We know that the sun, the winds, the waves, running water is energetic and can be harnessed for human purposes. Much has been done, and more will come. These energies have a high level of sustainability.
But there is more. The geothermal heat can also be used, and this is already done in many areas, especially where there is volcanic activity near the surface of the earth. Examples are the US, New Zealand, Philipines, Iceland and others where part of the energy is taken from these sources. This energy is quite close to the surface which makes it easy to utilize, although there are risks as well.
But we know that by going deeper – in non volcanic areas – heat can be found down there in the stone masses.
An example is found in the city of Oslo, Norway where a project will collect energy about 5 km underground. This energy will be green, sustainable and available for a long time. A certain cooling seems to be expected, maybe in 100 – 200 years. Here geological subterranean surveys have been undertaken, and good areas have been found. Down here there is a degradation of radioactive substances like uranium, thorium, kalium resulting in the creation of heat. No CO2!
The oil industry knows how to drill, and a number of wells will now be drilled, connected into a system, filled with water and pumped to the surface. The temperature down there is about 120 degrees C, and the temperature of the water coming up will be about 95 degrees C. The heated water will be distributed in the near area for private housing purposes, and the heat from one such well will be enough for about 2500 habitats.
So possibilities are opening up: you can drill more holes, much deeper, you can use the hot water for electricity generation, you can drill still deeper and have increasing temperatures – about 20-30 degrees C. per km down.
So now interest is increasing: several projects in Norway, many in Germany, and so on. And experience will tell – we will learn and grow this area. And it is much simpler and less risky than wind, waves – so here we will see substantial growth. And the economics? We will se as we learn. Maybe new risks will emerge?
Good work! Put it into your green energy plan.