Substantial Reduction Of CO2 Emissions Research Articles

Heterostructure Engineering of a Reverse Water Gas Shift Photocatalyst.

To achieve substantial reductions in CO2 emissions, catalysts for the photoreduction of CO2 into value‐added chemicals and fuels will most likely be at the heart of key renewable‐energy technologies. Despite tremendous efforts, developing highly active and selective CO2 reduction photocatalysts remains a great challenge. Herein, a metal oxide heterostructure engineering strategy that enables the gas‐phase, photocatalytic, heterogeneous hydrogenation of CO2 to CO with high performance metrics (i.e., the conversion rate of CO2 to CO reached as high as 1400 µmol g cat−1 h−1) is reported. The catalyst is comprised of indium oxide nanocrystals, In2O3− x(OH)y, nucleated and grown on the surface of niobium pentoxide (Nb2O5) nanorods. The heterostructure between In2O3− x(OH)y nanocrystals and the Nb2O5 nanorod support increases the concentration of oxygen vacancies and prolongs excited state (electron and hole) lifetimes. Together, these effects result in a dramatically improved photocatalytic performance compared to the isolated In2O3− x(OH)y material. The defect optimized heterostructure exhibits a 44‐fold higher conversion rate than pristine In2O3− x(OH)y. It also exhibits selective conversion of CO2 to CO as well as long‐term operational stability.

Optimum Turf Grass Irrigation Requirements and Corresponding Water- Energy-CO2 Nexus across Harris County, Texas

Harris County is one of the most populated counties in the United States. About 30% of domestic water use in the U.S. is for outdoor activities, especially landscape irrigation and gardening. Optimum landscape and garden irrigation contributes to substantial water and energy savings and a substantial reduction of CO2 emissions into the atmosphere. Thus, the objectives of this work are to (i) calculate site-specific turf grass irrigation water requirements across Harris County and (ii) calculate CO2 emission reductions and water and energy savings across the county if optimum turf grass irrigation is adopted. The Irrigation Management System was used with site-specific soil hydrological data, turf crop water uptake parameters (root distribution and crop coefficient), and long-term daily rainfall and reference evapotranspiration to calculate irrigation water demand across Harris County. The Irrigation Management System outputs include irrigation requirements, runoff, and drainage below the root system. Savings in turf irrigation requirements and energy and their corresponding reduction in CO2 emission were calculated. Irrigation water requirements decreased moving across the county from its north-west to its south-east corners. However, the opposite happened for the runoff and excess drainage below the rootzone. The main reason for this variability is the combined effect of rainfall, reference evapotranspiration, and soil types. Based on the result, if the average annual irrigation water use across the county is 25 mm higher than the optimum level, this will result in 10.45 million m3 of water losses (equivalent water use for 30,561 single families), 4413 MWh excess energy use, and the emission of 2599 metric tons of CO2.

Hybrid renewable energy systems for household ancillary services

The development of Hybrid Renewable Energy Systems (HRES) under the Distributed Generation (DG) paradigm is the support for substantial reduction of CO2 emissions and for greater penetration of renewable energy sources. The performance and reliability of HRES depend on the interaction between demand, generation, storage and the energy management strategy. In this study a comparison between two different control strategies is presented. In particular, a Rule Based Control (RBC) strategy has been compared with a more sophisticated Model Predictive Control (MPC) for the management of an HRES for residential applications.Results show that a HRES operating in a connected mode has potential to support grid balancing actions giving economic benefits for both end-users and providers. Moreover, the MPC strategy gives a potential reduction of the unbalanced energy exchange with the grid and a more efficient use of the HRES components. The MPC strategy allows thus for a more effective use of renewable sources if compared with a conventional RBC for a Microgrid of same size, thus allowing for a greater penetration of renewable sources into the energy mix, or equivalently, toward downsizing of storage and programmable source subsystems with economic benefits.

Carbon footprint of tourism in Barcelona

This study evaluates the carbon footprint (CF) of Barcelona tourist activity taking into account the above 30 million visitors who visit the city every year. This study analyzes the main sources of emissions considering direct (Scope 1) and indirect emissions (Scope 2 and 3) as a consequence of energy use. This research has been carried out in close collaboration with Barcelona City Council and in the context of the new Strategic Tourism Plan for Barcelona city. The impacts of arrival and departure transport, accommodation, leisure and professional activities and Intra-urban transport from Barcelona city were all included. The total CF of Barcelona tourist activity is about 9.6MtCO2eq/year, which represents an emission of 96.9 kg CO2eq/visitor·day. The main source of emissions is arrival and departure transport (95.6%), and particularly aviation. These results show that if substantial reductions in CO2 emissions are to be achieved, initiatives strategically focused on transport and also accommodation are necessary.

Measuring the effects of an urban freight policy package defined via a collaborative governance model

In recent years the European Commission has increasingly focused its attention on the development of sustainable city logistics by promulgating legislation and formal directives. Despite the efforts made, reducing freight-related congestion and polluting emissions without penalising social and economic activities within cities is still a challenging issue. City logistics measures frequently fail mainly due to a lack of support and commitment from stakeholders. A participatory approach in freight transport planning represents a reasonable and valuable option.This paper describes the innovative governance model developed in the city of Turin in Italy that was based on a proactive and effective stakeholders' cooperation for achieving a resilient urban development. The added value of the paper also relates to the real-life assessment of the impacts the non-mandatory policy-mix implemented, based on a collaborative governance model, have on the environment and service delivery thus providing a realistic measure of the viability and effectiveness of the solution proposed. Its voluntary adoption, in fact, produces an increase in commercial vehicles’ speed and a substantial reduction in CO2 emissions while also allowing logistic service providers to perform more deliveries.

Smart cooling systems for the urban environment. Using renewable technologies to face the urban climate change

Urban heat island and global warming increase the urban ambient temperature. Increased temperatures have a tremendous effect on the energy demand for cooling, with a great impact on peak and total electricity demand.Renewable technologies in the urban environment have been widely regarded as an increasingly important solution to deal with the climate change challenges and energy security. Significant effort is performed in the integration of photovoltaic panels (PV) and micro turbines in the urban context showing a substantial reduction in CO2 emissions. At the same time attention is drawn to an often-overlooked aspect regarding renewable energy technologies, in that despite having low operating costs their overall benefits are often not well understood and consequently are often evaluated as being less profitable than fossil fuel alternatives, even though they are future proof about energy cost.The aim of the present paper is to describe the role of renewable energy technologies and zero carbon technologies in covering the future increased energy demand for cooling.The integration of photovoltaics in the urban environment through PV facades, pavements, and shading devices are discussed.The role of Information and Computer Technology and smart grids in the efficient management of renewables in urban scale is discussed. The role of smart metering, users ‘integration and demand response capabilities for future zero energy urban neighborhoods is revealed.

Injection of nanosized CO2 droplets as a technique for stable geological sequestration

Geological sequestration of carbon dioxide (CO2) is considered an important technology to achieve a substantial reduction in CO2 emissions. However, leakage is a risk of geological sequestration because CO2 migrates upwards by buoyancy. This study proposes a new technique using nanosized CO2 droplets injected into a porous structure to decrease the buoyancy effect, thereby preventing the upward migration of CO2. We focus on the formation of nanosized CO2 droplets, their subsequent size variation over time, and their behavior in porous media. Experiments are performed using a volume ratio of CO2 to water of 1:1 and trisiloxane (0.4–1.6%) as a surfactant. In the experiments, nanosized CO2 droplets with initial diameters in the range of 20–100nm are successfully generated. The droplet coalescence rate depends on both temperature and CO2 density. Experimental results also indicate that sufficiently small CO2 droplets can be maintained throughout the injection process and readily introduced into an aquifer. Microfocus X-ray computed tomography shows that CO2 is stably trapped in a porous medium. This study suggests that nanosized CO2 droplets hold considerable promise as a means of stable geological sequestration. Surfactant optimization and cost reduction need to be addressed for field application of this approach.

Sustainable logistics network for wood flow considering cascade utilisation

To address the growing demand for wood as a renewable resource, a trend that has arisen in recent years is to follow the principle of cascade utilisation and to use wood residues from by-products. The cascading principle represents a method supporting resource efficiency through the sequential use of the remaining quality resources from previous commodities and substances. The logistics concept deserves special attention with respect to the utilisation of wood resources and the cascading principle as logistics processes constitute the largest share of costs.This work considers a logistics network for wood flow for different products in various sectors. Examples include a logistics network for particle board in the material-based sector, pulp and paper production in the chemical sector, and wood pellets production in the energy sector using cascade utilisation and recovered wood. A transportation problem is modelled using a mixed-integer linear programming (MILP) model, and it is applied to a case study in Lower Saxony using the software CPLEX v12.5. The aim is to minimise the total logistics costs of a logistics network, including those associated with harvesting, chipping, storage and transportation, for several companies in different sectors. UMBERTO, a life cycle assessment (LCA) software, is used to investigate the potential environmental impacts of the optimised logistics network. The approach is applied to three scenarios in Lower Saxony, a state in Germany. The initial results indicate that the total cost of the considered wood logistics network does not change significantly for the cascading scenarios in comparison to that associated with fresh wood, but there would be a substantial reduction in CO2 emissions if cascade utilisation is used in the logistics network.

Benefits From The Use Of Pellet Boilers In The Energy Rating Of Buildings

Using renewable energy contributes to reducing CO2 emissions and improves energy ratings. The building sector is responsible for a significant portion of global CO2 emissions. European Directive 2002/91/EC on the Energy Performance of Buildings, and the recast in Directive 2010/31/EU, configures the legislative framework of the European Union with respect to the energy rating of buildings in Member States. This chapter summarizes the different transpositions regarding energy ratings and renewable energy sources, and more specifically it examines the CO2 emissions and the energy rating using pellet boilers with different climatic conditions, based on real cases. It is concluded that replacing gasoil by wood pellets can lead to reductions in CO2 emissions that range from 82.91% to 95.28%. Such a substantial reduction of CO2 emissions directly affects the final energy rating, improving it as much as four levels on a scale of seven levels. Meanwhile, the economic savings from using wood pellets instead of gasoil may reach 68.82%.

Designing by Degrees: Flexibility and Cost-Effectiveness in Climate Policy

Substantially reducing carbon dioxide (CO2) emissions from electricity production will require a transformation of the resources used to produce power. This paper analyzes the economic consequences of a suite of different flexible and comprehensive policies to reduce CO2 emissions from the power sector, including a carbon tax, a tradable emissions rate performance standard, and two versions of a clean energy standard (CES). A technology-based CES can bring about substantial reductions in CO2 emissions but would neglect to harvest some economic reductions because it fails to affect decisions at three margins: emissions rate heterogeneity in the natural gas and coal generation fleets and electricity demand reductions. Natural gas emissions rate heterogeneity can be addressed by crediting clean generation based on emissions rates instead of technology. Coal emissions rate heterogeneity can be addressed by altering the policy to credit all generators instead of just a subset. Demand reductions can be harvested by removing the subsidy component of the policy and allowing retail electricity prices to rise. Harvesting emissions abatement on all three margins saves about 40 percent of the discounted cumulative economic welfare costs of a technology-based CES through 2035, although the distributional implications are different. All of the policies result in substantial increases in social welfare.

Analysis of the Bingaman clean energy standard proposal

A clean energy standard (CES) is a flexible approach to encouraging a cleaner technology mix for electricity production. The most recent federal CES proposal from former Senator Bingaman would transform the way electricity is produced and result in substantial reductions in CO2 emissions with small national average electricity price effects through 2025. After 2025, electricity prices would increase substantially. The alternative compliance payment (ACP) for clean energy credits will be binding, so actual deployment of clean energy will fall short of the intended targets, and cumulative emissions reductions by 2035 will be 12 percent smaller than they would be without an ACP. The small utility exemption from the CES requirements equates to roughly $29billion in avoided electricity expenditures by the customers of exempted utilities in 2035 alone. Excluding power generated by existing nuclear and hydroelectric facilities from CES compliance responsibility raises electricity prices in competitive regions to the benefit of owners of existing nuclear and hydroelectric capacity.

Emission Reduction Commitments and International Carbon Trading: Assessment of Impact on India and China Based on GTAP-E Model

The paper investigates how serious will be the impact on India’s economy if India were to make a commitment for substantial reduction in CO2 emissions. Such investigation is done also for China. The analysis is undertaken through counter-factual simulations for the year 2001 by developing scenarios in which India and China cut CO2 emissions by a specified percentage and there exists international trading in carbon. The analysis is undertaken with the help of GTAP-E model. The analysis brings out that the cost of meeting emissions reduction commitments for Annex-I countries can be substantially reduced by engaging in block-level or global carbon trading. The simulation results, obtained under the assumptions that both China and India accept the obligation of cutting CO2 emissions between 5 and 15 percent and there is international carbon trading, indicate that emission cuts in China will reduce welfare both under block carbon trading and global carbon trading. For India, on the other hand, there is an increase in welfare by about 0.2 to 0.3 per cent. Going by the simulation results, China and India would voluntarily cut CO2 emissions if profitable international carbon trading possibilities exist. Therefore, besides negotiating for legally binding commitments for emissions reduction, efforts should be directed at developing international markets for carbon.

Shallow geothermal energy in Denmark

The use of shallow geothermal energy instead of fossil fuels can lead to substantial reductions in CO2 emissions. However, the use of shallow geothermal energy in Denmark is limited compared to, e.g. Sweden and Germany and we still lack know-how and experience with its use in Denmark. In co-operation with research and industry partners, the Geological Survey of Denmark and Greenland is conducting a three-year project GeoEnergy, Tools for ground-source heating and cooling based on closed-loop boreholes (www.geoenergi.org). The objective of the project is to acquire knowledge and develop tools and best practice for the design and installation of shallow geothermal energy systems.

Mixtures of hydrogen and methane in the internal combustion engine – Synergies, potential and regulations

Taking advantage of the multi-fuel ability of internal combustion engines, mixtures of hydrogen and methane as fuel allow a substantial reduction of CO2-emissions at affordable costs. By means of a prototype vehicle that was adapted for the operation with mixtures of methane and hydrogen and approved for road traffic, necessary technical adjustments and safety measures for gas-powered vehicles are explained.Synergies in production, storage, distribution, and combustion of mixtures of hydrogen and methane in terms of technical specifications, safety, regulations, and infrastructure are analyzed.In the EU blends of hydrogen and methane are seen as an interesting option to reduce emissions in vehicle traffic. Legislation is updated to include these blends. A survey of international regulations and standards for gas-powered vehicles is given, addressing issues of type-approval, fuel consumption and pollutant emission in detail.

Introducing District Heating in a Norwegian town – Potential for reduced Local and Global Emissions

This paper presents the results of a municipal energy system analysis where the role of district heating is emphasised. A simplified energy system model based on linear programming is used to study the impact of introducing biomass based district heating in the community. Based on existing situation, some cases are outlined where district heating with varying degree is included as an option. Based on the assumed input data the analysis shows that district heating can play an important role in reshaping the municipal energy system which is dominated by electricity and fossil fuels. A substantial reduction of CO2 emissions can be achieved by replacing fossil fuels and electricity. There is also a possibility to improve local environment by replacing inefficient wood combustion which gives high values of particulate emissions and other harmful compounds.Unlike individual heating, district heating is associated with distribution costs that may be critical to its profitability (particularly in low heat demand areas). In addition, one should keep in mind the need for investment in possible building conversion (switching to hydronic heating system) measures. In relation to today’s energy costs, the total distribution cost of district heat appears to be at such a low level that this together with the assumed fuel prices and investment cost could provide favourable conditions for district heating. If viable, there is also potential for local combined heat and power production.

Reduction of power losses with smart grids fueled with renewable sources and applying EV batteries

Abstract This paper describes a low-voltage grid composed of small, domestic power plants fueled by clean and renewable energy sources and augmented with electric vehicle batteries as power storage devices. We propose that this grid could utilize a complex multifunctional control unit capable of optimizing the working point and charging current of the system, while also implementing active power factor correction, lowering extant harmonic distortion and controlling the voltage level in the low-voltage power lines. The complex controller structure proposed in this paper contains the following novel components: an upper harmonic controller which (together with the connection voltage controller) minimizes the amplitudes of the 3rd, 5th, 7th, 9th, and 11th high order components in the output voltage; and a connection voltage controller which controls the energy flow between the low-voltage network, its renewable energy sources and the electrical vehicle batteries. Unlike other similar approaches, the harmonic controller proposed in this paper does not rely on a measured current signal but rather optimizes the voltage shape, the latter of which depends on the nonlinear distortion of the whole low-voltage transformer area and determines additional power losses. We analyzed the proposed controller via simulations in a Matlab environment and as a result, achieved substantial improvements to the output voltage, current waveform and energy flow of the system’s low-voltage conditions. Our calculations show that the implementation of substantial reductions in CO2 emissions could be achieved for an average household. The robustness of the method against nonlinear loads and fluctuations in overloads and overproductions was also tested.

CCS Chain Capacity Selection for Flexible Load Power Plant

Coupling flexible power generation with Carbon Capture and Sequestration (CCS) technology may be important for substantial reductions in CO2 emissions. In this paper we consider some of the implications of flexible power plant operation on the CCS process. Specifically, we consider the CCS chain capacity selection decision, by which we mean the choice of the optimal plant size, to understand what determines the amount of CO2 that is efficient to capture and how the decision to invest in CCS chain capacity is affected by price volatility of CO2 emissions quotas. We found that the plant's emissions profile determined a range of CCS capacities that could be efficient with the tradeoff between the price of CO2 emissions quotas and the cost of CCS technology determining the specific optimal chain capacity. Secondly, investment into CCS technology for a flexible load power plant was more likely to be delayed in a multiple time point investment decision tree model as a result of price volatility, compared to investment in CCS technology on a base load power plant.

The client perspective on factors in the retrofitting of sustainable technologies to traditional rural homes in North East Scotland

Through the study of a project completed in 2009, this article seeks to determine what barriers can be encountered by homeowners when trying to improve the performance of older properties with regard to energy use and CO2 emissions. The scope of the study is determined by the type of dwelling that is its focus, the traditional farmhouse as constructed during the late nineteenth and early twentieth centuries in NE Scotland, along with the boundary set by the client's interpretation of ‘sustainability’. Within this scope, this article aims to report on the decision-making process that resulted in real-world ‘solutions’ to the identified barriers. Learning that results from the study relates to findings reported in the literature, particularly with regard to types of barriers encountered when attempting to mitigate against climate change by retrofitting technologies and materials to existing housing. In addition, there is learning related to the manner in which homeowners may make decisions in response to the identified barriers that result in a series of revisions of the initial list of technologies and materials. Such revisionary activity suggests that there remain significant problems to be addressed before substantial reductions in CO2 emissions from traditional dwellings can be achieved.

九州大学伊都キャンパスにおける流体工学モデルRIAM-COMPACT【○!R】を用いた100kW級風レンズ風車のマイクロサイティング : 第2報 土地造成を考慮した場合

As a countermeasure against global warming, a substantial reduction in CO2 emissions has become an urgent issue. Accordingly, the effective use of wind power energy is attracting attention as a clean and environmentally friendly solution. Given this background, we have developed RIAM-COMPACT【○!R】 (Research Institute for Applied Mechanics, Kyushu University, COMputational Prediction of Airflow over Complex Terrain, a non-stationary, non-linear wind synopsis simulator that is capable of predicting the optimum sites for wind turbine construction to the pin-point level within a target area of a few km or less. In this study, a high resolution micro-siting of 100kW wind-lens turbines, considering the land preparation, was performed in the new campus of Kyushu University.

Micro combined heat and power technologies and control for residential applications

Residential applications are considered among the most important areas for substantial reduction of CO2 emissions because they represent a major part of the total consumed energy in those countries. In order to achieve a significant CO2 reduction, many initiatives must be adopted in the policy of these countries. One of these initiatives is to introduce micro combined heat and power (μCHP) systems into residential energy systems, since they offer several advantages such as the ability to burn not just natural gas but renewable fuels (Taylor, 2005). This paper summarises key points that outline the trend of previous research carried out in the field of μCHP systems in residential energy systems, especially for single dwellings. The reviewed areas include: residential energy demand and μCHP, technologies and auxiliary components used in residential μCHP systems, and control strategies and techniques for these systems.