turn turbines to generate power. About 30% of Iceland’s electricity is generated from geothermal energy, with the remainder supplied by hydroelectric.
Lower temperature areas, at shallower depths and at the periphery of high temperature zones, produce water of around 85C, that’s used for space heating and domestic hot water. It’s conveyed to the city in well insulated pipes and only loses about 2C along the way. This hot water is used for virtually all the space heating, domestic hot water, and public swimming pools in Reykjavik. Water discharged from home heating radiators is used again, for heating roads to melt snow. In summer it’s even pumped into a contained oceanside “geothermal beach” so Icelandians can enjoy bathing in the otherwise chilly Atlantic (apparently winter bathing, when the water temperature is in the single digits, is also a thing here, but that’s another topic). There are over 3000km of pipes in Reykajavik. Sound extravagant? According to ON, it costs an average family of four about $60 per month for their heat, hot water and drinking water.
The tour guide explained that the company wants to focus more on expanding the uses of hot water, including for agriculture and industry, rather than electricity generation, since it’s a more efficient use of the resource. For example, 80% of Iceland’s tomatoes are produced domestically in geothermally heated greenhouses. A new company called Algaennovation has located near the power plant and uses hot water for producing algae for fish farming. ON has developed a geothermal park nearby with lots being offered for sale to other industrial businesses to take advantage of the resource.
Turning GHGs into Rock
Everyone who is paying attention knows we have a serious climate crisis on our hands. According to the IPCC, we need to transform our economies, industries and society away from reliance on fossil fuels and get to net zero greenhouse gas emissions by 2050, if not sooner, to limit global warming to 1.5C and avoid the most devastating impacts. Carbon sequestration and storage (CSS) has an important role to play, to get all the way to zero, and beyond, to negative emissions to eventually heal our climate. To be clear, however, CSS is not a substitute for reducing emissions. It’s a technology that’s still being developed and will be needed to mitigate the very small emissions (relative to today) from the most difficult to decarbonize industries and products. And yet, since new technologiy takes a while to ramp up, we can’t wait. We need to do it all.
That said, I was intrigued to hear about Carbfix, a project that has succeeded in transforming gaseous carbon dioxide (CO2) and hydrogen sulfide (H2S) into solid rock. It was previously thought that this process, called mineralization, would take hundreds of years. The researchers in this project thought they could get it down to about 20 years. So even they were surprised when the rock was formed in only two years.
The project is led by Reykjavik Energy, with other partners. It’s primarily focusing on capturing carbon pollution from industrial emitters, before it’s diffused into the atmosphere. The steam from the power plant, although mostly water, does contain some CO2 as well as H2S, and ON Power is focused on greening its operations, so it was a logical fit. Basically, the process consists of bubbling the gas through water, and injecting the gaseous water into a basalt rock deposit underground, where it reacts to produce calcite, in the case of CO2, and pyrite, also called fool’s gold, in the case of H2S. The project has reduced the power plant’s emissions by 40%, and annually removes 12,000 tonnes of CO2 and 6,000 tonnes of H2S, at a cost of about $25 per tonne. Once mineralized into rock, the scientists expect it to be stable for hundreds or even millions of years.
A pilot for capturing CO2 directly from the air is also underway at the Hellisheiði plant, in association with Climeworks, with a current capacity of 50 tonnes per year.
Calcite, from CO2 
Pyrite, from H2S
So, geothermal energy is pretty awesome, but how replicable is it? Can it only be used in highly active volcanic zones? Well, the short answer is, no, especially as the technology is improving to extract heat and power from a variety of different types of rock formations, at various temperatures. According to the Canadian Geothermal Energy Association, Canada has a “vast” potential for developing geothermal power, particularly across much of BC, the Yukon and Alberta. In BC alone, between 1000 and 3000 MW of electricity could be generated. Yet to date there are no installed projects.
As for carbon fixation, it can be done anywhere with basalt deposits, which are commonly found, both on land and in the ocean floor. Again, it is best used to enhance green energy, like Iceland’s geothermal power, and mitigate unavoidable carbon emissions where we do not have substitutes. If applied to dirty energy like coal power plants CSS technologies can actually cause more harm than good by forestalling a conversion to clean energy. And at any scale conceivable today, direct air capture will only be able to remove a tiny percentage of emissions. Stopping the “hemorrhage” of carbon into the atmosphere must remain our first priority.
Like Canada, Iceland is also blessed with abundant renewable energy resources, but their leadership in renewable energy didn’t happen by accident. For centuries, water from hot springs was used only for bathing and laundry. Up until the 1970s the country relied heavily on imported fossil fuels, and was classified as a developing nation by the UN. It took the shock of the oil crisis at that time, and a concerted and coordinated effort by various levels of government to develop the capacity and build the infrastructure that transformed the country. Today Iceland enjoys a strong economy, high standard of living, education and health care, largely as a result of their energy transition.
Canada’s expertise in oil and gas development could actually serve us well in exploiting geothermal energy, since much of the drilling and pipeline technology is the same. If a tiny, isolated country like Iceland can emerge from impoverishment to be global climate leaders, surely Canada can leverage our strong economy and expertise to do the same.
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