How environmentally friendly are Iceland’s data centers? Part two of the article by Fiona Jackson for Tech HQ magazine — published 1 December 2023
Part 2: Energy and cables
Iceland is ecologically blessed in many ways: gentle-sloping mountains, arctic foxes, geothermally-heated lagoons, and an abundance of renewable energy to harness. With a population of less than 400,000 people, there is more than enough power to go around, helping Iceland to frequently rank in the top ten most environmentally friendly countries in the world.
While the majority of the energy comes from controllable hydropower – the numerous rivers and reservoirs formed from a glacial and volcanic landscape allow for an abundance of free-flowing water – geothermal energy covers 90 percent of space heating in Iceland. The 464°F to 626°F (240°C to 330°C) steam produced by boreholes first powers electricity turbines, and there is so much potential that the Hellisheiði power plant, run by the largest geothermal energy company in Iceland, ON Power, is surrounded by a cloud of excess vapor. Once passed through the turbine, it is condensed to water at a temperature of about 356°F (180°C), and its heat is used to warm up fresh water that is then piped to homes around the country.
The secrets of Iceland’s renewable energy
Last year, OR Energy, ON Power’s parent company, produced 106 million m2 of hot water for district heating and 1,134 GWh of electricity for Icelandic consumption. Using 60 active boreholes with an average depth of about 2.5 km, Hellisheiði alone produces 303 MW of electricity with its seven turbines and almost 1,000 liters per second of hot water. About 11 percent of the hot water in the Reykjavík region is also pumped directly from wells in low-temperature fields which do not produce steam and, therefore, cannot be harnessed for electricity. This water also contains a high concentration of minerals and trace amounts of hydrogen sulfide, which can cause it to smell like rotten eggs.
But that is not all that comes out of the boreholes – in fact, 0.4 percent is carbon dioxide. While this only equates to about 7.6 g of carbon per kWh of energy production (compared to about 800 g for coal), those emissions are partly what inspired researchers at OR Energy to develop Carbfix. Carbfix is a relatively new carbon capture method involving carbon dioxide and hydrogen sulfide being dissolved in water before being injected into decommissioned boreholes at Hellisheiði.
The acidity of the liquid dissolves anything that has already settled in the porous underground basalt, and then the carbon dioxide reacts with this stone to form a calcite precipitate. The hydrogen sulfide simultaneously reacts with the iron in the basalt to form iron sulfide, and these two precipitates remain underground.
Thanks to this relatively recent innovation, 13,000 tonnes of mineralized carbon dioxide was stored underground last year rather than released into the atmosphere. Roughly 100 kg of carbon can be stored in a single cubic meter of basalt, meaning Iceland alone has enough rock to store 40 years’ worth of global emissions. The world is also covered in basalt, so there is plenty of scope for expansion, and researchers are currently looking into whether the gases can be dissolved in seawater rather than freshwater in the future. Landsvirkjun, the national power company of Iceland, intends to be carbon negative within two years and both of the ON Power plants will be carbon neutral by 2030.
Connecting Iceland to the world
Iceland has four active submarine communications cables that connect its data centers overseas, and three of these are operated by Farice. The company was established in 2002 to build its first cable, FARICE‑1, linking an Icelandic landing site to the Faroe Islands and Dunnet Bay in Scotland. Before then, Iceland relied on the outdated CANTAT‑3 submarine cable and a basic satellite connection, but this was not nearly sufficient when internet usage by the general population started to grow.
The second fiber optic cable, DANICE, went live in 2009, connecting Iceland to Denmark, and the third cable, IRIS, came online on March 1 this year, connecting to Galway, Ireland. IRIS, which cost $55 million (€50 million) to build, reduced the latency between Iceland and London from 18.5 ms to 15 ms, and between Iceland and Dublin from 24 ms to 10.5 ms. The fourth cable, Greenland Connect, is operated by TELE Greenland and links Iceland to Greenland and Canada.
Read the complete article online here and also review part 1 and part 3.