Anatomy of electric vehicle fast charging : Peak shaving through a battery energy storage—A case study from Oslo

The number of electric vehicle (EV) users is strongly increasing so that today roughly every second registered vehicle in Norway is an EV. To increase the EV utilization, politics, industry and the EV users strongly promote the integration of fast charging infrastructure. While the future demand of fast charging sites is a well-studied topic, not much is known about the utilization of the existing charging sites and daily load curves. To fill this knowledge gap, usage data of a charging site in Oslo is analysed. Further on, the impact of a battery energy storage (BES) as well as a photovoltaic generator on peak load reduction is studied. The analysis shows variations and trends in the daily and weekly charging behaviour depending on the degree of utilization of the charging station. On average, a single EV user charges around 10 kWh in 19 min. Furthermore, the evidence indicates that EV users may have adapted fast charging as a part of their daily travels and it is not used only during long distance journeys. The results suggest that a BES can reduce the peak load by up to 55%. By adding a photovoltaic generator, a minor additional reduction of peak load is seen.publishedVersionPeer reviewe

Signaling pathways of heat- and hypersalinity-induced polyp bailout in Pocillopora acuta\textit {Pocillopora acuta}

Polyp bailout is a drastic response to acute stress where coral coloniality breaks down and polyps detach. We induced polyp bailout in $\textit {Pocillopora acuta}$ with heat stress and tested for differential gene expression using RNAseq and a qPCR assay. Furthermore, we induced polyp bailout with hypersalinity and compared the results to identify stressor-independent signals and pathways active during polyp bailout. Both stressors led to the onset of polyp bailout and the detachment of vital polyps. We observed activation of microbe-associated molecular pattern receptors and downstream signaling pathways of the innate immune system. Further, we detected growth factors and genes active during Wnt-signaling potentially contributing to wound healing, regeneration, and proliferation. Upregulation of several genes encoding for matrix metalloproteinases and the fibroblast growth factor signaling pathway are the most likely involved in the remodeling of the extracellular matrix, as well as in the detachment of polyps from the calcareous skeleton during polyp bailout. Expression of genes of interest in our qPCR assay of vital polyps from our heat-stress experiment, showed a trend for a normalization of gene expression after polyp bailout. Our results provide new insights into the signaling cascades leading to the observed physiological responses during polyp bailout. Comparison between the two stressors showed that certain signaling pathways are independent of the stressor and suggested that polyp bailout is a general response of corals to acute stress. Furthermore, immune system responses during polyp bailout indicate that microbe-associated partners of corals may lead to the polyp bailout response