Retro-analysis of liquid bio-ethanol and bio-diesel in New Zealand

This paper uses a new approach of retro-analysis. Typically policy is informed by forward-looking analysis of potential for alternative energy technologies. But historical knowledge of energy and processing requirements and greenhouse effects is more reliable for engineering evaluation of biofuel production systems. This study calculates energy inputs and greenhouse gas emissions for the most efficient biomass feedstocks in New Zealand if the policy had been implemented to maximize liquid biofuel production in the year 2004/2005. The study uses existing processing technologies and agricultural statistics. Bioethanol production is calculated from putrescible wastes and starch crops, and biodiesel production from rapeseed, tallow, wood and waste paper. Each production system is further evaluated using measures of land use, energy input, crop production related to the energy product, plus relative measures of efficiency and renewability. The research findings are that maximum biofuel production in 2004/2005 would have provided only a few per cent of demand, and would not have reduced dependence on foreign imported oil or exposure to fuel price rise. Finally, we conclude that demand management and efficiency are more effective means of meeting policy objectives.     

Microalgal biodiesel in China: Opportunities and challenges

With rapid economic development, energy consumption in China has tripled in the past 20 years, exceeding 2.8 billion tons of standard coal in 2008. The search for new green energy as substitutes for nonrenewable energy resources has become an urgent task. Biodiesel is one of the most important bioenergy sources. According to the Mid- and Long-term Development Plan for Renewable Energy in China, the consumption of biodiesel in China will reach 0.2 million tons in 2010 and 2.0 million tons in 2020. However, large-scale production of biodiesel is restricted by the limited sources of raw materials. Microalgal oil is a prospective raw material for biodiesel production. Development of technology for the production and commercialization of biodiesel from microalgae has become a hot topic in the field of bioenergy and CO₂ emission mitigation. Biodiesel from microalgae can be produced at laboratory-scale, but the cost is too high. Few studies on the commercialization of the technology of producing biodiesel from microalgae have been reported. In this review, recent progress on the research and development of biodiesel from microalgae that have resulted in scientific breakthroughs and innovation in engineering in China are introduced. The existing challenges are also discussed. Based on a detailed analysis, several novel strategies on commercial biodiesel production from microalgae are proposed.     

Challenges and opportunities in improving the production of bio-ethanol

Bio-ethanol, as a clean and renewable fuel, is gaining increasing attention, mostly through its major environmental benefits. It can be produced from different kinds of renewable feedstock such as e.g. sugar cane, corn, wheat, cassava (first generation), cellulose biomass (second generation) and algal biomass (third generation). The conversion pathways for the production of bio-ethanol from disaccharides, from starches, and from lignocellulosic biomass are examined. The common processing routes are described, with their mass and energy balances, and assessed by comparing field data and simulations. Improvements through 5 possible interventions are discussed, being (i) an integrated energy-pinch of condensers and reboilers in the bio-ethanol distillation train; (ii) the use of Very High Gravity (VHG) fermentation; (iii) the current development of hybrid processes using pervaporation membranes; (iv) the substitution of current ethanol dewatering processes to >99.5 wt% pure ethanol by membrane technology; and (v) additional developments to improve the plant operation such as the use of microfiltration of the fermenter broth to protect heat exchangers and distillation columns against fouling, or novel distillation concepts.Whereas the benefits of introducing these techniques are recognized, extensive research is still needed to scientifically and economically justify their application. The paper finally presents a tentative economic assessment, with production costs not only depending on the extent of applying process improvements, but also on the raw material used in the process.     

Indirect land use change and biofuels: Mathematical analysis reveals a fundamental flaw in the regulatory approach

In the Renewable Fuel Standard (RFS2) program, the United States Environmental Protection Agency (U.S. EPA) has used partial equilibrium models to estimate the overall indirect land use change (iLUC) associated with the biofuel scenario mandated by the Energy Independence and Security Act of 2007 (EISA). For regulatory purposes, the U.S. EPA “shocks” (changes) the amount of each biofuel in the economic models one at a time to estimate the threshold values for specific biofuels (single-shock analysis). The primary assumption in the single-shock analysis is that iLUC is a linear process with respect to biofuels, i.e., that interactions between different biofuels are trivially small. However, the assumption of linearity in the single-shock analysis is not appropriate for estimating the threshold values for specific biofuels when the interactions between different biofuels are not small.Numerical results from the RFS2 program show that the effects of interactions between different biofuels are too large to be ignored. Thus, the threshold values for specific biofuels determined by the U.S. EPA are scenario-dependent and value choice-driven. They do not reflect real impacts of specific biofuels. Using scenario-dependent values for regulation is arbitrary and inappropriate. Failure to deal appropriately with interactions between different biofuels when assigning iLUC values to specific biofuels is a mathematical and systematic flaw; it is not an “uncertainty” issue. The U.S. EPA should find better ways to differentiate the contribution of one biofuel versus another when assigning iLUC values or find better means of regulating the land use change impact of biofuel production.     

A hydrogen economy: opportunities and challenges

A hydrogen economy, the long-term goal of many nations, can potentially confer energy security, along with environmental and economic benefits. However, the transition from a conventional petroleum-based energy system to a hydrogen economy involves many uncertainties, such as the development of efficient fuel-cell technologies, problems in hydrogen production and its distribution infrastructure, and the response of petroleum markets. This study uses the US MARKAL model to simulate the impacts of hydrogen technologies on the US energy system and to identify potential impediments to a successful transition. Preliminary findings highlight possible market barriers facing the hydrogen economy, as well as opportunities in new R&D and product markets for bioproducts. Quantitative analysis also offers insights on policy options for promoting hydrogen technologies.     

Development of a sustainability reporting scheme for biofuels: A UK case study

In 2008, the UK launched the first regulatory sustainability reporting scheme for biofuels. The development of the scheme, managed by the Low Carbon Vehicle Partnership for the Department for Transport, involved extensive stakeholder engagement. The scheme has significantly increased understanding by policy-makers, the biofuels industry and its supply chains on how to monitor and manage the sustainability risks of biofuels and increase their greenhouse-gas benefits. It is providing a practical model for similar developments globally. To receive certificates in order to meet volume obligations under the Renewable Transport Fuel Obligation (RTFO), suppliers must provide a monthly carbon and sustainability report on individual batches of renewable fuels they supply into the UK. The Renewable Fuels Agency produces aggregate monthly reports of overall performance and quarterly updates of individual supplier performance. This scheme is an important first step to assist the biofuels industry to demonstrate its environmental credentials and justify the subsidies received. The paper provides a case study of the development of the scheme, its initial outcomes and outstanding challenges.     

Life-cycle greenhouse gas emissions and energy balances of sugarcane ethanol production in Mexico

The purpose of this work was to estimate GHG emissions and energy balances for the future expansion of sugarcane ethanol fuel production in Mexico with one current and four possible future modalities. We used the life cycle methodology that is recommended by the European Renewable Energy Directive (RED), which distinguished the following five system phases: direct Land Use Change (LUC); crop production; biomass transport to industry; industrial processing; and ethanol transport to admixture plants. Key variables affecting total GHG emissions and fossil energy used in ethanol production were LUC emissions, crop fertilization rates, the proportion of sugarcane areas that are burned to facilitate harvest, fossil fuels used in the industrial phase, and the method for allocation of emissions to co-products. The lower emissions and higher energy ratios that were observed in the present Brazilian case were mainly due to the lesser amount of fertilizers applied, also were due to the shorter distance of sugarcane transport, and to the smaller proportion of sugarcane areas that were burned to facilitate manual harvest. The resulting modality with the lowest emissions of equivalent carbon dioxide (CO_2e) was ethanol produced from direct juice and generating surplus electricity with 36.8 kgCO_2e/GJ_ethanol. This was achieved using bagasse as the only fuel source to satisfy industrial phase needs for electricity and steam. Mexican emissions were higher than those calculated for Brazil (27.5 kgCO_2e/GJ_ethanol) among all modalities. The Mexican modality with the highest ratio of renewable/fossil energy was also ethanol from sugarcane juice generating surplus electricity with 4.8 GJ_ethanol/GJ_fossil.     

Nuclear energy development in China: A study of opportunities and challenges

With rapid economic development, China faces a great challenge to meet its increasing energy demand. Currently, China's energy supply is dominated by coal consumption, while natural gas and oil are in relative short supply. At the same time, nuclear energy is a relatively clean energy without green-house gas emissions. Considering the growing cost of fossil energy and the limited resources in China, oil supply security, coal mining disasters, the domestic environment pressure, and global climate warming, nuclear energy is an inevitable strategic option.     

Biofuel chain development in Germany: Organisation,opportunities, and challenges

Increasing production activities have been observed in many EU member states since the EU Commission sent a clear signal establishing and supporting the bioenergy industry. This article discusses current sector developments and therewith evolving biofuel value chain activities and management requirements by means of two German biofuel processing firms. Usually, the processing company can be regarded as the initiator of the regional value chains. In order to safeguard the high initial investments and secure efficient supply, the processing company relies on contract farming or profit participation rights rather than spot market interactions. In addition to discussing that point, this paper also explores opportunities and threats for the suppliers of raw materials as well as for the processors.     

Trombe walls: A review of opportunities and challenges in research and development

Green building and sustainable architecture are new techniques for addressing the environmental and energy crises. Trombe walls are regarded as a sustainable architectural technology for heating and ventilation. This article reviews the application of Trombe walls in buildings. The reviews discuss the characteristics of Trombe walls, including Trombe-wall configurations, and Trombe-wall technology. The advantages and disadvantages of this sustainable architectural technology have been highlighted, and future research questions have been identified.     

South-East Europe Regional Energy Market: challenges and opportunities for Romania

The paper takes as its starting point the Athens Memorandum signed by countries of South-East Europe whereby a regional energy market in power and gas will be developed. The aim under the Athens Memorandum is that the South-East Europe Regional Energy Market (SEEREM) will be liberalized in a phased manner from 2005, and—ultimately—that this will form part of the EU's internal energy market. The subject of the paper is the extent to which Romania, one of the biggest countries in South-East Europe and traditionally a net energy exporter to the region, complies with requirements under the Athens Memorandum, and outstanding challenges related to successful SEREM accession.The paper argues that much progress has been made in energy sector reform in Romania: power prices have increased, payments discipline in the power sector has improved, independent regulators have been established for power and gas sectors, and power and gas utilities have been restructured. Nevertheless, a number of challenges remain if Romania is to fully benefit from participation in the SEEREM. Further power price increases will be required in the medium term, whilst payments discipline remains poor by industry best practice standards. In the gas sector, retail prices do not reflect border prices, and payments discipline remains a problem. The paper argues that gas price reform would likely have adverse affordability impacts, and proposes means to mitigate these through rationalization of existing social safety nets for gas and heat. On investment requirements, the paper notes that these are significant in power generation, and proposes a contract framework that would support mobilization of finance.     

Power generation scenarios for Nigeria: An environmental and cost assessment

Exploratory scenarios for the power sector in Nigeria are analysed in this paper using possible pathways within the Nigerian context and then compared against the Government's power expansion plan in the short to medium term. They include two fossil-fuel (FF and CCGT) and two sustainable-development-driven scenarios (SD1 and SD2). The results from the FF scenarios indicate this is the preferred outcome if the aim is to expand electricity access at the lowest capital costs. However, the annual costs and environmental impacts increase significantly as a consequence. The SD1 scenario, characterised by increased penetration of renewables, leads to a reduction of a wide range of environmental impacts while increasing the annual costs slightly. The SD2 scenario, also with an increased share of renewables, is preferred if the aim is to reduce GHG emissions; however, this comes at an increased annual cost. Both the SD1 and SD2 scenarios also show significant increases in the capital investment compared to the Government's plans. These results can be used to help inform future policy in the Nigerian electricity sector by showing explicitly the range of possible trade-offs between environmental impacts and economic costs both in the short and long terms.     

Biomass supply from alternative cellulosic crops and crop residues: A spatially explicit bioeconomic modeling approach

This paper introduces a spatially-explicit bioeconomic model for the study of potential cellulosic biomass supply. For biomass crops to begin to replace current crops, farmers must earn more from them than from current crops. Using weather, topographic and soil data, the terrestrial ecosystem model, EPIC, dynamically simulates multiple cropping systems that vary by crop rotation, tillage, fertilization and residue removal rate. EPIC generates predicted crop yield and environmental outcomes over multiple watersheds. These EPIC results are used to parameterize a regional profit-maximization mathematical programming model that identifies profitable cropping system choices. The bioeconomic model is calibrated to 2007-09 crop production in a 9-county region of southwest Michigan. A simulation of biomass supply in response to rising biomass prices shows that cellulosic residues from corn stover and wheat straw begin to be supplied at minimum delivered biomass:corn grain price ratios of 0.15 and 0.18, respectively. At the mean corn price of $162.6/Mg ($4.13 per bushel) at commercial moisture content during 2007-2009, these ratios correspond to stover and straw prices of $24 and $29 per dry Mg. Perennial bioenergy crops begin to be supplied at price levels 2-3 times higher. Average biomass transport costs to the biorefinery plant range from $6 to $20/Mg compared to conventional crop production practices in the area, biomass supply from annual crop residues increased greenhouse gas emissions and reduced water quality through increased nutrient loss. By contrast, perennial cellulosic biomass crop production reduced greenhouse gas emissions and improved water quality.     

A review of urban energy system models: Approaches,challenges and opportunities

Energy use in cities has attracted significant research in recent years. However such a broad topic inevitably results in number of alternative interpretations of the problem domain and the modelling tools used in its study. This paper seeks to pull together these strands by proposing a theoretical definition of an urban energy system model and then evaluating the state of current practice. Drawing on a review of 219 papers, five key areas of practice were identified – technology design, building design, urban climate, systems design, and policy assessment – each with distinct and incomplete interpretations of the problem domain. We also highlight a sixth field, land use and transportation modelling, which has direct relevance to the use of energy in cities but has been somewhat overlooked by the literature to date. Despite their diversity, these approaches to urban energy system modelling share four common challenges in understanding model complexity, data quality and uncertainty, model integration, and policy relevance. We then examine the opportunities for improving current practice in urban energy systems modelling, focusing on the potential of sensitivity analysis and cloud computing, data collection and integration techniques, and the use of activity-based modelling as an integrating framework. The results indicate that there is significant potential for urban energy systems modelling to move beyond single disciplinary approaches towards a sophisticated integrated perspective that more fully captures the theoretical intricacy of urban energy systems.     

Imported palm oil for biofuels in the EU: Profitability,greenhouse gas emissions and social welfare effects

We examine the social desirability of renewable diesel production from imported palm oil in the EU when greenhouse gas emissions are taken into account. Using a partial market equilibrium model, we also study the sectoral social welfare effects of a biofuel policy consisting of a blend mandate in a small EU country (Finland), when palm oil based diesel is used to meet the mandated quota for biofuels. We develop a market equilibrium model for three cases: i) no biofuel policy, ii) biofuel policy consisting of socially optimal emission-based biofuel tax credit and iii) actual EU biofuel policy. Our results for the EU biofuel market, Southeast Asia and Finland show very little evidence that a large scale use of imported palm oil in diesel production in the EU can be justified by lower greenhouse gas emission costs. Cuts in emission costs may justify extensive production only if low or negative land-use change emissions result from oil palm cultivation and if the estimated per unit social costs of emissions are high. In contrast, the actual biofuel policies in the EU encourage the production of palm oil based diesel. Our results indicate that the sectoral social welfare effects of the actual biofuel policy in Finland may be negative and that if emissions decrease under actual biofuel policy, the emission abatement costs can be high regardless of the land use change emissions.     

Electric power grid interconnections in Northeast Asia: A quantitative analysis of opportunities and challenges

Power grid interconnection has gained attention in Northeast Asia (NEA) as a means to build an economically efficient power system and to effectively utilize renewable energy, such as wind and solar resources in the Gobi Desert and hydro resources in Eastern Russia.In order to quantify the potential economic and environmental benefits from connecting power grids and developing renewables in NEA, we build an NEA-wide multi-region power system model using linear programming techniques. Our analysis considers power system characteristics, such as the seasonal and daily electric load curves of the various NEA economies.Compared to a “no grid extension” scenario, increased access to renewables contributes significantly to emissions reductions and fuel cost savings. However, the results imply modest benefits in lowering total cost because of the large initial investments needed in developing the renewables and the transmission lines. These limited total cost savings are likely to pose an implementation challenge for NEA grid interconnections. Our results also suggest that grid interconnections become more economically attractive in higher fuel price or lower initial cost situations. The relevant planning organizations should carefully consider the initial cost and future fuel price trends when considering how to interconnect power girds in an economical manner.     

Liquid biofuels in China: Current status,government policies,and future opportunities and challenges

China, like many other countries, is promoting the development of liquid biofuel, including bioethanol and biodiesel. The Chinese government has set biofuel development targets for the coming decade and sanctioned a series of supportive policies. This paper provides a comprehensive overview of current liquid biofuel development in China, related government policies, and the potential opportunities and challenges for its future expansion. Our assessment is based on two rounds of in-depth fieldwork and a thorough literature review. The assessment shows that the prevailing concern on food security has pushed China to move from cereal-based to non-cereal-based biofuel production. Emphasis has also been put on utilizing new marginal land for feedstock production. Our assessment indicates that the targets of China's biofuel development are cautious and feasible, but on the other hand there are still severe challenges for the sustainability of such development. A better understanding of China's experience in striking a balance between energy security, food security and environmental protection would inform the debates across country boundaries and contribute to the efforts for global sustainability.     

Bioenergy for heat and electricity in the UK: A research atlas and roadmap

The UK has a significant biomass resource, estimated at an annual 20 million tonnes, but only a fraction of this is captured effectively for energy, contributing approximately 4.1% of the UK's heat and electricity production (Department for Environment, Food and Rural Affairs, 2007a. UK Biomass Strategy: http://www.defra.gov.uk/Environment/climatechange/uk/energy/renewablefuel/pdf/ukbiomassstrategy-0507.pdf (accessed 24 May 2008)). Much biomass combustion technology may be considered as mature, although bottlenecks in the quality and quantity of feedstock are apparent, and further fundamental research is required to increase crop yield in a sustainable manner, with low-chemical inputs to ensure efficient energy balance. In the short term, it could be useful for the UK to focus on developing a limited number of bioenergy chains, linked to combined heat and power microgeneration and the use of bioenergy for community and public sector projects. This should be linked to a joined-up policy and regulatory framework. A clear strategy for land management is also required, since many competing uses for land will emerge in the coming decades, including food production, nature conservation, carbon sequestration, urbanisation and other forms of renewable energy use. This finite resource must be managed effectively. In the long-term future, considerable excitement exists about the possibility of new bioscience technologies harnessed to improve photosynthetic gains for bioenergy, including the use of synthetic biology. It may be possible to produce the designer energy plant whose outputs would include high-quality chemical and liquid biofuels. Gasification of biomass also requires further technology development.     

Australian renewable energy policy: Barriers and challenges

Effective policy and regulatory frameworks are paramount to incentivising the deployment of renewable energy to achieve long term reductions in carbon emissions. Australia's renewable energy policy has taken significant steps towards encouraging the deployment of lower-emission energy generation. Significant policy barriers still exist at the federal and state levels, however, which have reduced the effectiveness of a concerted national effort to deploy renewables. The current policy landscape has favoured mature technologies which present the lowest investment risk at the expense of emerging options which may present greater efficiency and emissions reduction gains. The lack of support for emerging technologies delays their effective deployment and the accumulation of highly skilled human capital, until the medium to long term. This paper outlines the key policy frameworks, incentives and regulatory environment which encompasses the renewable energy sector, and presents a critical analysis of the barriers faced by the industry.