Effects of Kosovo’s energy use scenarios and associated gas emissions on its climate change and sustainable development

Climate change will be the first truly global challenge for sustainability. Energy production and consumption from fossil fuels has central role in respect to climate change, but also to sustainability in general. Because climate change is regionally driven with global consequences and is a result of economic imperatives and social values, it requires a redefinition as to the balance of these outcomes globally and regionally in Kosovo. Kosovo as one of the richest countries with lignite in Europe, with 95–97% of the electric power production from lignite and with 90% of vehicles over 10 years old, represents one of the regions with the greatest ratio of CO₂ emissions per unit of GDP, as well as one of the countries with the most polluted atmosphere in Europe. The modelling is carried out regionally for Kosovo for two dynamical systems which are the main emitters of greenhouse gases (CO₂, CH₄, NO_x, etc.) and air pollutants (CO, SO₂, dust CH_x, etc.): electricity generation and transportation emissions systems, for the time period 2000–2025. Various energy scenarios of the future are shown. We demonstrate that a transition to environmentally compatible sustainable energy use in Kosovo is possible. Implementing the emission reduction policies and introducing new technologies in electrical power production and transportation in Kosovo ensure a sustainable future development in Kosovo, electric power production and transport that become increasingly environmentally compatible.     

The lignite electricity‐generating sector in Greece: Current status and future prospects

Lignite plays an important role in Greece's energy sector as it satisfies over 70% of country's needs in electric power. The extraction of lignite takes place mainly in three regions of Greece, namely Ptolemais‐Amyndeon, Megalopolis and Florina. The annual production of lignite is around 60 million tons, out of which 48 million tons derive from the coal fields of northern Greece (Ptolemais‐Amyndeon and Florina). Almost the entire lignite production is consumed for electricity generation, while small amounts of lignite are used for briquettes and other applications. The Greek coal‐fired power plants, which are about 4500 MW, use conventional technology and they are old (an average of 30 years). In the coming years new coal fields will be exploited in Florina—another 2.5 million tons of coal—in order to satisfy the currently under construction 365 MW plant located at Meliti, Florina, Northern Greece. Even though the lignite reserves are widespread in Greece and other areas such as Elassona and Drama could possibly host power plants, it is expected that the Florina power plant will be the last coal‐fired plant to be build in the country. Lignite has to compete with natural gas—the construction of the main gas pipeline network has been completed—imported oil and renewable energy sources. The new EU regulations on power plant emissions raise obstacles for the firing of lignite, although it is low in sulphur. It must be shown that lignite produces low cost electricity in a environmentally friendly manner. The utilization of fly ash and land reclamation can improve the situation in lignite mining. In particular, specific attention was paid to further research and potential use of fly ash in road construction, the production of bricks and concrete, and the production of zeolites from lignitic fly ash. The use of clean coal technologies in power plants can solve many emission problems. Specific measures to increase the efficiency of lignite‐fired power units might include: identification of the loss sources of every unit, improvement of the cold end of the steam turbines, optimization of the beater wheel mills operation, and the combination of natural gas‐fired turbines with the existing boilers. The liberalization of the electricity market needs to be considered seriously from the lignite industry, since the potential electricity producers can freely choose from all kinds of fuels, such as imported coal, oil, gas and renewables. However, Greek lignite meets the requirements for the security of supply, as indicated in the EU's Green Paper. It needs only to be competitive in the new energy sector by improving mining and combustion conditions. Further research on these topics, through the European Commission's ECSC and Framework Programmes, as well as the national programmes, is required. Copyright © 2004 John Wiley & Sons, Ltd.     

Newer mining technology and plans for increased use of lignite in India

The total inferred reserves of lignite in India are about 3680 million t, out of which the Neyveli Lignite Field in Tamil Nadu State, South India, accounts for 3300 million t. This field is mined by the mechanized opencast method, using bucket wheel excavator-belt conveyor-spreader continuous mining technology. The lignite is mainly used for power generation. The present level of lignite production is 6.5 million t/yr. The mining of lignite at Neyveli is faced with major problems like tackling hard, abrasive Cuddalore sandstone overburden, high pressure aquifers below lignite seams and high monsoonic storm water. These problems have been successfully overcome in stages, and the mine has achieved very high capacity utilization during 1984–1985. Up to March 1985, about 83.8 million t of lignite have been mined from this field. Taking into consideration the future demand for power in the energy-starved southern region, Neyveli Lignite Corporation (NLC) plans to develop a second mine producing 10.5 million t/yr of lignite, and is also considering opening new mines to increase lignite output to 32 million t/yr by the year 2000. Measures are also being taken to maintain the environmental quality in the mining and industrial complex.     

Statistical Tests for Prediction of Lignite Quality

Abstract

Domestic lignite from large, bucket wheel excavators based open pit mines is the main fuel for electricity generation in Greece. Lignite from one or more mines may arrive at any power plant stockyard. The mixture obtained constitutes the lignite fuel fed to the power plant. The fuel is sampled in regular time intervals. These samples are considered as results of observations of values of spatial random variables. The aim was to form and statistically test many small sample populations. Statistical tests on the values of the humidity content, the ash-water free content, and the lower heating value of the lignite fuel indicated that the sample values form a normal population. The Kolmogorov-Smirnov test was applied for testing goodness-of-fit of sample distribution for a three year period and different power plants of the Kozani-Ptolemais area, western Macedonia, Greece. The normal distribution hypothesis can be widely accepted for forecasting the distribution of values of the basic quality characteristics even for a small number of samples.     

Implication of CO2 capture technologies options in electricity generation in Korea

This paper estimates the future mitigation potential and costs of CO₂ reduction technology options to the electricity generation facility in Korea. The monoethanolamine (MEA) absorption, membrane separation, pressure swing adsorption, and O₂/CO₂ input system were selected as the representative CO₂ reduction technology options. In order to analyze the mitigation potential and cost of these options, it uses the long-range energy alternative planning (LEAP) framework for setting future scenarios and assessing the technology options implication. The baseline case of energy planning scenario in Korea is determined in a business-as-usual (BAU) scenario. A BAU scenario is composed of the current account (2003) and future projections for 20 years. Alternative scenarios mainly deal with the installation planning options of CO₂ reduction technology (exogenous capacity, planning time, and existing electric plants). In each alternative scenario analysis, an alternation trend of existing electricity generation facilities was analyzed and the cost of installed CO₂ reduction plants and CO₂ reduction potential was assessed quantitatively.     

Steam gasification of Greek lignite and its chars by co-feeding CO2 toward syngas production with an adjustable H2/CO ratio

Low-rank lignite is among the most abundant and cheap fossil fuels, linked, however, to serious environmental implications when employed as feedstock in conventional thermoelectric power plants. Hence, toward a low-carbon energy transition, the role of coal in world's energy mix should be reconsidered. In this regard, coal gasification for synthesis gas generation and consequently through its upgrade to a variety of value-added chemicals and fuels constitutes a promising alternative. Herein, we thoroughly explored for a first time the steam gasification reactivity of Greek Lignite (LG) and its derived chars obtained by raw LG thermal treatment at 300, 500 and 800 °C. Moreover, the impact of CO₂ addition on H₂O gasifying agent mixtures was also investigated. Both the pristine and char samples were fully characterized by various physicochemical techniques to gain insight into possible structure-gasification relationships. The highest syngas yield was obtained for chars derived after LG thermal treatment at 800 °C, due mainly to their high content in fixed carbon, improved textural properties and high alkali index. Steam gasification of lignite and char samples led to H₂-rich syngas mixtures with a H₂/CO ratio of approximately 3.8. However, upon co-feeding CO₂ and H₂O, the H₂/CO ratio can be suitably adjusted for several potential downstream processes.     

The future developments of the electricity prices in view of the implementation of the Paris Agreements: Will the current trends prevail,or a reversal is ahead?

We assess the impact on the European electricity market of the European Union “Clean energy for all Europeans” package, which implements the EU Nationally Determined Contribution in Paris COP 21. We focus on the year 2030, which is the year with defined climate targets. For the assessment, we employ a game-theoretic framework of the wholesale electricity market, with high technical detail. The model is applied to two core scenarios, a Base scenario and a Low Carbon scenario to provide insights regarding the future electricity capacity, generation mix, cross-border trade and electricity prices. We also assess three additional variants of the core scenarios concerning different levels of: a) fossil and CO₂ prices; b) additional flexibility provided by batteries; c) market integration. We find that the electricity prices in 2030 substantially increase from today's level, driven by the increase in fuel and CO₂ prices. The flexibility from batteries helps in mitigating the price peaks and the price volatility. The increased low marginal cost electricity generation, the expansion of non-dispatchable and distributed capacities, and the higher market integration further reduce the market power from producers in the electricity markets from today's level.     

Lignite-fired thermal power plants and SO2 pollution in Turkey

About 80% of the electric energy production in Turkey is provided by thermal power plants which use fossil fuels. Lignite, the most abundant domestic energy source, is consumed in most of these plants. Turkey has approximately 0.85% of the world's lignite reserves; however, the Turkish lignites have low calorific value and contain relatively higher amounts of ash, moisture, and sulfur. Nearly 80% of the lignite mined in Turkey is consumed in the thermal power plants since it is not appropriate for use in other types of industry and heating. In Turkey, 13 large-scale lignite-fired thermal power plants are responsible for a considerable amount of air pollution. Therefore, it is crucial to decide on the optimal place and technology for the future thermal power plants, and to equip the currently operating plants with newer technologies that will reduce amount of contaminants released into the air.In this study, the effects of the lignite-fired thermal power plants which have an important place in the energy politics in Turkey on the air pollution are investigated. We focused on SO₂ pollution and the regions in which the SO₂ emissions were concentrated and diffused. The pollutant diffusion areas were projected and mapped based on parameters such as wind data, isotherm curves, population density, and topographic features by using Geographical Information System (GIS) software, ArcView. The contribution of the thermal power plants to SO₂ pollution was also examined.     

External costs from electricity generation of China up to 2030 in energy and abatement scenarios

This paper presents estimated external costs of electricity generation in China under different scenarios of long-term energy and environmental policies. Long-range Energy Alternatives Planning (LEAP) software is used to develop a simple model of electricity demand and to estimate gross electricity generation in China up to 2030 under these scenarios. Because external costs for unit of electricity from fossil fuel will vary in different government regulation periods, airborne pollutant external costs of SO₂, NO_x, PM₁₀, and CO₂ from fired power plants are then estimated based on emission inventories and environmental cost for unit of pollutants, while external costs of non-fossil power generation are evaluated with external cost for unit of electricity. The developed model is run to study the impact of different energy efficiency and environmental abatement policy initiatives that would reduce total energy requirement and also reduce external costs of electricity generation. It is shown that external costs of electricity generation may reduce 24–55% with three energy policies scenarios and may further reduce by 20.9–26.7% with two environmental policies scenarios. The total reduction of external costs may reach 58.2%.     

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.     

Cost versus emission minimization in thermal electricity generation: A case of so2 emissions reduction from the indian power system

There is a trade-off between cost and emission minimizing objectives for electricity generation because of the measures needed to reduce emissions. For SO₂ emissions reduction these are adjustment within the system which involve deviation from the least-cost generation schedule, changing power mix for future capacity and installation of abatement equipments, e.g. flue gas desulfurization unit. The linear programming modelling framework (INGRID) presented here brings out the nature of this trade-off for SO₂ emissions reduction from the Indian power system for existing capacity and future capacity addition. The adjustment within the existing system can take place through integrated optimal operations of various electricity utilities by substituting generation of more polluting plants by less emitting efficient plants as long as the cost of reduction is lower than that of flue gas desulfurization.     

Assessment of cleaner electricity generation technologies for net CO2 mitigation in Thailand

The choice of electricity generation technologies not only directly affects the amount of CO₂ emission from the power sector, but also indirectly affects the economy-wide CO₂ emission. It is because electricity is the basic requirement of economic sectors and final consumptions within the economy. In Thailand, although the power development plan (PDP) has been planned for the committed capacity to meet the future electricity demand, there are some undecided electricity generation technologies that will be studied for technological options. The economy-wide CO₂ mitigations between selecting cleaner power generation options instead of pulverized coal-thermal technology of the undecided capacity are assessed by energy input–output analysis (IOA). The decomposition of IOA presents the fuel-mix effect, input structural effect, and final demand effect by the change in technology of the undecided capacity. The cleaner technologies include biomass power generation, hydroelectricity and integrated gasification combined cycle (IGCC). Results of the analyses show that if the conventional pulverized coal technology is selected in the undecided capacity, the economy-wide CO₂ emission would be increased from 223 million ton in 2006 to 406 million ton in 2016. Renewable technology presents better mitigation option for replacement of conventional pulverized coal technology than the cleaner coal technology. The major contributor of CO₂ mitigation in cleaner coal technology is the fuel mix effect due to higher conversion efficiency. The demand effect is the major contributor of CO₂ mitigation in the biomass and hydro cases. The embedded emission in construction of power plant contributes to higher CO₂ emission.     

Options for net zero emissions hydrogen from Victorian lignite. Part 1: Gaseous and liquefied hydrogen

This two-part paper investigates the feasibility of producing export quantities (770 t/d) of blue hydrogen meeting international standards, by gasification of Victorian lignite plus carbon capture and storage (CCS). The study involves a detailed Aspen Plus simulation analysis of the entire production process, taking into account fugitive methane emissions during lignite mining. Part 1 focusses on the resources, energy requirements and greenhouse gas emissions associated with production of gaseous and liquefied hydrogen, while Part 2 focusses on production of ammonia as a hydrogen carrier.In this study, the proposed process comprises lignite mining, lignite drying and milling, air separation unit (ASU), dry-feed entrained flow gasification, gas cooling and cleaning, sour water-gas shift reaction, acid gas removal, pressure swing adsorption (PSA) for hydrogen purification, elemental sulphur recovery, CO₂ compression for transport and injection, hydrogen liquefaction, steam and gas turbines to generate all process power, plus an optional post-combustion CO₂ capture step. High grade waste heat is utilised for process heat and power generation. Three alternative process scenarios are investigated as options to reduce resource utilisation and greenhouse gas emissions: replacing the gas turbine with renewable energy from off-site wind turbines, and co-gasification of lignite with either biomass or biochar. In each case, the specific net greenhouse gas intensity is estimated and compared to the EU Taxonomy specification for sustainable hydrogen.This is the first time that a coal-to-hydrogen study has quantified the greenhouse gas emissions across the entire production chain, including upstream fugitive methane emissions. It is found that both gaseous and liquefied hydrogen can be produced from Victorian lignite, along with all necessary electricity, with specific emissions intensity (SEI) of 2.70 kg CO₂-e/kg H₂ and 2.73 kg CO₂-e/kg H₂, respectively. These values conform to the EU Taxonomy limit of 3.0 kg CO₂-e/kg H₂. This result is achieved using a Selexol™ plant for CO₂ capture, operating at 89.5%–91.7% overall capture efficiency. Importantly, the very low fugitive methane emissions associated with Victorian lignite mining is crucial to the low SEI of the process, making this is a critical advantage over the alternative natural gas or black coal processes.This study shows that there are technical options available to further reduce the SEI to meet tightening emissions targets. An additional post-combustion MDEA CO₂ capture unit can be added to increase the capture efficiency to 99.0%–99.2% and reduce the SEI to 0.3 kg CO₂-e/kg H₂. Emissions intensity can be further reduced by utilising renewable energy rather than co-production of electricity on site. Net zero emissions can then be achieved by co-gasification with ≤1.4 dry wt.% biomass, while a higher proportion of biomass would achieve net-negative emissions. Thus, options exist for production of blue hydrogen from Victorian lignite consistent with a ‘net zero by 2050’ target.     

Energy production from PV and carbon reduction in great lakes region of Masuria Poland: A case study of water park in Elk

The aim of the installation of photovoltaic panels in the object of the Water Park was to use the possibility of supporting the production of electricity using solar energy. The article shows the adopted technological solution installation of photovoltaic and presents the results of the analysis of plant performance in real conditions, not just computational theory. The analysis of the installation work was performed on the basis of monitoring of operating parameters conducted in 2012–2013. The use of photovoltaic helped reduce CO₂, SO₂, NO_x and dust emissions into the atmosphere on the value of installed power and reduce the amount of electricity drawn from the network (In Poland still based on coal and lignite).The results of energy and environmental analysis show the validity of installation of photovoltaic in objects like Water Parks.Energy and environmental effects combine necessarily the economic effects. It also helps to promote the local market to other forms of energy generation as well as improves the energy security of the Warmia and Mazury province, as well as part of the European Climate Change Programme (ECCP), which has lead to coordination of activities towards the reduction of greenhouse gas emissions.     

Biogas derived from municipal solid waste to generate electrical power through solid oxide fuel cells

Depleting fossil fuels and the pollution resulting from their consumption indicate an urgent need for clean and dependable alternatives such as renewable energies. Biomass is a free and abundant source of renewable energy. Municipal solid waste (MSW) as one of the main categories of biomass has always been an issue for metropolitan cities. It has, however, a high potential for biogas production. In this study, the technical and economic aspects of generating electrical power through solid oxide fuel cells (SOFCs) powered by injecting biogas derived from Tehran's MSW, as a case study, are investigated. The main objectives of the current study are to identify the power generation capability of the process and find out if it can result in a competitive energy resource. The total amount of obtainable methane through anaerobic digestion of MSW and then the achievable power generation capacity by using the obtained biogas are computed using the electrochemical relations inside the SOFC. The economic calculations are carried out to estimate the final price of the generated electricity, taking into account the major capital and ongoing costs of the required equipment. The effect of variations of MSW composition on the power generation capability and final electricity price is also studied. Moreover, the application of a gas turbine (GT) with the SOFC as a hybrid SOFC–GT system to recover the produced heat by SOFC and its effect on the power generation capability and the final electricity price are investigated. Results indicate that around 997.3 tons day^?1 biomethane can be generated using Tehran's MSW. By using the SOFC, the produced biogas can generate 300 MW_AC electrical power with a final cost of Depleting fossil fuels and the pollution resulting from their consumption indicate an urgent need for clean and dependable alternatives such as renewable energies. Biomass is a free and abundant source of renewable energy. Municipal solid waste (MSW) as one of the main categories of biomass has always been an issue for metropolitan cities. It has, however, a high potential for biogas production. In this study, the technical and economic aspects of generating electrical power through solid oxide fuel cells (SOFCs) powered by injecting biogas derived from Tehran's MSW, as a case study, are investigated. The main objectives of the current study are to identify the power generation capability of the process and find out if it can result in a competitive energy resource. The total amount of obtainable methane through anaerobic digestion of MSW and then the achievable power generation capacity by using the obtained biogas are computed using the electrochemical relations inside the SOFC. The economic calculations are carried out to estimate the final price of the generated electricity, taking into account the major capital and ongoing costs of the required equipment. The effect of variations of MSW composition on the power generation capability and final electricity price is also studied. Moreover, the application of a gas turbine (GT) with the SOFC as a hybrid SOFC–GT system to recover the produced heat by SOFC and its effect on the power generation capability and the final electricity price are investigated. Results indicate that around 997.3 tons day^?1 biomethane can be generated using Tehran's MSW. By using the SOFC, the produced biogas can generate 300 MW_AC electrical power with a final cost of $0.178 kWh^?1. By using the hybrid SOFC–GT, the electrical power capacity is increased to 525 MW_AC, and the final electricity cost drops to $0.11 kWh^?1, which indicates its competitiveness with other common energy resources in the near future, especially by considering different governmental subsidy policies that support renewable energy resources. The considerable environmental benefits of the proposed procedure, from both MSW management and CO₂ emission reduction points of view, make it a promising sustainable energy resource for the future. Copyright © 2016 John Wiley & Sons, Ltd.     

Assessing the sustainability challenges for electricity industries in ASEAN newly industrialising countries

Rapid social and economic progress in fast developing countries such that among the countries in the Association of Southeast Asian Nations (ASEAN) have driven substantial growth in electricity consumption in this region. Whilst this represents significant societal and economic development, it has potentially growing adverse environmental impacts. This raises a concern on sustainable development in the electricity sector in this region. This study evaluates key sustainability challenges in the electricity industries in the five largest energy consumers in ASEAN: Indonesia, Thailand, Malaysia, the Philippines and Vietnam. The 3A's energy sustainability objectives: Accessibility, Availability and Acceptability are used as the sustainability analytical framework. This study also draws together a set of associated indicators and criteria within the analytical framework to analyse the status of the electricity industries in these countries. The analysis shows that key sustainability challenges in the ASEAN-5 are attributable to satisfying rapid demand growth; enhancing security of electricity supply; and mitigating the increase in CO₂ emissions from electricity generation. Given the promising resource and technical potential in this region, renewable energy emerges as a favourable option to address these challenges; however, increasing the share of renewable energy in electricity generation requires considerable policy support. This study suggests that there is an opportunity for the ASEAN countries to strengthen regional collaborations through experience and resource sharing to enhance sustainability in the electricity industries. This study also highlights some of the key issues facing the electricity industry, and the need for new generation investment decision support tools which can address these issues.     

Electricity consumption and CO2 capture potential in Spain

In this paper, different electricity demand scenarios for Spain are presented. Population, income per capita, energy intensity and the contribution of electricity to the total energy demand have been taken into account in the calculations. Technological role of different generation technologies, i.e. coal, nuclear, renewable, combined cycle (CC), combined heat and power (CHP) and carbon capture and storage (CCS), are examined in the form of scenarios up to 2050. Nine future scenarios corresponding to three electrical demands and three options for new capacity: minimum cost of electricity, minimum CO₂ emissions and a criterion with a compromise between CO₂ and cost (CO₂-cost criterion) have been proposed. Calculations show reduction in CO₂ emissions from 2020 to 2030, reaching a maximum CO₂ emission reduction of 90% in 2050 in an efficiency scenario with CCS and renewables. The contribution of CCS from 2030 is important with percentage values of electricity production around 22–28% in 2050. The cost of electricity (COE) increases up to 25% in 2030, and then this value remains approximately constant or decreases slightly.     

Sustainable electricity generation fuel mix analysis using an integration of multicriteria decision-making and system dynamic approach

To achieve a national energy access target of 90% urban and 51% rural by 2035, combat climate change, and diversify the energy sector in the country, the Zambian government is planning to integrate other renewable energy resources (RESs) such as wind, solar, biomass, and geothermal into the existing hydro generation–based power system. However, to achieve such targets, it is essential for the government to identify suitable combination of the RESs (electricity generation fuel mix) that can provide the greatest sustainability benefit to the country. In this paper, a multicriteria decision-making framework based on analytic hierarchy process and system dynamics techniques is proposed to evaluate and identify the best electricity generation fuel mix for Zambia. The renewable energy generation technologies considered include wind, solar photovoltaic, biomass, and hydropower. The criteria used are categorized as technical, economic, environmental, social, and political. The proposed approach was applied to rank the electricity generation fuel mix based on nine sustainability aspects: land use, CO₂ emissions, job creation, policy promotion affordability, subsidy cost, air pollution reduction, RES electricity production, RES cumulative capacity, and RES initial capital cost. The results indicate that based on availability of RESs and sustainability aspects, in overall, the best future electricity generation mix option for Zambia is scenario with higher hydropower (40%) penetration, wind (30%), solar (20%), and lower biomass (10%) penetration in the overall electricity generation fuel mix, which is mainly due to environmental issues and availability of primary energy resources. The results further indicate that solar ranks first in most of the scenarios even after the penetration weights of RES are adjusted in the sensitivity analysis. The wind was ranked second in most of the scenarios followed by hydropower and last was biomass. These developed electricity generation fuel mix pathways would enable the country meeting the future electricity generation needs target at minimized environmental and social impacts by 2035. Therefore, this study is essential to assist in policy and decision making including planning at strategic level for sustainable energy diversification.     

Fuel price and technological uncertainty in a real options model for electricity planning

Electricity generation is an important source of total CO₂ emissions, which in turn have been found to relate to an acceleration of global warming. Given that many OECD countries have to replace substantial portions of their electricity-generating capacity over the next 10–20 years, investment decisions today will determine the CO₂-intensity of the future energy mix. But by what type of power plants will old (mostly fossil-fuel-fired) capacity be replaced? Given that modern, less carbon-intensive technologies are still expensive but can be expected to undergo improvements due to technical change in the near future, they may become more attractive, especially if fossil fuel price volatility makes traditional technologies more risky. At the same time, technological progress is an inherently uncertain process itself. In this paper, we use a real options model with stochastic technical change and stochastic fossil fuel prices in order to investigate their impact on replacement investment decisions in the electricity sector. We find that the uncertainty associated with the technological progress of renewable energy technologies leads to a postponement of investment. Even the simultaneous inclusion of stochastic fossil fuel prices in the same model does not make renewable energy competitive compared to fossil-fuel-fired technology in the short run based on the data used. This implies that policymakers have to intervene if renewable energy is supposed to get diffused more quickly. Otherwise, old fossil-fuel-fired equipment will be refurbished or replaced by fossil-fuel-fired capacity again, which enforces the lock-in of the current system into unsustainable electricity generation.     

Spatial variation of emissions impacts due to renewable energy siting decisions in the Western U.S. under high-renewable penetration scenarios

One of the policy goals motivating programs to increase renewable energy investment is that renewable electric generation will help reduce emissions of CO₂ as well as emissions of conventional pollutants (e.g., SO₂ and NO_x). As a policy instrument, Renewable Portfolio Standards (RPS) encourage investments in wind, solar and other generation sources with the goal of reducing air emissions from electricity production. Increased electricity production from wind turbines is expected to displace electricity production from fossil-fired plants, thus reducing overall system emissions. We analyze the emissions impacts of incremental investments in utility-scale wind power, on the order of 1 GW beyond RPS goals, in the Western United States using a utility-scale generation dispatch model that incorporates the impacts of transmission constraints. We find that wind investment in some locations leads to slight increases in overall emissions of CO₂, SO₂ and NO_x. The location of wind farms influences the environmental impact by changing the utilization of transmission assets, which affects the overall utilization of power generation sources and thus system-level emissions. Our results suggest that renewable energy policy beyond RPS targets should be carefully crafted to ensure consistency with environmental goals.