Present status of research and utilization of geothermal energy in China

China is troubled by a shortage of energy sources. This shortage is even more serious in rural areas. However, about 3000 active hydrothermal systems are spread over China's territory and are presumed to be related either to intraplate or to plate marginal thermal anomalies. Their energy content could, in some cases, make a valid contribution to the local energy demand. Electricity is at present generated in Yangbajain geothermal field (10 MW), direct uses still represent a very minor utilization. Geothermal research is under way all over the country.     

Present status and potential role of geothermal energy in the world

Geothermal energy has come of age as an energy source. It is found in most parts of the world and is harnessed by conventional technology. Commercial production on the scale of hundreds of MW has been undertaken for over three decades both for electricity generation and direct utilization. Some 80 countries have identified geothermal resources, and about 50 have quantifiable geothermal utilization at present. Electricity is produced from geothermal in 21 countries (total production 38 TWh/a) and direct application is recorded in 35 countries (34 TWh/a). Geothermal electricity production is equally common in industrialized and developing countries, but plays a more important role in the latter. Apart from China, direct use is mainly in the industrialized countries and Central and Eastern Europe. Most of the developing countries as well as Central and Eastern European countries still lack trained manpower, but there is a surplus in many industrialized countries. During 1973–1992, investments in geothermal energy amounted to approximately 22 billion USD. The large share of the private sector in the investments shows its confidence in this energy source. Data presented in the WEC Survey of Energy Resources 1995 on the “new renewables” (geothermal, solar, wind, and tidal energy) shows that geothermal has the largest installed electrical capacity (61%) and electricity production (81%) in the world of these four sources.     

Hot springs and geothermal gradients in northern Thailand

Chemical geothermometry of hot springs in northern Thailand indicates that many have reservoir temperatures in excess of 150°C and some in excess of 180°C. Measurements of temperatures in abandoned oil wells in Fang Basin indicate geothermal gradients of 70 – 130 mK/m. The high geothermal gradient may be the result of extensional tectonics in northern Thailand, caused indirectly by sea-floor spreading in the Andaman Sea. Relatively high reservoir temperatures and shallow reservoir depths suggest that hot spring areas in northern Thailand may be potential sources of geothermal energy.     

Low enthalpy geothermal project in Zambia

The project, financed by the Italian Ministry of Foreign Affairs (MAE), is to implement the installation of two organic Rankine cycle (ORC) turbogenerators in remote, rural areas of Zambia.The Italian Government grant amounts to 2,000,000 US$. The Government of Zambia will bear all costs of the Zambian counterpart and will provide the low voltage transmission line and distribution grid.     

地热资源勘查项目的风险管理

地热资源既有普遍性、丰富性,又具有相对稀缺性,地热资源勘查一般具有很大的风险.文章依据当前北京地热资源勘查的一般程序,在分析地质勘查阶段和地热井钻探勘查阶段工作特点的基础上,针对地质勘查工作质量的风险因素,识别和分析了5项地质勘查风险和9项钻探勘查风险.勘查实践经验表明,通过加强项目风险管理,可有效降低或消除地热资源勘查风险引起的损失.     

Net energy production history of the Geysers geothermal project

Geothermal projects at the Geysers, California, have relatively high net energy ratios for electricity-production facilities. Comparison of the net cumulative electrical energy generated at the Geysers with the cumulative thermal energy invested for constrction and operation of the facility indicates a favorable energy return, even during periods of rapid systems expansion.     

Residual steam to energy: a project for Los Azufres geothermal field, Mexico

More than 500 t/h of residual steam are discharged into the atmosphere at Los Azufres geothermal field. Steam comes from nine back-pressure turbines that are at present generating 45 MW. A significant increase in output can be obtained if low pressure turbines are installed to expand residual steam from atmospheric pressure up to a vacuum pressure in condensing cycles. A net output optimization process for each unit in the condensing cycle is presented here. The exergy concept is also applied to compare efficiencies of back pressure cycles with new condensing schemes that include low pressure turbines. Results show that 27.8 MW of additional net output can be generated with the new schemes at competitive production costs and higher conversion efficiencies.     

International legal status of the use of shallow geothermal energy

Shallow geothermal energy (<400 m depth) is used in many countries worldwide, with a rising number of installations over the last decades. The use of ground source heat pump (GSHP) and groundwater heat pump (GWHP) systems results in local temperature anomalies (cold or heat plumes). Since groundwater is used in many countries as source for drinking water a balance between its use and protection has to be found. Therefore, to avoid detrimental environmental impacts it is necessary to define groundwater temperature limits for heating and cooling and minimum distances between such geothermal systems. The aim of the present study is to provide a comprehensive overview of the current international legal status for the use of shallow geothermal energy. Therefore, an international survey was performed using a questionnaire, which was sent to more than 60 countries worldwide. The questionnaire requested information on the corresponding national legislation, temperature limits and minimum distances for GSHP and GWHP systems. The answers to the inquiry showed an extremely heterogeneous outcome. Until now national and legally binding regulations only exist in few countries such as Denmark or Sweden. However, all existing regulations show a wide range for minimum distances (5–300 m) and temperature limits for groundwater. The highest inconsistency was observed for the acceptable temperature change with 3 K in Switzerland to 11 K in France. However, most countries have no legally binding regulations or even guidelines, which highlight the urgent need for further research on the environmental impact and legal management of shallow geothermal installations.     

Present status of fluidised-bed combustion

The worldwide interest in various fluidised-bed combustion systems is surveyed. The stage of development reached towards fully commercial boiler systems using fluidised-beds operating at atmospheric pressure for a range of applications from small shell boilers to power generating units is illustrated, using as specific examples projects based on NCB technology by UK boiler makers. Adaptation of the techniques to lowgrade fuels, tailings, waste incineration and crop drying has been demonstrated.Whilst commercial atmospheric boilers are likely to be operating in the next few years, the development of fluidised combustion at pressure waits on the demonstration by large test rigs that they can be successfully coupled with a gas turbine. Proposed rigs in the USA, Germany and the UK are described.     

Present status of solar distillation

In this communication an attempt has been made to review, in brief, work on solar distillation, its present status in the world today and its future perspective. The review also includes water sources, water demand, availability of potable water and purification methods including the state of art and historical background. The classification of distillation units has been done on the basis of literature survey till today. The basic heat and mass transfer relation responsible for developing, testing procedure for various designs of solar stills have also been discussed. The present status of solar distillation units in India, economics of single and double slope fibre re-inforced plastic on the basis of long-term performance and recommendations for future have been discussed in brief.     

The Bad Blumau geothermal project: a low temperature, sustainable and environmentally benign power plant

The 250 kW geothermal project at Bad Blumau is the first geothermal project developed in Austria by the private sector following the deregulation of the electricity industry in this country. What makes the project unique besides its private ownership structure is its ability to generate electrical power and district heating for the Rogner Bad Blumau Hotel & Spa by using a low temperature geothermal resource. Installed in the record time of less than a week, the air-cooled ORMAT ® Energy Converter (OEC) CHP module has been in commercial operation since July 2001. With an annual availability exceeding 99%, between October 2001 and December 2002 the plant delivered 1,560,000 kWh to the local grid. The geothermal CHP module utilizes brine at 110 °C, available from a 3000 m deep production well. Exiting the OEC unit at a temperature of 85 °C, the brine is then fed into the district heating system, providing heat for the Rogner Bad Blumau Hotel & Spa. The geothermal brine is returned from the district heating system and injected into a 3000 m depth reinjection well. The system is a pollution-free, unattended operating power generation module, which has avoided more than 1100 kg of CO₂ emissions over its first operating year.     

The status of world geothermal power production 1990–1994

A summary is presented of the status of geothermal power development in the world, based on the papers submitted by geothermists from each country to the World Geothermal Congress '95. Future prospects are also briefly discussed.     

光伏制造业:现状、前景及研究需求(四)

产品多样性使得分析c-Si状况更为复杂,但c-Si修正后的椭圆区也在格林最初提出的边界上。天合太阳能公司在2010第二季度报道晶体硅电池的光电转换效率在15%～22%之间,生产成本低至1.10美元/Wp。椭圆区上的箭头代表此技术的预期潜力。最大盈利需通过减少Si需求进一步降低制造成本,并提升组件效率趋近于25%。两者相结合可使成本降低到0.5美元/Wp。然而,FirstSolar公司的出现带来的一个结果就是c-Si工业已经具备快速响应、降低成本的能力。此外,重要的是硅并不需像CdTe一样去解决那么多问题。一旦     

西藏羊八井地热发电项目合作开发顺利推进

2019年12月27日,中核坤能与国网西藏电力有限公司(以下简称“国网西藏电力”)在拉萨顺利召开了西藏羊八井地热发电有限公司股东会第一次会议、第一届董事会第一次会议和第一届监事会第一次会议,会议选举产生了董事会和监事会,并签署了公司章程和投资协议。     

光伏制造业:现状、前景及研究需求(三)

四TW级/年制造的材料可获取性随着太阳电池制造年产量即将达到1TW,将使光伏行业面临原料是否充足的问题。Te和In这两种核心原料已引起人们广泛关注,它们分别是铜和锌矿冶炼时的副产品。Te和铂族元素一样同属于稀土元素,然而随着人们对Te角色认识的变化(批评到节约,再到寻求替代),致使对其资源的评估存在着广泛的争论和极大的不确定性。主流     

Takigami geothermal system, northeastern Kyushu, Japan

The Takigami geothermal reservoir is bounded by a system of faults and fractures oriented along two main directions, north to south and east to west. The Noine fault has a large vertical displacement and trends north to south, dividing the subsurface characteristics of resistivity, permeability, temperature and reservoir depth. The Takigami geothermal fluid has a near neutral pH and is of the Na–Cl type, with a chloride content ranging from 400 to 600 ppm. The southwestern part of the area has the highest subsurface temperature, up to 250°C. The deep fluid originates from the southwest, and flow is mainly to the north and partly to the east along faults and fractures, decreasing in temperature with increasing lateral flow.     

Present status of underground thermal utilization in Japan

Utilization of low-enthalpy geothermal energy in Japan, especially with the application of geothermal heat pumps, is far behind other industrial countries. In 1998, a feasibility study was made of utilizing Japan's low-enthalpy geothermal resources. Since 2001 the Geo-Heat Promotion Association of Japan (GeoHPJ) began its activities with the objective of installing 140,000 heat pump systems in private houses by the target year of 2010. The Geothermal Research Society of Japan has also launched new activities in this sector. Research groups in universities and other national institutes have started geoscientific research on the utilization of low-enthalpy resources and private, academic and governmental sectors have consequently begun promoting geothermal heat pump utilization.