Responding to Water Challenges Through Desalination: Energy Considerations

Desalination technology and reverse osmosis in particular, is used by several island authorities in Greece to address water scarcity. However, this is a highly energy‐intensive technique, requiring the consumption of significant quantities of fossil fuels. The case of Syros island is presented to demonstrate the strong water‐energy link in the operation of desalination plants. The use of renewable energy sources as a means for reducing water cost from desalination is also discussed. A simple algorithm to calculate estimating water costs with renewable energy sources (RES) is presented and is applied in the island of Patmos and in Hermoupolis, Syros island

Effect of phenylephrine on pyruvate dehydrogenase activity in rat hepatocytes and its interaction with insulin and glucagon

AbstractIn isolated rat hepatocytes phenylephrine promotes a rapid increase in the amount of pyruvate dehydrogenase present in its active form (PDHa). This action is mediated by α1-adrenergic receptors and is not observed in Ca2+-depleted hepatocytes. It is mimicked by the Ca2+ ionophore A23187. No changes in metabolites known to affect PDH activity are measured 3 min after addition of phenylephrine. Glucagon also increases PDHa, its action is additive to that of phenylephrine. The action of phenylephrine on PDHa could be explained by an increase in mitochondrial free Ca2+

Systemic eco-efficiency assessment of meso-level water use systems

Eco-efficiency has recently become an important concept of environmental decision making, serving as a policy objective and, if linked with resource efficiency, can be a measure of progress towards sustainability. The need for improving eco-efficiency leads to the challenge of identifying the most promising alternative solutions which improve both the economic and the environmental performance of a given system (“eco-innovations”). A methodological framework for the eco-efficiency assessment of a water use system at the meso level has been developed in the context of the EcoWater research project and consists of four distinct steps. The first step leads to a clear, transparent mapping of the system at hand and the respective value chain, while the second step provides the means to assess its eco-efficiency, following a life-cycle oriented approach using the midpoint impact categories. An important novelty is the distribution of economic costs/benefits and environmental pressures over different stages and stakeholders in the value chain. The third step includes the selection of innovative technologies, which are assessed in the last step and combined with mid-term scenarios in order to determine the feasibility of their implementation. The proposed methodological framework has been applied to eight alternative water use systems, revealing all their environmental weaknesses and identifying potential opportunities for eco-efficiency improvement. At the same time, through the systemic approach all the involved actors are urged to cooperate in order to (a) propose and build innovative technological solutions that will improve the overall eco-efficiency of the system; and (b) make suggestions on the necessary policy framework that will facilitate and promote their uptake. This ensures that upstream decisions in the value chain are coordinated with downstream activities and all potential synergies are identified, leading to the creation of “meso-level closed resource loops” and thus the promotion of a circular economy

Cost Effectiveness Analysis for Renewable Energy Sources Integration in the Island of Lemnos, Greece

The development of more efficient and least cost energy management interventions is of great importance for isolated energy systems. Islands are typical examples of isolated regions, often highly dependent on imported fossil fuels but with a significant and often unexploited Renewable Energy (RE) potential. This paper presents a least cost planning approach towards the integration of Renewable Energy Sources (RES) in such systems, which is applied to the island of Lemnos, Greece. The approach involves the application of Cost-Effectiveness Analysis (CEA) and Incremental Cost Analysis (ICA) for screening possible alternatives and determining the most economically efficient and effective plan for their implementation. The objective of the application of the proposed approach in the specific case study is to meet through the use of RE technologies all the additional electricity and thermal energy demand, compared to 2007. Various supply side options are evaluated, and an implementation plan is derived. The results indicate that the excess of both electricity and thermal energy demand can be met in the near future without any significant changes in existing infrastructure, while other options should be considered for a more extended time horizon