The influence of the global electric power system on terrestrial biodiversity.

Given its total contribution to greenhouse gas emissions, the global electric power sector will be required to undergo a fundamental transformation over the next decades to limit anthropogenic climate change to below 2 °C. Implications for biodiversity of projected structural changes in the global electric power sector are rarely considered beyond those explicitly linked to climate change. This study uses a spatially explicit consumption-based accounting framework to examine the impact of demand for electric power on terrestrial vertebrate biodiversity globally. We demonstrate that the biodiversity footprint of the electric power sector is primarily within the territory where final demand for electric power resides, although there are substantial regional differences, with Europe displacing its biodiversity threat along international supply chains. The relationship between size of individual components of the electric power sector and threat to biodiversity indicates that a shift to nonfossil sources, such as solar and wind, could reduce pressures on biodiversity both within the territory where demand for power resides and along international supply chains. However, given the current levels of deployment of nonfossil sources of power, there is considerable uncertainty as to how the impacts of structural changes in the global electric power system will scale. Given the strong territorial link between demand and associated biodiversity impacts, development of strong national governance around the electric power sector represents a clear route to mitigate threats to biodiversity associated with efforts to decarbonize society over the coming century.

Longevity of implantable cardioverter-defibrillators for cardiac resynchronization therapy in current clinical practice: an analysis according to influencing factors, device generation, and manufacturer.

AIMS: Device replacement at the time of battery depletion of implantable cardioverter-defibrillators (ICDs) may carry a considerable risk of complications and engenders costs for healthcare systems. Therefore, ICD device longevity is extremely important both from a clinical and economic standpoint. Cardiac resynchronization therapy defibrillators (CRT-D) battery longevity is shorter than ICDs. We determined the rate of replacements for battery depletion and we identified possible determinants of early depletion in a series of patients who had undergone implantation of CRT-D devices. METHODS AND RESULTS: We retrieved data on 1726 consecutive CRT-D systems implanted from January 2008 to March 2010 in nine centres. Five years after a successful CRT-D implantation procedure, 46% of devices were replaced due to battery depletion. The time to device replacement for battery depletion differed considerably among currently available CRT-D systems from different manufacturers, with rates of batteries still in service at 5 years ranging from 52 to 88% (log-rank test, P < 0.001). Left ventricular lead output and unipolar pacing configuration were independent determinants of early depletion [hazard ratio (HR): 1.96; 95% 95% confidence interval (CI): 1.57-2.46; P < 0.001 and HR: 1.58, 95% CI: 1.25-2.01; P < 0.001, respectively]. The implantation of a recent-generation device (HR: 0.57; 95% CI: 0.45-0.72; P < 0.001), the battery chemistry and the CRT-D manufacturer (HR: 0.64; 95% CI: 0.47-0.89; P = 0.008) were additional factors associated with replacement for battery depletion. CONCLUSION: The device longevity at 5 years was 54%. High left ventricular lead output and unipolar pacing configuration were associated with early battery depletion, while recent-generation CRT-Ds displayed better longevity. Significant differences emerged among currently available CRT-D systems from different manufacturers.

Health care during electricity failure: The hidden costs.

BACKGROUND: Surgery risks increase when electricity is accessible but unreliable. During unreliable electricity events and without data on increased risk to patients, medical professionals base their decisions on anecdotal experience. Decisions should be made based on a cost-benefit analysis, but no methodology exists to quantify these risks, the associated hidden costs, nor risk charts to compare alternatives. METHODS: Two methodologies were created to quantify these hidden costs. In the first methodology through research literature and/or measurements, the authors obtained and analyzed a year's worth of hour-by-hour energy failures for four energy healthcare system (EHS) types in four regions (SolarPV in Iraq, Hydroelectric in Ghana, SolarPV+Wind in Bangladesh, and Grid+Diesel in Uganda). In the second methodology, additional patient risks were calculated according to time and duration of electricity failure and medical procedure impact type. Combining these methodologies, the cost from the Value of Statistical Lives lost divided by Energy shortage ($/kWh) is calculated for EHS type and region specifically. The authors define hidden costs due to electricity failure as VSL/E ($/kWh) and compare this to traditional electricity costs (always defined in $/kWh units), including Levelized Cost of Electricity (LCOE also in $/kWh). This is quantified into a fundamentally new energy healthcare system risk chart (EHS-Risk Chart) based on severity of event (probability of deaths) and likelihood of event (probability of electricity failure). RESULTS: VSL/E costs were found to be 10 to 10,000 times traditional electricity costs (electric utility or LCOE based). The single power source EHS types have higher risks than hybridized EHS types (especially as power loads increase over time), but all EHS types have additional risks to patients due to electricity failure (between 3 to 105 deaths per 1,000 patients). CONCLUSIONS: These electricity failure risks and hidden healthcare costs can now be calculated and charted to make medical decisions based on a risk chart instead of anecdotal experience. This risk chart connects public health and electricity failure using this adaptable, scalable, and verifiable model.

Reframing nuclear power in the UK energy debate: nuclear power, climate change mitigation and radioactive waste.

In the past decade, human influence on the climate through increased use of fossil fuels has become widely acknowledged as one of the most pressing issues for the global community. For the United Kingdom, we suggest that these concerns have increasingly become manifest in a new strand of political debate around energy policy, which reframes nuclear power as part of the solution to the need for low-carbon energy options. A mixed-methods analysis of citizen views of climate change and radioactive waste is presented, integrating focus group data and a nationally representative survey. The data allow us to explore how UK citizens might now and in the future interpret and make sense of this new framing of nuclear power--which ultimately centers on a risk-risk trade-off scenario. We use the term "reluctant acceptance" to describe how, in complex ways, many focus group participants discursively re-negotiated their position on nuclear energy when it was positioned alongside climate change. In the concluding section of the paper, we reflect on the societal implications of the emerging discourse of new nuclear build as a means of delivering climate change mitigation and set an agenda for future research regarding the (re)framing of the nuclear energy debate in the UK and beyond.

Study of the factors influencing the metals solubilisation from a mixture of waste batteries by response surface methodology.

This paper presents an innovative process for the recovery of valuable metals from a mixture of spent batteries. Different types of batteries, including alkaline, zinc-carbon (Zn-C), nickel cadmium (Ni-Cd), nickel metal hydride (Ni-MH), lithium ion (Li-ion) and lithium metallic (Li-M) batteries, were mixed according to the proportion of the Canadian sales of batteries. A Box-Behnken design was applied to find the optimum leaching conditions allowing a maximum of valuable metal removals from a mixture of spent batteries in the presence of an inorganic acid and a reducing agent. The results highlighted the positive effect of sodium metabisulfite on the performance of metals removal, especially for Mn. The solid/liquid ratio and the concentration of H2SO4 were the main factors affecting the leaching behavior of valuable metals (Zn, Mn, Cd, Ni) present in spent batteries. Finally, the optimum leaching conditions were found as follows: one leaching step, solid/liquid ratio = 10.9%, [H2SO4] = 1.34 M, sodium metabisulfite (Na2S2O5) = 0.45 g/g of battery powder and retention time = 45 min. Under such conditions, the removal yields achieved were 94% for Mn, 81% for Cd, 99% for Zn, 96% for Co and 68% for Ni.

Challenges and opportunities of power systems from smart homes to super-grids.

The world's power systems are facing a structural change including liberalization of markets and integration of renewable energy sources. This paper describes the challenges that lie ahead in this process and points out avenues for overcoming different problems at different scopes, ranging from individual homes to international super-grids. We apply energy system models at those different scopes and find a trade-off between technical and social complexity. Small-scale systems would require technological breakthroughs, especially for storage, but individual agents can and do already start to build and operate such systems. In contrast, large-scale systems could potentially be more efficient from a techno-economic point of view. However, new political frameworks are required that enable long-term cooperation among sovereign entities through mutual trust. Which scope first achieves its breakthrough is not clear yet.

Batteries: from alkaline to zinc-air.

There is no perfect disposable battery--one that will sit on the shelf for 20 years, then continually provide unlimited current, at a completely constant voltage until exhausted, without producing heat. There is no perfect rechargeable battery--one with all of the above characteristics and will also withstand an infinite overcharge while providing an equally infinite cycle life. There are only compromises. Every battery selection is a compromise between the ideally required characteristics, the advantages, and the limitations of each battery type. General selection of a battery type to power a medical device is largely outside the purview of the biomed. Initially, these are engineering decisions made at the time of medical equipment design and are intended to be followed in perpetuity. However, since newer cell types evolve and the manufacturer's literature is fixed at the time of printing, some intelligent substitutions may be made as long as the biomed understands the characteristics of both the recommended cell and the replacement cell. For example, when the manufacturer recommends alkaline, it is usually because of the almost constant voltage it produces under the devices' design load. Over time, other battery types may be developed that will meet the intent of the manufacturer, at a lower cost, providing longer operational life, at a lower environmental cost, or with a combination of these advantages. In the Obstetrical Doppler cited at the beginning of this article, the user had put in carbon-zinc cells, and the biomed had unknowingly replaced them with carbonzinc cells. If the alkaline cells recommended by the manufacturer had been used, there would have been the proper output voltage at the battery terminals when the [table: see text] cells were at their half-life. Instead, the device refused to operate since the battery voltage was below presumed design voltage. While battery-type substitutions may be easily and relatively successfully made in disposable applications (for example, zinc-air for alkaline--if it is cost-effective), this is absolutely forbidden for secondary cells. Because of the differing cell voltages, charge characteristics and overcharge tolerance between different types of secondary cells, substituting a nickel-cadmium battery pack for the more expensive lithium-ion pack (if it is physically able to fit into the battery compartment), might appear to save money (e.g. $50 vs. $100) but it would be very ill advised. Since the cell characteristics are very different, it would be downright fatal to anyone within the 'kill radius' when the pack explodes. Those outside the kill radius would receive chemical burns from the electrolyte. Substitutions of secondary cell battery packs are generally not a good idea for biomeds to engage in. These are engineering decisions best left to either aftermarket battery pack manufacturers or the medical device manufacturer as a design engineering change.

Rechargeable lead-acid batteries.

Batteries used in medical equipment, like their counterparts in consumer products, attract little attention until they fail to function effectively. In some applications, such as in emergency medical devices, battery failure can have fatal consequences. While modern batteries are usually quite reliable, ECRI has received 53 written problem reports and countless verbal reports or questions related to battery problems in hospitals during the past five years. This large number of reports is due, at least in part, to the enormous quality of batteries used to operate or provide backup power in contemporary hospital equipment. As part of an ongoing evaluation of rehabilitation assistive equipment, ECRI has been studying the performance of 12 V rechargeable deep-cycle lead-acid batteries used in powered wheelchairs. During the course of this evaluation, it has become apparent that many professionals, both clinical and industrial, regard batteries as "black box" devices and know little about proper care and maintenance--and even less about battery selection and purchase. Because equipment performance and reliability can be strongly influenced by different battery models, an understanding of battery characteristics and how they affect performance is essential when selecting and purchasing batteries. The types of rechargeable batteries used most commonly in hospitals are lead-acid and nickel-cadmium (nicad), which we compare below; however, the guidance we provide in this article focuses on lead-acid batteries. While the examples given are for high-capacity 12 V deep-cycle batteries, similar analyses can be applied to smaller lead-acid batteries of different voltages.

Defibrillator/monitor/pacemakers.

Combined defibrillator/monitors enable the operator to assess and monitor the ECG and rapidly deliver a defibrillating countershock to patients suffering from ventricular fibrillation during a cardiac arrest. In addition, these units provide synchronized cardioversion for treating other arrhythmias, such as ventricular tachycardia, and most now offer external noninvasive pacemaker capability for treating patients with ventricular bradycardia or asystole. Defibrillator/monitors are critical resuscitation instruments and must perform effectively to avoid the otherwise preventable death of a cardiac arrest patient. However, both ECRI and the Food and Drug Administration (FDA) continue to receive a large number of problem reports on these devices each year. Device failures can occur for such reasons as operator error, depleted or defective batteries, or component failures. We evaluated eight units--three intended for crash-cart use and four intended for portable use, all with noninvasive pacemaker capability either standard or as an option, as well as one portable physiologic patient monitor to which a defibrillator (with or without a pacing option) can be attached--from six manufacturers.* We also evaluated one stand-alone noninvasive pacemaker. Although we did not include automated external defibrillators (AEDs) in our study, two of the evaluated units have options that allow them to function as AEDs. We rated the seven crash-cart and portable defibrillator/monitor/pacemakers according to three primary applications: (1) general crash-cart use, (2) prehospital (emergency medical service [EMS]) use, and (3) in-hospital transport. They are rated either Acceptable or Acceptable--Not Recommended for these applications, based primarily on technical performance (including battery operation, which is especially important in portable units), characteristics (such as line-powered operation and portability), features (such as automatic documentation), and human factors design (especially ease of use); some are inappropriate for specific uses because of their respective limitations in these applications. The portable physiologic patient monitor is not rated, but is discussed.** All of the pacemakers available as components of the evaluated units are acceptable for use; however, in most cases, purchasing decisions should be made according to defibrillator/monitor needs. The stand-alone pacemaker is rated Unacceptable because of its numerous performance, safety, and human factors disadvantages and because, other than its being a stand-alone unit, it offers no advantages over the other evaluated pacemakers; see "The Zoll NTP-1000 Stand-alone Noninvasive Pacemaker." Readers are cautioned not to base purchasing decisions on our ratings and rankings alone, but on a thorough understanding of the issues surrounding defibrillator/monitors and noninvasive pacemakers, which can be gained only by reading this study in its entirety.(ABSTRACT TRUNCATED AT 400 WORDS)

Chemical characterisation of spent rechargeable batteries.

A chemical characterisation of used batteries can give useful information to implement suitable recycling techniques and to estimate the flux of the different materials recovered. This work is aimed to provide quantitative data about the composition of mixed batteries (in particular, Ni-Cd, Ni-MH and Li-ion batteries) collected in a Northern Italian town in order to evaluate the feasibility of recovery processes applied to the selected material. The higher concentration of metals in the <3mm fraction suggested that significant quantities of valuable elements could be recovered: in particular, for a kg of the <3mm fraction deriving from disassembled batteries, about 390 g Ni and 330 g Cd can be recovered from Ni-Cd, 630 g Ni, 80 g Co from Ni-MH and 250 g Co, 110 g Ni, 120 g Cu from Li-ion ones. Leaching tests applied to the same fractions, to assess possible contaminant releases, resulted in low metal content in aqueous solutions (except for Al and Fe, the concentrations of all metals remained below 1mg/kg). Even so, great care is required in all handling activities due to the high pH values of leachate solutions.

Comparison of two U.S. power-plant carbon dioxide emissions data sets.

Estimates of fossil-fuel CO2 emissions are needed to address a variety of climate-change mitigation concerns over a broad range of spatial and temporal scales. We compared two data sets that report power-plant CO2 emissions in the conterminous U.S. for 2004, the most recent year reported in both data sets. The data sets were obtained from the Department of Energy's Energy Information Administration (EIA) and the Environmental Protection Agency's eGRID database. Conterminous U.S. total emissions computed from the data sets differed by 3.5% for total plant emissions (electricity plus useful thermal output) and 2.3% for electricity generation only. These differences are well within previous estimates of uncertainty in annual U.S. fossil-fuel emissions. However, the corresponding average absolute differences between estimates of emissions from individual power plants were much larger, 16.9% and 25.3%, respectively. By statistical analysis, we identified several potential sources of differences between EIA and eGRID estimates for individual plants. Estimates that are based partly or entirely on monitoring of stack gases (reported by eGRID only) differed significantly from estimates based on fuel consumption (as reported by EIA). Differences in accounting methods appear to explain differences in estimates for emissions from electricity generation from combined heat and power plants, and for total and electricity generation emissions from plants that burn nonconventional fuels (e.g., biomass). Our analysis suggests the need for care in utilizing emissions data from individual power plants, and the need for transparency in documenting the accounting and monitoring methods used to estimate emissions.

Comparative life-cycle air emissions of coal, domestic natural gas, LNG, and SNG for electricity generation.

The U.S. Department of Energy (DOE) estimates that in the coming decades the United States' natural gas (NG) demand for electricity generation will increase. Estimates also suggest that NG supply will increasingly come from imported liquefied natural gas (LNG). Additional supplies of NG could come domestically from the production of synthetic natural gas (SNG) via coal gasification-methanation. The objective of this study is to compare greenhouse gas (GHG), SOx, and NOx life-cycle emissions of electricity generated with NG/LNG/SNG and coal. This life-cycle comparison of air emissions from different fuels can help us better understand the advantages and disadvantages of using coal versus globally sourced NG for electricity generation. Our estimates suggest that with the current fleet of power plants, a mix of domestic NG, LNG, and SNG would have lower GHG emissions than coal. If advanced technologies with carbon capture and sequestration (CCS) are used, however, coal and a mix of domestic NG, LNG, and SNG would have very similar life-cycle GHG emissions. For SOx and NOx we find there are significant emissions in the upstream stages of the NG/ LNG life-cycles, which contribute to a larger range in SOx and NOx emissions for NG/LNG than for coal and SNG.

Power sources for portable electronics and hybrid cars: lithium batteries and fuel cells.

The activities in progress in our laboratory for the development of batteries and fuel cells for portable electronics and hybrid car applications are reviewed and discussed. In the case of lithium batteries, the research has been mainly focused on the characterization of new electrode and electrolyte materials. Results related to disordered carbon anodes and improved, solvent-free, as well as gel-type, polymer electrolytes are particularly stressed. It is shown that the use of proper gel electrolytes, in combination with suitable electrode couples, allows the development of new types of safe, reliable, and low-cost lithium ion batteries which appear to be very promising power sources for hybrid vehicles. Some of the technologies proven to be successful in the lithium battery area are readapted for use in fuel cells. In particular, this approach has been followed for the preparation of low-cost and stable protonic membranes to be proposed as an alternative to the expensive, perfluorosulfonic membranes presently used in polymer electrolyte membrane fuel cells (PEMFCs).

[The Italian experience with lithium pacemaker (author's transl)]. / L'esperienza italiana con i pacemaker al litio.

After explaining the concept and evolution of lithium-anode batteries, and the various types in use at present as power sources for pulse generators, the Authors examine the Italian studies, including pacemaker's clinical follow-up, technical trials and productions. In fact the first pulse-generators, powered by the best known battery prototypes, i.e. old Lithium-Iodine cell 702 C,P, and E, and Lithium-Silver Chromate cell Li 210 and Li 355, were implanted respectively in 1972, 1973 and 1974, at the Cardiology Department, Ferrara, Italy. The detailed account and analysis of the data supplied by both Italian and Foreign manufacturers, together with the observations furnished by 24 Pacing-Centres--2845 pacemakers implanted for a total amount of 31,794 months/pacemaker out of 8,475 pacemakers supplied for 77,606 months/pacemaker up to June, 30, 1977-indicate a promising future for the development of such pulse-generators. Indeed the latest improved power sources associated with the best and most reliable electronic and electrode pacing systems, already allow the manufactures to produce small, comfortable and long-term pacemakers. Furthermore the significant reduction in periodic controls and replacements, if actually needed, seems sufficient in itself to counterbalance the initial high cost. Thus, medical staff and equipment can be utilized for other purposes.