[en] On a $/kW basis, wind turbine prices in the U.S. have declined by nearly one-third on average since 2008, after having previously doubled over the period from 2002 through 2008. These two substantial and opposing trends over the past decade – and particularly the earlier price doubling – run counter to the smooth, gradually declining cost trajectories predicted by standard learning curve theory. Taking a bottom-up approach, we examine seven possible drivers of wind turbine prices in the U.S., with the goal of estimating the degree to which each contributed to the doubling in turbine prices from 2002 through 2008, as well as the subsequent decline in prices through 2010. In aggregate, these seven drivers – which include changes in labor costs, warranty provisions, manufacturer profitability, turbine scaling, raw materials prices, energy prices, and foreign exchange rates – explain from 70% to 90% (depending on the year) of empirically observed wind turbine price movements in the U.S. through 2010. Turbine scaling is found to have been the largest single contributor to the price doubling through 2008, although the incremental cost of scaling has been justified by greater energy capture, resulting in a lower cost of wind generation. - Highlights: ► Having doubled from 2002 to 2008, wind turbine prices have since fallen by one-third. ► We analyze seven potential drivers of wind turbine prices over the past decade. ► Turbine scaling has had the largest influence, followed by weakness in the dollar. ► Changes in the price of energy inputs had the smallest impact.

[en] This article presents an updated and upgraded methodology, the Fuel Economy and Environmental Impacts (FEEI) model ( (http://www.feeimodel.org/)), to project vehicle sales and stock in China on the basis of our previous studies. The methodology presented has the following major improvements: it simulates private car ownership on an income-level basis, takes into account car purchase prices, separates sales into purchases for fleet growth and for replacements of scrapped vehicles, and examines various possible vehicle scrappage patterns for China. The results show that the sales of private light-duty passenger vehicles in China could reach 23–42 million by 2050, with the share of new-growth purchases representing 16–28%. The total vehicle stock may be 530–623 million by 2050. We compare this study to other publicly available studies in terms of both projection methodology and results. A sensitivity analysis shows that vehicle sales are more affected than levels of vehicle stock by the model parameters, which makes projecting sales more difficult owing to the lack of reliable input data for key model parameters. Because it considers key factors in detail, the sales and stock projection module of the FEEI model offers many advantages over previous models and is capable of simulating various policy scenarios. - Highlights: ► An upgraded methodology to project vehicle sales and stock in China is presented. ► It analyzes intrinsic factors that cause the growth of car sales. ► Sales of private light-duty passenger vehicles could reach 23–42 million by 2050. ► The total vehicle stock in China will be 530–623 million by 2050.

[en] We established a bottom-up model to deliver the future trends of fuel consumption and life cycle greenhouse gas (GHG) emissions by China's on-road trucks. The mitigation measures of mileage utilization rate (MUR) improvement, fuel consumption rate (FCR) improvement, and penetration of liquefied natural gas (LNG) fueled trucks were evaluated. With no mitigation measures implemented, in the year 2050, the total fuel consumption and life cycle GHG emissions by China's on-road trucks were projected to reach 498 million toe and 2125 million tons, respectively, approximately 5.2 times the level in 2010. If the MUR of trucks in China is increased from the current status as those of the developed countries, a 13% reduction of total fuel consumption can be achieved after 2020. If the FCR of trucks is reduced by 10% in 2011, 2016, 2021, and 2026, a 30% reduction of total fuel consumption can be achieved after 2030. Moreover, if the share of LNG fueled trucks in all newly registered semi-trailer towing trucks and heavy-duty trucks is increased to 20% in 2030, an estimate of 7.9% and 10.9% of the total diesel consumption by trucks will be replaced by LNG in 2030 and 2050, respectively. - Highlights: ► We establish a bottom–up model to deliver the fuel consumption and GHG emissions by China's trucks. ► Without mitigation measures, the truck fuel consumption in 2050 will be 5.2 times the level in 2010. ► Fuel conservation and GHG reduction effects of three mitigation measures were evaluated.

[en] To promote the reduction of greenhouse gas emissions, research and development of bioethanol technologies are encouraged in Japan and a plan to utilize untilled fields to develop rice for bioethanol production as a substitute for petroleum fuel is being devised. This study applies emergy methods to compare the sustainability of petroleum fuel production and two Japanese rice-to-ethanol production scenarios: (a) ethanol from rice grain, while straw and chaff are burned as energy and (b) ethanol from rice+straw+chaff. The major emergy indices, Emergy Yield Ratio (EYR), Environmental Loading Ratio (ELR), Emergy Investment Ratio (EIR), Emergy Sustainability Index (ESI), Environmental Impacts Ratio (EVR) and system transformity (Tr), are analyzed to assess the production processes. The results show that (1) petroleum fuel production presents higher ELR, EIR, EVR and lower EYR, ESI, Tr than rice-to-ethanol production, indicating rice-to-ethanol production makes sense for reduction of greenhouse gases (GHG); (2) scenario (a) performs similarly on major indicators (EYR, ESI, ELR, EIR and EVR) to scenario (b), yet the system efficiency indicator (Tr) of scenario (a, 7.572×10⁵ semj/J) is much higher than (b, 4.573×10⁵ semj/J), and therefore (b) is a better alternative for policy decisions; (3) both petroleum fuel production and rice-to-ethanol processes are mainly driven by purchased resources and are unsustainable and nonrenewable in the long run. - Highlights: ► We compare petrol fuel and rice-to-ethanol production using emergy indices. ► Rice-to-ethanol reduces green house gas emissions as a substitute for petrol fuel. ► Rice-to-ethanol production has better sustainability than that of petrol fuel. ► Neither petrol fuel nor biofuel production are sustainable in the long term. ► Bioethanol is not a renewable fuel.

[en] Demand managers currently draw on a limited range of psychology and economic theories in order to shift and shed peak electricity demand. These theories place individual consumers and their attitudes, behaviours and choices at the centre of the problem. This paper reframes the issue of peak electricity demand using theories of social practices, contending that the ‘problem’ is one of transforming, technologically-mediated social practices. It reflects on how this body of theory repositions and refocuses the roles and practices of professions charged with the responsibility and agency for affecting and managing energy demand. The paper identifies three areas where demand managers could refocus their attention: (i) enabling co-management relationships with consumers; (ii) working beyond their siloed roles with a broader range of human and non-human actors; and (iii) promoting new practice ‘needs’ and expectations. It concludes by critically reflecting on the limited agency attributed to ‘change agents’ such as demand managers in dominant understandings of change. Instead, the paper proposes the need to identify and establish a new group of change agents who are actively but often unwittingly involved in reconfiguring the elements of problematic peaky practices. - Highlights: ► I reframe peak electricity demand as a problem of changing social practices. ► Micro-grids, and dynamic pricing reorient household routines and enable co-management. ► Infrastructures inside and outside the home configure peaky practices. ► Demand managers are encouraged to promote and challenge consumer ‘needs’. ► I identify a new group of change agents implicated in peaky practices.

[en] This paper presents a first assessment of the renewable energy projects, proposed by the nine Mediterranean Partner Countries (MPCs) under the Mediterranean Solar Plan (MSP) and the associated potential economic impacts. As one of the priority projects of the Union for the Mediterranean (UfM), the MSP's objective which attracted most attention until now is the intention to deploy an additional 20 GW of renewable electrical capacity in the Southern and Eastern Mediterranean region (covering the MPCs plus Turkey) by 2020. The main findings of this research are: (1) as of February 2010, a total of 10.3 GW of renewable project proposals were identified in the MPCs, corresponding to about half of the 20 GW target; (2) investment needs for the identified projects could amount to EUR 21 billion by 2020, which represents about five times the amount invested by the region in conventional electricity generation in the last decade; and (3) the difference between the cost of renewable electricity generation and the economic cost of its fossil fuel alternatives could amount to EUR 1.2 billion. Insights stemming from the results of this research can generate useful regional messages for energy policy leaders in the MPCs to accelerate the development of renewable energy projects. - Highlights: ► We conducted a systematic survey of renewable energy projects in the Mediterranean. ► The identified projects correspond to half the MSP 20 GW target. ► Maturity assessment is used to classify the advancement of the projects. ► We estimated the investment needs and required subsidies in the region by 2020.

[en] Many international policies encourage a switch from fossil fuels to bioenergy based on the premise that its use would not result in carbon accumulation in the atmosphere. Frequently cited bioenergy goals would at least double the present global human use of plant material, the production of which already requires the dedication of roughly 75% of vegetated lands and more than 70% of water withdrawals. However, burning biomass for energy provision increases the amount of carbon in the air just like burning coal, oil or gas if harvesting the biomass decreases the amount of carbon stored in plants and soils, or reduces carbon sequestration. Neglecting this fact results in an accounting error that could be corrected by considering that only the use of ‘additional biomass’ – biomass from additional plant growth or biomass that would decompose rapidly if not used for bioenergy – can reduce carbon emissions. Failure to correct this accounting flaw will likely have substantial adverse consequences. The article presents recommendations for correcting greenhouse gas accounts related to bioenergy.

[en] This paper addresses the policy challenges of adjusting established regulations to accommodate evolving and new technologies. We examine energy and emissions regulations for older petroleum powered vehicles and newer plug-in electric vehicles. Until now, vehicle regulations across the world have ignored energy consumption and emissions upstream of the vehicle (at refineries, pipelines, etc), largely because of the convenient fact that upstream emissions and energy use are nearly uniform across petroleum-fueled vehicles and play a relatively minor role in total lifecycle emissions. Including upstream impacts would greatly complicate the regulations. But because the vast majority of emissions and energy consumption for electric vehicles (and hydrogen and, to a lesser extent, biofuels) are upstream, the old regulatory design is no longer valid. The pressing regulatory question is whether to assign upstream GHG emissions to electric vehicles, or not, and if so, how. We find that assigning zero upstream emissions—as a way of incentivizing the production and sale of PEVs—would eventually lead to an erosion of 20% of the GHG emission benefits from new vehicles, assuming fixed vehicle standards. We suggest alternative policy mechanisms and strategies to account for upstream emissions and energy use. - Highlights: ► We quantify the effects of electric vehicles within greenhouse gas (GHG) regulation. ► Electric vehicle GHG impacts are substantial and vary greatly by grid power sources. ► Existing “zero emission” electric vehicle incentives undermine regulation benefits. ► 10% electric vehicle sales leads to 20% erosion in regulation benefits by 2020–2025. ► Lifecycle crediting improves policy cost-effectiveness and technology neutrality.

[en] Government policy continues to play a crucial role in the development of wind power industry in China. The 2005 “Renewable Energy Law” and related policies have driven the rapid increase in wind power installed capacity in China over the past half-decade, with capacity doubling annually since 2005. However, a large number of wind farms generate electricity well below their installed capacity, resulting in considerable wastage of resources. Non-grid-connected wind power theory proposes that large-scale wind power output does not necessarily have to be fed into the grid, but can be used directly in industrial production. Thus, the use of the theory can promote the sustainable development of the wind power industry by obviating the need for power grid. In this paper we analyze the influence of government policy on wind power industry from the perspective of institutional change, by employing the basic theories of new institutional economics. A development model for non-grid-connected wind power is proposed in order to implement institutional change in accordance with the specific characteristics of wind power industry in China. This model requires the government to play an active role in institutional development by increasing economic efficiency in order to promote the sustainable development of wind power. - Highlights: ► New institutional economics-based analysis paradigm for wind power policy proposed. ► Policies for China's wind power industry analyzed according to the paradigm. ► Hybrid development mode of institutional change is the best pathway for wind power. ► Potential development policy for China's wind power industry recommended.

[en] We examine the economic feasibility of using dedicated DC circuits to operate lighting in commercial buildings. We compare light-emitting diodes (LEDs) and fluorescents that are powered by either a central DC power supply or traditional AC grid electricity, with and without solar photovoltaics (PV) and battery back-up. Using DOE performance targets for LEDs and solar PV, we find that by 2012 LEDs have the lowest levelized annualized cost (LAC). If a DC voltage standard were developed, so that each LED fixture's driver could be eliminated, LACs could decrease, on average, by 5% compared to AC LEDs with a driver in each fixture. DC circuits in grid-connected PV-powered LED lighting systems can lower the total unsubsidized capital costs by 4–21% and LACs by 2–21% compared to AC grid-connected PV LEDs. Grid-connected PV LEDs may match the LAC of grid-powered fluorescents by 2013. This outcome depends more on manufacturers' ability to produce LEDs that follow DOE's lamp production cost and efficacy targets, than on reducing power electronics costs for DC building circuits and voltage standardization. Further work is needed to better understand potential safety risks with DC distribution and to remove design, installation, permitting, and regulatory barriers. - Highlights: ► We model a 48,000 ft² commercial building lighting system with AC and DC circuits. ► At 2012 efficacies and costs, LEDs are lowest levelized annual cost (LAC) option. ► DC LEDs can lead from an LAC increase of 5% to a decrease of 15% (vs. AC LEDs). ► Grid-connected DC LEDs with PV can lower LACs by 2–21% (vs. PV-AC LEDs). ► PV-DC LEDs may match the LAC of grid-powered AC fluorescents by ∼2013.