Higher-efficiency for combined photovoltaic-thermoelectric solar power generation

Solar energy application in a large spectrum has the potential for high-efficiency energy conversion. Though, solar cells can only absorb photon energy of the solar spectrum near their band-gap energy, and the remaining energy will be converted into thermal energy. The use of the thermoelectric generator becomes a necessity for convert this thermal energy dissipated so as to increase efficiency conversion.

This paper analyses the feasibility of photovoltaic-thermoelectric hybrid system and reviews their performance in order to optimize harvested energy. Regarding the thermoelectric effect, a new method of the ambient energy harvesting is presented. This method combines thermoelectric generators and the effects of heat sensitive materials associated to photovoltaic cells in phase change for generating both energy day and night. Experimental measures have been conducted primarily in laboratory conditions for a greater understanding of hybridization phenomena under real conditions and to test the actual performance of devices made. Results show that the hybrid system can generate more power than the simple PV and TEG in environmental conditions. This hybrid technology will highlight the use of renewable energies in the service of the energy production.     

Changes in electrical generator cooling systems: Are they cost-effective sources of water now and under climate change?

In the United States, thermal power plant electrical generators (EGs) are large water diverters and consumptive users who need water for cooling. Retrofitting existing cooling systems to dry cooling and building new facilities with dry cooling can save water and reduce EG's vulnerability to drought. However, this can be an expensive source of water. We estimate that the cost of water saved by retrofitting cooling in existing EGs ranges from $0.04/m³ to $18/m³ depending on facility characteristics. Also water savings from building new EGs with dry cooling ranges in cost per unit water from $1.29/m³ to $2.24/m³. We compare costs with that for water development projects identified in the Texas State Water Plan. We find the water cost from converting to dry cooling is lower than many of the water development possibilities. We then estimate the impact of climate change on the cost of water saved, finding climate change can increase EG water use by up to 9.3% and lower the costs of water saved. Generally, it appears that water planners might consider cooling alterations as a cost competitive water development alternative whose cost would be further decreased by climate change.     

Oil and power industries’ responses to EU emissions trading: laggards or low-carbon leaders?

ABSTRACT

How have petroleum and power companies and their European industry associations responded to the EU emissions trading system (ETS)? Responses can be political, directed externally towards the initiation and reforms of the EU ETS itself, or internally and market-based, directed at low-carbon solutions. Proactive response strategies shape companies’ leadership potential. Variation in responses is explained by two models that differ in assumptions about corporate behaviour as well as the wider multilevel regulatory context in which companies operate. Responses are found to have converged within the two industries, with reactive companies following the proactive ones. Secondly, responses between the two industries increasingly diverge, with the power industry becoming much more proactive than the petroleum industry. The main explanation is found in the differing relevance of the two models and the wider regulatory context, particularly differing exposure to international competition and weak international climate agreements.     

Fast,cheap, and imperfect? US public opinion about solar geoengineering

ABSTRACT

Solar geoengineering, which seeks to cool the planet by reflecting a small fraction of sunlight back into space, has drawn the attention of scientists and policymakers as climate change remains unabated. Unlike mitigation, solar geoengineering could quickly and cheaply lower global temperatures. It is also imperfect. Its environmental impacts remain unpredictable, and its low cost and immediate effects may result in ‘moral hazard,’ potentially crowding out costly mitigation efforts. There is little understanding about how the public will respond to such tradeoffs. To address this, a 1000-subject nationally representative poll focused on solar geoengineering was conducted as part of the Cooperative Congressional Election Study (CCES) of the US electorate in October–November 2016. The importance that individuals place on solar geoengineering’s speed and cost predicts their support for it, but there is little to no relationship between their concerns about its shortcomings and support for its research and use. Acquiescence bias appears to be an important factor for attitudes around solar geoengineering and moral hazard.     

Climate engineering and human rights

ABSTRACT

In this Forum, three scholars discuss how climate engineering will pose novel human rights challenges, and may well force reconsideration of how human rights are applied as a guide to action. Following a short introduction, the first section introduces three competing approaches to human rights, arguing views which emphasize fairness or attempt to maximize satisfaction are more promising than one viewing human rights as inviolable ‘side-constraints’. The second section draws lessons from climate migration that are relevant for climate engineering in terms of incorporating a human rights approach to duties, rights, and participation. The final section compares the ‘needs-based’ and ‘rights-based’ approaches to humanitarian work in the face of climate change and climate engineering, raising concerns for duty-bearers and right-holders. The Forum’s conclusion draws together points of overlap and suggests a path forward for policy and research on this topic.     

录井系统雷击危害分析及模拟试验研究

针对雷击电磁辐射对录井系统的危害问题，建立了录井系统线路雷击危害模拟试验模型，采用8/20 μs冲击电流发生器，开展了录井系统的雷击耦合试验，定量分析了雷击电磁辐射对录井系统的影响。研究结果表明:随着电流的增大和距离电流通道的减小，耦合的电压随之增大；线缆长度越长耦合的电压越大，最大耦合电压达到了2 720 V；屏蔽层接地可以有效地减小电磁辐射对线缆的耦合作用。     

The accounting method and application of CO2 emissions responsibility by the electricity sector at the provincial level in China

When accounting the CO₂ emissions responsibility of the electricity sector at the provincial level in China,it is of great significance to consider the scope of both producers’ and the consumers’ responsibility,since this will promote fairness in defining emission responsibility and enhance cooperation in emission reduction among provinces.This paper proposes a new method for calculating carbon emissions from the power sector at the provincial level based on the shared responsibility principle and taking into account interregional power exchange.This method can not only be used to account the emission responsibility shared by both the electricity production side and the consumption side,but it is also applicable for calculating the corresponding emission responsibility undertaken by those provinces with net electricity outflow and inflow.This method has been used to account for the carbon emissions responsibilities of the power sector at the provincial level in China since 2011.The empirical results indicate that compared with the production-based accounting method,the carbon emissions of major power-generation provinces in China calculated by the shared responsibility accounting method are reduced by at least 10%,but those of other power-consumption provinces are increased by 20% or more.Secondly,based on the principle of shared responsibility accounting,Inner Mongolia has the highest carbon emissions from the power sector while Hainan has the lowest.Thirdly,four provinces,including Inner Mongolia,Shanxi,Hubei and Anhui,have the highest carbon emissions from net electricity outflow- 14 million t in 2011,accounting for 74.42% of total carbon emissions from net electricity outflow in China.Six provinces,including Hebei,Beijing,Guangdong,Liaoning,Shandong,and Jiangsu,have the highest carbon emissions from net electricity inflow- 11 million t in 2011,accounting for 71.44% of total carbon emissions from net electricity inflow in China.Lastly,this paper has estimated the emission factors of electricity consumption at the provincial level,which can avoid repeated calculations when accounting the emission responsibility of power consumption terminals（e.g.construction,automobile manufacturing and other industries）.In addition,these emission factors can also be used to account the emission responsibilities of provincial power grids.     

宁夏地区光伏发电环境效益分析及建模

在阐述了宁夏地区光伏发电发展的优势及发展现状的基础上，分析了光伏发电开发利用对宁夏生态环境产生的积极和消极的影响，并为降低消极影响提出了相应的对策；为了定量直观的评估光伏发电积极影响和消极影响所产生的环境效益，分别建立了节能减排、防风固沙和土地增值、景观效应、植被恢复费用、噪声污染超标罚款、光污染费用等价值模型及光伏发电总的生态环境效益价值模型；最后以中电投宁夏能源铝中卫香山光伏电站为例进行计算验证，结果表明模型的合理性和准确性，同时光伏电站的节能减排效益显著。相对于传统的火力发电，表现了优越的环境效益。     

燃煤电厂大气污染物排放考核时间间隔的建议

新的《火电厂大气污染物排放标准》和新《环境保护法》实施后，燃煤火电企业的依法治企自觉性不断提高，但由于不同的环保管理文件对超标处罚依据和处罚手段不同，造成政府对企业处罚的自由裁量权加大，对企业造成一定的压力与困惑。结合企业实际运行情况对燃煤电厂大气污染物排放考核时间间隔提出建议。     

超低空航拍技术在输变电环评工作中的应用研究

分析了环评工作中收集的影像资料存在的问题，提出了超低空航拍的解决方法。通过对比分析，选择了多旋翼无人机作为超低空航拍平台。该设备具有携带方便，飞行稳性的优点。从实际应用效果来看，基于该技术获得的影像信息含量全面、工作效率高、评价结果更客观可信，为提高环评工作质量提供了一个可靠的技术方案。