H2-based synthetic fuels: A techno-economic comparison of alcohol,ether and hydrocarbon production

Electricity-based fuels are one promising option to achieve the transition of the energy system, and especially the transport sector, in order to minimize the role of fossil energy carriers. One major problem is the lacking compatibility between different techno-economic assessments, such that recommendations regarding the most promising Power-to-Fuel technology are difficult to make. This work provides a technically sound comparison of various Power-to-Fuel options regarding technological maturity and efficiency, as well as cost. The investigated options include methanol, ethanol, butanol, octanol, DME, OME_3-5 and hydrocarbons. To guarantee the comparability, all necessary chemical plants were designed in Aspen Plus® to determine material and energy consumption, as well as investment costs within the same boundary conditions and assumptions in all simulations and calculations. Individual technical aspects of the various synthesis routes, as well as their advantages and disadvantages, are highlighted.With an assumed electrolysis efficiency of 70% and considering the energy demand for the CO₂ supply and the energy and operating material demand of the chemical plants, depending on the selected electrofuel, 30–60% of the primary energy in renewable electricity can be stored in the lower heating value of the electrofuel. In the presented results, the costs of H₂ supply are responsible for 58–83% of the total manufacturing costs and thus have the greatest potential to reduce the latter. For the base case (4.6 €/kg_H2), various electrofuels will have costs of manufacturing of between 1.85 and 3.96 €/l_DE, with DME being the cheapest.     

Options for CO2-lean hydrogen export from Norway to Germany

Norway is a nation with an abundant supply of energy, both from fossil and renewable resources. Due to limited domestic demand, Norway is today exporting large amounts of petroleum products. For the future, various options for export of CO₂-lean energy exist, both from Northern and Southern Norway, and both from fossil sources (including carbon capture and storage), and renewable energies (particularly wind power). Transport vectors are hydrogen pipelines, liquid hydrogen ships and HVDC cables, and a plausible customer is central Europe due to its proximity, high population density and lack of domestic energy resources.     

Greenhouse gas reduction benefits and costs of a large-scale transition to hydrogen in the USA

Hydrogen is an energy carrier able to be produced from domestic, zero-carbon sources and consumed by zero-pollution devices. A transition to a hydrogen-based economy could therefore potentially respond to climate, air quality, and energy security concerns. In a hydrogen economy, both mobile and stationary energy needs could be met through the reaction of hydrogen (H₂) with oxygen (O₂). This study applies a full fuel cycle approach to quantify the energy, greenhouse gas emissions (GHGs), and cost implications associated with a large transition to hydrogen in the United States. It explores a national and four metropolitan area transitions in two contrasting policy contexts: a “business-as-usual” (BAU) context with continued reliance on fossil fuels, and a “GHG-constrained” context with policies aimed at reducing greenhouse gas emissions. A transition in either policy context faces serious challenges, foremost among them from the highly inertial investments over the past century or so in technology and infrastructure based on petroleum, natural gas, and coal. A hydrogen transition in the USA could contribute to an effective response to climate change by helping to achieve deep reductions in GHG emissions by mid-century across all sectors of the economy; however, these reductions depend on the use of hydrogen to exploit clean, zero-carbon energy supply options.     

Energy analysis of electricity supply and energy conservation options

A methodology is developed to compute the total energy requirements for electricity-generating systems using an input-output model that explicitly accounts for the physical flow of energy. The capital and operating requirements of 16 separate energy supply facilities are used to evaluate the total energy required by 9 alternative means of producing and delivering electricity. Evaluated electricity-generating systems rely on either fossil or nuclear energy as their fuel source. Energy payback periods are computed based on an equivalent electricity basis. These results are compared to a number of alternative capital investments to reduce energy demand. In general, the conservation options return their energy requirements sooner than the supply alternatives.     

“Green” path from fossil-based to hydrogen economy: An overview of carbon-neutral technologies

While the dominant role of hydrogen in a sustainable energy future is widely accepted, the strategies for the transition from fossil-based to hydrogen economy are still actively debated. This paper emphasizes the role of carbon-neutral technologies and fuels during the transition period. To satisfy the world's growing appetite for energy and keep our planet healthy, at least 10 TW (or terawatt) of carbon-free power has to be produced by mid-century. Three prominent options discussed in the literature include: decarbonization of fossil energy, nuclear energy and renewable energy sources. These options are analyzed in this paper with a special emphasis on the role of hydrogen as a carbon-free energy carrier. In particular, the authors compare various fossil decarbonization strategies and evaluate the potential of nuclear and renewable energy resources to meet the 10 TW target. An overview of state-of-the-art technologies for production of carbon-free energy carriers and transportation fuels, and the assessment of their commercial potential is provided. It is shown that neither of these three options alone could provide 10 TW of carbon-neutral power without major changes in the existing infrastructure, and/or technological breakthroughs in many areas, and/or a considerable environmental risk. The authors propose a scenario for the transition from current fossil-based to hydrogen economy that includes two key elements: (i) changing the fossil decarbonization strategy from one based on CO₂ sequestration to one that involves sequestration and/or utilization of solid carbon, and (ii) producing carbon-neutral synthetic fuels from bio-carbon and hydrogen generated from water using carbon-free sources (nuclear, solar, wind, geothermal). This strategy would allow taking advantage of the existing fuel infrastructure without an adverse environmental impact, and it would secure a smooth carbon-neutral transition from fossil-based to future hydrogen economy.     

Impact of climate policy uncertainty on the adoption of electricity generating technologies

This paper presents a real options model where multiple options are evaluated simultaneously so that the effect of the individual options on each other is accounted for. We apply this model to the electricity sector, where we analyze three typical technologies based on fossil fuel, fossil fuel with carbon capture and renewable energy, respectively. In this way, we can analyze the transition from CO₂-intensive to CO₂-neutral electricity production in the face of rising and uncertain CO₂ prices. In addition, such a modelling approach enables us to estimate precisely the expected value of (perfect) information, i.e. the willingness of investors and producers to pay for information about the correct CO₂ price path. As can be expected, the expected value of information rises with increasing CO₂ price uncertainty. In addition, the larger the price uncertainty, the larger are the cumulative CO₂ emissions over the coming century. The reason for this is that the transition to less CO₂-intensive technologies is increasingly postponed with rising CO₂ price uncertainty. By testing different price processes (geometric Brownian motion versus jump processes with different jump frequencies), we can also make useful recommendations concerning the importance of policy predictability. We find that it is better to have climate change policies that are stable over a certain length of time and change abruptly than less abrupt but more frequently changing policies. Less frequent fluctuations reduce the expected value of information and result in smaller cumulative CO₂ emissions.     

Development forecast of renewable energy power generation in China and its influence on the GHG control strategy of the country

CO₂ emissions of the electricity supply sector in China account for about half of the total volume in the country. Thus, reducing CO₂ emissions in China’s electricity supply sector will contribute significantly to the efforts of greenhouse gas (GHG) control in the country and the rest of the world. This paper introduces the development status of renewable energy and other main CO₂ mitigation options in power generation in China and makes a preliminary prediction of the development of renewable energy in the country for future decades. Besides, based on the situation in China, the paper undertakes a comprehensive analysis of CO₂ mitigation costs, mitigation potential, and fossil energy conversation capacity of renewable energy and other mitigation options, through which the influence of renewable energy on the mitigation strategy of China is analyzed.     

Household consumption,associated fossil fuel demand and carbon dioxide emissions: The case of Greece between 1990 and 2006

This paper explores how Greece’s household consumption has changed between 1990 and 2006 and its environmental implications in terms of fossil fuel demand and carbon dioxide (CO₂) emissions. The results show that the 44% increase in Greece’s household expenditure between 1990 and 2006 was accompanied by a 67% increase in fossil fuel demand. Of this total, indirect demand accounted for approximately 60% throughout the 16-year period, increasing by 56% overall, whereas direct fossil fuel demand grew by 80%. The results also show that associated CO₂ emissions increased by 60%, resulting in a “relative decoupling” from energy demand. This relative decoupling is shown to be due to fossil fuel mix changes from the supply side rather than action from consumers. These insights highlight the opportunities for demand-side policies to further reduce fossil fuel demand and CO₂ emissions, allowing Greece to set more proactive and ambitious post-Kyoto targets.     

The achievement,significance and future prospect of China's renewable energy initiative

China's high-speed economic growth and ambitious urbanization depend heavily on the massive consumption of fossil fuel. However, the over-dependence on the depleting fossil fuels causes severe environmental problems, making China the largest energy consumer and the biggest CO₂ emitter in the world. Faced with significant challenges in terms of managing its environment and moving forward with the concept of sustainable economic development, the Chinese government plans to move away from fossil fuels and rely on renewables such as hydropower, wind power, solar power, biomass power and nuclear power. In this paper, the current status of China's renewable energy deployment and the ongoing development projects are summarized and discussed. Most recent developments of major renewable energy sources are clearly reviewed. Additionally, the renewable energy development policies including laws and regulations, economic encouragement, technical research and development are also summarized. This study showcases China's achievements in exploiting its abundant domestic renewable energy sources to meet the future energy demand and reducing carbon emissions. To move toward a low carbon society, technological progress and policy improvements are needed for improving grid access (wind), securing nuclear fuel supplies and managing safety protocols (nuclear), integrating supply chains to achieve indigenous manufacture of technologies across supply chains (solar). Beyond that, a preliminary prediction of the development of China's future renewable energy developments, and proposes targeted countermeasures and suggestions are proposed. The proposal involves developing smart-grid system, investing on renewable energy research, improving the feed-in tariff system and clarifying the subsidy system.     

Switching towards coal or renewable energy? The effects of financial capital on energy transitions

Does a country's stock of financial capital affect its ability to achieve energy transitions? This paper uses data for up to 137 countries for the period 1998–2013 to investigate the importance of financial capital for changes in the use of each energy type. I find that financial capital supports transition to more capital-intensive energy types. For high-income countries, financial capital facilitates transitions from fossil fuels to modern renewable energy sources, especially wind. Both private credit from banks and domestic private debt securities support greater shares of wind energy. For lower-income countries, financial capital supports progression from biomass towards fossil fuel energy sources such as coal. I also find that countries with larger stocks of financial capital are more likely to move to more capital-intensive electricity generation systems.     

The value chain of green hydrogen for fuel cell buses – A case study for the Rhine-Main area in Germany

As an immanent necessity to reduce global greenhouse gas emissions, the energy transition poses a major challenge for the next 30 years, as it includes a cross-sectoral increase of fluctuating renewable energy production, grid extension to meet regional electricity supply and demand as well as an increase of energy storage capacity. Within the power-to-gas concept, hydrogen is considered as one of the most promising solutions.The paper presents a scenario-based bottom-up approach to analyse the hydrogen supply chain to substitute diesel with fuel cell buses in the Rhine-Main area in central Germany for the year 2025. The analysis is based on field data derived from the 6 MW power-to-gas plant “Energiepark Mainz” and the bus demonstration project “H₂-Bus Rhein-Main”. The system is modelled to run simulations on varying demand scenarios. The outcome is minimised hydrogen production costs derived from the optimal scheduling of a power-to-gas plant in terms of the demand. The assessment includes the energy procurement for hydrogen production, different hydrogen delivery options and spatial analysis of potential power-to-gas locations.     

Macro-economic impact of large-scale deployment of biomass resources for energy and materials on a national level—A combined approach for the Netherlands

Biomass is considered one of the most important options in the transition to a sustainable energy system with reduced greenhouse gas (GHG) emissions and increased security of enegry supply. In order to facilitate this transition with targeted policies and implementation strategies, it is of vital importance to understand the economic benefits, uncertainties and risks of this transition. This article presents a quantification of the economic impacts on value added, employment shares and the trade balance as well as required biomass and avoided primary energy and greenhouse gases related to large scale biomass deployment on a country level (the Netherlands) for different future scenarios to 2030. This is done by using the macro-economic computable general equilibrium (CGE) model LEITAP, capable of quantifying direct and indirect effects of a bio-based economy combined with a spread sheet tool to address underlying technological details. Although the combined approach has limitations, the results of the projections show that substitution of fossil energy carriers by biomass, could have positive economic effects, as well as reducing GHG emissions and fossil energy requirement. Key factors to achieve these targets are enhanced technological development and the import of sustainable biomass resources to the Netherlands.     

An evaluation of greenhouse gas mitigation options for coal-fired power plants in the US Great Lakes States

We assessed options for mitigating greenhouse gas emissions from electricity generation in the US Great Lakes States, a region heavily dependent on coal-fired power plants. A proposed 600 MW power plant in northern Lower Michigan, USA provided context for our evaluation. Options to offset fossil CO₂ emissions by 20% included biomass fuel substitution from (1) forest residuals, (2) short-rotation woody crops, or (3) switchgrass; (4) biologic sequestration in forest plantations; and (5) geologic sequestration using CO₂ capture. Review of timber product output data, land cover data, and expected energy crop productivity on idle agriculture land within 120 km of the plant revealed that biomass from forestry residuals has the potential to offset 6% and from energy crops 27% of the annual fossil fuel requirement. Furthermore, annual forest harvest in the region is only 26% of growth and the surplus represents a large opportunity for forest products and bioenergy applications. We used Life Cycle Assessment (LCA) to compare mitigation options, using fossil energy demand and greenhouse gas emissions per unit electricity generation as criteria. LCA results revealed that co-firing with forestry residuals is the most attractive option and geologic sequestration is the least attractive option, based on the two criteria. Biologic sequestration is intermediate but likely infeasible because of very large land area requirements. Our study revealed that biomass feedstock potentials from land and forest resources are not limiting mitigation activities, but the most practical approach is likely a combination of options that optimize additional social, environmental and economic criteria.     

APPLICATION OF CONCENTRATED SOLAR RADIATION TO HIGH TEMPERATURE DETOXIFICATION AND RECYCLING PROCESSES OF HAZARDOUS WASTES

In many cases, hazardous wastes are subject to thermal treatment at elevated temperatures. Some types of wastes do not have a sufficient calorific value to cover the heat demand of the high temperature process. For thermal treatment of e.g. filter residues, dusts, sulfuric acid, aluminium dross, foundry sand, or waste water, supplementary energy supply is needed. The specific energy demand ranges from 0.5 to 2.5 kWh/kg (2–10 MJ/kg). An important aim of process optimisation is the reduction of (fossil) energy consumption and exhaust gas flow. Concentrated solar energy promises advantages when applied to high energy consuming waste treatment processes with regard to substitute fossil or electric energy consumption, to reduce CO₂ emissions, and exhaust gas flow. In parallel to conceptional studies, a solar-heated rotary kiln mini-plant has been designed and constructed for tests in the DLR solar furnace. The tests will give indications of boundary conditions for solar thermal treatment or conversion of selected hazardous materials.     

Implementation of biofuels in Malaysian transportation sector towards sustainable development: A case study of international cooperation between Malaysia and Japan

Modern transportation nowadays has evolved into an important economic activity for human civilisation. Even though various alternative energy solutions have been put forward to reduce the dependency on fossil fuels, biofuels remain one of the few options which are capable of replacing the roles of fossil fuels in transportation sector without suffering from major economic losses. Malaysia with a huge supply of palm oil for biofuels production is intended to implement mandatory biodiesel blends in its transportation sector in 2011 in order to achieve its carbon reduction commitment towards a more sustainable development. This implementation was originally targeted to start in 2009 but had to be postponed due to several obstacles such as expensive cost, lack of sufficient infrastructure and low public demand. On the other hand, Japan is also trying to fulfil its carbon reduction obligation as outlined under Kyoto Protocol with the usage of biofuels to replace fossil fuels in the transportation sector. However, it lacks sufficient biofuels supply to support its high transportation energy demand. In this case study, the mutual cooperation between Malaysia and Japan in the implementation of biofuels in transportation sector will be studied and analysed in order to overcome the challenges presented in both countries. It is hope to ascertain potential cooperation opportunities amongst those two countries to promote biofuels energy as Malaysia is rich in natural resources whilst Japan has the relevant expertise and technology. It is believed that the strengths from one country can help to cover for the weaknesses from the other and vice versa via closer bilateral partnership which will be extremely crucial when dealing with global energy issues. Ultimately, it is hope that this case study will enable both Malaysian and Japanese government to achieve their renewable energy target in domestic transportation sector.     

The slow search for solutions: Lessons from historical energy transitions by sector and service

This paper reviews past energy transitions by sector and service to identify features that may be useful for future transitions. Although often considered a single event, the transition from traditional energy sources to fossil fuels involved numerous services and sectors at different times between 1500 and 1920. The main economic drivers identified for energy transitions were the opportunities to produce cheaper or better energy services. The existence of a niche market willing to pay more for these characteristics enabled new energy sources and technologies to be refined gradually until they could compete with the incumbent energy source. Nevertheless, this implied that, on average, the whole innovation chain took more than 100 years and the diffusion phase nearly 50 years. In the same way, low-carbon energy sources and technologies offer an additional characteristic (i.e. low carbon impact), which might be able to develop gradually in a niche market until they can compete with fossil fuels. However, because of consumers’ tendency to free-ride, a successful transition will need governments to provide protection of this niche market—possibly for decades. Based on past experiences, a complete transition to a low carbon economy is likely to be very slow.     

The savings of energy saving: interactions between energy supply and demand-side options—quantification for Portugal

Reducing demand by increasing end-use energy efficiency on the demand side of energy systems may also have advantages in reducing fossil dependency and greenhouse gas (GHG) emissions on the supply side. This paper addresses interactions between energy supply- and demand-side policies, by estimating the impact of measures addressing end-use energy efficiency and small-scale renewables uses in terms of (1) avoided large-scale electricity generation capacity, (2) final energy consumption, (3) share of renewables in final energy and (4) reduction of GHG emissions. The Portuguese energy system is used as a case study. The TIMES_PT bottom-up model was used to generate four scenarios covering the period up to 2020, corresponding to different levels of efficiency of equipment in buildings, transport and industry. In the current policy scenario, the deployment of end-use equipment follows the 2000–2005 trends and the National Energy Efficiency Action Plan targets. In the efficient scenarios, all types of equipment can be replaced by more efficient ones. Results show that aggressive demand-side options for the industry and buildings sector and the small-scale use of renewables can remove the need for the increase in large-scale renewable electricity capacity by 4.7 GW currently discussed by policy makers. Although these measures reduce total final energy by only 0–2 %, this represents reductions of 11–14 % in the commercial sector, with savings in total energy system costs of approximately 3,000 million euros₂₀₀₀—roughly equivalent to 2 % of the 2010 Portuguese GDP. The cost-effectiveness of policy measures should guide choices between supply shifts and demand reduction. Such balanced policy development can lead to substantial cost reductions in climate and energy policy.     

Assessing the energy vulnerability: Case of industrialised countries

The emergence of new big consumer countries on the energy markets and the perspective of oil and gas depletion at the end of the current century raise the concerns about fair distribution of the remaining resources for the common and sustainable well-being of the mankind. High volatility of energy prices discourages the investment and delays the energy technology transition. Voluntary measures are needed mainly in industrialised countries in order to develop alternative and sustainable energy sources, to enable technology transfer towards emerging and developing countries and to avoid struggle for energy procurement. In this paper, a composite index of energy demand/supply weaknesses is defined as a proxy of energy vulnerability. The proposed index is based on several indicators such as energy intensity, oil and gas import dependency, CO₂ content of primary energy supply, electricity supply weaknesses and non-diversity in transport fuels. The assessment of this composite index for selected industrialised countries is discussed as well as the sensitivity to various factors.     

Energy demand and associated CO2 emissions for the Indian steel industry

Steel manufacturing is energy-intensive and hence a significant contributor of CO₂ emissions. We project steel demand in India using regression analysis. A linear dynamic programming model has been developed to analyse the supply options and estimate the energy demand and CO₂ emissions from the industry for the period 1992 to 2021.     

Emissions reduction scenarios in the Argentinean Energy Sector

In this paper the LEAP, TIAM-ECN, and GCAM models were applied to evaluate the impact of a variety of climate change control policies (including carbon pricing and emission constraints relative to a base year) on primary energy consumption, final energy consumption, electricity sector development, and CO₂ emission savings of the energy sector in Argentina over the 2010–2050 period. The LEAP model results indicate that if Argentina fully implements the most feasible mitigation measures currently under consideration by official bodies and key academic institutions on energy supply and demand, such as the ProBiomass program, a cumulative incremental economic cost of 22.8 billion US$(2005) to 2050 is expected, resulting in a 16% reduction in GHG emissions compared to a business-as-usual scenario. These measures also bring economic co-benefits, such as a reduction of energy imports improving the balance of trade. A Low CO₂ price scenario in LEAP results in the replacement of coal by nuclear and wind energy in electricity expansion. A High CO₂ price leverages additional investments in hydropower. By way of cross-model comparison with the TIAM-ECN and GCAM global integrated assessment models, significant variation in projected emissions reductions in the carbon price scenarios was observed, which illustrates the inherent uncertainties associated with such long-term projections. These models predict approximately 37% and 94% reductions under the High CO₂ price scenario, respectively. By comparison, the LEAP model, using an approach based on the assessment of a limited set of mitigation options, predicts an 11.3% reduction. The main reasons for this difference include varying assumptions about technology cost and availability, CO₂ storage capacity, and the ability to import bioenergy. An emission cap scenario (2050 emissions 20% lower than 2010 emissions) is feasible by including such measures as CCS and Bio CCS, but at a significant cost. In terms of technology pathways, the models agree that fossil fuels, in particular natural gas, will remain an important part of the electricity mix in the core baseline scenario. According to the models there is agreement that the introduction of a carbon price will lead to a decline in absolute and relative shares of aggregate fossil fuel generation. However, predictions vary as to the extent to which coal, nuclear and renewable energy play a role.