Smart grids or smart users? Involving users in developing a low carbon electricity economy

This article analyses practices and perceptions of stakeholders on including users in smart grids experiments in the Netherlands. In-depth interviews have been conducted and smart grid projects have been analysed, using a Strategic Niche Management framework. The analysis shows that there is a clear trend to pay more attention to users in new smart grid projects. However, too much focus on technology and economic incentives can become a barrier. Some institutional barriers have been identified. New innovative business models should be developed to explore different options to involve users. The many pilot and demonstration projects that are taking shape or are being planned offer an excellent opportunity for such an exploration. Learning on the social dimensions of smart grids, and the international exchange of experiences can prevent a premature lock-in in a particular pathway.     

Towards a low carbon energy future – Renewable energy cooperation between Germany and Norway

Renewable energy is a cornerstone of German climate change policies. Germany has adopted particularly ambitious renewable energy targets, and is now implementing an Energiewende – a transition to a nuclear-free and low-carbon energy system. The transition could be eased through European cooperation. This article investigates the economic, political, environmental and technological factors that act as drivers and barriers to renewable energy cooperation between Germany and Norway. The article finds that German actors see Norwegian electricity as a means for enhancing the stability of their electricity system as Germany shifts to a greater reliance on renewables. In Norway the picture is more mixed. Norwegian state-owned electricity producers and grid operators are interested in cooperation largely out of profit motives, but expect Germany to create a favorable environment for investors. Energy-intensive industries and consumers on the other hand, are afraid that more electricity cooperation with Germany will raise electricity prices. The Norwegian environmental movement is split on the issue. Parts of the movement see renewable energy cooperation as an important step towards a European low-carbon energy future. Nature and outdoor organizations, however, argue that new renewable energy infrastructure, including pumped-storage hydropower, will result in major environmental impacts. If cooperation is to be achieved, these economic and environmental concerns will have to be taken seriously.     

Is there a relationship between public expenditures in energy R&D and carbon emissions per GDP? An empirical investigation

Energy innovation plays a crucial role in the reduction of carbon emissions. In order to design climate and energy policies that promote the development, deployment and diffusion of new energy technologies, policy makers not only require a theoretical understanding of the energy innovation system, but also empirical evidence of the effects that policy actions have had. This paper focuses on public energy R&D, a traditional and controversial option among the various climate technology policies, and empirically analyses its relationship with carbon emissions per GDP (i.e. carbon intensity) and its two components: energy intensity and the carbon factor. Evidence of the causality links that have prevailed in 13 advanced economies over the 1980–2004 period has been obtained through dynamic panel models. Our findings confirm that government R&D spending is not sufficient by itself to boost the energy innovation process. Public energy R&D has been successful in improving energy efficiency at country level, but it has failed to have a significant impact on the carbon factor and carbon intensity. At the same time the formation of energy R&D budgets is found to be significantly affected by carbon trends.     

Lost carbon emissions: the role of non-manufacturing “other industries” and refining in industrial energy use and carbon emissions in IEA countries

We present a review of trends in energy use and output in branches of industry not often studied in detail: petroleum refining and what we call the other industries — agriculture, mining, and construction. From a sample of IEA countries we analyze eight with the most complete data from the early 1970s to the mid-1990s. We carry out a decomposition analysis of changes in energy use and carbon emissions in the “other industries” sector. We also review briefly the impact of including refining in the evolution of manufacturing energy use, usually studied without refining. Despite many data problems, we present our results as a way of enticing others to study these important “lost” sectors more carefully. We have five basic findings. First, “other industries” tends to be a minor consumer of energy in many countries, but in some, particularly Denmark, the US, and Australia, mining or agriculture can be a major sector too large to be overlooked. Second, refining is an extremely energy intensive industry which despite a relatively low share of value added consumes as much as 20% of final energy use in manufacturing. Third, as a result of a slower decline in the carbon-intensity of these industries vis-à-vis the manufacturing industries, their share of industrial emissions has been rising. Fourth, for other industries variation in per capita output plays a relatively small role in differentiating per capita carbon emissions compared to the impact of subsectoral energy intensities. Finally, including this energy in CO₂ calculations has little impact on overall trends, but does change the magnitude of emissions in most countries significantly. Clearly, these industries provide important opportunities for searching for carbon emissions reductions.     

Building low carbon communities in China: The role of individual’s behaviour change and engagement

Low carbon sustainability has been addressed in China’s national development strategies. This research explores individual behaviour change and engagement in building low carbon communities in China through a case study looking at the building of a low carbon campus at Fudan University, Shanghai. Individual behaviour directly influences the overall energy consumption and carbon emissions on Fudan University’s campus. Even though relevant polices have been issued for energy conservation, the energy consumption increased by 5% every year, which suggests that the “top-down” approach telling students and staff “what to do” does not work effectively. Based on a comprehensive method which includes the individual and social aspects related to the energy behaviour, the research analyses the promotion of individual engagement in building a low carbon campus through behaviour change based on four main aspects: (1) awareness raising and behaviour forming; (2) approaches to encourage behaviour change; (3) beyond the barriers and the constraints; and (4) systems and mechanisms for the long-term engagement. A low carbon management system is proposed for not only addressing management and technical solutions at the university level, but also based on the contributions from behaviour changes in establishing a low carbon campus at Fudan University at the individual level.     

Stuck between a ROC and a hard place? Barriers to the take up of green energy in the UK

This paper examines the UK mechanisms for ensuring future investment in renewable energy through consumer adoption of green energy tariffs and the Renewable Obligation Certificate (ROC) system. Using a national survey and focus groups the stated willingness by UK customers to pay a premium for renewable or green energy and actual take up of such tariffs is assessed. Substantial differences between willingness to pay for and the adoption of green energy tariffs are reported. This disparity is linked to a range of factors including consumer confusion, lack of supply, complexities of constructing ‘green source’ tariffs under the ROC system and a lack of customer trust. It is concluded that the re-definition of the green energy market in favour of ‘green source’ tariffs, greater direct compliance with the Renewable Obligation by addressing supply constraints, and efforts in providing clearer information and choices for consumers via a compulsory green energy accreditation scheme are required if willing consumers’ are to contribute to investment in renewable energy.     

Renewable and low carbon hydrogen for California – Modeling the long term evolution of fuel infrastructure using a quasi-spatial TIMES model

This paper describes the development and use of a hydrogen infrastructure optimization model using the TIMES modeling framework, H2TIMES, to analyze hydrogen development in California to 2050. H2TIMES is a quasi-spatial model that develops the infrastructure to supply hydrogen fuel in order to meet demand in eight separate California regions in a least cost manner subject to various resource, technology and policy constraints. A Base case, with a suite of hydrogen policies now in effect or proposed in California (renewable hydrogen mandate, fuel carbon intensity constraint and prohibition on using coal without carbon capture and sequestration) leads to hydrogen fuel with significant reductions in carbon intensity (85% below gasoline on an efficiency-adjusted basis, 75% below on a raw energy basis) and competitive hydrogen costs (∼$4.00/kg in 2025–2050). A number of sensitivity scenarios investigate the cost and emissions implications of altering policy constraints, technology and resource availability, and modeling decisions. The availability of biomass for hydrogen production and carbon capture and sequestration are two critical factors for achieving low-cost and low-emission hydrogen.     

Energy and environmental optimization in thermoelectrical generating processes—application of a carbon dioxide capture system

Increased thermodynamic efficiency coupled with reduced impact on the environment are fundamental aims in the generation and rational use of energy if a contribution is to be made towards sustainable development on both a local and worldwide scale. Technological developments over recent years in the field of thermal electricity generation, together with research and technologies emerging from environmentally friendly systems, are allowing increases in the efficiency of energy generating processes accompanied by a reduction in polluting gases released into the atmosphere. This work develops the methodology for defining and designing a cogeneration plant based on a combined cycle and using a computer program to provide time simulation. By way of example, the results obtained from the thermal power station of a chemical complex are given. As a novel feature, the work includes the application of a system to capture carbon dioxide, a gas that makes a significant contribution to the so-called ‘greenhouse effect’, the main cause of global warming. The work carried out allows highly accurate forecasting of future working of the cogeneration system in the proposed application, and analysis of the performance of the plant as a function of its capacity to capture carbon dioxide. The work also considers the feasibility of long-term confinement of the captured carbon dioxide in the deep ocean, and analyses its impact on plant efficiency. Finally, an economical analysis of the proposed plant is included in order to evaluate the impact of the potential carbon dioxide capture and storage system.     

Heat transfer enhancement in a small pipe by spinodal decomposition of a low viscosity,liquid–liquid,strongly non-regular mixture

We report experimental evidence of a 20–40 % enhancement of the effective heat transfer coefficient for laminar flow of a partially miscible binary liquid–liquid mixture in a small diameter horizontal tube that obtains when phase separation occurs in the tube. A mixture of acetone–hexadecane is quenched into the two-phase region so as to induce spinodal decomposition. The heat transfer rate is enhanced by self-induced convective effects sustained by the free energy liberated during phase separation. The experimental heat transfer coefficients obtained when separation occurs are compared to the corresponding values predicted for flow of a hypothetic mixture with identical properties but undergoing separation. For such comparison, the energy balance equation must carefully take into account both the sensible heat and the excess enthalpy difference between the inlet and the outlet streams because our liquid–liquid binary mixture is a very asymmetric system with large excess enthalpies. The non-ideal mixture thermodynamic properties needed for the energy balance are obtained by an empirical procedure from the experimental data available in the literature for our mixture. The experimental setup and calculation procedure is tested by experiments performed using single-phase water flow and single-phase mixture flow (above the critical point). The convective heat transfer augmentation that results in the presence of liquid–liquid phase separation may be exploited in the cooling or heating of small scale systems where turbulent convection cannot be achieved.     

Green economy and green jobs: Myth or reality? The case of China’s power generation sector

This paper investigates the relationship between the green economy and green jobs in China through the following question: Can the current GHG mitigation policies in China’s power generation sector bring more jobs to China? Using both analytical and input–output models this paper analyzes the direct and indirect employment impacts of two main mitigation policies in the power generation sector. This paper proves that the above-mentioned question is not simple. Mitigation policies in China’s power generation sector from 2006 to 2009 caused a total of 44 thousand net jobs losses. However, as the share of renewable energy that has an indirect employment impacts increased in 2010, the policies from 2006 to 2010 actually resulted in 472 thousand net job gains. This paper asserts that to ensure the co-existence of green economy and green jobs in China’s power generation sector, policy makers should further promote solar PV, biomass and wind technologies. In 2010, for every one percent increase in the share of solar PV generation there could be a 0.68% increase in total employment in China, larger than any other power generation technology. Finally, this paper argues that a matching educational system and personnel structure is also needed.     

How does tax system on energy industries affect energy demand,CO2 emissions,and economy in China?

Energy savings and CO₂ emission reduction have become a major issue in recent years. Taxes on energy production sectors may be an effective way to save energy, reduce CO₂ emissions, and improve environmental quality. This paper constructs a dynamic recursive Computable General Equilibrium (CGE) model to analyze the impact of the energy tax on energy, economy, and environment from the perspective of tax rates and tax forms (specific tax and ad valorem tax). The results show that adjusting the tax system and the tax rate has important implications for energy conservation while having minor impacts on the output of other industries. The impact of an increasing energy tax on the energy demand is greater than the impact on sectoral output, indicating that energy efficiency will be increased to some extent. The CO₂ reduction will increase over time when an ad valorem tax is implemented on enterprises. We found that ad valorem tax has greater elasticity of economic output, energy demand, and CO₂ emission reduction. The results support the direction of China's resource tax reform. However, we argue that it is better to increase the tax rate relatively and relax the control on energy prices so that energy efficiency will increase.     

Study on China's low carbon development in an Economy–Energy–Electricity–Environment framework

Emissions mitigation is a major challenge for China's sustainable development. We summarize China's successful experiences on energy efficiency in past 30 years as the contributions of Energy Usage Management and Integrated Resource Strategic Planning, which are essential for low-carbon economy. In an Economy–Energy–Electricity–Environment (E4) framework, the paper studies the low-carbon development of China and gives an outlook of China's economy growth, energy–electricity demand, renewable power generation and energy conservation and emissions mitigation until 2030. A business-as-usual scenario is projected as baseline for comparison while low carbon energy and electricity development path is studied. It is defined as low carbon energy/electricity when an economy body manages to realize its potential economic growth fueled by less energy/electricity consumption, which can be characterized by indexes of energy/electricity intensity and emissions per-unit of energy consumption (electricity generation). Results show that, with EUM, China, could save energy by 4.38 billion ton oil equivalences (toes) and reduce CO₂ emission by 16.55 billion tons; with IRSP, China, could save energy by 1.5 Btoes and reduce CO₂ emission by 5.7 Btons, during 2010–2030. To realize the massive potential, China has to reshape its economic structure and rely much on technology innovation in the future.     

Appearance of a low superheat “quasi-Leidenfrost” regime for boiling on superhydrophobic surfaces

Pool boiling experiments were performed with degassed water on stainless steel substrates with different surface topographies and wettabilities. Boiling curves and visual observations of the boiling process have been carried out. The onset of nucleate boiling (ONB) has been measured and the influence of roughness and wettability has been quantified. Boiling curve shape is different between the hydrophilic and the superhydrophobic cases; superhydrophobic surfaces reaching the ONB heat flux at a lower superheat and presenting a "quasi-Leidenfrost" regime, without showing the typical boiling curve. Bubbles are easier to form on superhydrophobic surfaces, therefore the nucleation temperature is smaller, and bubbles are larger and stable. The ONB appears after less than 5 K of superheat on superhydrophobic surfaces, while on hydrophilic surfaces, with the same surface roughness, the superheat is above 7 K. Furthermore, superhydrophobic samples with a different roughness present the same boiling curve, meaning that, when the contact angle exceeds a certain value, the wettability has a predominant role on the surface roughness.     

Dynamic production,storage, and use of renewable hydrogen: A technical-economic-environmental analysis in the public transport system in São Paulo state,Brazil

This article proposes a calculation methodology that starts from the demand calculation to supply a fleet bus with renewable hydrogen based on the electrolysis process until the energetic, economic, and environmental analyses, involving all the processes of the productive chair. Also considering the dynamic behaviour of the following hydrogen processes: production, storage, and use. The simplified scheme of the proposed system configuration to be studied consists of the use of alternative and renewable sources of energy (solar-wind-biogas) to generate electrical energy in order to produce hydrogen from electrolysis of the water, which is stored in its gaseous state and subsequently redirected to a filling station to be used as vehicle fuel in buses. The results show that to feed one bus the hybrid system generates an average of 78,110 kWh/month with an installed capacity of 1101.905 kW, producing 1209.90 kgH₂/month through the electrolysis process from water. The results also show a range of electricity generation costs between 1.130 and 0.123 US$/kWh and H₂ production between 0.963 and 0.110 US$/kWh. Concluding that the application of renewable energies to produce hydrogen and electricity for the public transport sector is an attractive alternative in the future throughout the country, because the proposed system is technically, economically and ecologically viable.     

Price drivers and structural breaks in European carbon prices 2005–2007

This article aims at characterizing the daily price fundamentals of European Union Allowances (EUAs) traded since 2005 as part of the Emissions Trading Scheme (ETS). The presence of two structural changes on April 2006 following the disclosure of 2005 verified emissions and on October 2006 following the European Commission announcement of stricter Phase II allocation allows to isolate distinct fundamentals evolving overtime. The results extend previous literature by showing that EUA spot prices react not only to energy prices with forecast errors, but also to unanticipated temperatures changes during colder events. Besides, the sub-period decomposition of the pilot phase gives a better grasp of institutional and market events that drive allowance price changes.     

Mathematical model for gas–liquid two-phase flow and biodegradation of a low concentration volatile organic compound (VOC) in a trickling biofilter

A theoretical model is established for predicting the biodegradation of a low concentration volatile organic compound (VOC) in a trickling biofilter. To facilitate the analysis, the packed bed is simplified to a series of straight capillary tubes covered by the biofilm in which the liquid film flow on the surface of biofilm and the gas core flow in the center of tube. The theoretical formulas to calculate liquid film thickness in the capillary tube are obtained by simultaneously solving a set of hydrodynamic equations representing the momentum transport behaviors of the gas–liquid two-phase flow under co-current flow and counter-current flow. Subsequently, the mass transport equations are respectively established for the gas core, liquid film, and biofilm with considering the mass transport resistance in the liquid film and biofilm, the biochemical reaction in the biofilm, and the limitation of oxygen to biochemical reaction. Meanwhile, the surface area of mass transport in the capillary tube is modified by introducing the active biofilm surface area, namely the specific wetted surface area available for biofilm formation. The predicted purification efficiencies of VOC waste gas are found to be in good agreement with the experimental data for the trickling biofilters packed with ?8 mm, ?18 mm, and ?25 mm ceramic spheres under the gas–liquid co-current flow mode and counter-current flow mode. It has been revealed that for a fixed inlet concentration of toluene, the purification efficiency of VOC waste gas decreases with the increase in the gas and liquid flow rate, and increases with the increase in the specific area of packed materials and the height of packed bed. Additionally, it is found that there is an optimal porosity of packed bed corresponding to the maximal purification efficiency.     

Cattaneo–Christov heat flux model and multiple slip effect on carbon nanofluid over a stretching sheet in a Darcy–Forchheimer porous medium

In several biotechnological processes, multiple slips are the most paramount, such as blood pumping from the heart to different body components, endoscopy treatment, pabulum distribution, and the heat transport phenomenon regulation. In the current research, we have studied the multiple slips, Darcy–Forchheimer, and Cattaneo–Christov heat flux model on a stretching surface exposed to magnetic carbon nanotube nanofluid. We have additionally included a heat source or sink, a chemical reaction for manipulating the heat and mass transport phenomena. The resulting governing partial differential equations have been transformed into ordinary differential equations. With the Runge–Kutta–Fehlberg fourth–fifth-order procedure, the transformed governing equations are numerically solved. Numerical solutions for different parameters for velocity, temperature, and concentration profiles (Eckert number, velocity slip, thermal slip, mass slip, etc.) are highlighted. Graphical and numerical results for the various parameters in the modeled problem have been outlined. The present numerical results are compared with the published ones for some limiting cases. The slip has been found to control the flow of the boundary layer.     

Fe,N codoped porous carbon nanosheets for efficient oxygen reduction reaction in alkaline and acidic media

Electrospinning typically employed to fabricate nanofibers was first used to prepare Fe and N doped porous carbon nanosheets (Fe–N/CNs) as oxygen reduction reaction (ORR) electrocatalysts. Polyacrylonitrile nanofibers containing a small amount of ferrocenes (Fer-PAN) were produced by electrospinning. When Fer-PAN was preoxidized at 300 °C in the air (Fer-PAN-300), nanosheets were formed and occupied the interspace between nanofibers. Fe–N/CNs was finally obtained using carbonized Fer-PAN-300 at 900 °C in N₂. The Fe–N/CNs incorporated the advantages of carbon nanofiber webs and porous nanocarbon materials, inclusive of comparatively high conductivity and large specific surface area. In both alkaline and acidic electrolyte, the Fe–N/CNs took on similar even better ORR catalytic activity than other catalysts reported elsewhere, and better stability than those of commercial Pt/C.     

Synergies of carbon neutrality,air pollution control,and health improvement——a case study of China Energy Interconnection scenario

Climate change and air pollution are primarily caused by the combustion and utilization of fossil fuels.Both climate change and air pollution cause health problems.Based on the development of China,it is extremely important to explore the synergies of the energy transition,CO₂ reduction,air pollution control,and health improvement under the target of carbon peaking before 2030 and carbon neutrality before 2060.This study introduces the policy evolution and research progress related to...