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Photovoltaic (PV) technologies have shown remarkable progress recently in terms of annual production capacity and life cycle environmental performances, which necessitate timely updates of environmental indicators. Based on PV production data of 2004–2006, this study presents the life-cycle greenhouse gas emissions, criteria pollutant emissions, and heavy metal emissions from four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride. Life-cycle emissions were determined by employing average electricity mixtures in Europe and the United States during the materials and module production for each PV system. Among the current vintage of PV technologies, thin-film cadmium telluride (CdTe) PV emits the least amount of harmful air emissions as it requires the least amount of energy during the module production. However, the differences in the emissions between different PV technologies are very small in comparison to the emissions from conventional energy technologies that PV could displace. As a part of prospective analysis, the effect of PV breeder was investigated. Overall, all PV technologies generate far less life-cycle air emissions per GWh than conventional fossil-fuel-based electricity generation technologies. At least 89% of air emissions associated with electricity generation could be prevented if electricity from photovoltaics displaces electricity from the grid.

Material flows and emissions in all the stages of production of zinc, copper, aluminum, cadmium, indium, germanium, gallium, selenium, tellurium, and molybdenum were investigated. These metals are used selectively in the manufacture of solar cells, and emission and energy factors in their production are used in the life cycle analysis (LCA) of photovoltaics. Significant changes have occurred in the production and associated emissions for these metals over the last 10 years, which are not described in the LCA databases. Furthermore, emission and energy factors for several of the by-products of the base metal production were lacking. This review article aims in updating the life cycle inventories associated with the production of the base metals (Zn, Cu), and defining the production paths and emission and energy allocations for the minor metals (Cd, Ge, In, Mo, Se, and Te) used in photovoltaics.

The effects of combined driving and vehicle-to-grid (V2G) usage on the lifetime performance of relevant commercial Li-ion cells were studied. We derived a nominal realistic driving schedule based on aggregating driving survey data and the Urban Dynamometer Driving Schedule, and used a vehicle physics model to create a daily battery duty cycle. Different degrees of continuous discharge were imposed on the cells to mimic afternoon V2G use to displace grid electricity. The loss of battery capacity was quantified as a function of driving days as well as a function of integrated capacity and energy processed by the cells. The cells tested showed promising capacity fade performance: more than 95% of the original cell capacity remains after thousands of driving days worth of use. Statistical analyses indicate that rapid vehicle motive cycling degraded the cells more than slower, V2G galvanostatic cycling. These data are intended to inform an economic model.

Conventional internal combustion engines waste a lot of energy in creating heat, but by applying a ‘Rankine cycle,’ a process where hot exhaust gases are used to heat up a water reservoir and create steam to spin a turbine, electricity can be generated. This electricity can then be used to charge up an array of batteries and help power a hybrid-electric powertrain.

A new report has found that thin-film cadmium telluride solar cells have the lowest life-cycle emissions primarily because they consume the least amount of energy during the module production of the four types of major commercial PV systems: multicrystalline silicon, monocrystalline silicon, ribbon silicon, and thin-film cadmium telluride (CdTe).

One of the leading alternatives for producing clean power from coal -- Integrated Combined Cycle Gasification (IGCC) technology faces a precarious future due to rising capital costs and regulatory uncertainty. A process of gasifying coal that allows capture of carbon dioxide emissions, IGCC has tremendous potential for meeting future baseload generation demand but project momentum has slowed dramatically in 2007, according to a new study from Emerging Energy Research (EER). Despite delays or cancellations of several prominent IGCC projects in 2007, 48 projects with a combined capacity of over 25,000 MW remain in the global IGCC pipeline, according to EER.

Forever moving - our restless oceans have enough energy to power the world. As long as the Earth turns and the moon keeps its appointed cycle, the oceans will absorb and dissipate vast amounts of kinetic energy - a renewable energy resource of enormous potential.

A company called M2E Power has announced plans today to release a charger that will powered by kinetic motion. The released date is expected to be next summer. The charger derives power from the motion of walking, jogging, cycling, or driving. Six hours of motion provides 30 to 60 minutes of charging power. It will be priced between $25 and $40.