Exploiting this source of energy requires techniques similar to those used in oil and gas, with the objective of extracting a hot geothermal fluid (hot water, steam) which is then used in power plants to generate electricity. Clearly, electricity is much more versatile than heat as it can be converted with high efficiency in most other sources of energy.
Three ingredients are generally needed for geothermal exploration (Boyle, 2012): an aquifer containing water within reach of drilling techniques, a relatively impermeable cap rock which retains the fluid at depth and a heat source. In some regions (e.g. Iceland, Azores, Hawaii), abundant heat is available from volcanic sources. Other geothermal developments are located within extinct volcanic regions, such as North Italy and West USA, which is made possible because the cap rock is able to trap heat for sufficient time to allow its exploration even today.
Preliminary studies indicate that Mongolia is comparatively rich in low temperature geothermal resources (Lkhagvadorj & Tseesuren, 2005). There are over 40 hot springs primarily in the northwest and north-central regions. These are associated with regions of geologically-recent volcanic activity or basin formation (where the crust is extended and thinned by tectonic activity) resulting in an increase in the local crustal geothermal gradient.
Heat flow measurements range from 44 mW/m2 to 80 mW/m2. Measurements are limited to the north and central parts of the country and many of the measurements are from shallow boreholes or near-surface measurements. It is unknown whether these are local anomalies or representative of region-wide heat flow. The greatest heat flow measurements are recorded in Lake Hovsgol on the southern flank of the Baikal Rift, a zone of significant crustal attenuation; heat flow in this region is 92 mW/m2 (Lysak & Dorofeeva, 2003). These values are similar to those measured in the two most promising UK regions in terms of enhanced geothermal systems: the South-West (Devon and Cornwall) and the Lake District.
The most promising regions for geothermal resources are the geologically young intermontaine basins; essentially the low-lying regions of the country. In these regions the crust has been thinned, allowing the underlying, partially molten, mantle to come closer to the surface. This results in an increase in the geothermal gradient. All the areas with elevated heat flow measurements and/or hot springs have been subject to recent geological activity and/or contain recently active fault systems. The latter can act as conduits for warm/hot groundwater from lower crustal levels to reach the surface. Based on this observation it is expected that similar geothermal anomalies may be found in the southern parts of the country, particularly along the northern margin of the Gobi Altay (see next slide).
An as-yet-to-be-evaluated source of geothermal heat may be radiogenic crystalline rock. Many igneous (commonly granite) and metamorphic rocks contain significant amounts of radiogenic material that through their decay series, generate heat.
The Trust has also chosen Chongming Island in Shanghai which is a demonstrator region for China State Government’s ecological development plans, Kigali in Rwanda which aims to implement Rwanda’s low carbon action plan and the Swansea Region of South Wales which aims to regenerate the local economy through green sustainable growth.
Эрсдэлд Уян Ухаалаг Улаанбаатар - Financing Resilience in UB City - Peter Head - 2015-6-10
Prof. Peter Head CBE FREng FRSA
University of Bristol-Cabot Institute Fellow
Chief Executive The Ecological Sequestration Trust
Тус Сангийн төлөвлөгөөт жишиг хотууд
Eco Demo Regions
African Centre for
African Urban Research
ICLEI GIZ Climate KIC-IFS
Rio de Janeiro
UN ADB FCO
9-Jun-15 www.theriseinitiative.org 49
Дэлхийн хотуудын төсөл, хөтөлбөр, боломж
New Orleans / Gulf Coast
CRC + Small business fragility
assessment + Green infrastructure
Rio de Janeiro
RCbD + ECR
ECR + RCbD
Ho Chi Minh City
Manila, Tacloban, Makati
ECR, Green Infrastructure
Mining supply chain
Live R!SE Contributors and Endorsing
Organizations Programs, Projects and
Enhancing City Resilience (Scorecard,
Resilient Cities by Design
Community Resilience Coalitions
The Ecological Sequestration Trust
Silicon Valley, CA