What is the global potential for renewable energy?

World energy demand is projected to rise to 1000 EJ (EJ = 10¹⁸ J) or more by 2050 if economic growth continues its course of recent decades. Both reserve depletion and greenhouse gas emissions will necessitate a major shift from fossil fuels as the dominant energy source. Since nuclear power is now unlikely to increase its present modest share, renewable energy (RE) will have to provide for most energy in the future. This paper addresses the questions of what energy levels RE can eventually provide, and in what time frame. We find that when the energy costs of energy are considered, it is unlikely that RE can provide anywhere near a 1000 EJ by 2050. We further show that the overall technical potential for RE will fall if climate change continues. We conclude that the global shift to RE will have to be accompanied by large reductions in overall energy use for environmental sustainability.     

Who turns the global thermostat and by how much?

Increasing attention is being given to the option of engineering the climate via Solar Radiation Management (SRM) as a potential component in future climate policies. We set up a quantitative model to analyze efficient levels of SRM deployment against the climatic and economic background conditions projected by the various Shared Socioeconomic Pathways (SSPs) baseline scenarios for the year 2050. The model combines three features of the data: i) SRM deployment is regionally uneven in the way it affects grid-cell temperature and precipitation, ii) temperature and precipitation affect Gross Value Added (GVA) at the grid-cell level and the effect for both takes the form of an inverted U-shape relationship, implying that optimal temperature and precipitation levels with respect to output do exist, and iii) different assumptions about economic growth and its distribution over regions, as projected by the SSPs, increase the relative share of global GVA for currently rather poor countries with high average temperatures. We find that in global terms, economically efficient levels of SRM are affected more by region-specific economic growth projections than by regional climate-change impacts. Globally, the economically efficient SRM level is proportional to the (global) GVA-weighted mean temperature increase, which varies considerably according to the various growth projections (for equal climatic background conditions). Achieving the optimal temperature in each scenario is constrained by the influence of SRM on precipitation.     

Who benefits from energy policy incentives? The case of jatropha adoption by smallholders in Mexico

Understanding the distribution of policy incentives is important in evaluating the impact of promotion programmes. This study investigates the allocation of economic subsidies to jatropha cultivation by using adoption models at both the community and household levels in Chiapas. At the community level, we compared socioeconomic and environmental variables of the communities that adopted jatropha to non-adopters. At the household level, 420 farm households were surveyed to analyse both the determinants of adoption and the extent of adoption (i.e. hectares dedicated to jatropha). The variables determining adoption were analysed at both levels using generalised linear models. The extent of jatropha adoption was assessed using ordinary least squares multiple regression. Quantitative data was complemented with key stakeholder interviews and focus groups. Results show that subsidies tend to be allocated to larger, better-connected communities which have access to better services. Within adopter communities, the subsidy is distributed among households that have more resources, better risk-coping strategies, better access to information, more experience with similar technologies and whose attitude towards risk is positive. This study provides lessons that can be useful for the introduction of new energy crops to better reach the target group and ultimately achieve the aims of energy promotion strategies.     

Does energy efficiency save energy? The debate and its consequences

This paper considers the debate in the UK and the USA on some economists' claims that improving energy efficiency will lead to a greater energy consumption (than would have otherwise occurred), a concept termed the Khazzoom–Brookes postulate. It analyses the criticisms of this claim and of the responses, particularly of the concept of ‘dematerialization’. The paper attempts to tackle the paucity of empirical evidence in the UK by looking at long-term trends in efficiency and use with respect to UK public lighting. Finally, it focuses on the views of two economists, namely Len Brookes and William Rees, who both accept the postulate but have differing views and policies on measures to reduce carbon emissions from fossil fuels. Brookes believes in free-market solutions, whereas Rees puts forward a vision of a sustainable future based on ecological tax-reform and reafforestation.     

Greener energy: Issues and challenges for Pakistan—Solar energy prospective

Energy plays a pivotal role in socio-economic development by raising standard of living. It is becoming gradually accepted that current energy systems, networks encompassing every thing from primary energy sources to final energy services, are becoming unsustainable. Development of conventional forms of energy for meeting the growing energy needs of society at a reasonable cost is the responsibility of the Governments. In recent years, public and political sensitivities to environmental issues and energy security have led to the promotion of renewable energy resources. Diversification of fuel sources is imperative to address these issues; and limited fossil resources and environmental problems associated with them have emphasized the need for new sustainable energy supply options that use renewable energies. Development and promotion of new non-conventional, alternate and renewable sources of energy such as solar, wind and bio-energy, etc. are now getting sustained attention. Solar power is one of the hottest areas in energy investment right now, but there is much debate about the future of solar technology and solar energy markets. This investigates the progress and challenges for solar power in Pakistan according to the overall concept of sustainable development, and identifies the region wise potential of solar power in Pakistan and its current status. Barriers are examined over the whole solar energy spectrum and policy issues and institutional roles and responsibilities are discussed.     

China’s energy—challenges and strategies

In this century, China started facing five major challenges in the energy field: energy supply, shortage of liquid fuel, environmental pollution, green house gas (GHG) emission, and energy supply in rural areas. In this paper, the Chinese energy development strategy and general technical scheme (including energy conservation, utilization of coal, alternative fuel and renewable energy) are discussed, and some key scientific problems in the fundamental research of energy are put forward.     

The role of hydrogen and fuel cells to store renewable energy in the future energy network – potentials and challenges

The penetration of renewable energy sources is expected to rapidly increase from 15% to 50% in 2050 due to their vital contribution to the global energy requirements, sustainability and quality of life in economical, environmental and health aspects. This huge rise highlights the necessity of development of energy storage systems, especially for intermittency renewable energies such as solar photovoltaic and wind turbine, in order to balance the energy network. In this study, renewable energy options including pumped hydro, pressurized air, flywheels, Li ion batteries, hydrogen and super-capacitors are compared based on a specific set of criteria. The criteria considered are energy/power density, ease of integration with the existing energy network, cost effectiveness, durability, efficiency and safety. Our study showed that storing renewable energy sources in the form of hydrogen through the electrolysis process is ranked as the most promising option considering the mentioned criteria. It brings about several benefits suggesting that hydrogen and fuel cells are promising contributors towards a more sustainable future, both in energy demand and environmental sustainability.     

Who does what in China’s new energy vehicle industry?

This paper provides an overview of the Chinese new energy vehicle industry and discusses the role of state in the industry’s development. Chinese policies have aimed to promote the development of new energy technologies and to reduce the consumer price of new energy vehicles. Chinese authorities have also been concerned about the balance between collaboration and competition in the sector, since most key actors are owned by the state. One solution has been the establishment of a number of industry alliances linking auto enterprises, universities and research institutes, to promote both collaboration (within each alliance) and competition (between alliances).     

Switching towards coal or renewable energy? The effects of financial capital on energy transitions

Does a country's stock of financial capital affect its ability to achieve energy transitions? This paper uses data for up to 137 countries for the period 1998–2013 to investigate the importance of financial capital for changes in the use of each energy type. I find that financial capital supports transition to more capital-intensive energy types. For high-income countries, financial capital facilitates transitions from fossil fuels to modern renewable energy sources, especially wind. Both private credit from banks and domestic private debt securities support greater shares of wind energy. For lower-income countries, financial capital supports progression from biomass towards fossil fuel energy sources such as coal. I also find that countries with larger stocks of financial capital are more likely to move to more capital-intensive electricity generation systems.     

Communication on energy: Who pays for the long-term costs of nuclear power?

The question in the title arises in making a fair comparison between a coal-fired station, which has no long-term costs, and a nuclear station, whose large long-term costs are discounted into insignificance by the present method of calculation. This problem was raised by the present author in his evidence to the Sizewell Inquiry, and has recently been discussed by the House of Commons Select Committee on Energy, who expressed grave disquiet that ‘the costs of decommissioning become almost irrelevant to the current economics of nuclear power’. The present article analyses the bizarre effects of long-term discounting, and suggests a method of making a fair and symmetrical comparison between coal-fired and nuclear stations.     

The German energy audit program for firms—a cost-effective way to improve energy efficiency?

In 2008, a program was established in Germany to provide grants for energy audits in small- and medium-sized enterprises. It aims to overcome barriers to energy efficiency, like the lack of information or a lack of capacity, and is intended to increase the adoption of energy efficiency measures. We evaluate the program's impact in terms of energy savings, CO₂ mitigation, and cost-effectiveness. We find that firms adopt 1.7?C2.9 energy efficiency measures, which they would not have adopted without the program. Taking a firm's perspective, the program shows a net present value ranging from ?0.4 to 6??/MWh saved, which very likely implies a net benefit. For the government, each ton of CO₂ mitigated costs between 1.8 and 4.1??. Each euro of public expenditure on audit grants led to 17?C33?? of private investment. The cost-effectiveness of the program for firms and the low share of public expenditure underline its value for the German energy efficiency policy mix and suggest that it should be expanded in Germany. Further, the good experiences with the program in Germany should encourage countries which have not yet established an audit program to do so.     

Engaging the public on paths to sustainable energy: Who has to trust whom?

The aim is to observe how hydrogen, in its wider meaning as a ‘system innovation’, is understood by a cross section of the general public in three regions of the UK that have embryonic developments: Teesside, South West Wales and London.     

The fossil energy/climate change crunch: Can we pin our hopes on new energy technologies?

There is a growing perception by society of the risks of dramatic global climate changes due to anthropogenic greenhouse gases, in particular energy related emissions of CO₂. This has spurred a renewed interest in carbon free or carbon neutral technologies for converting sources of renewable primary energy to electricity and to transportation fuels. However, it takes energy to produce energy, even when the primary source is energetically cost free, such as solar or wind. The aim of this letter is to present a model which allows the simulation of the energy costs of the deployment of a new energy technology. We show that the new technology may actually be an energy sink, instead of an energy source, relative to the global total primary energy supply (TPES) for many years or decades, depending on its intrinsic energy costs and deployment path, even though stated aims for its gross energy output are achieved. As expected, the energy payback time of the conversion devices, as well as fuel and maintenance costs are critical parameters. We illustrate the general model with simulations of the deployment of photovoltaic electricity, at global and national levels.     

Fuelwood: The “other” renewable energy source for Africa?

In recent years, increasing concerns over rising oil prices, supply shortfalls and the environmental impacts of fossil fuel use have fed growing interest in renewable energy sources for Sub-Saharan Africa. Although traditional biofuels already enjoy widespread popularity, their use has often been actively discouraged due to the lingering influence of “fuelwood crisis” era narratives. In particular, urban fuelwood consumption is frequently portrayed as a cause of environmental degradation leading to energy insecurity among low-income households, especially where the resource is commercialized. Such views have had significant influence among policy makers, often resulting in repressive forestry legislation. In contrast, however, a number of researchers have demonstrated that wood energy dependence is often not a significant cause of deforestation and can provide important livelihood opportunities. This article reassesses urban fuelwood sourcing and its impacts using a recent case study conducted by the authors in Maun, Botswana and results previously reported in the literature. Findings indicate that although harvesting is unregulated, its impacts are significantly mitigated by collectors' strong preferences for source sites with abundant dead wood, low competition and recognized access rights. As well, fuelwood vending is found to provide critical support to rural incomes and a key source of low-cost urban energy. As such, the benefits of fuelwood use and avoidance of negative effects will most effectively be achieved by decentralised management approaches that build on local institutions and understandings of the resource.     

The embodied energy in trade: What role does specialization play?

Many industrialized countries are net importers of embodied energy and emissions, while many developing countries are net exporters. We examine the role of specialization in driving these trade patterns by conducting a spatial index decomposition analysis on the embodied energy in net exports for 41 economies. The results reveal that industrialized countries have generally offshored energy intensive production, which many developing countries specialize in. We find that specialization, on average, makes the biggest contribution, accounting for roughly 50% of a country's embodied energy in net exports. However, other factors, namely energy intensity and the trade balance, combine to make an equally important contribution. In summary, specialization, despite its significant role, is not the only cause of the embodied energy trade patterns observed between industrialized and developing countries.     

Is there a space for additional renewable energy in the Norwegian power system? Potential for reduced global emission?

This paper presents the results of a Norwegian power system analysis. An energy system analysis model based on linear programming is used for modelling and optimisation. The analyses cover a number of scenarios where the studied system is subjected to changes by introducing other renewable energy sources, energy conservation measures and measures to promote renewable energy. The study shows that due to a combination of cheap hydropower and high investment costs, it is quite difficult for new generation units to be profitable. This is also true during periods of low precipitation where the system tends to survive on imported power instead of investing in new generation units. However, this does not apply to energy conservation measures that easily enter the system. On the other hand, biomass based CHP, wind power and wave power could be viable if measures are introduced to promote their use. Most of the scenarios show a high potential for reducing global emissions.     

Are energy statistics useful for making energy scenarios?

One can measure “energy quantities” – e.g. joules, BTU, quads – but only at a given scale and within a specific narrative about energy conversions at the time. Therefore, at the moment of generating aggregate indicators, the arithmetic summing of assessments of energy quantities referring to different scales and narratives is meaningless. This paper addresses epistemological problems typical of energy accounting, which are at the moment tackled by acknowledging the existence of unspecified “qualitative differences” among different energy forms – e.g. a joule of electricity has more “value” than a joule of coal. Three energy forms referring to different scales and narratives about energy conversions are relevant for national accounting: Primary Energy Sources (PES), Energy Carriers (EC), and End Uses (EU). We critically examine the usefulness of current energy statistics in relation to this distinction. The conventional linear representation – flow chart – based on a single scale and a single quantitative accounting confuses the three semantic categories and entails an important loss of information. Finally, we illustrate an innovative scheme for energy accounting across hierarchical levels that: (i) addresses the autocatalytic nature of energy transformations; (ii) provides a multi-scale quantitative representation; and (iii) preserves the semantic distinction between relevant energy forms (PES, EC, and EU).