Pricing mechanism for flexible loads using distribution grid Hedging Rights

This paper proposes a new pricing mechanism for the integration of flexible loads in distribution grids. This price is calculated from an envisioned two-layer local distribution grid market, where flexible load aggregators are price takers and the distribution system operator (DSO) is the market operator. On a day-ahead basis, the DSO runs the local market and clears distribution locational marginal prices (DLMPs). Aggregators purchase energy based on these DLMPs. However, depending upon grid conditions (losses/congestion), the DLMP value increases, causing aggregators to bear high energy procurement cost. To mitigate this issue, a second layer is introduced to compute ex-ante scenario-based Hedging Rights. Through a combination of these two layers, the proposed mechanism 1) improves market competition among the involved entities, 2) maintain the congestion alleviation property of DLMPs, and 3) incorporate the intertemporal energy requirements of flexible loads. The proposed framework is tested on an IEEE benchmark distribution grid. The simulation results show that the proposed pricing mechanism allows aggregators to achieve higher cost-savings, while preserving physical power flow evaluation feature of DLMP.NRF (Natl Research Foundation, S’pore

Probing active sites on Pd/Pt alloy nanoparticles by CO adsorption

We studied the adsorption of CO on PdPt nanoparticles with different metal ratio using theoretical calculations (DFT) and experimental investigations. A model catalyst was employed, where platinum (Pt) and palladium (Pd) were co-deposited via physical vapor deposition on the surface of α-Al2O3(0001). CO was used as a probe molecule for the particles’ surface composition. Polarized infrared reflection absorption spectroscopy (FT-IRRAS) enabled the observation of CO adsorption on top and side facets. The role of the Pd/Pt alloy ratio on the adsorption was investigated by comparing the FT-IRRAS data for different alloy arrangements and pure Pd and Pt nanoparticles. The dependence of the IR bands on the local atomic pattern was investigated via DFT calculations, revealing that both bulk alloy composition, as well as nearby atoms, influence the wavenumber of the bands