Electricity generation: options for reduction in carbon emissions

Historically, the bulk production of electricity has been achieved by burning fossil fuels, with unavoidable gaseous emissions, including large quantities of carbon dioxide: an average-sized modern coal-burning power station is responsible for more than 10 Mt of CO(2) each year. This paper details typical emissions from present-day power stations and discusses the options for their reduction. Acknowledging that the cuts achieved in the past decade in the UK CO(2) emissions have been achieved largely by fuel switching, the remaining possibilities offered by this method are discussed. Switching to less-polluting fossil fuels will achieve some measure of reduction, but the basic problem of CO(2) emissions continues. Of the alternatives to fossil fuels, only nuclear power represents a zero-carbon large-scale energy source. Unfortunately, public concerns over safety and radioactive waste have still to be assuaged. Other approaches include the application of improved combustion technology, the removal of harmful gases from power-station flues and the use of waste heat to improve overall power-station efficiency. These all have a part to play, but many consider our best hope for emissions reduction to be the use of renewable energy. The main renewable energy contenders are assessed in this paper and realistic estimates of the contribution that each could provide are indicated. It appears that, in the time-scale envisaged by planners for reduction in CO(2) emission, in many countries renewable energy will be unlikely to deliver. At the same time, it is worth commenting that, again in many countries, the level of penetration of renewable energy will fall short of the present somewhat optimistic targets. Of renewable options, wind energy could be used in the short to medium term to cover for thermal plant closures, but for wind energy to be successful, the network will have to be modified to cope with wind's intermittent nature. Globally, hydroelectricity is currently the largest developed source of renewable electricity, but future large-scale projects will probably be limited to the less-developed world: the best schemes in the developed countries have already been exploited. Wave and tidal can be looked on as medium- to long-term generators of electricity, as their respective industries are not as mature as competing renewable resources. Municipal solid-waste combustion and landfill gas technologies can also be seen as short term, as can their rural equivalents, agriculture and forestry waste. Any widespread exploitation of renewable energy will depend on being able to transmit the energy from source to point of use, so the implications for the electrical network from the penetration of substantial levels of renewable energy are presented. Effective management of renewable energy installations will require technical assessment of the range of exploitation strategies, to compare local production of, say, hydrogen and the more traditional transmission of electricity. Such resources will have to compete with others in any national, or grid, system and detailed economic analysis will be necessary to determine the deployment that best fits the trading regime under which the energy will be sold. Consideration will also be necessary to determine how best to control the introduction of this radically new resource such that it does not attract punitive cost overheads until it is mature enough to cope. Finally, it is inescapable that nuclear power is a proven technology that could take its place in any future generation portfolio. Unfortunately, suspicion and mistrust surround waste management and radioactivity release. Unless this is overcome, the lack of confidence engendered by this public mistrust may result in few, if any, new nuclear power stations being built. In the event of that decision, it is difficult to see how CO(2) levels can be significantly reduced: the irony is that nuclear energy may emerge as environmentally essential.     

Sustainable energy and environmental impact: role of renewables as clean and secure source of energy for the 21st century in Jordan

In this article, present and future energy consumption, electricity demand, potential of renewable energy sources and national energy policy in Jordan are presented. The related environmental impacts are discussed from the sustainable development point of view, including the future role of renewable energy sources. Jordan is a net energy importing country, with almost 96% of its annual needs relying on imported crude oil and refined products from neighboring Arab countries. Due to increasing fossil fuel combustion to meet growing national energy demand, especially electricity generation, air pollution is becoming an important issue in urban areas. Profound cuts in current emission rates, including carbon dioxide, are possible at a bearable cost, and that the government must now invest in low carbon options because of the long lead in time of some technologies. A great deal more could be done to improve energy efficiency, and new and renewable energy schemes should be advocated on different levels. To achieve this, all obstacles including institutional barriers to investment in renewable technologies and national energy plan need to be addressed urgently. Thus, the government is invited to create a Sustainable Energy Unit, which will coordinate government cross-departmental thinking and provide adequate information to the public and to private investors.     

Evaluation of current status and future directions of wind energy in India

Wind energy is the fastest growing electricity generation technology. During the last decade of the 20th century, grid-connected wind capacity worldwide has doubled approximately every 3 years. Climate change is a major challenge to sustainable development worldwide and is increasingly recognized by forward-looking political and business leaders. One of the tasks we are facing is a profound transformation of our energy system over the next few decades of replacing fossil fuels with renewable energies and dramatically increasing energy efficiency. At present, wind energy is receiving considerable attention in the world. In this study, development of wind energy system and the potential of wind energy in India have been investigated. This paper presents the progress made by wind energy in the recent years, and discusses the potential of this technology. The aim of the work is to investigate the wind energy plants and projects in India. It can be concluded from this analysis that wind energy utilization in India and throughout world has sharply increased.     

Foundations for offshore wind turbines

An important engineering challenge of today, and a vital one for the future, is to develop and harvest alternative sources of energy. This is a firm priority in the UK, with the government setting a target of 10% of electricity from renewable sources by 2010. A component central to this commitment will be to harvest electrical power from the vast energy reserves offshore, through wind turbines or current or wave power generators. The most mature of these technologies is that of wind, as much technology transfer can be gained from onshore experience. Onshore wind farms, although supplying 'green energy', tend to provoke some objections on aesthetic grounds. These objections can be countered by locating the turbines offshore, where it will also be possible to install larger capacity turbines, thus maximizing the potential of each wind farm location. This paper explores some civil-engineering problems encountered for offshore wind turbines. A critical component is the connection of the structure to the ground, and in particular how the load applied to the structure is transferred safely to the surrounding soil. We review previous work on the design of offshore foundations, and then present some simple design calculations for sizing foundations and structures appropriate to the wind-turbine problem. We examine the deficiencies in the current design approaches, and the research currently under way to overcome these deficiencies. Designs must be improved so that these alternative energy sources can compete economically with traditional energy suppliers.     

燃料电池分布式供能技术发展现状与展望

燃料电池作为一种清洁高效的发电方式,兼具效率高、排放低、安全无噪音等优点,是分布式供能领域的一项重要技术。燃料电池既可以利用传统煤炭、天然气,也可以融合可再生能源实现削峰填谷。在传统煤电领域,散煤的利用是环境污染的重要来源,通过直接碳燃料电池技术,有望解决散煤利用效率低下、污染严重的问题。联合天然气管网,基于燃料电池的微型热电联供系统可实现能源的梯级利用,相比传统的热电分供模式可大大提高能源利用效率。同时,电解池作为燃料电池的逆过程,可将可再生能源富余电力转化为化学能进行储存,实现"三弃"电力的有效转化,在可再生能源的分布式供应系统中具有广阔的发展前景。     

“双碳”目标下的电能价值分析与市场机制设计

自“2030年前碳达峰、2060年前碳中和”的目标提出后,中央财经委员会第九次会议又进一步提出实现该目标的基本思路和主要举措,特别是实施可再生能源替代行动,深化电力体制改革,构建以新能源为主体的新型电力系统。这些举措必将导致电源结构的重大调整。另一方面,近年来世界范围内电力市场中各类负面事件接连不断,引起各方广泛关注。这些事件产生的原因与电源结构缺陷和电力市场设计不合理有很大的关系。结合近期全球电力市场典型事故的介绍和原因分析,重点探讨了电源结构的变化所引起的安全风险和电能价值的多样化等问题,分析了电力市场体制机制所面临的挑战,并提出了初步解决方案。电力定价和电力市场设计应建立在电能价值规律的基础之上。在可再生能源大规模接入的背景下,电能除了传统电力市场中的容量价值、电量价值,还具有灵活性、安全性和弹性价值等多种不同的价值,使得问题更加复杂,因此针对这些问题进行了初步分析。     

Correlation analysis of small wind–solar–biomass hybrid energy system installed at RGTU Bhopal, MP (India)

The perspective of this paper represents all types of correlation existing among the various renewable power sources in the hybrid system to find out its feasibility. Among the different energy alternatives available, the wind energy system clubbed with solar photo voltaic panels and biomass gasifier for the production of electricity is found more suitable. As wind, solar and biomass hybrid energy systems stand out distinctly for their use in tropical regions. Keeping this in view a statistical correlation analysis of the said hybrid energy system has been evolved for a remote area (wind and solar data of which are collected from weather monitoring station installed at University Institute of Technology, Bhopal, India).     

Energy savings and CO2 emission reduction by using geothermal heat pumps

The renewable energy will play significant role in the world primary energy consumption in the future. Geothermal energy is immense with 5000 EJ/yr of technical potential; however, its utilization has been limited to areas with special geological conditions. Geothermal heat pumps (GHPs) are one of the fastest growing applications of renewable energy in the world with annual increases of 10% and much faster in China. Its main advantage is that it uses normal ground or groundwater temperatures (between about 5 and 30℃), which are available in all countries of the world and make geothermal more attractive and practicable. With high Coefficient of Performance (COP) up to 6, GHPs make efficiency of primary energy more than 240% with assumed a 40% of electricity generation efficiency, which means energy savings and CO2 emission reduction. In this paper geothermal and GHP technology is introduced and the energy savings and CO2 emission reduction by GHPs are analyzed.     

Centring radiological protection on today's global challenges in energy, climate change, environment and health--with nuclear energy playing a key role

The climate change issue includes meeting the growing demand for electricity while reducing the impacts from energy sources. Applying carbon capture and storage technology to fossil fuel energy and increasing renewable energy pose greater challenges than increasing nuclear energy. International Energy Agency's (IEA) electricity demand of 30 000 TWh by 2030 can be met with 10 000 TWh each from renewable, nuclear and fossil fuel energy. However, the ill-imposed very strict control of tiny public exposure to ionising radiation from nuclear energy continues to pose a serious hindrance. Effort needs to be re-balanced to produce an even-handed control of public exposure with emphasis on the most significant sources (i.e. natural background radiation and medical use) and vice versa. The on-going revision of the International Atomic Energy Agency Basic Safety Standards (BSS) provides an opportunity to achieve this internationally so that national regulations can be subsequently remediated. There can be no urgency in a BSS revision that fails to encompass such perspective.     

Impact of renewable energy on rural electrification in Malaysia: a review

Malaysia is rich in renewable energy (RE) resources. Hybrid systems of these resources can contribute strongly to the electrification and sustainable development of rural areas that do not have access to electricity grids. The integration of the generation of hybrid renewable power in remote and rural areas supplies the required power demand and mitigates emissions. Thus, this study reviews the latest literature (theses, journals articles, and conference proceedings) on the need for electricity in remote rural communities, on hybrid RE systems, on environmental impact, and on economic regulation in Malaysia. Power in this country is mainly generated by fossil fuels that emit high concentrations of greenhouse gases. Thus, RE is a potential alternative for to electrify rural areas, to meet current and future energy demands, and to mitigate emissions. Moreover, Malaysia has pledged to reduce its carbon-emission intensity by a maximum of 40 % (2005 level) by the year 2020. Therefore, the implementation of RE technologies in this country is significantly aided by RE projects, research and development activities, technologies, energy policies, and future direction. This review concludes that solar, wind, hydro, and biomass energy, as well as a hybrid of these, can effectively electrify rural areas.     

海上风机桩式基础结构形式综合模糊优选

针对海上风机基础设计中经常遇到复杂的方案优化选型问题,将多因素、多级模糊优选理论引入到基础的设计选型中。针对影响因素复杂、确定隶属函数主观因素较强的情况,成功引入因素的优先关系法来确定优选矩阵的隶属度,较好地解决了确定隶属函数的人为影响。通过此优选模型成功地将影响基础设计选型的13种主要因素和4种桩基基础设计形式进行了多级模糊综合优选决策,得到了比较理想的决策结果,为海上风机基础设计选型提供了新的思路。     

A vision of true costing [renewable energy]

In recent years, most new generating plant installed in the UK electricity supply industry has been gas turbine. In the near future, this trend could change as both environmental pressures and international agreements legislate towards a significant increase in the level of exploitation of renewable energy. Options for new generating plant must be assessed and compared using several bases before a choice is made. This paper describes the initial stages of development of techniques to accommodate externalities into the decision-making process. An illustrative example, wind energy, is presented     

South Africa's electrical energy economy: environmental impacts,future developments and constraints

South Africa alone produces move than half of the electricity generated in the entire African continent. In spite of this about, half of South Africans are without electricity in their homes. South Africa's energy production and distribution patterns bear a striking resemblance to its overall economy-a heterogeneous intermingling of First and Third World characteristics. South Africa as a whole is responsible for about 2% of the world's greenhouse gas emissions although it has only 1% of the world's population. The normalisation and democratisation of the country will require enormous efforts to provide electricity, running water and education for the majority of the South Africans previously disadvantaged in the apartheid era. South Africa is trying to comply with the global demand for sustainable development by improving the technologies of its power plants, implementing renewable energy sources, improving efficiency of utilisation of electricity in industry and homes, adopting more efficient standards for electrical appliances, changing of the way of life etc. Although there are some constraints, the country is capable of overcoming these in the years ahead given the political will and proper international assistance     

Bottlenecks and Countermeasures of High-Penetration Renewable Energy Development in China

China has become the world’s largest producer and consumer of energy, and ranks first in its wind and solar power installation capacity. However, serious wind and solar curtailment in China has significantly hindered the development and utilization of renewable energy. To address problems in the consumption of renewable energy, this paper analyzes four key factors affecting the capacity of power generated from renewable energy sources: power balance, power regulation performance, transmission capacity, and load level. Focusing on these bottlenecks, we propose seven solutions: centralized and distributed development of renewable energy, improving the peak-load regulation flexibility of thermal power, increasing the proportion of gas turbines and pumped-hydropower storage, construction of transmission channels and a flexible smart grid developing demand response and virtual power plants, adopting new energy active support and energy storage, and establishing appropriate policies and market mechanisms. The Chinese Government and energy authorities have issued a series of policies and measures, and in the past three years, China has had remarkable achievements in the adoption of renewable energy. The rate of idle wind capacity decreased from 17% in 2016 to 7% in 2018, and that of solar decreased from 10% in 2016 to 3% in 2018.     

Exploring the determinants of renewable energy innovation considering the institutional factors: A negative binomial analysis

Replacing traditional energy sources with renewable energy sources is an effective way to achieve emission reduction targets. Focusing on OECD countries from 1990 to 2018, this study examines the determinants of renewable energy innovation by applying a negative binomial model. There are four main findings: (1) Renewable energy patents show an inverted U-shaped curve, peaking in 2010; solar energy accounts for the largest share of patents; and the US is the largest renewable energy innovator, followed by South Korea and Germany. (2) Renewable electricity installed capacity, share of expenditure on research and development (R&D) of GDP, and implementation of the Kyoto Protocol are all found to promote innovation; by comparison, the proportion of renewable energy power generation of the total electricity generating capacity shows a negative effect. The price of crude oil shows no significant effect due to the offset effect between the European and non-European country groups. (3) Share of R&D expenditure of GDP is confirmed to be the force driving technological progress in the solar, geothermal, and marine sectors, and it plays a more important role in Japan than in the US or Europe. Implementation of the Kyoto Protocol has no significant effect on innovation in European countries. (4) Three institutional factors—namely, the legal system and property rights; regulations; and freedom to trade internationally—are confirmed to be the driving forces, whereas this is not the case for the growth and free circulation of money. Policy implications for the optimization of the renewable energy sector's structure, the enhancement of renewable energy capacity, and the improvement of R&D investment and the institutional environment are proposed. Future research should shed light on a broader sample, using micro-level and socio-technical analysis.     

风光储联合发电运行技术研究

随着能源需求的日益增长和新能源的快速发展,利用风能、太阳能的发电技术已经逐步成熟,且在电网中的渗透率也在不断提高。为弥补风能、太阳能发电所带来的功率不稳定、电能质量低等问题,有必要对风能、太阳能、储能联合发电进行深入研究。文中依据简单平抑方法、考虑一定约束的平抑方法、考虑功率预测与人工智能的平抑方法对储能的平抑控制策略进行了归纳总结。在储能平抑风光波动的研究中滤波算法是最为常见的方法,加入一定的约束会使平抑效果更佳,储能平抑配合精准的预测使整个系统更加平滑。多储能技术混合可以发挥各储能技术优越性。加入储能装置的风光储互补系统可以有效降低原风光互补系统对电网的不利影响。可以在更高程度上平滑风光发电系统的输出特性,增加电网对可再生能源的吸收接纳程度,取得良好的经济和社会效益。     

Natural fibre-reinforced composites for bioengineering and environmental engineering applications

Recently, the mankind has realized that unless environment is protected, he himself will be threatened by the over consumption of natural resource as well as substantial reduction of fresh air produced in the world. Conservation of forests and optimal utilization of agricultural and other renewable resources like solar and wind energies, and recently, tidal energy have become important topics worldwide. In such concern, the use of renewable resources such as plant and animal based fibre-reinforce polymeric composites, has been becoming an important design criterion for designing and manufacturing components for all industrial products. Research on biodegradable polymeric composites, can contribute for green and safe environment to some extent. In the biomedical and bioengineered field, the use of natural fibre mixed with biodegradable and bioresorbable polymers can produce joints and bone fixtures to alleviate pain for patients. In this paper, a comprehensive review on different kinds of natural fibre composites will be given. Their potential in future development of different kinds of engineering and domestic products will also be discussed in detail.     

Renewable energy transition: a market-driven solution for the energy and environmental concerns in Chile

Chile is undergoing a remarkable energy matrix transition to renewable energy. Renewable energies are expanding extraordinarily fast, exceeding earlier predictions. As a result, the country is expected to meet its 2025 goal of generating 20% of its electricity from renewable energy sources quite before. Chile has become one of the first countries in the world with subsidy-free markets, where renewable projects compete directly with other conventional sources. Favorable market conditions and successful policy reforms were keys to fostering this renewable energy development. Although the country has achieved a substantial growth in renewable energy investment in a relatively short period of time, this optimism should be treated with caution. A successful transition requires a combination of a clear decision making, persistent and consistent government policies, and a clear commitment to tackling challenges to accommodate renewable energy in the power system. In this context, this paper analyses the Chilean renewable industry and the required government policies to succeed in this transition. For this purpose, we identify several critical factors that have attracted and that could attract investment to the renewable energy sector and propose key recommendations to effectively address the major challenges faced for the future development of the industry.     

The quest for carbon-neutral industrial operations: renewable power purchase versus distributed generation

Integrating renewable energy into the manufacturing facility is the ultimate key to realising carbon-neutral operations. Although many firms have taken various initiatives to reduce the carbon footprint of their facilities, there are few quantitative studies focused on cost analysis and supply reliability of integrating intermittent wind and solar power. This paper aims to fill this gap by addressing the following question: shall we adopt power purchase agreement (PPA) or onsite renewable generation to realise the eco-economic benefits? We tackle this complex decision-making problem by considering two regulatory options: government carbon incentives and utility pricing policy. A stochastic programming model is formulated to search for the optimal mix of onsite and offsite renewable power supply. The model is tested extensively in different regions under various climatic conditions. Three findings are obtained. First, in a long term onsite generation and PPA can avoid the price volatility in the spot or wholesale electricity market. Second, at locations where the wind speed is below 6 m/s, PPA at $70/MWh is preferred over onsite wind generation. Third, compared to PPA and wind generation, solar generation is not economically competitive unless the capacity cost is down below $1.5 M/MW.     

新形势下蓄能蓄电与各种电源的可持续发展

当今水电发展受限于水能资源,在原有基础上再考虑蓄能蓄电可利用电网低谷剩余电能储存转换,变成和再生能源一样,可周而复始更新使用,形成各种电源持续发展的循环机制。蓄能蓄电涵盖抽水蓄能和其他蓄能蓄电设施后,特别有利于节能减排和可再生新能源的发展。今后应关注风险分析、风险设计和风险管理。