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[en] This decree presents the regulation related to requests of exploration and exploitation titles for geothermal sites. It defines various economic and technical notions (search and exploitation costs, efficient operator and hydraulic connection), frames the notion of related, and addresses the assessment of the title validity duration
[en] The last market study (2016) carried out in France by the French Association of Geothermal Professionals regarding the geothermal domain has demonstrated that the installed power for heating and cooling reaches 2500 MWth. Nearly 600 MWth are related to the exploitation of the deep reservoirs in the Paris area but the main part is linked to the recent and strong development of shallow geothermal resources in the whole country. The market for single housing using vertical geothermal probes is dramatically decreasing since 2009 due to the competition with natural gas and tax credit at 30% for geothermal without any bonus compared with efficient gas boiler neither air-air heat pumps. The market for single housing has been divided by 7 in between 2010 and 2018 from more than 20 000 installations to less than 2500. On the contrary, the number of installations to feed collective housing and residential blocks including offices buildings is growing constantly. The direct uses are concentrated mainly in Ile de France, the geothermal doublet construction restarted with the support of the Heat funds managed by Ademe and the two last years, more than 20 new deep wells have been drilled in Ile de France. The main barrier remains the energy calculation rules for new buildings (RT2012) which still encourage gas. In 2023, the market will reach 3000 MWth installed; if ecologically driven, the target objectives at 3500 MWth could be largely attained. For electricity generation no more installations have been commissioned even the Soultz-sous Forets plant has been revamped. The Bouillante plant has been sold by BRGM to ORMAT mid-2016 and the plant capacity will be upgraded from 15 to 25 MWe in the next years. Two geothermal are in drilling operations (doublets between 3500 and 5000 m depth) around Strasbourg with successful preliminary tests, in order to co-generate electricity (10 MWe) and heat (20 MWth). (authors)
[en] Elevated temperatures of the rock and underground water under the cities, known as thermal islands, have been investigated for a long time. Nevertheless, all the causes of the origin and the influence of the individual factors on the degree of thermal contamination are still unknown. This phenomenon exists in all layers of the city, such as the atmosphere, surface, or subsurface. In our paper, we focused on examining and analyzing the temperatures in selected samples within the wider area of Bratislava and analyzing data from monitoring using geographic information systems - GIS. Such information is a valuable asset because it is known that the temperature below the city is higher than in rural areas in its vicinity. (authors)
[en] This article provides the review of thirty chemical geothermometers of foreign authors for estimation of water temperature in geothermal aquifers in the central depression of the Danube Basin. The results of estimated water temperatures using chemical geothermometers were compared with the temperatures measured in respective geothermal boreholes. Consideration of the comparison resulted in a summary including selection of most suitable chemical geothermometers for each site to be used in hydrogeothermal praxis for water temperature determination. (authors)
[en] Geothermal resources in China are distributed throughout the country, with hydrothermal systems of high temperature in the Tibet Autonomous Region, Yunnan Province and Taiwan Island and hydrothermal systems of low-medium temperature mainly in various sedimentary basins. Development and exploration of geothermal energy in China are below expectations. The purpose of this study is to comparatively review the characteristics (geology, hydrogeology, hydrochemistry and geophysical data) of typical hydrothermal fields/areas and suggest development and utilization approaches in the future. Hydrothermal systems formed by mountain lifting contain a considerable amount of energy for geothermal power generation, especially in the Tibet Autonomous Region, Yunnan Province and Taiwan Island. However, geothermal water in the Tatun geothermal field has high TDS (total dissolved solids), an issue that requires more research to resolve this problem for power generation. The large storage of geothermal resources has been investigated in Meso–Cenozoic sedimentary basins; it is basically used for heating, bathing or greenhouse plantation. Moreover, hydrothermal resources of low-medium temperature can also be used in binary power plants. Although the enhanced geothermal systems (EGS) in China are promising, the resources have not yet been commercially exploited, because the emerging technologies (hydraulic fracturing) and concerns over environmental impacts (induced micro-seismicity) lead to slow development. On the contrary, shallow geothermal energy has been directly utilized mainly for heating and cooling buildings. Cities like Beijing, Tianjin and Shenyang have established a series of ground-source heat-pump systems, which has led to a massive reduction of CO2 emission of 19.87×106 t.
[en] The Urban Heat Island is an area of the city that is significantly warmer than its immediate surroundings. This phenomenon exists in all layers of places, such as the atmosphere, the surface, or the subsurface. The greatest impact on this phenomenon is the anthropogenic activity of people, as the green areas (meadow, forest, fields) are replaced by artificial surfaces (asphalt, concrete, glass), which much more inhibit heat from the sun, not least heating, air conditioning, industry, to the right, because the air in the city heats up and increases the temperature in the cities. (authors)
[en] Correlation is the simplest case of statistical dependence on determining the severity of dependence between variable characters or properties of two or more variables. In our analysis, we used the Pearson correlation coefficient, which expresses the intensity of the linear correlation between the two random variables. The aim of the paper was to find out which landscape component most affected the temperature of the groundwater logically influenced the most. (authors)
[en] At Brady Hot Springs, a geothermal field in Nevada, heated fluids have been extracted, cooled, and re-injected to produce electrical power since 1992. Analysis of daily pumping records and catalogs of microseismicity between 2010 and 2015 indicates a statistically significant correlation between days when the daily volume of production was at or above its long-term average rate and days when no seismic event was detected. Conversely, shutdowns in pumping for plant maintenance correlate with increased microseismicity. Our hypothesis is that the effective stress in the subsurface has adapted to the long-term normal operations (deep extraction) at the site. Under this hypothesis, extraction of fluids inhibits fault slip by increasing the effective stress on faults; in contrast, brief pumping cessations represent times when effective stress is decreased below its long-term average, increasing the likelihood of microseismicity.
[en] This report presents the results of the qualitative aspect of the 2017 follow up study of the French market of individual heat pumps. These results complement those of the quantitative study of the 2016 French market activity follow up: 1 - Methodology of the study; 2 - 2016 aero-thermal heat pumps market; 3 - 2016 geothermal heat pumps market; 4 - Market perspectives and R and D; 5 - Qualifications and institutional environment; 6 - Recommendations for the individual heat pumps industry.
[en] Heat pumps with the help of electricity use a renewable energy source to supply heat for homes or industrial buildings and to heat tap water. Heat Pumps is a heating unit that will provide us with heat for our home for some 20 to 30 years to come and has a potential to replace traditional heating systems powered by gas, oil or coal. At this time, there is no other heating system that supplies clean heat with the help of up to 80 percent of the renewable solar energy during all year. The paper points to the technology of heat pumps as a renewable energy source, unlike other, neither of alternative ways not to use ecologically and as much energy as the heat pump. (authors)