Green energy?

The UK gets nearly all its energy from the fossil fuels (coal, oil, gas etc.) and nuclear power, approximately 15% being consumed in the form of electricity. It is now well known that the burning of fossil fuels is accompanied by atmospheric pollution in the form of acid rain, ozone depletion and the greenhouse effect. Renewable energy sources, e.g. wind, solar, tidal, wave, hydroelectric and geothermal power do not at present contribute significantly to the UK energy supply and are also accompanied by adverse effects on the environment. The best hope for meeting future energy needs may lie in containing energy consumption, increased generation efficiency and an expanded nuclear power programme. The author discusses the problems of acid rain and the greenhouse effect and describes several forms of renewable energy: wind energy, solar energy, tidal power, wave power, hydroelectricity, biomass geothermal power and nuclear power     

The pace and practicality of decarbonization

There is a widely believed myth that replacing the use of fossil fuels largely by renewable forms of energy is, with a possible exception of nuclear power, critically dependent on the development of appropriate new technologies. Accordingly, it is held that decarbonizing straight away is particularly difficult and expensive. There was a time when this idea had an element of reality, but this is no longer the case. Unfortunately, belief in this myth is shared by those in positions of influence. This paper serves to document that this presumed reality no longer holds, although the misconception may have been based on fact in the past. Whilst the survey of the available technology offered concentrates on electricity supply, it also documents that manufacture of synthetic fuels via hydrogen obtained by electrolysis of water and CO₂ integrates smoothly with electricity grid stabilization as well as reducing the CO₂ content of the atmosphere. The likely price and cost development in the energy market is also reviewed. In addition the role of CCS, in practice mainly capture from the air and industrial processes other than power generation is reviewed against the background of the cost effective generation of electricity by harvesting renewable forms of energy.     

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.     

Energie- und CO2-Bilanzen von Solarkollektoranlagen

Energy systems based on solar collectors or other renewable energy sources are normally regarded as CO₂ zero-emission systems because nearly no fossil fuels are used to operate the systems. But the complete evaluation of an energy system concerning its CO₂ reduction potential must not be restricted to the emissions during the operation of the system. The cumulative energy demand and the cumulative CO₂ emissions during the life cycle have to be considered. In case of a solar collector system, in particular the production-determined emissions and emissions due to the requirement of auxiliary electric power for the collector pump are important. An energy analysis is this kind was performed for solar domestic hot water systems. It is shown that the consideration of the life cycle emissions reduces significantly the CO₂ reduction potential of solar collector systems whereby the design of the system has a major influence.     

Impact of including land-use change emissions from biofuels on meeting GHG emissions reduction targets: the example of Ireland

The greenhouse gases (GHG) emissions from land-use change are of particular concern for land-based biofuels. Emissions avoided by substituting fossil fuels with biofuels may be offset by emissions from direct and indirect land-use changes (LUC). There is an urgent need to investigate what impact land-use change emissions may have on the expansion of bioenergy and biofuels, in the context of EU mitigation policies. This paper focuses on Ireland, which faces a number of challenges in delivering its renewable energy and GHG reduction targets. The Irish TIMES energy systems model was used to assess the impact of a range of land-use change emissions’ levels on the evolution of Ireland’s low-carbon energy system. A reference scenario was developed where LUC is ignored and Ireland achieves a least-cost low-carbon energy system by 2050. If high indirect land-use change (ILUC) emissions are included, this results in a decrease by 30 % in bioenergy and a 68 % increase in marginal abatement costs by 2050. Hydrogen is used instead of bioenergy in the freight sector in this scenario, while private cars are fuelled by renewable electricity. If GHG emissions from ILUC were considered less severe, indigenous grass biomethane becomes the key biofuel representing 31 % of total bioenergy consumption. This is in line with recent research in Ireland of the key role that grass biomethane can play.     

A Technological Overview of Biogas Production from Biowaste

The current irrational use of fossil fuels and the impact of greenhouse gases on the environment are driving research into renewable energy production from organic resources and waste. The global energy demand is high, and most of this energy is produced from fossil resources. Recent studies report that anaerobic digestion (AD) is an efficient alternative technology that combines biofuel production with sustainable waste management, and various technological trends exist in the biogas industry that enhance the production and quality of biogas. Further investments in AD are expected to meet with increasing success due to the low cost of available feedstocks and the wide range of uses for biogas (i.e., for heating, electricity, and fuel). Biogas production is growing in the European energy market and offers an economical alternative for bioenergy production. The objective of this work is to provide an overview of biogas production from lignocellulosic waste, thus providing information toward crucial issues in the biogas economy.     

The effect on the environment of electricity privatisation

The UK's electricity supply industry (ESI) was privatised in 1989 with, it was thought at the time, little, if any, thought being given to its effect on the environment. This paper examines the effect of the Electricity Act on the fuels used in power stations, the gaseous emissions from these stations and the growth of renewable energy sources for electricity generation. It finds that, because of the increase in gas-fired generation, sulphur and carbon dioxide emissions have reduced, as has the quantity of solid wastes produced. The effect of the nonfossil fuel obligation has been to increase and diversify the use of renewable sources for electricity generation     

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。     

Production of green energy from co-digestion: perspectives for the Province of Cuneo, energetic balance and environmental sustainability

In Italy and many European countries, energy production from biomass is encouraged by strong economic subsidies so that biomass energy plants are getting large diffusion. Nevertheless, it is necessary to define the environmental compatibility taking into account global parameters as well as environmental impacts at regional and local scales coming from new polluting emissions. The environmental balances regarding new energy plants are of primary importance within very polluted areas such as Northern Italy where air quality limits are systematically exceeded, in particular for PM₁₀, NO₂, and ozone. The paper analyzes the renewable energy scenario relating to manure anaerobic digestion and biogas production for the Province of Cuneo, N–W Italy, and the environmental sustainability of the possible choices. The study is focused on energy producibility, heat and power, nitrogen oxides and ammonia emissions, GHG (greenhouse gases) balances dealing also with indirect releases of CH₄ and N₂O, as well as emissions due to energy crops production. The most important conclusion that can be drawn is that the production of renewable energy from anaerobic digestion could cover up to 13 % of the Province electricity consumption, but sustainability in terms of CO₂ emissions can be reached only through an overriding use of agricultural waste products (manure and by-products instead of energy crops) and cogeneration of thermal energy at disposal; the application of the best available techniques to waste gas cleaning, energy recovery, and digestate chemical–physical treatments allows positive emissive balances.     

Spatial optimization of biomass power plant site using fuzzy analytic network process

Electricity has a significant role in the sustainable development of societies. Traditional methods of generating electricity face several challenges. The ever-increasing demand for electricity generation on the one hand, and the lack of adequate resources for fossil fuels on the other, has led to the use of renewable energy. Biomass is a renewable energy supply that can be used in electricity generation for a sustainable environment. This study aims to introduce a multi-criteria decision-making framework which integrates a geographical information system with a fuzzy analytic network process together with weighted linear combination to optimize the location of a biomass power plant in Guilan Province, Iran. For this purpose, the environmental and socioeconomic factors were identified, and the main contributing criteria were selected. The results showed that about 27.73 and 41.06% of the region has high or moderate suitability, respectively, for constructing a biomass power plant. In addition, a sensitivity analysis was performed to investigate the robustness of the outcomes of decision making by changing the weighting of the criteria. Results indicated that the ranking of alternative locations is independent of the weights chosen.     

Technology assessment for clean energy technologies: The case of the Pacific Northwest

This study presents a technology assessment for clean power generation in the Pacific Northwest. Our goal is to incorporate clean production principles into the evaluation process for power alternatives. Two types of technologies are considered: one is for a renewable energy source (wind) and the other is for a traditional, fossil fuel based energy source (coal). The Analytical Hierarchy Process is used to assess the feasibility of both the wind energy and clean burning coal energy technologies. Criteria such as location, cost, feasibility, and availability are used for evaluations. For the wind energy, cost was determined to be the most important criterion when making a technology decision. For the SO₂ emissions technology, the regenerative process was determined to be the best technology to scrub SO₂ emissions from the air. Additionally, efforts towards renewable energy in Oregon should continue. Both federal and state governments offer tax credits that can help mitigate costs and facilitate the adoption of renewable energy options for power companies.     

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.     

“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。     

减排二氧化碳发展低碳经济首先要重视节约使用化石能源

分析了能源消费和经济发展的规律,可再生能源的特点、大量开发利用存在的技术瓶颈和减排二氧化碳的效果,认为我国能源消费总量正处在持续增长期,未来40年内可再生能源不可能成为我国的主要能源,化石能源仍将是我国能源的主体,提出减排二氧化碳、发展低碳经济,要首先重视节约使用化石能源。归纳了我国化石能源开发利用取得的成就和存在的问题,提出了节约使用化石能源的对策,一是确定比较合理的GDP增长速度,建立化石能源消费总量控制指标体系;二是建立化石能源加工利用过程全寿命周期能效及二氧化碳排放的评价方法,通过不断优化提高化石能源利用效率;三是从我国化石能源资源状况出发,研究建立符合国情的低碳现代化生活消费模式;四是充分利用财政税收政策和行政手段鼓励和强制节能;五是加强节约使用化石能源的技术、材料、产品的研究开发和推广应用;六是加大资金投入,实现化石能源的优化利用和节约使用。     

Costs of sustainable electricity generation

This article is based on a report commissioned by the IEE Professional Network on Engineering for a Sustainable Future. It looks at the actual present-day costs of generating electricity from all the available technologies, and also summarises the sustainability characteristics of each technology. It discusses the current situation of power in the UK, the development of new generation plant, fossil fueled power generation, hydroelectric power, nuclear power and renewable energy resources     

Optimal site selection for solar power plants using multi-criteria evaluation: A case study from the Ayranci region in Karaman,Turkey

Currently, coal, oil and natural gas are mainly used for energy in most countries. These sources, called fossil fuels, are not renewable. Fossil fuels are limited, and their reserves are steadily decreasing. This situation causes the prices to rise constantly. On the contrary, renewable energy is clean, economical and unlimited. Turkey has a very high potential for renewable energy, and the Turkish government has made significant reforms for solar energy investments over the last decade. Site selection for solar power plants is a critical issue for large investments because of quality of terrain, local weathering factors, proximity to high transmission capacity lines, agricultural facilities and environmental conservation issues. Multi-criteria evaluation is a tool that allows one to choose the best criterion among multiple and offer a structure with a wide range of applications. In this paper, the ideal locations for solar power plant were selected using the geographic information system and analytic hierarchy process which is one of the multi-criteria evaluation methods. The resulting land suitability was grouped into three categories: low suitable, suitable and best suitable using an equal interval classification method. Consequently, 15,550 ha or 6.23% of the evaluated region was determined as the best suited areas for solar power plants.     

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.     

Nuclear energy: current situation and prospects to 2020

For close to half a century nuclear fission has been providing reliable supplies of electricity to the UK, with virtually no emissions of carbon dioxide. Over that period, the UK nuclear industry has avoided the emission of over one and a half billion tonnes of CO2. Yet no nuclear plant has been built in the UK for over two decades even though many of the stations in our current fleet are now within a decade or so of the end of their lifetime. Without new plants being ordered soon, the UK's nuclear capacity will decline dramatically, from 23% today to 3% post-2020--just as considerations of supply security and climate change are becoming increasingly important. Elsewhere in the world, many countries such as China, India, Japan, South Korea, Finland and France are building new stations. Other countries such as the USA, South Africa, and some nations that currently do not have nuclear stations (such as Indonesia and Poland) are making preparations for future nuclear stations. Globally capacity factors for nuclear plants are higher than they have ever been, averaging around 85% and with the best stations achieving well over 90%. Lifetime can be 60 years. That the economics of such stations compete well with other technologies is well founded and easily verifiable--especially in the face of rising fossil fuel prices and the pricing in of costs for CO2 emissions--both of which stand to improve the economics of nuclear energy still further. Waste volumes arising from modern plants are just a fraction of those of some earlier stations, and the technologies are in place to deal with them safely and effectively. Following recent reviews and international developments, there is growing confidence that internationally available competitive designs of nuclear plant will provide part of the solution to the UK's long-term energy needs.     

Synthetic carbohydrate compounds and their integration with renewable electricity supplies

The world runs a serious risk of sliding into catastrophic climate change. It is to all practical purposes impossible to bring the emissions of greenhouse gases to a halt straight away. This article discusses a number of sources of uncertainty and the possibility of bias in climate forecasting. It identifies a specific approach towards rapid decarbonization combined with a systematic reduction in fossil fuel extraction: the manufacture of synthetic hydrocarbon compounds for use as fuel as well as plastics, using carbon dioxide from power stations and cement factories as feedstock during a transitional phase. Policymakers and even researchers working on renewable energy seem to be insufficiently aware of the potential of this mature chemical technology to reduce emissions. The paper also surveys several economic and managerial issues regarding the implementation of the transition to a world using only renewable energy, and provides some information concerning the latest state of the technology of renewable electricity generation.     

Assessment of bioenergy production from mid-rotation thinning of hardwood plantation: life cycle assessment and cost analysis

Forestry thinning logs, a low-value by-product of the forestry industry, present an opportunity for bioenergy production. It can be converted into solid, liquid, and gaseous fuels via different conversion techniques. Comparative life cycle assessment and life cycle costing (LCC) analysis were conducted to evaluate six options: woodchip gasification for power generation; wood pellets gasification in combined heat and power plant; wood pellet combustion for domestic water and space heating; pyrolysis for power generation; pyrolysis with bio-oil upgrading to transportation fuels; and ethanol production for transportation fuel mix. The functional unit used in this study was the treatment of 1 Mg of biomass. Global warming; acidification; eutrophication; fossil depletion, human toxicity; and land use impact categories were considered. The LCC also included greenhouse gas (GHG) emissions costs. The effects of uncertainties in the system on the overall performance of the scenarios were also evaluated. The results showed that all options except for ethanol production are GHG emission negative. Woodchips gasification performed best in all environmental impact categories and had the lowest LCC ($177.6/Mg). Biomass drying consumed more than 50% of the energy requirement for all options except for production of liquid transportation fuels via upgrading of pyrolytic oil, in which case the fuel upgrading process was the most energy intensive. In terms of energy return, all options, except electricity production through pyrolysis, offered positive return. The results highlight the importance of using biomass with least possible processing in order to maximise environmental and energy return and minimise LCC.