Renewable Energy Transportation Research Articles

The potential of photovoltaic carports to cover the energy demand of road passenger transport

ABSTRACTTransport accounts for 31% of Swiss green house gas emissions due to the high degree of oil dependence in transport energy supply. The emissions of transport could be reduced significantly if all the vehicles that ran on fossil fuels would be replaced by electric vehicles powered by photovoltaic solar energy. Compared with other sources of renewable transport energy, photovoltaic generation of electricity has two advantages: it requires little space and can also be applied to built‐up areas or transport infrastructure. In this paper, we will examine the potential of parking lots for the photovoltaic generation of solar electricity. The paper is based on simulations that were carried out for 48 parking lots in Frauenfeld, a typical Swiss medium‐sized city of 22 665 inhabitants. Covered with solar carports, these parking lots alone would cover 15–40% of the energy demand by the city's road passenger transport. Copyright © 2011 John Wiley & Sons, Ltd.

Economic and European Union Environmental Sustainability Criteria Assesment of Bio-Oil-Based Biofuel Systems: Refinery Integration Cases

The biofuel mix in transport in the U.K. must be increased from currently exploited 3.33% to the EU target mix of 10% by 2020. Under the face of this huge challenge, the most viable way forward is to process infrastructure-compatible intermediate, such as bio-oil from fast pyrolysis of lignocellulosic biomass, into biofuels. New facilities may integrate multiple distributed pyrolysis units producing bio-oil from locally available biomass and centralized biofuel production platforms, such as methanol or Fischer–Tropsch liquid synthesis utilizing syngas derived from gasification of bio-oil. An alternative to bio-oil gasification is hydrotreating and hydrocracking (upgrading) of bio-oil into stable oil with reduced oxygen content. The stable oil can then be coprocessed into targeted transportation fuel mix within refinery in exchange of refinery hydrogen to the upgrader. This Article focuses on the evaluation of economic and environmental sustainability of industrial scale biofuel production systems from bio-oils. An overview of bio-oil gasification-based system evaluation is presented, while comprehensive process reaction modeling (with 40 overall bio-oil hydrocracking and hydrotreating reaction steps), simulation, integration, and value analysis frameworks are illustrated for bio-oil upgrading and refinery coprocessing systems. The environmental analysis shows that the former technologies are able to meet the minimum greenhouse gas (GHG) emission reduction target of 60%, to be eligible for the European Union (EU) Directive’s 2020 target of 10% renewable energy in transport, while at least 20% renewable energy mix from an upgrader is required for meeting the EU GHG emission reduction target. Increases in the price of biodiesel and hydrogen make coprocessing of stable oils from bio-oil upgrader using refinery facilities economically more favorable than final biofuel blending from refineries and create win–win economic scenarios between the bio-oil upgrader and the refinery. The range of the cost of production (COP) of stable oil (328 MW or 0.424 t/t bio-oil), steam (49.5 MW or 0.926 t/t bio-oil), and off-gas or fuel gas (72.3 MW or 0.142 t/t bio-oil) from a bio-oil (LHV of 23.3 MJ/kg) upgrader process is evaluated on the basis of individual product energy values and global warming potential (GWP) impacts. The minimum and the maximum annualized capital charges predicted by the Discounted Cash Flow (DCF) analysis correspond to 25 operating years and 10% IRR, and 10 operating years and 20% IRR, respectively. On the basis of this DCF strategy and 1200 $/t of hydrogen and 540 $/t of biodiesel market prices, the selling prices of 259.32 $/t, 34.85 $/t, and 174.27 $/t of the stable oil, steam, and fuel gas, respectively, from the upgrader to the refinery were obtained to create win–win marginal incentive for the upgrader and refinery systems, individually. If stable oil from a bio-oil upgrader can be launched as a product potentially to be used in refinery hydrocracker (at a competitive price of 490 $/t), for the production of renewable diesel, upgrader can be operated independently, such as purchase hydrogen from vendors at competitive price, with comparative marginal incentives. The bio-oil upgraders, either stand-alone or integrated, were designed to meet desired product specifications, diesel with specific gravity 0.825 and cetane number 57 and stable oil with API 30.1 and cetane number 28.7, for coprocessing through the refinery hydrocracker, respectively.

The water footprint of biofuel-based transport

The EU target to replace 10 percent of transport fuels by renewables by 2020 requires additional water. This study calculates water footprints (WFs) of transport modes using first generation bio-ethanol, biodiesel or bio-electricity and of European transport if 10 percent of transport fuels is bio-ethanol. Results are compared with similar goals for other regions. It is more efficient to use bio-electricity and bio-ethanol than biodiesel. Transport by train or car using bio-electricity (8–19 and 11–13 litres per passenger km) is more water efficient than transport by car (36–212) or airplane (65–136) using bio-ethanol. For cars, there is a factor of ten between water-efficient cars using bio-ethanol and water-inefficient cars using biodiesel. Biofuel-based freight transport is most water-efficient by ship or train; airplanes are least efficient. Based on first generation biofuels, the EU goal for renewable transport energy results in a WF of 62 Gm3 per year, 10 percent of the current WF. Differences in transport energy use and in production systems result in a broad range of annual transport-related WFs: from 60 m3 per capita in Bulgaria to 500 m3 in Finland. If similar targets are applied in other regions, the additional WF of North America and Australia will be 52 percent of the present regions WFs. The global WF for biofuel-based transport in this scenario will be 9 percent of the current global WF. Trends towards increased biofuel application enhance the competition for freshwater resources.

Can we meet targets for biofuels and renewable energy in transport given the constraints imposed by policy in agriculture and energy?

The deployment of biofuels is significantly affected by policy in energy and agriculture. In the energy arena, concerns regarding the sustainability of biofuel systems and their impact on food prices led to a set of sustainability criteria in EU Directive 2009/28/EC on Renewable Energy. In addition, the 10% biofuels target by 2020 was replaced with a 10% renewable energy in transport target. This allows the share of renewable electricity used by electric vehicles to contribute to the mix in achieving the 2020 target. Furthermore, only biofuel systems that effect a 60% reduction in greenhouse gas emissions by 2020 compared with the fuel they replace are allowed to contribute to meeting the target. In the agricultural arena, cross-compliance (which is part of EU Common Agricultural Policy) dictates the allowable ratio of grassland to total agricultural land, and has a significant impact on which biofuels may be supported. This paper outlines the impact of these policy areas and their implications for the production and use of biofuels in terms of the 2020 target for 10% renewable transport energy, focusing on Ireland. The policies effectively impose constraints on many conventional energy crop biofuels and reinforce the merits of using biomethane, a gaseous biofuel. The analysis shows that Ireland can potentially satisfy 15% of renewable energy in transport by 2020 (allowing for double credit for biofuels from residues and ligno-cellulosic materials, as per Directive 2009/28/EC) through the use of indigenous biofuels: grass biomethane, waste and residue derived biofuels, electric vehicles and rapeseed biodiesel.

Biodiesel blend effects on common-rail diesel combustion and emissions

Biodiesel (fatty acid methylesters) blends with fossil diesel at a mixing ratio between 0.5 and 5 vol.% are widely offered as automotive fuels in Europe. The target for the future is to bring this ratio to at least 10%, in order to increase the share of renewable energy in transport. There is however limited evidence on the effects of such blends on the combustion and emissions of diesel engines not originally designed to operate on biodiesel blends. In this study, a number of experiments with 10 vol.% (B10) biodiesel fuel of palmoil origin were performed on a light-duty common-rail Euro 3 engine. The measurements included in-cylinder pressure, pollutants emissions, and fuel consumption. Combustion effects were limited but changes in the start of ignition and heat-release rate could be identified. Emission effects included both higher and lower smoke and NOx, depending on the operation point. The results on the engine bench were compared against a Euro 3 common-rail light-duty vehicle driven on the chassis dynamometer, in order to include the effects of emission control systems (EGR and oxidation catalyst). In addition to the palm biodiesel, an RME-diesel blend was also tested to examine the effects of a fuel with different characteristics. Both biodiesel blends reduced PM emissions and only marginal effects on NOx over the certification test could be identified. The results of this study show that up to 10% biodiesels could be used on current diesel vehicles, without significantly affecting vehicle emission performance.

Can Rape Seed Biodiesel Meet the European Union Sustainability Criteria for Biofuels?

The European Union (EU) Renewable Energy Directive stipulates that only biofuel systems that achieve greenhouse gas emission savings of 60% will be eligible to be considered for the 2020 target of 10% renewable energy in transport. Rape seed biodiesel is a very popular indigenous European biofuel; however, this 60% target is very challenging for the biofuel produced. Tropical biofuels such as palm oil biodiesel tend to be sustainable, due to use of residues and byproduct to satisfy parasitic energy demands. This paper explores, through life cycle assessment methodologies, the whole rape seed system and the potential to improve sustainability. Allocation by energy content attributes almost half the greenhouse gas emissions to rape cake (a coproduct). Indeed rape cake as animal feed displaces imported soybean from Latin America and potential destruction to rain forests. Together with use of glycerol as a source of heat, greenhouse gas savings of 75% maybe attained, indicating a sustainable system. Furthermore use of rape straw pellets in lieu of the environmentally unsound practice of using peat produced from Irish Bogs as a source of domestic heating can lead to a 135% savings on diesel. Interestingly, rape cake as a source of biomethane greatly improves the energy balance of the system but is of little benefit to emissions.

The EU–Africa Energy Partnership: Towards a mutually beneficial renewable transport energy alliance?

The European Union's EU–Africa Energy Partnership, with respect to its emphasis on transport fuels, aims to ensure that Member States can fulfil agreed upon commitments to sustainable energy via the importation of biomass grown in sub-Saharan Africa. This policy aims to reduce the dependence of developing sub-Saharan nations on fossil-fuels, while ensuring the global proliferation of alternative transport energy generation as a means to combat climate change. Though the policy seems equitable in theory, and indeed mutually beneficial, several important issues arise. The paper examines the EU–Africa Energy Policy in the context of biofuels in particular, with a view to identifying potential flaws and imbalances and making policy recommendations. Aside from establishing critical uncertainties, the study adduces environmental science, historical comparanda and economic theory in order to assess the various threats associated with aspects of the policy, especially in light of previous policies that have stifled the development of sub-Saharan economies. In addition, the paper has substantial relevance to developing and newly industrialized nations in Asia and South America also seeking to invest in biomass cultivation and production.

Environmental sustainability assessment of bio-ethanol production in Thailand

Bio-ethanol is playing an important role in renewable energy for transport according to Thai government policy. This study aims to evaluate the energy efficiency and renewability of bio-ethanol system and identify the current significant environmental risks and availability of feedstocks in Thailand. Four of the seven existing ethanol plants contributing 53% of the total ethanol fuel production in Thailand have been assessed by the net energy balance method and Life Cycle Assessment (LCA). A renewability and net energy ratio portfolio has been used to indicate whether existing bio-ethanol production systems have net energy gain and could help reduce dependency on fossil energy. In addition, LCA has been conducted to identify and evaluate the environmental hotspots of 'cradle to gate' bio-ethanol production. The results show that there are significant differences of energy and environmental performance among the four existing production systems even for the same feedstock. The differences are dependent on many factors such as farming practices, feedstock transportion, fuel used in ethanol plants, operation practices and technology of ethanol conversion and waste management practices. Recommendations for improving the overall energy and environmental performance of the bio-ethanol system are suggested in order to direct the bio-ethanol industry in Thailand towards environmental sustainability.

Intellectual property landscape and patenting opportunity in biofuels

The oil embargo of the 1970s forced a realisation that our fossil fuel resources are finite and fast dwindling. Three decades later, this realisation is once again hitting us hard. The good news is that this time around there is a high degree of scientific confidence that a commercially viable, renewable transportation energy resource, competitive with fossil fuel in terms of cost, may be realised within the next 10 to 20 years. Much of this is the result of the recent scientific breakthroughs in genomics and bioengineering. In recent years, a significant number of start-up biofuel companies have emerged and are offering novel biofuel technologies that promise to move these emerging technologies past the research and development stage and into commercialisation. These companies are well advised to develop a viable intellectual property (IP) strategy and a strong patent portfolio to attract investment. This paper is intended to introduce the reader to the emerging biofuel IP landscape and to identify patenting opportunity.

Wind to Wheels Hydrogen Project

A great deal of research funding is being devoted to the use of hydrogen for transportation fuel, particularly in the development of fuel cell vehicles. When this research bears fruit in the form of consumer-ready vehicles, will the fueling infrastructure be ready? Will the required fueling systems work in cold climates as well as they do in warm areas? Will we be sure that production of hydrogen as the energy carrier of choice for our transit system is the most energy efficient and environmentally friendly option? Will consumers understand this fuel and how to handle it?Those are questions addressed by the EVermont Wind to Wheels Hydrogen Project: Sustainable Transportation. The hydrogen fueling infrastructure consists of three primary subcomponents: a hydrogen generator (electrolyzer), a compression and storage system, and a dispenser. The generated fuel is then used to provide transportation as a motor fuel.EVermont Inc., started in 1993 by then-governor Howard Dean, is a public-private partnership of entities interested in documenting and advancing the performance of advanced technology vehicles that are sustainable and less burdensome on the environment, especially in areas of cold climates, hilly terrain and with rural settlement patterns.EVermont has developed a demonstration wind powered hydrogen fuel producing filling system that uses electrolysis, compression to 5000 psi and a hydrogen burning vehicle that functions reliably in cold climates. And that fuel is then used to meet transportation needs in a hybrid electric vehicle whose internal combustion engine has been converted to operate on hydrogen Sponsored by the DOE EERE Hydrogen, Fuel Cells & Infrastructure Technologies (HFC&IT) Program, the purpose of the project is to test the viability of sustainably produced hydrogen for use as a transportation fuel in a cold climate with hilly terrain and rural settlement patterns. Specifically, the project addresses the challenge of building a renewable transportation energy capable system. The prime energy for this project comes from an agreement with a wind turbine operator.

Intellectual property landscape and patenting opportunity in biofuels

The oil embargo of the 1970s forced a realisation that our fossil fuel resources are finite and fast dwindling. Three decades later, this realisation is once again hitting us hard. The good news is that this time around there is a high degree of scientific confidence that a commercially viable, renewable transportation energy resource, competitive with fossil fuel in terms of cost, may be realised within the next 10 to 20 years. Much of this is the result of the recent scientific breakthroughs in genomics and bioengineering. In recent years, a significant number of start-up biofuel companies have emerged and are offering novel biofuel technologies that promise to move these emerging technologies past the research and development stage and into commercialisation. These companies are well advised to develop a viable intellectual property (IP) strategy and a strong patent portfolio to attract investment. This paper is intended to introduce the reader to the emerging biofuel IP landscape and to identify patenting opportunity.