Reductions in emissions of local air pollutants and co-benefits of Chinese energy policy: a Shanghai case study

To better understand the reductions in local air pollution that will result from the implementation of current Chinese energy policy, as well as the co-benefit for greenhouse-gas emission reductions, a Shanghai case study was conducted. The MARKAL model was used to forecast energy consumption and emissions of local air pollutants under different energy policy scenarios and also to analyze the associated reductions in CO₂ emissions. The results show that energy policies in Shanghai will significantly reduce SO₂ and PM₁₀ emissions and will also achieve the co-benefit of mitigating the increase of CO₂ emissions. In energy policy scenarios, SO₂ emissions during the period 2000–2020 will maintain the same level as in 2000; and the annual rate of increase of CO₂ emissions will be reduced to 1.1–1.2%, compared with 2.7% under a business-as-usual scenario. The problem for the future will be NO_x emissions, which are projected to increase by 60–70% by 2020, due to expansion of the transportation system.     

Modelling the UK residential energy sector under long-term decarbonisation scenarios: Comparison between energy systems and sectoral modelling approaches

The UK government has set a groundbreaking target of a 60% reduction in carbon dioxide (CO₂) emissions by 2050. Scenario and modelling assessment of this stringent target consistently finds that all sectors need to contribute to emissions reductions. The UK residential sector accounts for around 30% of the total final energy use and more than one-quarter of CO₂ emissions. This paper focuses on modelling of the residential sector in a system wide energy–economy models (UK MARKAL) and key UK sectoral housing stock models. The UK residential energy demand and CO₂ emission from the both approaches are compared. In an energy system with 60% economy-wide CO₂ reductions, the residential sector plays a commensurate role. Energy systems analysis finds this reduction is primarily driven by energy systems interactions notably decarbonisation of the power sector combined with increased appliance efficiency. The stock models find alternate decarbonisation pathways based on assumptions related to the future building stock and behavioural changes. The paper concludes with a discussion on the assumptions and drivers of emission reductions in different models of the residential energy sector.     

Hydrogen and fuel cells: Towards a sustainable energy future

A major challenge—some would argue, the major challenge facing our planet today—relates to the problem of anthropogenic-driven climate change and its inextricable link to our global society's present and future energy needs [King, D.A., 2004. Environment—climate change science: adapt, mitigate, or ignore? Science 303, 176–177]. Hydrogen and fuel cells are now widely regarded as one of the key energy solutions for the 21st century. These technologies will contribute significantly to a reduction in environmental impact, enhanced energy security (and diversity) and creation of new energy industries. Hydrogen and fuel cells can be utilised in transportation, distributed heat and power generation, and energy storage systems. However, the transition from a carbon-based (fossil fuel) energy system to a hydrogen-based economy involves significant scientific, technological and socioeconomic barriers to the implementation of hydrogen and fuel cells as clean energy technologies of the future. This paper aims to capture, in brief, the current status, key scientific and technical challenges and projection of hydrogen and fuel cells within a sustainable energy vision of the future. We offer no comments here on energy policy and strategy. Rather, we identify challenges facing hydrogen and fuel cell technologies that must be overcome before these technologies can make a significant contribution to cleaner and more efficient energy production processes.     

Renewable energy storage system via coal hydrogasification with co-production of electricity and synthetic natural gas

In this paper a novel integrated plant, designed for the co-production of electricity and synthetic natural gas (SNG), has been proposed as suitable strategy for renewable energy storage and CO₂ emission control.     

Implications of high energy prices for energy system and emissions—The response from an energy model for Germany

Against the background of strongly increasing prices for primary energy carriers we examine how trends towards high energy prices could affect the development of the German energy system, the corresponding carbon dioxide emissions as well as costs. With the IKARUS bottom-up time-step model we look at a scenario with steadily increasing prices and a price shock scenario, both compared to a moderate price scenario. The results show that high prices lead to a significant reduction of the total primary energy supply and also structural changes of primary energy supply with less oil and natural gas and a noticeable increase of renewables. The corresponding cumulated CO₂ emission reduction for the period 2005–2030 is in the range of 830–1310 Mt or 4.1–6.4% as compared to the reference scenario. In the high price scenario there is a continuous additional decrease of energy demand and emissions while in the price shock scenario we find a temporary minimum around 2015 and subsequently a remarkable relaxation towards the reference scenario. Due to technical measures in the model the extra system costs caused by higher prices are reduced by 65–75 billion _€2000${€}_{2000}$ for the period 2005–2030.     

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.     

The 2 °C scenario—A sustainable world energy perspective

A target-oriented scenario of future energy demand and supply is developed in a backcasting process. The main target is to reduce global CO₂ emissions to around 10 Gt/a in 2050, thus limiting global average temperature increase to 2 °C and preventing dangerous anthropogenic interference with the climate system. A 10-region energy system model is used for simulating global energy supply strategies. A review of sector and region-specific energy efficiency measures resulted in the specification of a global energy demand scenario incorporating strong energy efficiency measures. The corresponding supply scenario has been developed in an iterative process in close cooperation with stakeholders and regional counterparts from academia, NGOs and the renewable energy industry. The 2 °C scenario shows that renewable energy could provide as much as half of the world's energy needs by 2050. Developing countries can virtually stabilise their CO₂ emissions, while at the same time increasing energy consumption through economic growth. OECD countries will be able to reduce their emissions by up to 80%.     

Optimisation based design of a district energy system for an eco-town in the United Kingdom

The reduction of CO₂ emissions linked with human activities (mainly energy services and transport), together with the increased use of renewable energies, remain high priorities on various political agendas. However, considering the increased consumption of energy services (especially electricity), and the stochastic nature of some of the most promising renewable energies (wind for instance), the challenge is to find the optimal mix of technologies that will provide the energy services, without increasing the CO₂ emissions, but nonetheless ensuring reliability of supply. The focus of this paper is to present the DESDOP tool, based on mixed integer linear optimisation technics, that helps giving insight in the optimal mix of technologies that will simultaneously help decrease the emissions while at the same time guarantee resilience of supply. The results show that while it is not yet possible to avoid electricity from the grid completely (hence nuclear or fossil fuel), CO₂ reductions up to 20%, at no extra costs compared to the business-as-usual case, are easily achievable.     

Clean energy scenarios for Australia

Australia, a major producer and user of coal, has the highest per capita greenhouse gas emissions in the industrialised world. This study investigates whether in theory such a ‘fossil-fuel dependent’ country could achieve a 50% reduction in CO₂ emissions from stationary energy by 2040, compared with its 2001 emissions. To do this scenarios are developed, using a combination of forecasting and backcasting methods, under conditions of continuing economic growth and a restriction to the use of existing commercial technologies with small improvements. The principal scenario achieves the above target by implementing on the demand-side a medium-level of efficient energy use and substantial solar hot water together with a supply side combination of mainly natural gas, bioenergy and wind power. In doing so the scenario also achieves a 78% reduction in CO₂ emissions from electricity. Within the large uncertainties in future prices, it is possible that the economic savings from efficient energy use could pay for all or a large part of the additional costs of renewable energy.     

Electricity sector reforms in four Latin-American countries and their impact on carbon dioxide emissions and renewable energy

This paper analyzes carbon dioxide (CO₂) emissions related to energy consumption for electricity generation in four Latin-American countries in the context of the liberalization process. From 1990 to 2006, power plants based on renewable energy sources decreased its share in power installed capacity, and the carbon index defined as CO₂ emission by unit of energy for electricity production stayed almost constant for all countries with the exception of Colombia, where the index reduced due to increase in hydroelectricity generation in the last years. The paper also presents a new set of policies to promote renewable energy sources that have been developed in the four countries. The paper concludes that restructuring did not bring about environmental benefits related to a decrease in CO₂ emissions because this depend on the existence of committed policies, and dedicated institutional and regulatory frameworks.     

Renewable energy strategies for sustainable development

This paper discusses the perspective of renewable energy (wind, solar, wave and biomass) in the making of strategies for a sustainable development. Such strategies typically involve three major technological changes: energy savings on the demand side, efficiency improvements in the energy production, and replacement of fossil fuels by various sources of renewable energy. Consequently, large-scale renewable energy implementation plans must include strategies for integrating renewable sources in coherent energy systems influenced by energy savings and efficiency measures. Based on the case of Denmark, this paper discusses the problems and perspectives of converting present energy systems into a 100% renewable energy system. The conclusion is that such development is possible. The necessary renewable energy sources are present, and if further technological improvements of the energy system are achieved the renewable energy system can be created. Especially technologies of converting the transportation sector and the introduction of flexible energy system technologies are crucial.     

CO2 Emissions Mitigation Potential of Some Renewable Energy Technologies in India

Abstract

An attempt to develop simple frameworks for quantification of the CO₂ emissions mitigation potential of renewable energy technologies for domestic water heating, domestic lighting, water pumping, and crop drying has been made. The annual useful energy provided by each of the renewable energy technology and the annual saving of fuel/electricity have been estimated. The gross annual amount of CO₂ emissions mitigation, as well as net amount of annual CO₂ emissions mitigation potential of each technology, is estimated by taking into account the CO₂ emissions embodied in the device.     

Impacts of CO2 emission constraints on technology selection and energy resources for power generation in Bangladesh

This paper examines the impacts of CO₂ emission reduction target and carbon tax on future technologies selection and energy use in Bangladesh power sector during 2005–2035. The analyses are based on a long-term energy system model of Bangladesh using the MARKAL framework. The analysis shows that Bangladesh will not be able to meet the future energy demand without importing energy. However, alternative policies on CO₂ emission constraints reduce the burden of imported fuel, improve energy security and reduce environmental impacts. The results show that the introduction of the CO₂ emission reduction targets and carbon taxes directly affect the shift of technologies from high carbon content fossil-based to low carbon content fossil-based and clean renewable energy-based technologies compared to the base scenario. With the cumulative CO₂ emission reduction target of 10–20% and carbon tax of 2500 Taka/ton, the cumulative net energy imports during 2005–2035 would be reduced in the range of 39–65% and 37%, respectively, compared to the base scenario emission level. The total primary energy requirement would be reduced in the range of 4.5–22.3% in the CO₂ emission reduction targets and carbon tax 2500 Taka/ton scenarios and the primary energy supply system would be diversified compared to the base scenario.     

Implications of process energy efficiency improvements for primary energy consumption and CO2 emissions at the national level

The improvement of energy efficiency is seen as one of the most promising measures for reducing global CO₂ emissions. However, the emission reduction potential may seem different from the industrial plant and policy-maker’s perspectives. This paper evaluates the influences of process heat conservation on CHP electricity production, primary energy consumption and CO₂ emissions from both the mill site and national perspectives. The results indicate that heat conservation in an industrial process may lead to varying results in primary energy consumption and CO₂ emissions, depending on the form of marginal heat production used at the mill site. In the CHP process, reduction of the heat load lowers electricity production, and this reduction may have to be compensated for at the national level. Therefore, the energy conservation potential in industry has to be evaluated by taking into account the connections to the outside society, which means that a wider system boundary than a mill site has to be used. This study demonstrates by theoretical analysis and case mill studies the magnitude of the effects of system boundary definition when evaluating the contribution of an individual energy efficiency investment towards fulfilling the commitment to reduce CO₂ emissions at the national level.     

Renewable energy planning for India in 21st century

Energy is a vital input for economic and social development of any country. With increasing industrial and agricultural activities in the country, the demand for energy is also rising. Solar, wind and biomass are accepted as dependable and widely available renewable sources of energy. Development of an energy model will help in the proper allocation of these renewables in meeting the future demand of energy in India. The present work deals with the development of an Optimal Renewable Energy Model (OREM) for the effective utilisation of renewable energy sources in India for the year-2020-21. The objective of the Optimal Renewable Energy Model (OREM) was minimising cost/efficiency ratio based on social acceptance, reliability, demand and potential constraints. The OREM model allocated renewable energy sources for different end-uses such as lighting, cooking, pumping, heating, cooling and transportation for the year 2020-21.     

Economic growth,energy consumption and CO2 emissions in India: a disaggregated causal analysis

This study examines the long-run and short-run causal relationships among energy consumption, real gross domestic product (GDP) and CO₂ emissions using aggregate and disaggregate (sectoral) energy consumption measures utilising annual data from 1971 to 2011. The autoregressive distributed lag bounds test reveals that there is a long-run relationship among the variables concerned at both aggregate and disaggregate levels. The Toda–Yamamoto causality tests, however, reveal that the long-run as well short-run causal relationship among the variables is not uniform across sectors. The weight of evidences of the study indicates that there is short-run causality from electricity consumption to economic growth, and to CO₂ emissions. The results suggest that India should take appropriate cautious steps to sustain high growth rate and at the same time to control emissions of CO₂. Further, energy and environmental policies should acknowledge the sectoral differences in the relationship between energy consumption and real gross domestic product.     

Renewable energy sources for clean and sustainable energy policies in Turkey

Energy is an essential factor to achieve sustainable development. So, countries striving to this end are seeking to reassess their energy systems with a view towards planning energy programmes and strategies in line with sustainable development goals and objectives. As would be expected, the rapid expansion of energy production and consumption has brought with it a wide range of environmental issues at the local, regional and global levels. States have played a leading role in protecting the environment by reducing emissions of greenhouse gases. Turkey is an energy importing country with more than half of the energy requirement being supplied by imports, and air pollution is becoming a great environmental concern in the country. On the other hand, Turkey's geographical location has several advantages for extensive use of most of the renewable energy sources. In this regard, renewable energy resources appear the most efficient and effective solutions for clean and sustainable energy development in Turkey. This paper provides an overview of global energy use and renewables for clean and sustainable energy policies in Turkey.     

Renewable energy for sustainable development in Africa: a review

Renewable energy usage in Africa has been reviewed using South Africa, Egypt, Nigeria and Mali as case studies. The various national energy policies of these countries were analysed and areas that require attention to achieve sustainability were highlighted. On the overall, the success of sustainable development in Africa lies in addressing the imminent energy crisis in the continent. Excessive usage of fuel wood is already creating considerable environmental problems especially in the Sahel. Africa has all the potentials to solve its energy problems if appropriate infrastructural support can be provided for harnessing the abundant renewable resources in the continent, and if skills are pooled together and experiences shared in addressing the key issues.     

Renewable energy in India: Historical developments and prospects

Promoting renewable energy in India has assumed great importance in recent years in view of high growth rate of energy consumption, high share of coal in domestic energy demand, heavy dependence on imports for meeting demands for petroleum fuels and volatility of world oil market. A number of renewable energy technologies (RETs) are now well established in the country. The technology that has achieved the most dramatic growth rate and success is wind energy; India ranks fourth in the world in terms of total installed capacity. India hosts the world's largest small gasifier programme and second largest biogas programme. After many years of slow growth, demand for solar water heaters appears to be gaining momentum. Small hydro has been growing in India at a slow but steady pace. Installation of some of the technologies appears to have slowed down in recent years; these include improved cooking stoves (ICSs) and solar photovoltaic (PV) systems. In spite of many successes, the overall growth of renewable energy in India has remained rather slow. A number of factors are likely to boost the future prospects of renewable energy in the country; these include global pressure and voluntary targets for greenhouse gas emission reduction, a possible future oil crisis, intensification of rural electrification program, and import of hydropower from neighbouring countries.     

Renewable energy programme and vision in India

In the present world, renewable sources of energy have begun to make a significant contribution to meeting heat and power needs. In India, the Government is implementing a wide ranging programmes on renewable energy technologies. Several policy and fiscal measures have contributed to the rapid expansion of the progress during the last few years. This paper presents a review of renewable energy programme and vision in India. The present situation is seen to be much more promising and favourable for renewables.