Ausilio Bauen

Progress in renewable energy

This paper provides an overview of some of the key technological and market developments for leading renewable energy technologies--wind, wave and tidal, photovoltaics (PV) and biomass energy. Market growth, innovation and policy are closely interrelated in the development of renewables and the key issues in each area are explored for each of the main types of renewable energy technology. This enables the prospects for future development and cost reduction to be considered in detail. Key issues for policy are outlined.

Modelling supply and demand of bioenergy from short rotation coppice and Miscanthus in the UK.

Biomass from lignocellulosic energy crops can contribute to primary energy supply in the short term in heat and electricity applications and in the longer term in transport fuel applications. This paper estimates the optimal feedstock allocation of herbaceous and woody lignocellulosic energy crops for England and Wales based on empirical productivity models. Yield maps for Miscanthus, willow and poplar, constrained by climatic, soil and land use factors, are used to estimate the potential resource. An energy crop supply-cost curve is estimated based on the resource distribution and associated production costs. The spatial resource model is then used to inform the supply of biomass to geographically distributed demand centres, with co-firing plants used as an illustration. Finally, the potential contribution of energy crops to UK primary energy and renewable energy targets is discussed.

Assessment of the environmental benefits of transport and stationary fuel cells

Fuel cells (FCs) offer significant environmental benefits over competing technologies and hence the environment is a strong driving force behind the development of FC systems for transport and stationary applications. This paper provides a comprehensive comparison of FC and competing systems, and points out strengths and weaknesses of the different FC systems, suggesting areas for improvement. The results presented build on earlier work [D. Hart, G. Hormandinger, Initial assessment of the environmental characteristics of fuel cells and competing technologies, ETSU F/02/00111/REP/1, ETSU, Harwell, UK, 1997.] and provide a detailed analysis of a wider range of systems. The analysis takes the form of a model, which compares system emissions (global, regional and local pollutants) and energy consumption on a full fuel cycle basis. It considers a variety of primary energy sources, intermediate fuel supply steps and FC systems for transport and stationary end-uses. These are compared with alternative systems for transport and stationary applications. Energy and pollutant emission reductions of FC systems compared to alternative vehicle technology vary considerably, though all FC technologies show reductions in energy use and CO2 emissions of at least 20%; as well as reductions of several orders of magnitude in regulated pollutants compared to the base-case vehicle. The location of emissions is also of importance, with most emissions in the case of FC vehicles occurring in the fuel supply stage. The energy, CO2 and regulated emissions advantages of FC systems for distributed and baseload electricity are more consistent than for transport applications, with reductions in regulated pollutants generally larger than one order of magnitude compared to competing technologies. For CHP applications, the advantages of FC systems with regard to regulated pollutants remain large. However, energy and CO2 emission advantages are reduced, depending largely on the assumptions made for the heat/power ratio and system comparison.

The greenhouse gas emissions performance of cellulosic ethanol supply chains in Europe.

BackgroundCalculating the greenhouse gas savings that may be attributed to biofuels is problematic because production systems are inherently complex and methods used to quantify savings are subjective. Differing approaches and interpretations have fuelled a debate about the environmental merit of biofuels, and consequently about the level of policy support that can be justified. This paper estimates and compares emissions from plausible supply chains for lignocellulosic ethanol production, exemplified using data specific to the UK and Sweden. The common elements that give rise to the greatest greenhouse gas emissions are identified and the sensitivity of total emissions to variations in these elements is estimated. The implications of including consequential impacts including indirect land-use change, and the effects of selecting alternative allocation methods on the interpretation of results are discussed.ResultsWe find that the most important factors affecting supply chain emissions are the emissions embodied in biomass production, the use of electricity in the conversion process and potentially consequential impacts: indirect land-use change and fertiliser replacement. The large quantity of electricity consumed during enzyme manufacture suggests that enzymatic conversion processes may give rise to greater greenhouse gas emissions than the dilute acid conversion process, even though the dilute acid process has a somewhat lower ethanol yield.ConclusionThe lignocellulosic ethanol supply chains considered here all lead to greenhouse gas savings relative to gasoline An important caveat to this is that if lignocellulosic ethanol production uses feedstocks that lead to indirect land-use change, or other significant consequential impacts, the benefit may be greatly reduced.Co-locating ethanol, electricity generation and enzyme production in a single facility may improve performance, particularly if this allows the number of energy intensive steps in enzyme production to be reduced, or if other process synergies are available. If biofuels policy in the EU remains contingent on favourable environmental performance then the multi-scale nature of bioenergy supply chains presents a genuine challenge. Lignocellulosic ethanol holds promise for emission reductions, but maximising greenhouse gas savings will not only require efficient supply chain design but also a better understanding of the spatial and temporal factors which affect overall performance.

The commercial performance of cellulosic ethanol supply-chains in Europe

BackgroundThe production of fuel-grade ethanol from lignocellulosic biomass resources has the potential to increase biofuel production capacity whilst minimising the negative environmental impacts. These benefits will only be realised if lignocellulosic ethanol production can compete on price with conventional fossil fuels and if it can be produced commercially at scale. This paper focuses on lignocellulosic ethanol production in Europe. The hypothesis is that the eventual cost of production will be determined not only by the performance of the conversion process but by the performance of the entire supply-chain from feedstock production to consumption. To test this, a model for supply-chain cost comparison is developed, the components of representative ethanol supply-chains are described, the factors that are most important in determining the cost and profitability of ethanol production are identified, and a detailed sensitivity analysis is conducted.ResultsThe most important cost determinants are the cost of feedstocks, primarily determined by location and existing markets, and the value obtained for ethanol, primarily determined by the oil price and policy incentives. Both of these factors are highly uncertain. The best performing chains (ethanol produced from softwood and sold as a low percentage blend with gasoline) could ultimately be cost competitive with gasoline without requiring subsidy, but production from straw would generally be less competitive.ConclusionSupply-chain design will play a critical role in determining commercial viability. The importance of feedstock supply highlights the need for location-specific assessments of feedstock availability and price. Similarly, the role of subsidies and policy incentives in creating and sustaining the ethanol market highlights the importance of political engagement and the need to include political risks in investment appraisal. For the supply-chains described here, and with the cost and market parameters selected, selling ethanol as a low percentage blend with gasoline will maximise ethanol revenues and minimise the need for subsidies. It follows, therefore, that the market for low percentage blends should be saturated before markets for high percentage blends.

OPTIONS FOR REFUELLING HYDROGEN FUEL CELL VEHICLES IN ITALY

Abstract Hydrogen fuel cell vehicle (H 2 FCV) trials are taking place in a number of cities around the world. In Italy, Milan and Turin are the first to have demonstration projects involving hydrogen-fuelled vehicles, in part to satisfy increasing consumer demand for improved environmental performance. The Italian transport plan specifically highlights the potential for FCVs to enter into the marketplace from around 2005. A scenario for FCV penetration into Italy, developed using projected costs for FCV and hydrogen fuel, suggests that by 2015, 2 million Italian cars could be powered by fuel cells. By 2030, 60% of the parc could be FCVs. To develop an infrastructure to supply these vehicles, a variety of options is considered. Large-scale steam reforming, on-site reforming and electrolysis options are analysed, with hydrogen delivered both in liquid and gaseous form. Assuming mature technologies, with over 10,000 units produced, on-site steam reforming provides the most economic hydrogen supply to the consumer, at US

Fuel cells for distributed generation in developing countries—an analysis

2.6/kg. However, in the early stages of the infrastructure development there is a clear opportunity for on-site electrolysis and for production of hydrogen at centralised facilities, with delivery in the form of liquid hydrogen. This enables additional flexibility, as the hydrogen may also be used for fuel refining or for local power generation. In the current Italian context, energy companies could have a significant role to play in developing a hydrogen infrastructure. The use of hydrogen FCVs can substantially reduce emissions of regulated pollutants and greenhouse gases. Using externality costs for regulated pollutants, it is estimated that the use of hydrogen fuel cell buses in place of 5% of diesel buses in Milan could avoid US

Methanol infrastructure — will it affect the introduction of SPFC vehicles?

2 million per year in health costs. The addition of even very low externality costs to fuel prices makes the use of untaxed hydrogen in buses and cars, which is slightly more expensive for the motorist than untaxed gasoline or diesel, competitive on a social cost basis.

Chapter 1 – Biomass Supply Assessments in Europe: Research Context and Methodologies

Abstract Fuel cells are still in development as power generation technologies. They are potentially efficient and low-emissions power generation technologies with a wide range of applications. Their deployment world wide and in developing countries in particular could result in mitigation of future greenhouse gas emissions and possibly other environmental and social benefits. The economics of the systems and their competitiveness with other power generation systems will be heavily dependent on local costs and infrastructure. Modelling, based energy demand projection and on fuel cell demand curves derived from expert interviews, suggests that worldwide, projected future cost reductions in fuel cells could result in fuel cell penetration of up to 50% of the world distributed generation market by 2020. This penetration, coupled with the use of a mix of low-carbon fuels, such as natural gas, would result in significant avoided emissions of CO2 over the same period. Also, a comparison of the levelised costs of generation for the Philippines and South Africa suggests that some fuel cell technologies could become competitive with centralised generation within the next decade. Assuming that fuel cell durability can be demonstrated, the potential for fuel cells to be introduced into distributed generation in certain developing countries appears high, from a technical, economic and environmental perspective.

Sustainable Heat and Electricity from Sugarcane Residues Gasification in Brazil

The possibility that future solid polymer fuel cell vehicles will be fuelled by methanol has been suggested. If this is the case, it will have significant implications for the future structure of the methanol supply industry, and methanol supply and availability may have an impact on the take-up of these SPFC vehicles. In this study, a model assessing the possible future penetration of methanol SPFC vehicles was constructed. This suggested that it would be possible for SPFC vehicles to achieve rapid market penetration after an initially slow start. A further model indicated that methanol supply would be adequate for vehicle demand until about 2013, when significant new capacity would be required. The cost of this new capacity was estimated, along with the cost of providing refuelling infrastructure such as road tankers, storage, and suitable fuelling stations. Amortising the cost over a short period (to 2013) could double the pre-tax price of methanol as a fuel, while over a longer timeframe (to 2029) it would add less than 10% to this value. The model suggests that methanol capacity need not be a constraint to the future introduction of SPFC vehicles using it as a fuel, but that other factors such as fuel purity and safety must be carefully considered before real costs can be calculated.