The IDDP was founded in the year 2000 by a consortium of three Icelandic energy companies: (Hitaveita Sudurnesja (HS) (since 2008: HS Orka hf), Landsvirkjun (LV) and Orkuveita Reykjavíkur (OR)) (since 2023: Orkuveitan), and Orkustofnun (OS), the National Energy Authority of Iceland. Later it was joined by international partners such as Statoil, Alco and others.
The main purpose of the IDDP project is to find out if it is economically feasible to extract energy and chemicals out of hydrothermal systems at supercritical conditions. To study the supercritical hydrous fluid, an advanced drilling technology needs to be applied and a novel fluid handling and evaluation system designed. The improvement of this basic idea by the IDDP is to drill deep enough into the roots of a conventional high temperature hydrothermal system to produce fluid at supercritical conditions and bring it to the surface as 400-600°C superheated steam, at subcritical pressures (<220 bar). In the case of low permeability systems, by injecting cold fluid into the hot rocks, fractures can be induced to complete the thermal mining cycle.
The IDDP is a long term research and development project. Its success could dramatically increase energy output and will also unlock new knowledge about superhot geothermal systems.
The IDDP is supported by The Government of Iceland and has a strong international collaboration.
Two deep wells have already been drilled, IDDP-1 and IDDP-2, and the drilling of IDDP-3 will start at the end of the year 2026.
The first step was to design the project in a feasibility report, extending from the geo-scientific background and site selection to drilling technology and fluid handling and evaluation. The main results of the feasibility study were the following: (i) It is possible to drill the IDDP well to 5 km, (ii) It is possible to deal with a 400-600°C hot fluid, (iii) it is not possible to predict the chemical composition of the fluid prior to drilling, (iv) Some 12 potential drill sites for IDDP wells were selected, (v) Estimated cost of a full scale IDDP well: U$ 14-16 millions, (vi) Estimated cost of 5 km deep production well: US$ 8-9 millions, (vii) Estimated cost of coring to 4 km depth in “wells of opportunity”: US $ 6 millions, (viii) Estimated cost of fluid handling and evaluation by using the “pipe”: US $ 5,5 millions. (ix) The IDDP wells should also be considered for fluid injection tests in order to gain experience in heat sweeping (enhanced geothermal systems (EGS)), (x) The knowledge gained by the IDDP experiment will be beneficial to the energy company holding the geothermal field, irrespective of the result to meet the IDDP primary goal of tapping supercritical fluid from a geothermal system.
The drilling of the first full scale IDDP-1 well was led by Landsvirkjun in Krafla in 2009.
It was meant to be completed to 4.5 km depth late summer 2009 and the first flow test to be performed some months later. However, that drilling operation was abruptly terminated by late June at 2.1 km depth when drilling penetrated molten rock. Rapidly quenched magma of rhyolitic composition was returned to the surface in the form of quenched obsidian glass that plugged the lowest 20 m of the hole. Fortunately, due to earlier drilling problems, the well had been cased down to 1958 m depth, and was completed with a slotted liner down to 2080 m depth. This was in preparation for a flow test of the superheated regime just above a magma chamber, which should be performed autumn 2009. The flow test began in March 2010, and by July 2010 the well was producing some 30 kg/s of 330°C hot superheated steam at 16,5 bar-g pressure, and is still heating. This corresponds to some 20 MW of electric power. For closer details on the drilling and the flow test of IDDP-1 see this webpage from 27 May and 7 July 2010.
Drilling of IDDP-2
Drilling of the IDDP-2 well was led by HS Orka and completed on the 25th of January at 4,659 meters depth.
Five years before IDDP-1 was made, a borhole was drilled at Reykjanesvirkjun. It was named RN-15 or REY H015 (Reykjanes-15) and is one of many geothermal boreholes drilled in the Reykjanes peninsula since 1956. It reached a maximum depth of 2.5 km (1.55 mi).
It was always known that RN-15 could be deepened, and about 10 years later IDDP decided to continue driling under the project name IDDP-2. The plan was to reach a maximum depth of 5 km (3.11 mi) before the end of 2016, making it by far the deepest borehole in Iceland, breaking the former record of the IDDP-1.
Drilling began on August 11, 2016, and was completed 167 days later on January 25, 2017. The final depth was 4,659 m (15,285 ft) th a temperature of 427°C and fluid pressure of 340 bars (4,900 psi). Core samples were taken, showing rocks at the bottom that appeared to be permeable, and fluids in supercritical conditions were successfuly reached, accomplishing all of the main objectives of the drilling operation.
DRILLING OF IDDP-3
IDDP-1 and IDDP-2 demonstrated that superhot geothermal resources exist and that power production is technically possible. The remaining challenge is primarily an engineering challenge, and there, IDDP-3 is a critical next step.
IDDP-3 is led by Reykjavik Energy (Orkuveitan). Drilling will start at the end of 2026. IDDP-3 is not about a single well, but proving consepts, materials and operating approaches that can be replicated – first within the Hengill geothermal system and then across other high- temperature geothermal fields.
The approach is to pilot in shallow high-temperature zones before going deep to lower cost and enable more iterations faster, solving one challenge at the time. This will reduce risk and build a repeatable pathway to scale.
The first step is to drill IDDP-3 in a known area where hot conditions are to be found to test controlled production. Next, injection into shallow superheated systems will be tested. Finally, it will be explored if an enhanced system can be created in our geolocial setting to increase permeability in superhot formation. If successful, it will pave the way for scaling up further with the aim to drill 3-5 km deep production well.
Since 2016, Reykjavik Energy / ON Power (subsidiary of Reykjavik Energy) has advanced deep utilization development with EU support, focused on reducing uncertainty and technical risk:
- Compass
- GeoConnect
- DEEPEN
- GeoPro
- HEATSTORE
- DEPPUti
- HotCase
The IDDP-3 is a part of the SuperHot geothermal – Integrated demonstration and Flow testing (SHiFT) research consortium, a long-term national and international collaborate consisting of 17 companies, institutions and universities across Europe. It connects Reykjavik Energy’s Deep Utilization Development Plan to power production and scale-up, and brings together drilling, reinjection, monitoring and research to reduce technical and financial risk. SHiFT is a three-year program led by Reykjavik Energy and was launched in May 2026. IDDP-3 is phase 1 of the SHiFT program.
SHiFT has received a EUR 10 million grant from Horizon Europe, the European Union’s research and innovation programme. The grant will support the development and testing of technologies to harness geothermal energy at temperatures exceeding 400°C.
- Increased power output per well, perhaps by an order of magnitude, and production of higher-value, high-pressure, high-temperature steam.
- Development of an environmentally benign, high-enthalpy energy source below currently producing geothermal fields.
- Extended lifetime of the exploited geothermal reservoirs and power generation facilities.
- Re-evaluation of the geothermal resource base.
- Industrial, educational, and economic spin-off.
- Knowledge of permeabilities within drillfields below 2 km depth.
- Knowledge of heat transfer from magma to water.
- Heat sweeping by injection of water into hot, deep wells.
- Possible extraction of valuable chemical products?
- Advances in research on ocean floor hydrothermal systems.
