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.     

Spanish energy roadmap to 2020: Socioeconomic implications of renewable targets

The European Union has established challenging targets for the share of renewable energies to be achieved by 2020; for Spain, 20% of the final energy consumption must be from renewable sources at such time. The aim of this paper is the analysis of the consequences for the electricity sector (in terms of excess cost of electricity, investment requirements, land occupation, CO₂ emissions and overcapacity of conventional power) of several possibilities to comply with the desired targets. Scenarios are created from different hypotheses for energy demand, biofuel share in final energy in transport, contribution of renewables for heating and cooling, renewable electricity generation (generation mix, deployment rate, learning curves, land availability) and conventional power generation (lifetime of current installations, committed deployment, fossil fuel costs and CO₂ emissions cost). A key input in the estimations presented is the technical potential and the cost of electricity from renewable sources, which have been estimated in previous, detailed studies by the present authors using a methodology based on a GIS (Geographical Information System) and high resolution meteorological data. Depending on the scenario, the attainment of the targets will lead to an increase in the cost of electricity from 19% to 37% with respect to 2007.     

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.     

Decomposition of CO2 emissions change from energy consumption in Brazil: Challenges and policy implications

This study evaluates the changes in CO₂ emissions from energy consumption in Brazil for the period 1970–2009. Emissions are decomposed into production and consumption activities allowing computing the full set of energy sources consumed in the country. This study aims to develop a comprehensive and updated picture of the underlying determinants of emissions change from energy consumption in Brazil along the last four decades, including for the first time the recently released data for 2009. Results demonstrate that economic activity and demographic pressure are the leading forces explaining emission increase. On the other hand, carbon intensity reductions and diversification of energy mix towards cleaner sources are the main factors contributing to emission mitigation, which are also the driving factors responsible for the observed decoupling between CO₂ emissions and economic growth after 2004. The cyclical patterns of energy intensity and economy structure are associated to both increments and mitigation on total emission change depending on the interval. The evidences demonstrate that Brazilian efforts to reduce emissions are concentrated on energy mix diversification and carbon intensity control while technology intensive alternatives like energy intensity has not demonstrated relevant progress. Residential sector displays a marginal weight in the total emission change.     

Overview of thermal energy storage (TES) potential energy savings and climate change mitigation in Spain and Europe

Thermal energy storage (TES) is nowadays presented as one of the most feasible solutions in achieving energy savings and environmentally correct behaviors. Its potential applications have led to R&D activities and to the development of various technology types. However, so far there is no available data on a national scale in Spain and on a continental level in Europe, to corroborate the associated energetic and environmental benefits derived from TES. This is why, based on a previous potential calculation initiative model performed in Germany, this work intends to provide a first overview of the Spanish TES potential as well as an European overview. Load reductions, energy savings, and CO₂ emissions reductions are tackled for the buildings and industrial sector. Results depend on the amount of implementation and show that, in the case of Europe for instance, yearly CO₂ emissions may get to be cut down up to around 6% in reference to 1990 emission levels.     

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.     

Fluctuating renewables in a long-term climate change mitigation strategy

Integrated Assessment models, widely applied in climate change mitigation research, show that renewable energy sources (RES) play an important role in the decarbonization of the electricity sector. However, the representation of relevant technologies in those models is highly stylized, thereby omitting important information about the variability of electricity demand and renewables supply. We present a power system model combining long time scales of climate change mitigation and power system investments with short-term fluctuations of RES. Investigating the influence of increasingly high temporal resolution on the optimal technology mix yields two major findings: the amount of flexible natural gas technologies for electricity generation rises while the share of wind energy only depends on climate policy constraints. Furthermore, overall power system costs increase as temporal resolution is refined in the model, while mitigation costs remain unaffected.     

Achieving 60% CO2 reductions within the UK energy system—Implications for the electricity generation sector

This paper explores how investment in the UK electricity generation sector can contribute to the UK goal of reducing CO₂ emissions with 60% by the year 2050 relative to the 1990 emissions. Considering likely development of the transportation sector and industry over the period, i.e. a continued demand growth and dependency on fossil fuels and electricity, the analysis shows that this implies CO₂ emission reductions of up to 90% by 2050 for the electricity sector. Emphasis is put on limitations imposed by the present system, described by a detailed database of existing power plants, together with meeting targets on renewable electricity generation (RES) including assumptions on gas acting as backup technology for intermittent RES. In particular, it is investigated to what extent new fossil fuelled and nuclear power is required to meet the year 2050 demand as specified by the Royal Commission on Environmental Pollution (RCEP). In addition, the number of sites required for centralized electricity generation (large power plants) is compared with the present number of sites. A simulation model was developed for the analysis. The model applies the UK national targets on RES, taken from Renewable Obligation (RO) for 2010 and 2020 and potentials given by RCEP for 2050, and assumed technical lifetimes of the power plants of the existing system and thus, links this system with targets for the years 2010, 2020 and 2050.     

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.     

The role of energy-service demand reduction in global climate change mitigation: Combining energy modelling and decomposition analysis

In order to reduce energy-related CO₂ emissions different options have been considered: energy efficiency improvements, structural changes to low carbon or zero carbon fuel/technologies, carbon sequestration, and reduction in energy-service demands (useful energy). While efficiency and technology options have been extensively studied within the context of climate change mitigation, this paper addresses the possible role of price-related energy-service demand reduction. For this analysis, the elastic demand version of the TIAM–UCL global energy system model is used in combination with decomposition analysis. The results of the CO₂ emission decomposition indicate that a reduction in energy-service demand can play a limited role, contributing around 5% to global emission reduction in the 21st century. A look at the sectoral level reveals that the demand reduction can play a greater role in selected sectors like transport contributing around 16% at a global level. The societal welfare loss is found to be high when the price elasticity of demand is low.     

The impact of lifestyle on energy use and CO2 emission: An empirical analysis of China's residents

Based on the application of a Consumer Lifestyle Approach (CLA), this paper quantifies the direct and indirect impact of lifestyle of urban and rural residents on China's energy use and the related CO₂ emissions during the period 1999–2002. The results show that approximately 26 per cent of total energy consumption and 30 per cent of CO₂ emission every year are a consequence of residents’ lifestyles, and the economic activities to support these demands. For urban residents the indirect impact on energy consumption is 2.44 times greater than the direct impact. Residence; home energy use; food; and education, cultural and recreation services are the most energy-intensive and carbon-emission-intensive activities. For rural residents, the direct impact on energy consumption is 1.86 times that of the indirect, and home energy use; food; education, and cultural recreation services; and personal travel are the most energy-intensive and carbon-emission-intensive activities. This paper provides quantitative evidence for energy conservation and environmental protection focused policies. China's security for energy supply is singled out as a serious issue for government policy-makers, and we suggest that government should harmonize the relationships between stakeholders to determine rational strategies.     

Economic and environmental implications of demand-side management options

End-use electricity efficiency improvements offer an inexpensive way to reduce power shortages. The present study estimates the potential of demand-side management efficiency improvement targeted at (1) short-term efficiency improvement (agricultural pump rectification) that can provide immediate relief, and (2) long-term efficiency improvement (appliance standards such as AC and refrigerator, new agricultural pump purchase and pump replacement) for Gujarat state in India. The methodology includes the calculation of cost of conserved energy for each technology, which works out to be (−1.18) US$ cents/kW h for new agriculture pump sets, 1.03 US$ cents/kW h for refrigerators and 5.21 US$ cents/kW h for air conditioners. The price of power varies around 1.13 US$ cents to 12.1 cents/kW h in Gujarat. The annual energy savings from the selected energy-efficient technologies are approximately 8767 GW h over a period of 10 yr, while the estimated peak power savings are about 1814 MW, large enough to eliminate one-fourth of the state's electricity shortages. Also, the estimated CO₂ emissions savings are about 7715 Giga grams (Gg) from implementation of the selected energy efficiency measures over a period of 10 yr.     

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.     

The social return on investment in the energy efficiency of buildings in Germany

The German government has developed a variety of policy instruments intended to reduce national CO₂ emissions. These instruments include a programme administered by KfW bank, which aims at improving the energy efficiency of buildings. It provides attractive credit conditions or subsidies to finance refurbishment measures which improve the energy efficiency of buildings significantly.     

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.     

Decomposition analysis of CO2 emission in long-term climate stabilization scenarios

To achieve the stabilization of greenhouse gas (GHG) concentrations in the atmosphere, the international community will need to intensify its long-term efforts. Many EU countries have released national long-term scenarios toward 2050, and their ambitious targets for CO₂ emission reduction are aiming at a decrease of more than 50% of today's emission. In April 2004, Japan began a research project on its long-term climate policy. This paper discusses the long-term scenarios in other countries and the medium-term scenarios in Japan to support the development of a Japan's long-term climate stabilization scenario. In this study, CO₂ emission is decomposed with an extended Kaya identity (indexes: CO₂ capture and storage, carbon intensity, energy efficiency, energy intensity, economic activity) and a Reduction Balance Table is developed.     

Modeling Lebanon’s electricity sector: Alternative scenarios and their implications

This paper is concerned with modeling possible future paths for Lebanon’s electricity future and evaluating them. The baseline scenario (BS) reflects the business-as-usual state of affairs and thus describes the most likely evolution of the power sector in the absence of any climate change-related or other policies. Two alternative scenarios are examined in contrast to the BS; the renewable energy scenario (RES) and the natural gas scenario (NGS). Using the Long range Energy Alternatives Planning System (LEAP) software we conduct a full-fledged scenario analysis and examine the technical, economic, and environmental implications of all scenarios.From an economic standpoint as well as from an environmental perspective both alternative scenarios are superior to the baseline. Hence, the results of the simulation show that the alternative scenarios are more environmentally and economically attractive than the BS. They would help Lebanon meet its social, environmental, and economic development goals, while at the same time providing other unquantifiable benefits that are discussed further in the paper. Anticipated barriers to the shift in energy mix from conventional sources to renewable energy sources are also presented and discussed     

The effect of renewable energy and urbanization on CO2 emissions: A panel data

Europe has experienced fast-paced urbanization development over the past three decades. This paper empirically investigates the long-run equilibrium relationships and causal relationships among urbanization, renewable energy consumption, and CO₂ emissions, and this is important for EU countries’ future sustainable development. DOLS and FMOLS approaches are used for the period 1992–2014 .

Granger causality results show that there is a unidirectional relationship from CO₂ emissions to urbanization, and there is no causality between renewable energy consumption and CO₂ emissions. The results have important implications for EU policymakers on the path toward a sustainable society. Urbanization can have negative impacts on the natural environment with the net effect being hard in EU countries.     

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.