Potential for Solar Energy in Food Manufacturing, Distribution and Retail

The overall aim of the study was to assess the potential for increasing the use of solar energy in the food sector. For comparative purposes the study also included an assessment of the benefits that could arise from the use of other renewable energy sources, and the potential for more effective use of energy in food retail and distribution. Specific objectives were to: i) establish the current state of the art in relevant available solar technology; ii) identify the barriers for the adoption of solar technology; iii) assess the potential for solar energy capture; iv) appraise the potential of alternative relevant technologies for providing renewable energy; v) assess the benefits from energy saving technologies; vi) compare the alternative strategies for the next 5-10 years and vii) Consider the merits of specific research programmes on solar energy and energy conservation in the food sector. To obtain the views of the main stakeholders in the relevant food and energy sectors on the opportunities and barriers to the adoption of solar energy and other renewable energy technologies by the food industry, personal interviews and structured questionnaires tailored to the main stakeholders (supermarkets, consultants for supermarket design; energy and equipment suppliers) were used. The main findings from the questionnaires and interviews are: - Key personnel in supermarkets and engineers involved in the design of supermarkets are aware of the potential contribution of renewable energy technologies and other energy conservation measures to energy conservation and environmental impact reduction in the food industry. A number of supermarket chains have implemented such technologies at pilot scale to gain operating experience, and more importantly, for marketing reasons, to gain competitive advantage through a green image. - From installations to date in the UK the most notable are a 600 kW wind turbine at a Sainsbury's distribution centre in East Kilbride and a 60 kWp photovoltaic array at a Tesco store in Swansea. - The main barrier to the application of renewable energy technologies in the food sector is the capital cost. Even though significant progress has been made towards the improvement of the energy conversion efficiencies of photovoltaic technologies (PVs) and reduction in their cost, payback periods are still far too long, for them to become attractive to the food industry. - Wind energy can be more attractive than PVs in areas of high wind speed. Apart from relatively high cost, the main barrier to the wide application of wind turbines for local power generation is planning restrictions. This technology is more attractive for application in food distribution centres that are normally located outside build-up areas where planning restrictions can be less severe than in urban areas. In these applications it is likely that preference will be for large wind turbines of more than 1.0 MW power generation capacity as the cost of generation per unit power reduces with the size of the turbine

Carbon dioxide in European coastal waters

We compiled from literature annually integrated air-water fluxes of carbon dioxide (CO2) computed from field measurements, in 20 coastal European environments that were gathered into 3 main ecosystems: inner estuaries, upwelling continental shelves and non-upwelling continental shelves. The comparison of annual cycles of the partial pressure of CO2 (pCO(2)) in 5 contrasting continental shelves provided insights into the biogeochemical drivers of the CO2 fluxes. The latter were also investigated by comparing CO2 fluxes to net ecosystem (NEP) and net community production (NCP) in 3 contrasted coastal ecosystems. Air-water CO2 fluxes were scaled at European regional level and compared to fluxes of atmospheric CO2 in other aquatic and terrestrial compartments. Continental shelves are significant sinks for atmospheric CO2 at an average rate of -1.9 molC m(-2) yr(-1) that scaled at European level corresponds to an absorption of atmospheric CO2 of -68.1 TgC yr(-1). This sink is equivalent to the one reported for the terrestrial biosphere of -66.1 TgC yr(-1), based on carbon-stock change models. Estuaries are significant sources of CO2 to the atmosphere at an average rate of 49.9 molC m(-2) yr(-1) that is higher than the CO2 emission to the atmosphere from rivers, streams and lakes. The scaled emission of CO2 to the atmosphere from inner estuaries of about 67.0 TgC yr(-1) would almost fully balance the sink of atmospheric CO2 computed for continental shelves. However, the scaled emission of CO2 from estuaries to the atmosphere is inconsistent with the potential emission of CO2 based on the fate of river organic carbon during estuarine transit. This discrepancy is most probably due to the poorly constrained surface area estimate of inner estuaries. (c) 2006 Elsevier Ltd. All rights reserved.Carboeurope-GHG, CARBOOCEAN, EUROPTROPH, CANOPY, PEACE, SOLAS.B

Where does the methane entrapped in Antarctic sea ice come from?

info:eu-repo/semantics/publishe

Estimates of ikaite export from sea ice to the underlying seawater in a sea ice-seawater mesocosm

The precipitation of ikaite and its fate within sea ice is still poorly understood.We quantify temporal inorganic carbon dynamics in sea ice from initial formation to its melt in a sea ice.seawater mesocosm pool from 11 to 29 January 2013. Based on measurements of total alkalinity (TA) and total dissolved inorganic carbon (TCO2), the main processes affecting inorganic carbon dynamics within sea ice were ikaite precipitation and CO2 exchange with the atmosphere. In the underlying seawater, the dissolution of ikaite was the main process affecting inorganic carbon dynamics. Sea ice acted as an active layer, releasing CO2 to the atmosphere during the growth phase, taking up CO2 as it melted and exporting both ikaite and TCO2 into the underlying seawater during the whole experiment. Ikaite precipitation of up to 167 μmolkg-1 within sea ice was estimated, while its export and dissolution into the underlying seawater was responsible for a TA increase of 64.66 μmolkg-1 in the water column. The export of TCO2 from sea ice to the water column increased the underlying seawater TCO2 by 43.5 μmolkg-1, suggesting that almost all of the TCO2 that left the sea ice was exported to the underlying seawater. The export of ikaite from the ice to the underlying seawater was associated with brine rejection during sea ice growth, increased vertical connectivity in sea ice due to the upward percolation of seawater and meltwater flushing during sea ice melt. Based on the change in TA in the water column around the onset of sea ice melt, more than half of the total ikaite precipitated in the ice during sea ice growth was still contained in the ice when the sea ice began to melt. Ikaite crystal dissolution in the water column kept the seawater pCO2 undersaturated with respect to the atmosphere in spite of increased salinity, TA and TCO2 associated with sea ice growth. Results indicate that ikaite export from sea ice and its dissolution in the underlying seawater can potentially hamper the effect of oceanic acidification on the aragonite saturation state (ωaragonite) in fall and in winter in ice-covered areas, at the time when ωaragonite is smallest

Non-Gaussian power grid frequency fluctuations characterized by Levy-stable laws and superstatistics

Multiple types of fluctuations impact the collective dynamics of power grids and thus challenge their robust operation. Fluctuations result from processes as different as dynamically changing demands, energy trading and an increasing share of renewable power feed-in. Here we analyse principles underlying the dynamics and statistics of power grid frequency fluctuations. Considering frequency time series for a range of power grids, including grids in North America, Japan and Europe, we find a strong deviation from Gaussianity best described as Lévy-stable and q-Gaussian distributions. We present a coarse framework to analytically characterize the impact of arbitrary noise distributions, as well as a superstatistical approach that systematically interprets heavy tails and skewed distributions. We identify energy trading as a substantial contribution to today’s frequency fluctuations and effective damping of the grid as a controlling factor enabling reduction of fluctuation risks, with enhanced effects for small power grids

Determination of air‐sea ice transfer coefficient for CO2: Significant contribution of gas bubble transport during sea ice growth

Air‐ice CO2 fluxes were measured continuously from the freezing of a young sea‐ice cover until its decay. Cooling seawater was as a sink for atmospheric CO2 but asthe ice crystalsformed,sea ice shifted to a source releasing CO2 to the atmosphere throughout the whole ice growth. Atmospheric warming initiated the decay, re‐shifting sea‐ice to a CO2 sink. Combining these CO2 fluxes with the partial pressure of CO2 within sea ice, we determined gas transfer coefficients for CO2 at air‐ice interface for growth and decay. We hypothesize that this difference originates from the transport of gas bubbles during ice growth, while only diffusion occurs during ice melt. In parallel, we used a 1D biogeochemical model to mimic the observed CO2 fluxes. The formation of gas bubbles was crucial to reproduce fluxes during ice growth where gas bubbles may account for up to 92 % of the upward CO2 fluxes