Canetique (Canada)

In this simulation study, a cluster of residential and commercial/institutional (CI) buildings undergoes flexibility strategies to reduce electric power during winter demand response (DR) events and the effect of these measures is analysed on the cluster level and on the individual building level. The portfolio used to simulate the flexibility strategies is comprised of 2430 buildings, of which 2400 are modelled as residential and 30 as CI buildings; this ratio roughly represents the real ratio of residential to commercial floor area in the location of study. The residential homes are all-electric, while the CI buildings have heating available through both an electric and a gas boiler, providing a dual-fuel heating system to work with for flexibility measures. The flexibility strategies tested are reactive and predictive, in which reactive measures are considered as not having any preplanning required, while predictive measures include preheating outside of peak hours for residential buildings, and fuel-switching during, before, and/or after DR events for CI buildings. The study investigates and verifies the complimentary nature of a mixed building cluster in order to provide flexibility during DR events, through peak power reductions of 24-37% during demand response events for the aggregated cluster. Compared to the power reductions obtained for only residential building clusters or only CI building clusters, the joining of all buildings to create the mixed cluster presents a greater benefit and confirms the synergy possible between mixed building types in flexibility studies.

The oxygen reduction catalytic activity of carbon-supported FeN4 moieties bridging micropores between two graphene sheets was investigated by density functional theory (DFT). Based on the FeN(2+2)/C structure proposed earlier by our group, two types of FeN(2+2)/C structures were considered: one mostly planar and one in which the Fe ion is significantly displaced out of the graphitic plane. A structure in which the FeN4 moiety is embedded in an extended graphene sheet (FeN/C) was also considered. In addition, we have investigated the influence of an axial pyridine group approaching the Fe centre. The formation energy is lowest for the planar FeN(2+2)/C structure. The overall downhill behaviour of the relative free energy vs. the reaction step suggests that most structures have catalytic activity near zero potential. This conclusion is further supported by calculations of the binding energies of adsorbed O2 and H2O and of the O-O bond lengths of adsorbed O2 and OOH. The side-on interaction of adsorbed O2 is preferred over the end-on interaction for the three basic structures without the axial pyridine. The pyridine coordination produces a stronger binding of O2 for the planar FeN(2+2)/C and the FeN/C structures as well as a dominant end-on interaction of O2. The energy levels of the planar FeN(2+2)/C structure with and without the pyridine ligand are nearly equal for iron spin states S = 1 and S = 2, suggesting that both configurations are formed with similar concentration during the preparation process, as also previously found for two of the iron sites by Mössbauer spectroscopy experiments.