Energy Equivalent Basis Research Articles

Experimental driving performance evaluation of battery-powered medium and heavy duty all-electric vehicles

As the push to reduce air pollutants and carbon dioxide for global warming continues, there is increasing interest in the development and deployment of battery electric vehicles for heavy-duty applications as one of the critical and challenging steps of a broader effort to fully electrify the transportation sector. This study evaluated and quantified the energy consumption rates and energy regeneration rates for three heavy-duty battery electric vehicles (a step van, a yard tractor, and a class 8 truck) using driving cycle tests with a heavy-duty vehicle chassis dynamometer. Information in this area is currently very limited, and yet it is critical to understanding how effective heavy-duty battery electric vehicles will be for a wide range of applications as the electrification of the heavy-duty vehicle market continues to expand. Energy consumption rates ranged from 0.37 and 2.71 kWh/km for most vehicle/cycle combinations. On a diesel liter energy-equivalent basis, the heavy-duty vehicles had approximately 3 to 6 times better energy consumption rates compared to comparable diesel vehicles, with weight normalized energy consumption rates also comparing favorably to the current and future greenhouse gas/fuel economy standards for equivalent diesel vehicles. Based on battery capacities ranging from 80 to 215 kWh, the vehicle ranges varied from 38.18 km to 171.2 km, with ranges of 115.9 km to 171.2 km for most types of driving and lower ranges of 38.18 to 42.20 km for sustained grade cycles. Overall, the advantage of improved energy consumption rates coupled with improvements that can be expected for battery technology and vehicle range, provide promise for expanded use of heavy-duty vehicles going into the future.

Environmental and techno-economic analyses of bio-jet fuel produced from jatropha and castor oilseeds in China

Bio-jet fuel derived from energy crops has been promoted by governments around the world through policies such as the Carbon Offsetting and Reduction Scheme for International Aviation. The environmental impact and techno-economic analysis of bio-jet fuel are particularly pertinent to China because China is under huge pressure to reduce emissions, endeavouring to meet bio-economic goals. An LCA study was conducted on the production of bio-jet fuel from jatropha and castor by estimating the well-to-wake emissions and its economic impact. The functional unit was 1 MJ of bio-jet fuel, and field survey data was used in inventory analysis. A scenario analysis was performed to measure diverse conditions, including the planting conditions, planting regions, allocation methods, and hydrogen sources. A techno-economic analysis that combined the production costs and co-product credits was performed to calculate the minimum bio-jet fuel selling price (MJSP) based on a plant capacity of 2400 metric tonnes of feedstock per day. Compared to the environmental impacts to the fossil jet fuel, the use of biofuel would reduce the majority environmental impacts by 36–85%, when a 1:1 displacement of fossil jet fuel is considered, though the human toxicity potential impact was 100% higher. The scenario analysis indicated that (i) planting castor in harsh and unevenly distributed conditions and jatropha in stable or fertile conditions can leverage their respective advantage; (ii) the global warming potential (GWP) from castor planting in the region of north-east China ranges from 34 to 48 g CO2 eq/MJ; (iii) the GWP produced through the steam methane reforming process can be reduced by 16–17%, using advances in technological processes. The MJSP for fuel produced from jatropha and castor under the basic scenario is estimated to be 5.68 and 4.66 CNY/kg, respectively, which falls within the current market price range of 4.5–7.5 CNY/kg. Bio-jet fuel from jatropha and castor oilseeds offers potential environmental benefits if they can reduce fossil jet fuel on an energy-equivalent basis. However, these benefits are likely to be reduced by the rebound effect of the fuel market. Future research is needed to better understand the magnitude of the rebound effect in China and what policy interventions can be implemented to alleviate it. Scenario analysis demonstrated the feasibility and potential of bio-jet fuel development from multiple perspectives and technological progress are conducive to the realization of environmental protection policies.

H2 Economy: Hype, Horizon, or Here?

Clean-burning hydrogen (H2) - and scenarios for a future economy powered by it - is big news at the moment. This is no surprise, given the current environment of low demand for oil, growing unease over greenhouse gas emissions, and projections that post-pandemic stimulus measures could do for hydrogen what stimulus measures after the 2008 financial crisis did for solar power. Oil and gas majors have spent tens of millions of dollars on pilot projects, as have other industrial giants. Germany, which has allocated $10 billion to its nascent hydrogen industry, is one of a growing number of governments whose spending to satisfy climate commitments while restarting their economies could provide a major funding kickstart. But for the moment, most analysts agree that the future for a hydrogen economy is still uncertain and that the biggest obstacles to scaling will be costs, technology scaleup, and policy. H2 101 - From Feedstock to Fuel Hydrogen is the most abundant chemical substance in the universe, constituting roughly 75% of all mass. Today approximately 3% of global energy consumption is used to produce hydrogen, at a rate of more than 110 million tons per year, according to BloombergNEF (BNEF). So, hydrogen production is already a large and thriving industry. Yet, according to the Hydrogen Council, only 0.002% of currently produced hydrogen is used as fuel. Some 90% is used for ammonia production, petroleum refining, and methanol production. DNV GL, in a recent report on hydrogen as an energy carrier, describes hydrogen as a unique zero-emission energy carrier that can be converted to electrical energy in a fuel cell two to three times more efficiently than in a combustion engine. Hydrogen as an energy carrier can exist in a variety of forms and can be converted from one form to another, while energy sources such as oil and gas are the original resource from which the energy carrier is produced. Hydrogen can be used as fuel for mobility and heating in buildings; to decarbonize industrial processes; and as price support and storage for excess electricity during periods when production output from renewables alone exceeds demand. BNEF reports in its Hydrogen Economy Outlook that deploying clean hydrogen in the coming decades could reduce up to 34% of global greenhouse gas emissions from fossil fuels and industry at manageable cost. Renewable hydrogen could be produced for $0.70 to $1.60/kg in most parts of the world before 2050 - the equivalent of gas priced at $6-$12/MMBtu, making it competitive with current natural gas prices in Brazil, China, India, Germany, and Scandinavia on an energy-equivalent basis.

Associations of sugar intake with anthropometrics in children from ages 2 until 8years in the EU Childhood Obesity Project.

We determined the association of total sugar intake with body weight and fat mass in children on an energy-equivalent basis and potential changes in the association from 2 to 8years of age. Data were available from the Childhood Obesity Project Trial initiated in 2002. Sugar intake was measured by 3-day weighed food protocols at 2, 3, 4, 5, 6, and 8years of age. Body mass index (BMI) and fat mass index (FMI) were available at the same time points. To investigate the association of sugar intake with anthropometrics over time, linear mixed models were applied. Odds ratios for having a high BMI or FMI (above one standard deviation) were estimated by logistic random-effects models. To control for total energy intake, the residual method was chosen and models were additionally adjusted for total energy intake. Data were available for 809 children with in total 2846 observations. In an isocaloric model, an increase of 100kcal from sugar per day was significantly associated with lower zBMI (- 0.033; 95% CI -0.061, - 0.005) and zFMI (- 0.050; 95% CI - 0.089, - 0.011). In addition, a 100kcal higher sugar intake was related to lower odds of having a high zBMI (OR 0.743; 95% CI 0.611, 0.903). This study provides no indication that increased total sugar intake positively affects BMI on an energy-equivalent basis. Whether the negative association of sugar is due to physiological effects or points more to macronutrient preferences or a reporting bias (lower sugar intake) in children with higher BMI can be debated. ClinicalTrials.gov Identifier: NCT00338689; Registered: June 19, 2006. URL: http://clinicaltrials.gov/ct2/show/NCT00338689?term=NCT00338689&rank=1 .

Bipolar Electrodeposition: A Wireless Method for Deposition of Electrocatalysts Onto Semiconducting Particles

Global climate change due to combustion of fossil fuels and a lack of grid-scale energy storage will continue to negatively affect our environment and impede our ability to diversify energy sources and increase energy independence. However, if we can harness the power of the Sun, much like plants, then we can achieve a sustainable, net carbon neutral future with inherent energy storage capacity in chemical bonds. Solar photoelectrochemical water splitting produces H2, which can be used as a fuel. Proposed technologies to achieve this photochemistry typically use either a separate photovoltaic and electrolyzer, or an integrated wafer-based system. Unfortunately, these systems are costly, relying on relatively large quantities of precious metal electrocatalysts and intensive fabrication/processing methods. In contrast to these designs is the particle slurry reactor where the hydrogen evolution reaction and the oxygen evolution reaction are separated into different compartments, connected ionically and electronically via a solution redox shuttle, and stacked optically in series. This design is predicted to be cost-competitive with hydrogen produced from fossil fuels on an energy equivalent basis. Herein, we report on the reductive and oxidative depositions of electrocatalysts (e.g. Pt, Au, CoOPi, NiMo, and NiFe(O)OH) on state-of-the-art semiconducting nanoparticles (e.g. TiO2, WO3, and BiVO4). The unique aspect of this work is that this deposition occurs in the bulk without physically contacting the particles with electrodes. Instead, bipolar electrochemistry is used to electrodeposit these catalysts, which is a wireless, non-contact technique. After deposition, the composite materials were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and x-ray diffraction (XRD) to determine the efficiency of the deposition process. Using a variety of electrochemistry techniques, electrodes of these materials will be fabricated and evaluated for the efficiency for either the hydrogen or oxygen evolution reaction. Deposition of electrocatalysts was controlled by changing the particle and electrolyte concentrations, the solution viscosity, and the applied bias. We show that these controls allow tuning of the morphology, geometry, and material deposition of the electrocatalysts. This work expands on the robustness of bipolar electrochemical techniques and suggests that a flowable bipolar electrochemical system may allow more control and flexibility of electrocatalyst deposition than other bulk deposition methods. This work was supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Fuel Cell Technologies Incubator Program under Award No. DE-EE0006963.

Evaluation of State-of-the-Art Visible-Light-Absorbing Photocatalysts for Use in New Particle Slurry Reactors for Solar Water Splitting

Global warming, predominantly driven by combustion and utilization of fossil fuels, has catastrophic effects on our communities and health. The climate goal of limiting warming to 2 °C to likely prevent catastrophic and irreversible damage to our planet, is becoming more challenging and costly with each year that passes. If action is not taken soon, humankind will face far-reaching repercussions on the Earth's climate patterns and on all living beings. Solar photoelectrochemical water splitting produces hydrogen, an environmentally benign gas that is a clean alternative to fossil fuels. Most conventional designs for solar photoelectrochemical water splitting reactors are wafer-based, i.e. similar to photovoltaic panels as electrode systems. One of the downsides of such a system is cost, partially due to the use of expensive electrode materials and fabrication techniques. In comparison, certain particle slurry reactors are projected to be the cost-competitive with H2 produced from fossil fuels, on an energy equivalent basis. One inexpensive design consists of two transparent baggies that are stacked and filled with aqueous particle suspensions and a redox shuttle that mediates charge between the baggies. This design will be presented along with its beneficial characteristics. Moreover, we will report on the synthesis and in-depth characterization of the following state-of-the-art materials for use in the proposed reactor design: Rh-doped SrTiO3, C3N4, (Ga1-x Zn x )(N1-x O x ), and ZrO2-TaON light-absorbing particles. An in-depth chemical composition study of the synthesized materials was performed using x-ray diffraction (XRD) and x-ray photoelectron spectroscopy (XPS). The optical bandgap, i.e., the threshold for photons to be absorbed, and sub-bandgap absorption analysis of the aforementioned particles were determined using diffused reflectance spectroscopy (DRS). Charge dynamics were investigated using pulsed laser spectroscopy and electrochemical impedance spectroscopy. Photoelectrochemical characterizations were carried out in a three-electrode setup comprised of a drop-casted working electrode of the synthesized visible-light photocatalysts, a Pt counter electrode, and an Ag/AgCl reference electrode under simulated solar irradiation. The gases evolved in the reaction were quantified by inline mass spectrometry and compared to the electrochemical measurements. An assessment of the collection of data will be performed for its overall impact on the proposed new stacked reactor design consisting of particle slurries for solar water splitting. This work provides an experimental baseline for future work into optimization of particle and reactor conditions for the most efficient and cost-effective solar water splitting. This work was supported by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Fuel Cell Technologies Incubator Program under Award No. DE-EE0006963.

Impact of non-petroleum vehicle fuel economy on GHG mitigation potential

The fuel economy of gasoline vehicles will increase to meet 2025 corporate average fuel economy standards (CAFE). However, dedicated compressed natural gas (CNG) and battery electric vehicles (BEV) already exceed future CAFE fuel economy targets because only 15% of non-petroleum energy use is accounted for when determining compliance. This study aims to inform stakeholders about the potential impact of CAFE on life cycle greenhouse gas (GHG) emissions, should non-petroleum fuel vehicles displace increasingly fuel efficient petroleum vehicles. The well-to-wheel GHG emissions of a set of hypothetical model year 2025 light-duty vehicles are estimated. A reference gasoline vehicle is designed to meet the 2025 fuel economy target within CAFE, and is compared to a set of dedicated CNG vehicles and BEVs with different fuel economy ratings, but all vehicles meet or exceed the fuel economy target due to the policy’s dedicated non-petroleum fuel vehicle incentives. Ownership costs and BEV driving ranges are estimated to provide context, as these can influence automaker and consumer decisions. The results show that CNG vehicles that have lower ownership costs than gasoline vehicles and BEVs with long distance driving ranges can exceed the 2025 CAFE fuel economy target. However, this could lead to lower efficiency CNG vehicles and heavier BEVs that have higher well-to-wheel GHG emissions than gasoline vehicles on a per km basis, even if the non-petroleum energy source is less carbon intensive on an energy equivalent basis. These changes could influence the effectiveness of low carbon fuel standards and are not precluded by the light-duty vehicle GHG emissions standards, which regulate tailpipe but not fuel production emissions.

Biomass catalytic pyrolysis: process design and economic analysis

The estimation of catalytic pyrolysis oil (CPO) production cost in a biomass catalytic pyrolysis (BCP) process is the objective of this study. Experiments carried out with a woody biomass (Beechwood) and a commercially available ZSM‐5 catalyst in a circulating fluid bed (CFB) reactor are the basis for the design of a commercial unit. In the CFB unit, the catalytic pyrolysis step takes place at 482°C and at a catalyst to biomass ratio of 15–20. Following this step, the vapor temperature exiting the reactor is cooled from 482 to 340°C by recovering energy for steam production. The vapors are condensed in two quench towers with recirculated oil and water. Following water separation, the CPO flows to storage. A commercial scale process was designed for a capacity of 180,000 metric tons (MT) per year (8 wt% moisture, 0.54 wt% ash) or 500 MT/day of moisture ash free (MAF) biomass (90% operating factor). The projected costs are valid only for an nth plant and they underestimate the cost for a first of its kind plant. Following procedures used for estimating investment and operating costs for a fluid catalytic cracking unit (FCCU), it is found that for BCP the estimated cost of producing CPO with 18 wt% oxygen is 615 US$/MT or 22 US$/GJ. A sensitivity analysis showed that the price of CPO could vary from 615 to 841 US$/MT (22–31 US$/GJ). On a crude oil energy equivalent basis, the bio‐oil cost lies in the range of 36–49 US$/GJ. WIREs Energy Environ 2016, 5:370–383. doi: 10.1002/wene.192This article is categorized under: Bioenergy > Science and Materials

Monetization of Oil-Gas Price Differentials

The energy sector has been one of the few bright spots in the global economy over the past five years and the unconventionals revolution is creating waves that will carry through the economy, including infrastructure and manufacturing. We acknowledge the many challenges for energy investing – beyond the traditional sub-surface risks that always present difficulties – including: Surging gas supplies have created a very weak price environment in several regions of the world; Shortages of infrastructure and take-away capacity have created bottlenecks, leading to significant market price differentials; and, A frenzy of investment activity in the upstream sector – both organic and M&A – has led to some relatively high transaction prices. The same trends behind these challenges create windows of opportunity – in both public and private markets, and at both the company and project levels. The unconventionals revolution has led to an abundance of low-cost natural gas, and sources of supply around the world growing faster than the demand or take-away capacity of their surrounding infrastructure. Coupled with high oil prices, this has created wide price gaps between gas and oil on an energy-equivalent basis. Oil is nearly six times the price of natural gas on an energy equivalent basis, and we do not see this disparity disappearing soon. Thus, many investors are looking at real asset investments to exploit the price arbitrage. This arbitrage investment activity will eventually drive a closer indexation of gas prices to oil, but we are many years away from that. We see this discontinuity creating several actionable real asset investment theses, and outline some of what we are seeing in liquids, gas, and the supply chain technology and services.

Second generation biofuels: Economics and policies

This study reviews economics of production of second generation biofuels from various feedstocks, including crop and wood/forestry residues, lignocellulosic energy crops, jatropha, and algae. The study indicates that while second generation biofuels could significantly contribute to the future energy supply mix, cost is a major barrier to its commercial production in the near to medium term. Depending upon type of biofuels, feedstock prices and conversion costs, the cost of cellulosic ethanol is found to be two to three times higher than the current price of gasoline on an energy equivalent basis. The median cost (across the studies reviewed) of biodiesel produced from microalgae, a prospective feedstock, is seven times higher than the current price of diesel, although much higher cost estimates have been reported. As compared with the case of first generation biofuels, in which feedstock can account for over two-thirds of the total costs, the share of feedstock in the total costs is relatively lower (30–50%) in the case of second generation biofuels. While significant cost reductions are needed for both types of second generation biofuels, the critical barriers are at different steps of the production process. For cellulosic ethanol, the biomass conversion costs needs to be reduced. On the other hand, feedstock cost is the main issue for biodiesel. At present, policy instruments, such as fiscal incentives and consumption mandates have in general not differentiated between the first and second generation biofuels except in the cases of the US and EU. The policy regime should be revised to account for the relative merits of different types of biofuels.

Chapter 9 Oil and gas resource potential north of the Arctic Circle

Abstract The US Geological Survey recently assessed the potential for undiscovered conventional petroleum in the Arctic. Using a new map compilation of sedimentary elements, the area north of the Arctic Circle was subdivided into 70 assessment units, 48 of which were quantitatively assessed. The Circum-Arctic Resource Appraisal (CARA) was a geologically based, probabilistic study that relied mainly on burial history analysis and analogue modelling to estimate sizes and numbers of undiscovered oil and gas accumulations. The results of the CARA suggest the Arctic is gas-prone with an estimated 770–2990 trillion cubic feet of undiscovered conventional natural gas, most of which is in Russian territory. On an energy-equivalent basis, the quantity of natural gas is more than three times the quantity of oil and the largest undiscovered gas field is expected to be about 10 times the size of the largest undiscovered oil field. In addition to gas, the gas accumulations may contain an estimated 39 billion barrels of liquids. The South Kara Sea is the most prospective gas assessment unit, but giant gas fields containing more than 6 trillion cubic feet of recoverable gas are possible at a 50% chance in 10 assessment units. Sixty per cent of the estimated undiscovered oil resource is in just six assessment units, of which the Alaska Platform, with 31% of the resource, is the most prospective. Overall, the Arctic is estimated to contain between 44 and 157 billion barrels of recoverable oil. Billion barrel oil fields are possible at a 50% chance in seven assessment units. Undiscovered oil resources could be significant to the Arctic nations, but are probably not sufficient to shift the world oil balance away from the Middle East.

Life Cycle Energy and Greenhouse Gas Emissions for an Ethanol Production Process Based on Blue-Green Algae

Ethanol can be produced via an intracellular photosynthetic process in cyanobacteria (blue-green algae), excreted through the cell walls, collected from closed photobioreactors as a dilute ethanol-in-water solution, and purified to fuel grade ethanol. This sequence forms the basis for a biofuel production process that is currently being examined for its commercial potential. In this paper, we calculate the life cycle energy and greenhouse gas emissions for three different system scenarios for this proposed ethanol production process, using process simulations and thermodynamic calculations. The energy required for ethanol separation increases rapidly for low initial concentrations of ethanol, and, unlike other biofuel systems, there is little waste biomass available to provide process heat and electricity to offset those energy requirements. The ethanol purification process is a major consumer of energy and a significant contributor to the carbon footprint. With a lead scenario based on a natural-gas-fueled combined heat and power system to provide process electricity and extra heat and conservative assumptions around the ethanol separation process, the net life cycle energy consumption, excluding photosynthesis, ranges from 0.55 MJ/MJ(EtOH) down to 0.20 MJ/ MJ(EtOH), and the net life cycle greenhouse gas emissions range from 29.8 g CO₂e/MJ(EtOH) down to 12.3 g CO₂e/MJ(EtOH) for initial ethanol concentrations from 0.5 wt % to 5 wt %. In comparison to gasoline, these predicted values represent 67% and 87% reductions in the carbon footprint for this ethanol fuel on a energy equivalent basis. Energy consumption and greenhouse gas emissions can be further reduced via employment of higher efficiency heat exchangers in ethanol purification and/ or with use of solar thermal for some of the process heat.

Ethanol technical potential in Hawaii based on sugarcane, banagrass, Eucalyptus, and Leucaena

An assessment of ethanol production potential from dedicated energy crops was conducted for the State of Hawaii considering lands, crop species, and conversion technologies. Evaluation of the spatial distributions of soil types, zoning, and annual rainfall was conducted using geographic information system data. Saccharum officinarum (sugarcane), Pennisetum purpureum (banagrass), Leucaena leucocephala, and Eucalyptus grandis were selected as potential feedstocks for sugar-based and lignocellulosic ethanol production. The analysis shows that only one cropping scenario applied to all available agriculturally zoned lands in the state would be capable of producing enough ethanol to meet the state's current motor gasoline consumption on an energy equivalent basis. State goals of displacing 20% (volume) of highway fuels by 2020 could be met by 14 of the 16 cropping and land use combinations. This indicates that the State of Hawaii could promote energy diversification through its choice of land leases. Distribution of suitable lands among islands is not consistent with motor fuel demand, suggesting that provisions must be made to support development of adequate storage and harbor facilities to enable movement of fuel between points of production and use. Comparison of possible production volumes with economic plant sizes indicates that sufficient feedstocks could be available on Maui, Hawaii, Oahu, and Kauai to realize economies of scale in production facilities. This study should be refined in the future to adequately address issues of environmental preservation, water consumption, and land use to provide additional guidance for policy and economic decision making.

Glycaemic and satiating properties of potato products

To investigate glycaemic and satiating properties of potato products in healthy subjects using energy-equivalent or carbohydrate-equivalent test meals, respectively. Thirteen healthy subjects volunteered for the first study, and 14 for the second. The tests were performed at Applied Nutrition and Food Chemistry, Lund University, Sweden. EXPERIMENTAL DESIGN AND TEST MEALS: All meals were served as breakfast in random order after an overnight fast. Study 1 included four energy-equivalent (1000 kJ) meals of boiled potatoes, french fries, or mashed potatoes; the latter varying in portion size by use of different amounts of water. The available carbohydrate content varied between 32.5 and 50.3 g/portion. Capillary blood samples were collected during 240 min for analysis of glucose, and satiety was measured with a subjective rating scale. Study 2 included four carbohydrate-equivalent meals (50 g available carbohydrates) of french fries, boiled potatoes served with and without addition of oil, and white wheat bread (reference). The energy content varied between 963 and 1534 kJ/portion. Capillary blood samples were collected during 180 min for analysis of glucose, and satiety was measured using a subjective rating scale. Study 1: boiled potatoes induced higher subjective satiety than french fries when compared on an energy-equivalent basis. The french fries elicited the lowest early glycaemic response and was less satiating in the early postprandial phase (area under the curve (AUC) 0-45 min). No differences were found in glycaemic or satiety response between boiled or mashed potatoes. Study 2: french fries resulted in a significantly lower glycaemic response (glycaemic index (GI)=77) than boiled potatoes either with or without addition of oil (GI=131 and 111, respectively). No differences were found in subjective satiety response between the products served on carbohydrate equivalence. Boiled potatoes were more satiating than french fries on an energy-equivalent basis, the effect being most prominent in the early postprandial phase, whereas no difference in satiety could be seen on a carbohydrate-equivalent basis. The lowered GI for french fries, showing a typical prolonged low-GI profile, could not be explained by the fat content per se.

An evaluation of the U.S. Geological Survey World Petroleum Assessment 2000

This study compares the additions to conventional crude oil and natural gas reserves as reported from January 1996 to December 2003 with the estimated undiscovered and reserve-growth volumes assessed in the U.S. Geological Survey World Petroleum Assessment 2000, which used data current through 1995. Approximately 28% of the estimated additions to oil reserves by reserve growth and approximately 11% of the estimated undiscovered oil volumes were realized in the 8 yr since the assessment (27% of the time frame for the assessment). Slightly more than half of the estimated additions to gas reserves by reserve growth and approximately 10% of the estimated undiscovered gas volumes were realized. Between 1995 and 2003, growth of oil reserves in previously discovered fields exceeded new-field discoveries as a source of global additions to reserves of conventional oil by a ratio of 3:1. The greatest amount of reserve growth for crude oil occurred in the Middle East and North Africa, whereas the greatest contribution from new-field discoveries occurred in sub-Saharan Africa. The greatest amount of reserve growth for natural gas occurred in the Middle East and North Africa, whereas the greatest contribution from new-field discoveries occurred in the Asia Pacific region. On an energy-equivalent basis, volumes of new gas-field discoveries exceeded new oil-field discoveries.

Energy in central Asia and northwest China: major trends and opportunities for regional cooperation

On an energy-equivalent basis Central Asia is predominantly a gas producing region. Potential for oil and hydropower development is vast however. This paper examines the current and predicted future status of the energy industry of Central Asia, and assesses opportunities for regional-wide cooperation in development, transportation, and trade. The findings are based on a just-completed Asian Development Bank survey of Uzbekistan, Kazakstan, the Kyrgyz Republic, and Xinjiang, People’s Republic of China. Investment and trade of energy is being sought by government officials in the region as a means of boosting local economies. Importantly, the cooperation is being influenced by centuries-old cultural and ethnic ties.

Northern Ireland lignite

There is no doubt that Northern Ireland's lignite deposits are of high quality and constitute a natural resource of considerable potential value in this small, peripheral part of the European Community. Whether or not one or more will be used commercially and, if so, when depends on an interacting complex of economic, social and political factors. In purely economic terms, use will be effectively determined by lignite's economic competitiveness as a fuel dor electricity generation and on the relationship between capital and fuel costs. The economics of other possibly viable products such as lignite briquettes will be heavily dependent on the use of by-products of electricity generation, most notably surplus heat. The availability of lignite offers an alternative fuel option to those charged with formulating the Province's energy policy. If, as now seems likely, it is no longer a serious competitor for the power station planned for the mid-1990's, it most certainly is a competitor for the early part of the next century. This is particularly so in view of its low sulphur content which is about half that of Scottish coal on an energy equivalent basis. Lignite also offers security of supply at predictable prices, an important advantage, and thus carries a premium over coal, oil and natural gas which are imported at prices determined wholly exogenously. As the Province has by far the highest rate of regional unemployment in the United Kingdom, one argument advanced for the use of indigenous lignite is that its use in electricity generation would create much needed additional employment — an estimated 400 jobs being associated with the mining operations needed to support a 450 MW power station. But the Coagh example shows that other considerations must be taken seriously. It is extremely unlikely that the lignite in this area will ever be worked unless local attitudes change dramatically or there is some national fuel crisis which would over-ride local opposition. It is difficult enough developing lignite without having to contend with such strong resistance at the local level. This study has shown that certainly in the Northern Irish context it is highly important for the policy makers not only to consider the economic factors involved in choice of an energy fuel but to work closely with local communities and the various environmental bodies, to take their perceptions, right or wrong, into consideration.