Ugrás a tartalomhoz

Local resources and product path management

Ruszkai Csaba

Eszterházy Károly College Faculty of Natural Sciences

Earth heat (geothermal energy)

Earth heat (geothermal energy)

Our geological facilities are excellent, the continental bed rock of the Pannonian basin is thinner and its thermal conductivity is better than the world average, thus heat flows form magma more efficiently heats water quantities which lie in upper-Pannon loose sandstone and cracked lime-stone reservoirs. The average value of the geothermal gradient is about 11°C 20 metres when moving down.

This heat may be utilized in many ways as a source of energy. From large and complex power-stations to minor and relatively simple pumping systems. This heat-energy, in its known name geothermal energy , can be found almost anywhere, thus much more generally than most of us would think. In some applications of geothermal energy, earth heat that is near to surface is utilized, than in other cases sometimes more kilometres distance have to be drilled down to the end of the earth.

  • Direct utilization and district heating systems utilize the close to the ground wells or the warm waters of reservoirs.

  • Electric current production in power stations, high-temperature water or steam is necessary (150-370°C). Geothermal power stations are usually established where the geothermal reservoir can be found in some kilometres deepness in the ground

  • Geothermal heat-pumps, they use constant earth or water temperature close to earth surface for regulating the inner temperature of aboveground establishments.

Nowadays annually something like 80 million m3 (, higher than 30°C- so called – thermal water are being exploited from variant depths layers (from 300 meter to 2500 meter) and only slightly less than one third of these thermal waters serves energetic purposes, approximately with 2,8 PJ heat magnitude, which does not reach even the 0,3 % of the about 1000 PJ annual primer energy demand of the country. According to some expert modeling our serious stocks are characterized by the following facts: in the event of nourishing back the ‘ already heated ‘medium to exploitation depth- the quantum of the so-called dynamic, movable thermal water would be 380 million m3 annually, a heat content of which - in the case of adequate utilizing efficiency, with complex heat – pump supplementation,- would be at least 63 PJ, what can constitute the 6 % -large-slice of the national „energy –cake”, by making easier the 13 % expected European Union threshold.

The geothermal energy or the earth heat may be extracted from the earth in many ways

  • Through droughty heat getting out (hot-rock projects)

  • through thermal water exploitation

  • through the supplement of the previous methods with heat-pump that utilizes earth heat

  • by means of independent heat –pump solution utilizing earth heat, in such places where there is no thermal opportunity.

The year 2004 meant a turning-point in the emplacement of thermal waters. In the future there merely will be an opportunity to utilize geothermal energy in the case when the “down-heated” fludium is nourished back and extruded back to the deepness level what is close to exploitation.

Herewith not only the environment protection dilemma of thermal energy is terminated but at the same time, it has become renewing, renewable, since after more decades it may be utilized in superterrestial exothermal in warm statement and it will be sustainable in long term for 30-50 years.