Geothermal power

reothermal po er

Strategic challenges for Norwegian competences

Drilling technology has been developed mainly through the oil and gas industries, but with the shift towards sustainable forms of energy production, a new perspective develops. The expertise that Norway possesses with regard to drilling can be effectively utilized in the national and global markets, if sufficient care is given to overcoming a number of yet unsolved technological barriers.

For renewable energy it has been estimated that the energy reserves of geothermal energy alone exceed the total global demand. However, the possibilities to access these sources outside volcanic areas are yet limited. Currently, drilling and well costs are some of the main obstacles that impede larger scale implementation worldwide. Norway has today a leading role in developing new technology for oil and gas production. This is based on a strong industrial value chain and the Norwegian model for research and research-based education. The combination of the industrial research and the public funding schemes for R&D has resulted in an oil and gas cluster, made up of industrial companies and international leading environments in universities and research institutes. Many players in this cluster see new opportunities in the development of technical solutions for extraction of geothermal energy and related industrial production of products for serving this goal.

Technology status

Geothermal energy is traditionally divided into shallow (down to approx. 300m) and deep geothermal energy. Shallow geothermal energy is mainly derived from stored solar heat, while deep geothermal energy comes from radioactive fission and/or heat of the Earth. While

Norway is advanced in the use of shallow geothermal heating (via heat pump systems), it has yet no deep geothermal systems. Geologically, Norway has long been thought to have a poor thermal gradient down into the depths. Subsequent mapping and drilling samples, including those from NGU, have shown that we are likely to have areas with higher thermal gradient than previously expected. This particularly applies to Svalbard where up to 40 °C/km has been measured.

In recent years there has been a fluctuating interest for deep geothermal energy in Europe, partly due to some seismic problems and lack of new cost effective technologies for drilling and well completion of geothermal wells. The interest is, however, now on the rise again, especially for plants that can produce heatto-heat distribution and/or low temperature electricity. Geothermal energy for electricity production is currently harvested mainly in volcanic areas where high geothermal values (300°C or higher) can be measured at 1.5 to 3 km depth. A better utilization of this potential is currently of great interest, particularly in Africa (countries bordering the Rift Valley) and around “The Ring of Fire” (Asia (Philippines, Indonesia, New Zealand, and Japan) and the Pacific coast of America).

Challenges

The problems related to exploitation of geothermal energy vary with geological and geographical location. In Norway, the drilling costs have traditionally been

the biggest hurdle for the mainstream use of shallow geothermal energy. This situation has changed significantly in recent years due to better equipment and more players on the market. For deeper geothermal drilling, costs outside volcanic or hoot geological areas are currently so large that it is not possible to achieve economic plants without subsidies (as is the case in Germany).For deep geothermal plants, drilling and well activities may account for 50-80% of the cost. Drilling and well completions are done mostly with traditional oil equipment and procedures. This technology only applies sufficient to around 5000 meter depth and 200 °C. At greater depth/temperatures the cost increases exponentially due to equipment failure (materials and electronic). In addition, drilling in hard rock lacks technology for fast drilling (1-2 m/hr to 30-40m/hr in sandstone). In volcanic/hot geothermal areas and at great well depth, chemical conditions are often also very challenging (examples here are CO2, H2S, scale). The geographic location of a suitable geothermal site can be a major problem. In urban areas (most of Europe) induced seismic activities due to geothermal plants have to be avoided or minimized. In other parts of the world geothermal attractive areas may be located far from major cities and infrastructure is poorly developed (e.g. Indonesia and Australia).

Outlook

In Norway there is enough expertise in deep drilling and well technologies, new materials and electronics in order to develop ways and methods to facilitate the more effective use of deep geothermal energy. This position can be exploited by developing similar or new technologies as for the oil and gas industry, where for example the Node group in southern Norway is a world leader, manufacturing 80% of innovative new drilling equipment for oil and gas. The strategic challenge for Norway will be to change our technical competence and industry from oil and gas to deep geothermal energy as a major export article in the future.

R&D recommendations:

• Adaptation of existing technologies and know how (such as those in the oil and gas industry) for use in geothermal energy exploration development.

• Development of new electronics and materials for high temperatures and pressures.

• Development and manufacturing of new specialised equipment for deep geothermal drilling and well completion.