Wim Turkenburg

Exploration of the ranges of the global potential of biomass for energy

Abstract This study explores the range of future world potential of biomass for energy. The focus has been put on the factors that influence the potential biomass availability for energy purposes rather than give exact numbers. Six biomass resource categories for energy are identified: energy crops on surplus cropland, energy crops on degraded land, agricultural residues, forest residues, animal manure and organic wastes. Furthermore, specific attention is paid to the competing biomass use for material. The analysis makes use of a wide variety of existing studies on all separate categories. The main conclusion of the study is that the range of the global potential of primary biomass (in about 50 years) is very broad quantified at 33−1135 EJy −1 . Energy crops from surplus agricultural land have the largest potential contribution (0– 988 EJy −1 ) . Crucial factors determining biomass availability for energy are: (1) The future demand for food, determined by the population growth and the future diet; (2) The type of food production systems that can be adopted world-wide over the next 50 years; (3) Productivity of forest and energy crops; (4) The (increased) use of bio-materials; (5) Availability of degraded land; (6) Competing land use types, e.g. surplus agricultural land used for reforestation. It is therefore not “a given” that biomass for energy can become available at a large-scale. Furthermore, it is shown that policies aiming for the energy supply from biomass should take the factors like food production system developments into account in comprehensive development schemes.

Global experience curves for wind farms

In order to forecast the technological development and cost of wind turbines and the production costs of wind electricity, frequent use is made of the so-called experience curve concept. Experience curves of wind turbines are generally based on data describing the development of national markets, which cause a number of problems when applied for global assessments. To analyze global wind energy price development more adequately, we compose a global experience curve. First, underlying factors for past and potential future price reductions of wind turbines are analyzed. Also possible implications and pitfalls when applying the experience curve methodology are assessed. Second, we present and discuss a new approach of establishing a global experience curve and thus a global progress ratio for the investment cost of wind farms. Results show that global progress ratios for wind farms may lie between 77% and 85% (with an average of 81%), which is significantly more optimistic than progress ratios applied in most current scenario studies and integrated assessment models. While the findings are based on a limited amount of data, they may indicate faster price reduction opportunities than so far assumed. With this global experience curve we aim to improve the reliability of describing the speed with which global costs of wind power may decline.

Techno-economic analysis of natural gas combined cycles with post-combustion CO2 absorption, including a detailed evaluation of the development potential

We performed a detailed analysis of the potential future costs and performance of post-combustion CO2 absorption in combination with a natural gas combined cycle (NGCC). After researching state-of-the-art technology, an Excel model was created to analyze possible developments in the performance of energy conversion, CO2 capture, and CO2 compression. The input variables for the three time frames we used were based on literature data, product information, expert opinions, and our own analysis. Using a natural gas price of 4.7 €/GJ, we calculated a potential decrease in the costs of electricity from 5.6 €ct/kWh in the short term to 4.8 €ct/kWh in the medium term and 4.5 €ct/kWh in the long term. The efficiency penalty is calculated to decline from 7.9%-points LHV in the short term to 4.9%-points and 3.7%-points in the medium and long terms, respectively. In combination with NGCC improvements, this may cause an improvement in the net efficiency, including CO2 capture, from 49% in the short term to 55% and 58% in the medium and long terms, respectively. The total capital costs including capital costs of the NGCC ware calculated to decline from 880 in the short term to 750 and 690 €/kW in the medium and long terms, respectively, with a decline in the incremental capital costs due to capture from 350 in the short term to 270 and 240 €/kW in the medium and long terms, respectively. Finally, the avoidance costs may decline from 45 €/tCO2 in the short term to 33 €/tCO2 in the medium term and 28 €/tCO2 in the long term.

Gasification of biomass wastes and residues for electricity production

Abstract The technical feasibility and the economic and environmental performance of atmospheric gasification of biomass wastes and residues integrated with a combined cycle for electricity production are investigated for Dutch conditions. The system selected for study is an atmospheric circulating fluidized bed gasifier-combined cycle (ACFBCC) plant based on the General Electric LM 2500 gas turbine and atmospheric gasification technology, including flue gas drying and low-temperature gas cleaning (similar to the Termiska Processer AB process). The performance of the system is assessed for clean wood, verge grass, organic domestic waste, demolition wood and a wood-sludge mixture as fuel input. System calculations are performed with an ASPEN plus model. The composition of the fuel gas was derived by laboratory-scale fuel reactivity tests and subsequent model calculations. The net calculated efficiencies for electricity production are 35.4–40.3% (LHV) for the fuels studied, with potential for further improvement. Estimated investment costs, based on vendor quotes, for a fully commercial plant are 1500–2300 ECU per kW e installed. Electricity production costs, including logistics and in some cases negative fuel price, vary between minus 6.7 and 8.5 ECUct/kWh. Negative fuel costs are obtained if current costs for waste treatment can serve as income to the facility. Environmental performance is expected to meet strict standards for waste incineration in the Netherlands. The system seems flexible enough to process a wide variety of fuels. The kWh costs are very sensitive to the system efficiency but only slightly sensitive to transport distance; this is an argument in favour of large power-scale plants. As a waste treatment option the concept seems very promising. There seem to be no fundamental technical and economic barriers that can hamper implementation of this technology.

Cost Reduction Prospects for Offshore Wind Farms

The economics of offshore wind farms are presently less favorable than for onshore wind energy. Consequently there is a strong need for significant cost reductions in order to become competitive. About 70% of the electricity cost of offshore wind farms is determined by the initial investment costs, which mainly consist of the wind turbines, foundations, internal and external grid-connections and installation. Possible cost reductions until 2020 are explored for each of these components. Technological developments and cost reduction trends in both the offshore and onshore wind sector are analyzed. Information is also taken from offshore oil and gas sector and from the experience with high-voltage submarine transmission of electricity. Where possible, cost reduction trends are quantified using the experience curve concept, or otherwise based on expert judgments. Main drivers for cost reduction appear to be (a) design improvements and upscaling of wind turbines, (b) the continuing growth of onshore wind capacity, and (c) the development and high utilization rates of purpose-built installation vessels. Other factors are: reduction of steel prices, technological development of HVDC converter stations and cables, standardization of turbine and foundation design, and economies of scale for the wind turbine production. It is concluded that under different growth scenarios, investment costs of offshore wind farms may decline about 25–39% by 2020. Assuming an identical decline of annual O&M costs, the levelized electricity production costs are reduced from 6.8–7.2 to 4.2–5.4 €ct/kWh.

Quantitative risk assessment of CO2 transport by pipelines : a review of uncertainties and their impacts

A systematic assessment, based on an extensive literature review, of the impact of gaps and uncertainties on the results of quantitative risk assessments (QRAs) for CO(2) pipelines is presented. Sources of uncertainties that have been assessed are: failure rates, pipeline pressure, temperature, section length, diameter, orifice size, type and direction of release, meteorological conditions, jet diameter, vapour mass fraction in the release and the dose-effect relationship for CO(2). A sensitivity analysis with these parameters is performed using release, dispersion and impact models. The results show that the knowledge gaps and uncertainties have a large effect on the accuracy of the assessed risks of CO(2) pipelines. In this study it is found that the individual risk contour can vary between 0 and 204 m from the pipeline depending on assumptions made. In existing studies this range is found to be between <1m and 7.2 km. Mitigating the relevant risks is part of current practice, making them controllable. It is concluded that QRA for CO(2) pipelines can be improved by validation of release and dispersion models for high-pressure CO(2) releases, definition and adoption of a universal dose-effect relationship and development of a good practice guide for QRAs for CO(2) pipelines.

The global technical and economic potential of bioenergy from salt-affected soils

This study assesses the extent and location of salt-affected soils worldwide and their current land use and cover as well as the current technical and economic potential of biomass production from forestry plantations on these soils (biosaline forestry). The global extent of salt-affected land amounts to approximately 1.1 Gha, of which 14% is classified as forest, wetlands or (inter)nationally protected areas and is considered unavailable for biomass production because of sustainability concerns. For the remaining salt-affected area, this study finds an average biomass yield of 3.1 oven dry ton ha−1 y−1 and a global technical potential of 56 EJ y−1 (equivalent to 11% of current global primary energy consumption). If agricultural land is also considered unavailable because of sustainability concerns, the technical potential decreases to 42 EJ y−1. The global economic potential of biosaline forestry at production costs of 2€ GJ−1 or less is calculated to be 21 EJ y−1 when including agricultural land and 12 EJ y−1 when excluding agricultural land. At production costs of up to 5€ GJ−1, the global economic potential increases to 53 EJ y−1 when including agricultural land and to 39 EJ y−1 when excluding agricultural land. Biosaline forestry may contribute significantly to energy supply in certain regions, e.g., Africa. Biosaline forestry has numerous additional benefits such as the potential to improve soil, generate income from previously low-productive or unproductive land, and soil carbon sequestration. These are important additional reasons for investigating and investing in biosaline forestry.

Electricity generation from eucalyptus and bagasse by sugar mills in Nicaragua: A comparison with fuel oil electricity generation on the basis of costs, macro-economic impacts and environmental emissions

Two sugar mills in Nicaragua plan to generate electricity from bagasse during the sugarcane season and eucalyptus during the rest of the year, and to sell it to the national grid. This study compared this concept with the most logical alternative at the moment, which is electricity generated from fuel oil. Costs, macro-economic impacts and environmental emissions are considered. The low cost of land and labour means that eucalyptus can be produced more cheaply than fuel oil (1.7 as compared to 3.2

Sustainable development, climate change, and carbon dioxide removal (CDR)

/GJLHV). Consequently, it was calculated that a sugar mill can produce electricity from biomass for 4.9 mc/kWh as compared to 5.8 mc/kWh for electricity from an oil fired plant. About 64% of the money spent on biomass power stays within Nicaragua, thus contributing to its GDP, whereas in the case of fuel oil 83% goes abroad. The employment generated by the production of electricity from fuel oil is 15 person yr/MW yr, compared to 32 person yr/MW yr for biomass. Comparing biomass with fuel oil, emissions of CO2 and SO2 equivalents are, respectively, 67 and 18 times lower. Particulate emissions can be much higher in the biomass case because of lack of flue gas cleaning. We can conclude that biomass electricity generation by sugar mills in Nicaragua can compete with power generation from fuel oil. Moreover, it has an overall better environmental performance, creates double the amount of jobs, and contributes about four times as much to the GDP of Nicaragua.

Policies for renewable energy in the European Union and its member states: an overview

Abstract In this article the characteristics and requirements of a sustainable energy system are described. Special attention is given to the need to reduce greenhouse gas emissions, especially CO2. It is indicated that we may have to reduce the annual CO2 emissions due to our energy consumption from 6 GtC at present to less than 3 GtC in the year 2100, and the cumulative CO2 emissions between the years 1990 and 2100 to 550–750 GtC. To reduce the CO2 emissions, one option we can develop and apply is improvement of the energy efficiency with 50–90%. In addition strong efforts are needed to develop a sustainable energy supply system with low or no CO2 emissions. Option number one, the use of renewable energy sources, offers a huge potential but major technological breakthroughs are required to allow a massive application of these sources at affordable costs, in a reliable way and in an acceptable manner. This probably also holds for another option, nuclear energy. The impact of a fuel switch from coal to oil and natural gas will depend on the recoverable amount of fossil fuels. Therefore, due attention should be given to Carbon Dioxide Removal (CDR), especially as it is the only option that may allow continuing large scale use of fossil fuels. Application of this option could prevent the emission of 300 GtC or more between the years 1990 and 2100. Studies in the Netherlands suggest its application would be accepted socially. One of the main implementation barriers is its high cost. In the power sector CDR may increase the electricity production costs with 30–100%, although there is room to reduce these costs. Lower cost CDR options are available outside the power sector, like CDR from natural gas recovery processes, from specific industrial processes and from the production of hydrogen from natural gas, coal or biomass. Consequently, CDR may be applied at a cost ranging from US