2．日本的地热利用

日本是环绕太平洋火山带的火山国之一,火山遍布全国,有丰富的地热资源,潜力雄厚,据日本新能源生产技术综合开发机构调查推算,日本全国地热资源约有250万KW的蕴藏量,目前的地热发电量仅为1／5。全国可供发电的地热田有40多处,所以地热开发利用前景相当好。     

天津率先颁布《地热利用工程设计标准》

日前，天津市在全国率先颁布了《天津市地热利用工程设计标准（试行）》，并于2006年12月1日起正式施行。该标准对于规范天津市地热开发行为，提高地热回灌率及资源开发利用技术水平，有效保护地热资源，实现地热开发系统规范化运行将起到积极作用。     

我国地热利用现状

地热资源按温度的高低划分为高中低三种类型。中国一般把高于150℃的称为高温地热,主要用于发电;低于此温度的叫中低温地热,通常直接用于采暖、工农业加温、水产养殖及医疗和洗浴等。与地热发电相比,地热直接利用的优点:①热能利用效率高达50%～70%,比传统地热发电的5%～20%高很多;②开发时间短得多,且投资也远比地热发电少;③地热直接利用,既可利用高温也可利用中低温地热资源,因此应用范围远比地热发电广泛。当然,地热直接利用也受到热水分     

中-菲地热利用研究在鄂启动

记者近日从湖北省地矿局获悉：由该局所属省地质环境总站承担的湖北省重点国际科技项目《湖北省低焓地热资源可持续性利用开发研究》项目正式启动。     

On the sources of technological change: Assessing the evidence

This paper uses a selective review of the economic literature on technological change to support four points that are important for interpreting and incorporating technological change into formal models of energy and the environment. The review (1) supports the notion that no single source dominates the process of technological change. It supports roles for R&D and learning-by-doing within an industry, as well as for spillovers from other industries engaged in both of these activities. The literature also (2) supports a strong role for spillovers; (3) indicates that these spillovers are often indirect, requiring own-industry activities to utilize; and (4) indicates that simple experience curve calibrations often used in formal models likely include a range of sources of technological change in addition to learning-by-doing, some of which might not be induced by the sorts of policies typically considered in the climate context.     

Resource constraints in a hydrogen economy based on renewable energy sources: An exploration

In order to tackle climate change, a transition to a renewable based energy system is crucial. A renewable based hydrogen economy is one of the possible implementations of such a system. The world receives ample energy from the sun that can be harvested by PV solar cells and, indirectly, by wind turbines. In order to use the most optimal locations for collecting and concentrating energy from these diffuse sources, a long distance transmission network is needed. Mature and semi-mature technologies are available for all parts of the system: from collection to transmission to end-use. In an early stage of development, when new technologies have to win market share from the existing energy system, their development is driven almost exclusively by the reduction of costs per J delivered. However, if a technology should be able to deliver tens to hundreds of EJ, resource constraints can become show stoppers. Many of the newest, most cost-efficient, energy technologies make use of scarce resources and, although they may play an important role in the transition process, they can not be scaled up the level we need for a complete transition. In most cases however other technologies are available that use more abundant materials, be it often at a cost of efficiency. The issue is not only with scarce resources. The sheer size of the energy transition will also challenge the industrial capacity for the mining and production of bulk materials like steel and copper.     

青海省太阳能资源的开发利用

在调查了解青海省光伏发电产业发展情况的基础上,深入分析了青海省光伏发电产业的发展现状和存在问题,并提出了光伏发电产业健康发展的对策与措施,从而有效地促进青海省太阳能资源优势的发挥.     

On the comparison of energy sources: Feasibility of radio frequency and ambient light harvesting

With growing interest in multi source energy harvesting including integrated microchips we propose a comparison of radio frequency (RF) and solar energy sources in a typical city. Harvesting devices for RF and solar energy will be competing for space of a compact micro or nano device as well as for orientation with respect to the energy source. This is why it is essential to investigate importance of every source of energy and make a decision whether it will be worthwhile to include such harvesters. We considered theoretically possible irradiance by RF signal in different situations, typical for the modern urban environment and compared it with ambient solar energy sources available through the night, including moonlight.Our estimations show that solar light energy dominates by far margin practically all the time, even during the night, if there is a full moon in the absence of clouds. At the same time, in the closed compartments or at the new moon RF harvesting can be beneficial as a source of “free” energy.     

On the physics of power,energy and economics of renewable electric energy sources - Part II

Renewable Energy Technologies (RETs) are often recognized as less competitive than traditional electric energy conversion systems. Obstacles with renewable electric energy conversion systems are often referred to the intermittency of the energy sources [1] and the relatively high maintenance cost. However, due to an intensified discourse on climate change and its effects, it has from a societal point of view, become more desirable to adopt and install CO₂ neutral power plants. Even if this has increased the competitiveness of RETs in a political sense, the new goals for RET installations must also be met with economical viability. We propose that the direction of technical development, as well as the chosen technology in new installations, should not primarily be determined by policies, but by the basic physical properties of the energy source and the associated potential for inexpensive energy production. This potential is the basic entity that drives the payback of the investment of a specific RET power plant. With regard to this, we argue that the total electric energy conversion system must be considered if effective power production is to be achieved, with focus on the possible number of full loading hours and the Degree of Utilization [2]. This will increase the cost efficiency and economical competitiveness of RET investments, and could enhance faster diffusion of new innovations and installations without over-optimistic subsidies. This paper elaborates on the overall problem of the economy of renewable electric energy conversion systems by studying the interface between physics, engineering and economy reported for RET power plants in different scientific publications. The core objective is to show the practical use of the Degree of Utilization and how the concept is crucial for the design and economical optimization disregarding subsidies. The results clearly indicate that the future political regulative frameworks should consider the choice of renewable energy source since this strongly affects the economical output from the RET power plants.     

On the economics of hydrogen from renewable energy sources as an alternative fuel in transport sector in Austria

The core objective of this work is to analyse the possible future relevance of hydrogen from renewable energy sources in the transport sector from an economic point-of-view with special focus on Austria. The analysis is conducted in a dynamic framework until 2050.     

北斗卫星导航定位系统在地质测绘中的应用

文中介绍了北斗卫星导航系统的基本原理,主要技术特征优势及在地质勘探测绘方面的主要应用。通过实例阐述了北斗导航系统实时动态定位功能在地质测绘中的应用,分析了北斗卫星导航系统的发展前景。     

Alternative energy sources in the Amazon

This paper discusses the evaluation of energy potential of palm oil for the generation of electricity in isolated communities. In Brazil, the energy sector culture has historically been directed almost exclusively toward major projects geared to meet the demands of those sectors of society that have the greatest economic and political influence. Prioritizing industrialization and an accelerated urbanization, they have oriented the national energy system toward centralized production of enormous blocks of energy adapted to meet major urban concentration consumption but incapable of satisfying the needs of a large part of the population that inhabits the rural areas. These small- and medium-sized communities are sometimes isolated from the developed urban centers and not connected to the conventional electricity networks. In this scenario, the Amazon region stands out due to its huge territorial extension and low demographic density, which is scattered among islands and other locations not easily accessible. As a rule, these areas lack electricity, and, when they do have it, supply is precarious and provided through fossil fuels for electricity production     

Heat transfer enhancement from protruding heat sources using perforated zone between the heat sources

This study is to experimentally investigate the heat transfer enhancement by perforation in air cooling of two in-line rectangular heat sources module. Two separation distances between the heat sources were investigated at s/L = 0.5 and 1.0. The area between the heat sources in both cases were perforated in aligned arrangement such that the holes open area ratio (β) are of 0, 0.0736, 0.1472 and 0.2944. The dimensionless temperature distribution and the average Nusselt number are considered at different values of Reynolds number (3391 ? Re_L ? 10798) and holes open area ratio. It could be seen that perforation could enhance the heat transfer coefficients and reduce the module temperature significantly. Correlations are obtained for the average Nusselt number utilizing the present measurements within the investigated range of the different parameters.